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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-05 17:28:19 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-05 17:28:19 +0000
commit18657a960e125336f704ea058e25c27bd3900dcb (patch)
tree17b438b680ed45a996d7b59951e6aa34023783f2 /ext/fts3/fts3.c
parentInitial commit. (diff)
downloadsqlite3-upstream.tar.xz
sqlite3-upstream.zip
Adding upstream version 3.40.1.upstream/3.40.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r--ext/fts3/fts3.c6116
1 files changed, 6116 insertions, 0 deletions
diff --git a/ext/fts3/fts3.c b/ext/fts3/fts3.c
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+/*
+** 2006 Oct 10
+**
+** The author disclaims copyright to this source code. In place of
+** a legal notice, here is a blessing:
+**
+** May you do good and not evil.
+** May you find forgiveness for yourself and forgive others.
+** May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This is an SQLite module implementing full-text search.
+*/
+
+/*
+** The code in this file is only compiled if:
+**
+** * The FTS3 module is being built as an extension
+** (in which case SQLITE_CORE is not defined), or
+**
+** * The FTS3 module is being built into the core of
+** SQLite (in which case SQLITE_ENABLE_FTS3 is defined).
+*/
+
+/* The full-text index is stored in a series of b+tree (-like)
+** structures called segments which map terms to doclists. The
+** structures are like b+trees in layout, but are constructed from the
+** bottom up in optimal fashion and are not updatable. Since trees
+** are built from the bottom up, things will be described from the
+** bottom up.
+**
+**
+**** Varints ****
+** The basic unit of encoding is a variable-length integer called a
+** varint. We encode variable-length integers in little-endian order
+** using seven bits * per byte as follows:
+**
+** KEY:
+** A = 0xxxxxxx 7 bits of data and one flag bit
+** B = 1xxxxxxx 7 bits of data and one flag bit
+**
+** 7 bits - A
+** 14 bits - BA
+** 21 bits - BBA
+** and so on.
+**
+** This is similar in concept to how sqlite encodes "varints" but
+** the encoding is not the same. SQLite varints are big-endian
+** are are limited to 9 bytes in length whereas FTS3 varints are
+** little-endian and can be up to 10 bytes in length (in theory).
+**
+** Example encodings:
+**
+** 1: 0x01
+** 127: 0x7f
+** 128: 0x81 0x00
+**
+**
+**** Document lists ****
+** A doclist (document list) holds a docid-sorted list of hits for a
+** given term. Doclists hold docids and associated token positions.
+** A docid is the unique integer identifier for a single document.
+** A position is the index of a word within the document. The first
+** word of the document has a position of 0.
+**
+** FTS3 used to optionally store character offsets using a compile-time
+** option. But that functionality is no longer supported.
+**
+** A doclist is stored like this:
+**
+** array {
+** varint docid; (delta from previous doclist)
+** array { (position list for column 0)
+** varint position; (2 more than the delta from previous position)
+** }
+** array {
+** varint POS_COLUMN; (marks start of position list for new column)
+** varint column; (index of new column)
+** array {
+** varint position; (2 more than the delta from previous position)
+** }
+** }
+** varint POS_END; (marks end of positions for this document.
+** }
+**
+** Here, array { X } means zero or more occurrences of X, adjacent in
+** memory. A "position" is an index of a token in the token stream
+** generated by the tokenizer. Note that POS_END and POS_COLUMN occur
+** in the same logical place as the position element, and act as sentinals
+** ending a position list array. POS_END is 0. POS_COLUMN is 1.
+** The positions numbers are not stored literally but rather as two more
+** than the difference from the prior position, or the just the position plus
+** 2 for the first position. Example:
+**
+** label: A B C D E F G H I J K
+** value: 123 5 9 1 1 14 35 0 234 72 0
+**
+** The 123 value is the first docid. For column zero in this document
+** there are two matches at positions 3 and 10 (5-2 and 9-2+3). The 1
+** at D signals the start of a new column; the 1 at E indicates that the
+** new column is column number 1. There are two positions at 12 and 45
+** (14-2 and 35-2+12). The 0 at H indicate the end-of-document. The
+** 234 at I is the delta to next docid (357). It has one position 70
+** (72-2) and then terminates with the 0 at K.
+**
+** A "position-list" is the list of positions for multiple columns for
+** a single docid. A "column-list" is the set of positions for a single
+** column. Hence, a position-list consists of one or more column-lists,
+** a document record consists of a docid followed by a position-list and
+** a doclist consists of one or more document records.
+**
+** A bare doclist omits the position information, becoming an
+** array of varint-encoded docids.
+**
+**** Segment leaf nodes ****
+** Segment leaf nodes store terms and doclists, ordered by term. Leaf
+** nodes are written using LeafWriter, and read using LeafReader (to
+** iterate through a single leaf node's data) and LeavesReader (to
+** iterate through a segment's entire leaf layer). Leaf nodes have
+** the format:
+**
+** varint iHeight; (height from leaf level, always 0)
+** varint nTerm; (length of first term)
+** char pTerm[nTerm]; (content of first term)
+** varint nDoclist; (length of term's associated doclist)
+** char pDoclist[nDoclist]; (content of doclist)
+** array {
+** (further terms are delta-encoded)
+** varint nPrefix; (length of prefix shared with previous term)
+** varint nSuffix; (length of unshared suffix)
+** char pTermSuffix[nSuffix];(unshared suffix of next term)
+** varint nDoclist; (length of term's associated doclist)
+** char pDoclist[nDoclist]; (content of doclist)
+** }
+**
+** Here, array { X } means zero or more occurrences of X, adjacent in
+** memory.
+**
+** Leaf nodes are broken into blocks which are stored contiguously in
+** the %_segments table in sorted order. This means that when the end
+** of a node is reached, the next term is in the node with the next
+** greater node id.
+**
+** New data is spilled to a new leaf node when the current node
+** exceeds LEAF_MAX bytes (default 2048). New data which itself is
+** larger than STANDALONE_MIN (default 1024) is placed in a standalone
+** node (a leaf node with a single term and doclist). The goal of
+** these settings is to pack together groups of small doclists while
+** making it efficient to directly access large doclists. The
+** assumption is that large doclists represent terms which are more
+** likely to be query targets.
+**
+** TODO(shess) It may be useful for blocking decisions to be more
+** dynamic. For instance, it may make more sense to have a 2.5k leaf
+** node rather than splitting into 2k and .5k nodes. My intuition is
+** that this might extend through 2x or 4x the pagesize.
+**
+**
+**** Segment interior nodes ****
+** Segment interior nodes store blockids for subtree nodes and terms
+** to describe what data is stored by the each subtree. Interior
+** nodes are written using InteriorWriter, and read using
+** InteriorReader. InteriorWriters are created as needed when
+** SegmentWriter creates new leaf nodes, or when an interior node
+** itself grows too big and must be split. The format of interior
+** nodes:
+**
+** varint iHeight; (height from leaf level, always >0)
+** varint iBlockid; (block id of node's leftmost subtree)
+** optional {
+** varint nTerm; (length of first term)
+** char pTerm[nTerm]; (content of first term)
+** array {
+** (further terms are delta-encoded)
+** varint nPrefix; (length of shared prefix with previous term)
+** varint nSuffix; (length of unshared suffix)
+** char pTermSuffix[nSuffix]; (unshared suffix of next term)
+** }
+** }
+**
+** Here, optional { X } means an optional element, while array { X }
+** means zero or more occurrences of X, adjacent in memory.
+**
+** An interior node encodes n terms separating n+1 subtrees. The
+** subtree blocks are contiguous, so only the first subtree's blockid
+** is encoded. The subtree at iBlockid will contain all terms less
+** than the first term encoded (or all terms if no term is encoded).
+** Otherwise, for terms greater than or equal to pTerm[i] but less
+** than pTerm[i+1], the subtree for that term will be rooted at
+** iBlockid+i. Interior nodes only store enough term data to
+** distinguish adjacent children (if the rightmost term of the left
+** child is "something", and the leftmost term of the right child is
+** "wicked", only "w" is stored).
+**
+** New data is spilled to a new interior node at the same height when
+** the current node exceeds INTERIOR_MAX bytes (default 2048).
+** INTERIOR_MIN_TERMS (default 7) keeps large terms from monopolizing
+** interior nodes and making the tree too skinny. The interior nodes
+** at a given height are naturally tracked by interior nodes at
+** height+1, and so on.
+**
+**
+**** Segment directory ****
+** The segment directory in table %_segdir stores meta-information for
+** merging and deleting segments, and also the root node of the
+** segment's tree.
+**
+** The root node is the top node of the segment's tree after encoding
+** the entire segment, restricted to ROOT_MAX bytes (default 1024).
+** This could be either a leaf node or an interior node. If the top
+** node requires more than ROOT_MAX bytes, it is flushed to %_segments
+** and a new root interior node is generated (which should always fit
+** within ROOT_MAX because it only needs space for 2 varints, the
+** height and the blockid of the previous root).
+**
+** The meta-information in the segment directory is:
+** level - segment level (see below)
+** idx - index within level
+** - (level,idx uniquely identify a segment)
+** start_block - first leaf node
+** leaves_end_block - last leaf node
+** end_block - last block (including interior nodes)
+** root - contents of root node
+**
+** If the root node is a leaf node, then start_block,
+** leaves_end_block, and end_block are all 0.
+**
+**
+**** Segment merging ****
+** To amortize update costs, segments are grouped into levels and
+** merged in batches. Each increase in level represents exponentially
+** more documents.
+**
+** New documents (actually, document updates) are tokenized and
+** written individually (using LeafWriter) to a level 0 segment, with
+** incrementing idx. When idx reaches MERGE_COUNT (default 16), all
+** level 0 segments are merged into a single level 1 segment. Level 1
+** is populated like level 0, and eventually MERGE_COUNT level 1
+** segments are merged to a single level 2 segment (representing
+** MERGE_COUNT^2 updates), and so on.
+**
+** A segment merge traverses all segments at a given level in
+** parallel, performing a straightforward sorted merge. Since segment
+** leaf nodes are written in to the %_segments table in order, this
+** merge traverses the underlying sqlite disk structures efficiently.
+** After the merge, all segment blocks from the merged level are
+** deleted.
+**
+** MERGE_COUNT controls how often we merge segments. 16 seems to be
+** somewhat of a sweet spot for insertion performance. 32 and 64 show
+** very similar performance numbers to 16 on insertion, though they're
+** a tiny bit slower (perhaps due to more overhead in merge-time
+** sorting). 8 is about 20% slower than 16, 4 about 50% slower than
+** 16, 2 about 66% slower than 16.
+**
+** At query time, high MERGE_COUNT increases the number of segments
+** which need to be scanned and merged. For instance, with 100k docs
+** inserted:
+**
+** MERGE_COUNT segments
+** 16 25
+** 8 12
+** 4 10
+** 2 6
+**
+** This appears to have only a moderate impact on queries for very
+** frequent terms (which are somewhat dominated by segment merge
+** costs), and infrequent and non-existent terms still seem to be fast
+** even with many segments.
+**
+** TODO(shess) That said, it would be nice to have a better query-side
+** argument for MERGE_COUNT of 16. Also, it is possible/likely that
+** optimizations to things like doclist merging will swing the sweet
+** spot around.
+**
+**
+**
+**** Handling of deletions and updates ****
+** Since we're using a segmented structure, with no docid-oriented
+** index into the term index, we clearly cannot simply update the term
+** index when a document is deleted or updated. For deletions, we
+** write an empty doclist (varint(docid) varint(POS_END)), for updates
+** we simply write the new doclist. Segment merges overwrite older
+** data for a particular docid with newer data, so deletes or updates
+** will eventually overtake the earlier data and knock it out. The
+** query logic likewise merges doclists so that newer data knocks out
+** older data.
+*/
+
+#include "fts3Int.h"
+#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)
+
+#if defined(SQLITE_ENABLE_FTS3) && !defined(SQLITE_CORE)
+# define SQLITE_CORE 1
+#endif
+
+#include <assert.h>
+#include <stdlib.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdarg.h>
+
+#include "fts3.h"
+#ifndef SQLITE_CORE
+# include "sqlite3ext.h"
+ SQLITE_EXTENSION_INIT1
+#endif
+
+typedef struct Fts3HashWrapper Fts3HashWrapper;
+struct Fts3HashWrapper {
+ Fts3Hash hash; /* Hash table */
+ int nRef; /* Number of pointers to this object */
+};
+
+static int fts3EvalNext(Fts3Cursor *pCsr);
+static int fts3EvalStart(Fts3Cursor *pCsr);
+static int fts3TermSegReaderCursor(
+ Fts3Cursor *, const char *, int, int, Fts3MultiSegReader **);
+
+/*
+** This variable is set to false when running tests for which the on disk
+** structures should not be corrupt. Otherwise, true. If it is false, extra
+** assert() conditions in the fts3 code are activated - conditions that are
+** only true if it is guaranteed that the fts3 database is not corrupt.
+*/
+#ifdef SQLITE_DEBUG
+int sqlite3_fts3_may_be_corrupt = 1;
+#endif
+
+/*
+** Write a 64-bit variable-length integer to memory starting at p[0].
+** The length of data written will be between 1 and FTS3_VARINT_MAX bytes.
+** The number of bytes written is returned.
+*/
+int sqlite3Fts3PutVarint(char *p, sqlite_int64 v){
+ unsigned char *q = (unsigned char *) p;
+ sqlite_uint64 vu = v;
+ do{
+ *q++ = (unsigned char) ((vu & 0x7f) | 0x80);
+ vu >>= 7;
+ }while( vu!=0 );
+ q[-1] &= 0x7f; /* turn off high bit in final byte */
+ assert( q - (unsigned char *)p <= FTS3_VARINT_MAX );
+ return (int) (q - (unsigned char *)p);
+}
+
+#define GETVARINT_STEP(v, ptr, shift, mask1, mask2, var, ret) \
+ v = (v & mask1) | ( (*(const unsigned char*)(ptr++)) << shift ); \
+ if( (v & mask2)==0 ){ var = v; return ret; }
+#define GETVARINT_INIT(v, ptr, shift, mask1, mask2, var, ret) \
+ v = (*ptr++); \
+ if( (v & mask2)==0 ){ var = v; return ret; }
+
+int sqlite3Fts3GetVarintU(const char *pBuf, sqlite_uint64 *v){
+ const unsigned char *p = (const unsigned char*)pBuf;
+ const unsigned char *pStart = p;
+ u32 a;
+ u64 b;
+ int shift;
+
+ GETVARINT_INIT(a, p, 0, 0x00, 0x80, *v, 1);
+ GETVARINT_STEP(a, p, 7, 0x7F, 0x4000, *v, 2);
+ GETVARINT_STEP(a, p, 14, 0x3FFF, 0x200000, *v, 3);
+ GETVARINT_STEP(a, p, 21, 0x1FFFFF, 0x10000000, *v, 4);
+ b = (a & 0x0FFFFFFF );
+
+ for(shift=28; shift<=63; shift+=7){
+ u64 c = *p++;
+ b += (c&0x7F) << shift;
+ if( (c & 0x80)==0 ) break;
+ }
+ *v = b;
+ return (int)(p - pStart);
+}
+
+/*
+** Read a 64-bit variable-length integer from memory starting at p[0].
+** Return the number of bytes read, or 0 on error.
+** The value is stored in *v.
+*/
+int sqlite3Fts3GetVarint(const char *pBuf, sqlite_int64 *v){
+ return sqlite3Fts3GetVarintU(pBuf, (sqlite3_uint64*)v);
+}
+
+/*
+** Read a 64-bit variable-length integer from memory starting at p[0] and
+** not extending past pEnd[-1].
+** Return the number of bytes read, or 0 on error.
+** The value is stored in *v.
+*/
+int sqlite3Fts3GetVarintBounded(
+ const char *pBuf,
+ const char *pEnd,
+ sqlite_int64 *v
+){
+ const unsigned char *p = (const unsigned char*)pBuf;
+ const unsigned char *pStart = p;
+ const unsigned char *pX = (const unsigned char*)pEnd;
+ u64 b = 0;
+ int shift;
+ for(shift=0; shift<=63; shift+=7){
+ u64 c = p<pX ? *p : 0;
+ p++;
+ b += (c&0x7F) << shift;
+ if( (c & 0x80)==0 ) break;
+ }
+ *v = b;
+ return (int)(p - pStart);
+}
+
+/*
+** Similar to sqlite3Fts3GetVarint(), except that the output is truncated to
+** a non-negative 32-bit integer before it is returned.
+*/
+int sqlite3Fts3GetVarint32(const char *p, int *pi){
+ const unsigned char *ptr = (const unsigned char*)p;
+ u32 a;
+
+#ifndef fts3GetVarint32
+ GETVARINT_INIT(a, ptr, 0, 0x00, 0x80, *pi, 1);
+#else
+ a = (*ptr++);
+ assert( a & 0x80 );
+#endif
+
+ GETVARINT_STEP(a, ptr, 7, 0x7F, 0x4000, *pi, 2);
+ GETVARINT_STEP(a, ptr, 14, 0x3FFF, 0x200000, *pi, 3);
+ GETVARINT_STEP(a, ptr, 21, 0x1FFFFF, 0x10000000, *pi, 4);
+ a = (a & 0x0FFFFFFF );
+ *pi = (int)(a | ((u32)(*ptr & 0x07) << 28));
+ assert( 0==(a & 0x80000000) );
+ assert( *pi>=0 );
+ return 5;
+}
+
+/*
+** Return the number of bytes required to encode v as a varint
+*/
+int sqlite3Fts3VarintLen(sqlite3_uint64 v){
+ int i = 0;
+ do{
+ i++;
+ v >>= 7;
+ }while( v!=0 );
+ return i;
+}
+
+/*
+** Convert an SQL-style quoted string into a normal string by removing
+** the quote characters. The conversion is done in-place. If the
+** input does not begin with a quote character, then this routine
+** is a no-op.
+**
+** Examples:
+**
+** "abc" becomes abc
+** 'xyz' becomes xyz
+** [pqr] becomes pqr
+** `mno` becomes mno
+**
+*/
+void sqlite3Fts3Dequote(char *z){
+ char quote; /* Quote character (if any ) */
+
+ quote = z[0];
+ if( quote=='[' || quote=='\'' || quote=='"' || quote=='`' ){
+ int iIn = 1; /* Index of next byte to read from input */
+ int iOut = 0; /* Index of next byte to write to output */
+
+ /* If the first byte was a '[', then the close-quote character is a ']' */
+ if( quote=='[' ) quote = ']';
+
+ while( z[iIn] ){
+ if( z[iIn]==quote ){
+ if( z[iIn+1]!=quote ) break;
+ z[iOut++] = quote;
+ iIn += 2;
+ }else{
+ z[iOut++] = z[iIn++];
+ }
+ }
+ z[iOut] = '\0';
+ }
+}
+
+/*
+** Read a single varint from the doclist at *pp and advance *pp to point
+** to the first byte past the end of the varint. Add the value of the varint
+** to *pVal.
+*/
+static void fts3GetDeltaVarint(char **pp, sqlite3_int64 *pVal){
+ sqlite3_int64 iVal;
+ *pp += sqlite3Fts3GetVarint(*pp, &iVal);
+ *pVal += iVal;
+}
+
+/*
+** When this function is called, *pp points to the first byte following a
+** varint that is part of a doclist (or position-list, or any other list
+** of varints). This function moves *pp to point to the start of that varint,
+** and sets *pVal by the varint value.
+**
+** Argument pStart points to the first byte of the doclist that the
+** varint is part of.
+*/
+static void fts3GetReverseVarint(
+ char **pp,
+ char *pStart,
+ sqlite3_int64 *pVal
+){
+ sqlite3_int64 iVal;
+ char *p;
+
+ /* Pointer p now points at the first byte past the varint we are
+ ** interested in. So, unless the doclist is corrupt, the 0x80 bit is
+ ** clear on character p[-1]. */
+ for(p = (*pp)-2; p>=pStart && *p&0x80; p--);
+ p++;
+ *pp = p;
+
+ sqlite3Fts3GetVarint(p, &iVal);
+ *pVal = iVal;
+}
+
+/*
+** The xDisconnect() virtual table method.
+*/
+static int fts3DisconnectMethod(sqlite3_vtab *pVtab){
+ Fts3Table *p = (Fts3Table *)pVtab;
+ int i;
+
+ assert( p->nPendingData==0 );
+ assert( p->pSegments==0 );
+
+ /* Free any prepared statements held */
+ sqlite3_finalize(p->pSeekStmt);
+ for(i=0; i<SizeofArray(p->aStmt); i++){
+ sqlite3_finalize(p->aStmt[i]);
+ }
+ sqlite3_free(p->zSegmentsTbl);
+ sqlite3_free(p->zReadExprlist);
+ sqlite3_free(p->zWriteExprlist);
+ sqlite3_free(p->zContentTbl);
+ sqlite3_free(p->zLanguageid);
+
+ /* Invoke the tokenizer destructor to free the tokenizer. */
+ p->pTokenizer->pModule->xDestroy(p->pTokenizer);
+
+ sqlite3_free(p);
+ return SQLITE_OK;
+}
+
+/*
+** Write an error message into *pzErr
+*/
+void sqlite3Fts3ErrMsg(char **pzErr, const char *zFormat, ...){
+ va_list ap;
+ sqlite3_free(*pzErr);
+ va_start(ap, zFormat);
+ *pzErr = sqlite3_vmprintf(zFormat, ap);
+ va_end(ap);
+}
+
+/*
+** Construct one or more SQL statements from the format string given
+** and then evaluate those statements. The success code is written
+** into *pRc.
+**
+** If *pRc is initially non-zero then this routine is a no-op.
+*/
+static void fts3DbExec(
+ int *pRc, /* Success code */
+ sqlite3 *db, /* Database in which to run SQL */
+ const char *zFormat, /* Format string for SQL */
+ ... /* Arguments to the format string */
+){
+ va_list ap;
+ char *zSql;
+ if( *pRc ) return;
+ va_start(ap, zFormat);
+ zSql = sqlite3_vmprintf(zFormat, ap);
+ va_end(ap);
+ if( zSql==0 ){
+ *pRc = SQLITE_NOMEM;
+ }else{
+ *pRc = sqlite3_exec(db, zSql, 0, 0, 0);
+ sqlite3_free(zSql);
+ }
+}
+
+/*
+** The xDestroy() virtual table method.
+*/
+static int fts3DestroyMethod(sqlite3_vtab *pVtab){
+ Fts3Table *p = (Fts3Table *)pVtab;
+ int rc = SQLITE_OK; /* Return code */
+ const char *zDb = p->zDb; /* Name of database (e.g. "main", "temp") */
+ sqlite3 *db = p->db; /* Database handle */
+
+ /* Drop the shadow tables */
+ fts3DbExec(&rc, db,
+ "DROP TABLE IF EXISTS %Q.'%q_segments';"
+ "DROP TABLE IF EXISTS %Q.'%q_segdir';"
+ "DROP TABLE IF EXISTS %Q.'%q_docsize';"
+ "DROP TABLE IF EXISTS %Q.'%q_stat';"
+ "%s DROP TABLE IF EXISTS %Q.'%q_content';",
+ zDb, p->zName,
+ zDb, p->zName,
+ zDb, p->zName,
+ zDb, p->zName,
+ (p->zContentTbl ? "--" : ""), zDb,p->zName
+ );
+
+ /* If everything has worked, invoke fts3DisconnectMethod() to free the
+ ** memory associated with the Fts3Table structure and return SQLITE_OK.
+ ** Otherwise, return an SQLite error code.
+ */
+ return (rc==SQLITE_OK ? fts3DisconnectMethod(pVtab) : rc);
+}
+
+
+/*
+** Invoke sqlite3_declare_vtab() to declare the schema for the FTS3 table
+** passed as the first argument. This is done as part of the xConnect()
+** and xCreate() methods.
+**
+** If *pRc is non-zero when this function is called, it is a no-op.
+** Otherwise, if an error occurs, an SQLite error code is stored in *pRc
+** before returning.
+*/
+static void fts3DeclareVtab(int *pRc, Fts3Table *p){
+ if( *pRc==SQLITE_OK ){
+ int i; /* Iterator variable */
+ int rc; /* Return code */
+ char *zSql; /* SQL statement passed to declare_vtab() */
+ char *zCols; /* List of user defined columns */
+ const char *zLanguageid;
+
+ zLanguageid = (p->zLanguageid ? p->zLanguageid : "__langid");
+ sqlite3_vtab_config(p->db, SQLITE_VTAB_CONSTRAINT_SUPPORT, 1);
+
+ /* Create a list of user columns for the virtual table */
+ zCols = sqlite3_mprintf("%Q, ", p->azColumn[0]);
+ for(i=1; zCols && i<p->nColumn; i++){
+ zCols = sqlite3_mprintf("%z%Q, ", zCols, p->azColumn[i]);
+ }
+
+ /* Create the whole "CREATE TABLE" statement to pass to SQLite */
+ zSql = sqlite3_mprintf(
+ "CREATE TABLE x(%s %Q HIDDEN, docid HIDDEN, %Q HIDDEN)",
+ zCols, p->zName, zLanguageid
+ );
+ if( !zCols || !zSql ){
+ rc = SQLITE_NOMEM;
+ }else{
+ rc = sqlite3_declare_vtab(p->db, zSql);
+ }
+
+ sqlite3_free(zSql);
+ sqlite3_free(zCols);
+ *pRc = rc;
+ }
+}
+
+/*
+** Create the %_stat table if it does not already exist.
+*/
+void sqlite3Fts3CreateStatTable(int *pRc, Fts3Table *p){
+ fts3DbExec(pRc, p->db,
+ "CREATE TABLE IF NOT EXISTS %Q.'%q_stat'"
+ "(id INTEGER PRIMARY KEY, value BLOB);",
+ p->zDb, p->zName
+ );
+ if( (*pRc)==SQLITE_OK ) p->bHasStat = 1;
+}
+
+/*
+** Create the backing store tables (%_content, %_segments and %_segdir)
+** required by the FTS3 table passed as the only argument. This is done
+** as part of the vtab xCreate() method.
+**
+** If the p->bHasDocsize boolean is true (indicating that this is an
+** FTS4 table, not an FTS3 table) then also create the %_docsize and
+** %_stat tables required by FTS4.
+*/
+static int fts3CreateTables(Fts3Table *p){
+ int rc = SQLITE_OK; /* Return code */
+ int i; /* Iterator variable */
+ sqlite3 *db = p->db; /* The database connection */
+
+ if( p->zContentTbl==0 ){
+ const char *zLanguageid = p->zLanguageid;
+ char *zContentCols; /* Columns of %_content table */
+
+ /* Create a list of user columns for the content table */
+ zContentCols = sqlite3_mprintf("docid INTEGER PRIMARY KEY");
+ for(i=0; zContentCols && i<p->nColumn; i++){
+ char *z = p->azColumn[i];
+ zContentCols = sqlite3_mprintf("%z, 'c%d%q'", zContentCols, i, z);
+ }
+ if( zLanguageid && zContentCols ){
+ zContentCols = sqlite3_mprintf("%z, langid", zContentCols, zLanguageid);
+ }
+ if( zContentCols==0 ) rc = SQLITE_NOMEM;
+
+ /* Create the content table */
+ fts3DbExec(&rc, db,
+ "CREATE TABLE %Q.'%q_content'(%s)",
+ p->zDb, p->zName, zContentCols
+ );
+ sqlite3_free(zContentCols);
+ }
+
+ /* Create other tables */
+ fts3DbExec(&rc, db,
+ "CREATE TABLE %Q.'%q_segments'(blockid INTEGER PRIMARY KEY, block BLOB);",
+ p->zDb, p->zName
+ );
+ fts3DbExec(&rc, db,
+ "CREATE TABLE %Q.'%q_segdir'("
+ "level INTEGER,"
+ "idx INTEGER,"
+ "start_block INTEGER,"
+ "leaves_end_block INTEGER,"
+ "end_block INTEGER,"
+ "root BLOB,"
+ "PRIMARY KEY(level, idx)"
+ ");",
+ p->zDb, p->zName
+ );
+ if( p->bHasDocsize ){
+ fts3DbExec(&rc, db,
+ "CREATE TABLE %Q.'%q_docsize'(docid INTEGER PRIMARY KEY, size BLOB);",
+ p->zDb, p->zName
+ );
+ }
+ assert( p->bHasStat==p->bFts4 );
+ if( p->bHasStat ){
+ sqlite3Fts3CreateStatTable(&rc, p);
+ }
+ return rc;
+}
+
+/*
+** Store the current database page-size in bytes in p->nPgsz.
+**
+** If *pRc is non-zero when this function is called, it is a no-op.
+** Otherwise, if an error occurs, an SQLite error code is stored in *pRc
+** before returning.
+*/
+static void fts3DatabasePageSize(int *pRc, Fts3Table *p){
+ if( *pRc==SQLITE_OK ){
+ int rc; /* Return code */
+ char *zSql; /* SQL text "PRAGMA %Q.page_size" */
+ sqlite3_stmt *pStmt; /* Compiled "PRAGMA %Q.page_size" statement */
+
+ zSql = sqlite3_mprintf("PRAGMA %Q.page_size", p->zDb);
+ if( !zSql ){
+ rc = SQLITE_NOMEM;
+ }else{
+ rc = sqlite3_prepare(p->db, zSql, -1, &pStmt, 0);
+ if( rc==SQLITE_OK ){
+ sqlite3_step(pStmt);
+ p->nPgsz = sqlite3_column_int(pStmt, 0);
+ rc = sqlite3_finalize(pStmt);
+ }else if( rc==SQLITE_AUTH ){
+ p->nPgsz = 1024;
+ rc = SQLITE_OK;
+ }
+ }
+ assert( p->nPgsz>0 || rc!=SQLITE_OK );
+ sqlite3_free(zSql);
+ *pRc = rc;
+ }
+}
+
+/*
+** "Special" FTS4 arguments are column specifications of the following form:
+**
+** <key> = <value>
+**
+** There may not be whitespace surrounding the "=" character. The <value>
+** term may be quoted, but the <key> may not.
+*/
+static int fts3IsSpecialColumn(
+ const char *z,
+ int *pnKey,
+ char **pzValue
+){
+ char *zValue;
+ const char *zCsr = z;
+
+ while( *zCsr!='=' ){
+ if( *zCsr=='\0' ) return 0;
+ zCsr++;
+ }
+
+ *pnKey = (int)(zCsr-z);
+ zValue = sqlite3_mprintf("%s", &zCsr[1]);
+ if( zValue ){
+ sqlite3Fts3Dequote(zValue);
+ }
+ *pzValue = zValue;
+ return 1;
+}
+
+/*
+** Append the output of a printf() style formatting to an existing string.
+*/
+static void fts3Appendf(
+ int *pRc, /* IN/OUT: Error code */
+ char **pz, /* IN/OUT: Pointer to string buffer */
+ const char *zFormat, /* Printf format string to append */
+ ... /* Arguments for printf format string */
+){
+ if( *pRc==SQLITE_OK ){
+ va_list ap;
+ char *z;
+ va_start(ap, zFormat);
+ z = sqlite3_vmprintf(zFormat, ap);
+ va_end(ap);
+ if( z && *pz ){
+ char *z2 = sqlite3_mprintf("%s%s", *pz, z);
+ sqlite3_free(z);
+ z = z2;
+ }
+ if( z==0 ) *pRc = SQLITE_NOMEM;
+ sqlite3_free(*pz);
+ *pz = z;
+ }
+}
+
+/*
+** Return a copy of input string zInput enclosed in double-quotes (") and
+** with all double quote characters escaped. For example:
+**
+** fts3QuoteId("un \"zip\"") -> "un \"\"zip\"\""
+**
+** The pointer returned points to memory obtained from sqlite3_malloc(). It
+** is the callers responsibility to call sqlite3_free() to release this
+** memory.
+*/
+static char *fts3QuoteId(char const *zInput){
+ sqlite3_int64 nRet;
+ char *zRet;
+ nRet = 2 + (int)strlen(zInput)*2 + 1;
+ zRet = sqlite3_malloc64(nRet);
+ if( zRet ){
+ int i;
+ char *z = zRet;
+ *(z++) = '"';
+ for(i=0; zInput[i]; i++){
+ if( zInput[i]=='"' ) *(z++) = '"';
+ *(z++) = zInput[i];
+ }
+ *(z++) = '"';
+ *(z++) = '\0';
+ }
+ return zRet;
+}
+
+/*
+** Return a list of comma separated SQL expressions and a FROM clause that
+** could be used in a SELECT statement such as the following:
+**
+** SELECT <list of expressions> FROM %_content AS x ...
+**
+** to return the docid, followed by each column of text data in order
+** from left to write. If parameter zFunc is not NULL, then instead of
+** being returned directly each column of text data is passed to an SQL
+** function named zFunc first. For example, if zFunc is "unzip" and the
+** table has the three user-defined columns "a", "b", and "c", the following
+** string is returned:
+**
+** "docid, unzip(x.'a'), unzip(x.'b'), unzip(x.'c') FROM %_content AS x"
+**
+** The pointer returned points to a buffer allocated by sqlite3_malloc(). It
+** is the responsibility of the caller to eventually free it.
+**
+** If *pRc is not SQLITE_OK when this function is called, it is a no-op (and
+** a NULL pointer is returned). Otherwise, if an OOM error is encountered
+** by this function, NULL is returned and *pRc is set to SQLITE_NOMEM. If
+** no error occurs, *pRc is left unmodified.
+*/
+static char *fts3ReadExprList(Fts3Table *p, const char *zFunc, int *pRc){
+ char *zRet = 0;
+ char *zFree = 0;
+ char *zFunction;
+ int i;
+
+ if( p->zContentTbl==0 ){
+ if( !zFunc ){
+ zFunction = "";
+ }else{
+ zFree = zFunction = fts3QuoteId(zFunc);
+ }
+ fts3Appendf(pRc, &zRet, "docid");
+ for(i=0; i<p->nColumn; i++){
+ fts3Appendf(pRc, &zRet, ",%s(x.'c%d%q')", zFunction, i, p->azColumn[i]);
+ }
+ if( p->zLanguageid ){
+ fts3Appendf(pRc, &zRet, ", x.%Q", "langid");
+ }
+ sqlite3_free(zFree);
+ }else{
+ fts3Appendf(pRc, &zRet, "rowid");
+ for(i=0; i<p->nColumn; i++){
+ fts3Appendf(pRc, &zRet, ", x.'%q'", p->azColumn[i]);
+ }
+ if( p->zLanguageid ){
+ fts3Appendf(pRc, &zRet, ", x.%Q", p->zLanguageid);
+ }
+ }
+ fts3Appendf(pRc, &zRet, " FROM '%q'.'%q%s' AS x",
+ p->zDb,
+ (p->zContentTbl ? p->zContentTbl : p->zName),
+ (p->zContentTbl ? "" : "_content")
+ );
+ return zRet;
+}
+
+/*
+** Return a list of N comma separated question marks, where N is the number
+** of columns in the %_content table (one for the docid plus one for each
+** user-defined text column).
+**
+** If argument zFunc is not NULL, then all but the first question mark
+** is preceded by zFunc and an open bracket, and followed by a closed
+** bracket. For example, if zFunc is "zip" and the FTS3 table has three
+** user-defined text columns, the following string is returned:
+**
+** "?, zip(?), zip(?), zip(?)"
+**
+** The pointer returned points to a buffer allocated by sqlite3_malloc(). It
+** is the responsibility of the caller to eventually free it.
+**
+** If *pRc is not SQLITE_OK when this function is called, it is a no-op (and
+** a NULL pointer is returned). Otherwise, if an OOM error is encountered
+** by this function, NULL is returned and *pRc is set to SQLITE_NOMEM. If
+** no error occurs, *pRc is left unmodified.
+*/
+static char *fts3WriteExprList(Fts3Table *p, const char *zFunc, int *pRc){
+ char *zRet = 0;
+ char *zFree = 0;
+ char *zFunction;
+ int i;
+
+ if( !zFunc ){
+ zFunction = "";
+ }else{
+ zFree = zFunction = fts3QuoteId(zFunc);
+ }
+ fts3Appendf(pRc, &zRet, "?");
+ for(i=0; i<p->nColumn; i++){
+ fts3Appendf(pRc, &zRet, ",%s(?)", zFunction);
+ }
+ if( p->zLanguageid ){
+ fts3Appendf(pRc, &zRet, ", ?");
+ }
+ sqlite3_free(zFree);
+ return zRet;
+}
+
+/*
+** Buffer z contains a positive integer value encoded as utf-8 text.
+** Decode this value and store it in *pnOut, returning the number of bytes
+** consumed. If an overflow error occurs return a negative value.
+*/
+int sqlite3Fts3ReadInt(const char *z, int *pnOut){
+ u64 iVal = 0;
+ int i;
+ for(i=0; z[i]>='0' && z[i]<='9'; i++){
+ iVal = iVal*10 + (z[i] - '0');
+ if( iVal>0x7FFFFFFF ) return -1;
+ }
+ *pnOut = (int)iVal;
+ return i;
+}
+
+/*
+** This function interprets the string at (*pp) as a non-negative integer
+** value. It reads the integer and sets *pnOut to the value read, then
+** sets *pp to point to the byte immediately following the last byte of
+** the integer value.
+**
+** Only decimal digits ('0'..'9') may be part of an integer value.
+**
+** If *pp does not being with a decimal digit SQLITE_ERROR is returned and
+** the output value undefined. Otherwise SQLITE_OK is returned.
+**
+** This function is used when parsing the "prefix=" FTS4 parameter.
+*/
+static int fts3GobbleInt(const char **pp, int *pnOut){
+ const int MAX_NPREFIX = 10000000;
+ int nInt = 0; /* Output value */
+ int nByte;
+ nByte = sqlite3Fts3ReadInt(*pp, &nInt);
+ if( nInt>MAX_NPREFIX ){
+ nInt = 0;
+ }
+ if( nByte==0 ){
+ return SQLITE_ERROR;
+ }
+ *pnOut = nInt;
+ *pp += nByte;
+ return SQLITE_OK;
+}
+
+/*
+** This function is called to allocate an array of Fts3Index structures
+** representing the indexes maintained by the current FTS table. FTS tables
+** always maintain the main "terms" index, but may also maintain one or
+** more "prefix" indexes, depending on the value of the "prefix=" parameter
+** (if any) specified as part of the CREATE VIRTUAL TABLE statement.
+**
+** Argument zParam is passed the value of the "prefix=" option if one was
+** specified, or NULL otherwise.
+**
+** If no error occurs, SQLITE_OK is returned and *apIndex set to point to
+** the allocated array. *pnIndex is set to the number of elements in the
+** array. If an error does occur, an SQLite error code is returned.
+**
+** Regardless of whether or not an error is returned, it is the responsibility
+** of the caller to call sqlite3_free() on the output array to free it.
+*/
+static int fts3PrefixParameter(
+ const char *zParam, /* ABC in prefix=ABC parameter to parse */
+ int *pnIndex, /* OUT: size of *apIndex[] array */
+ struct Fts3Index **apIndex /* OUT: Array of indexes for this table */
+){
+ struct Fts3Index *aIndex; /* Allocated array */
+ int nIndex = 1; /* Number of entries in array */
+
+ if( zParam && zParam[0] ){
+ const char *p;
+ nIndex++;
+ for(p=zParam; *p; p++){
+ if( *p==',' ) nIndex++;
+ }
+ }
+
+ aIndex = sqlite3_malloc64(sizeof(struct Fts3Index) * nIndex);
+ *apIndex = aIndex;
+ if( !aIndex ){
+ return SQLITE_NOMEM;
+ }
+
+ memset(aIndex, 0, sizeof(struct Fts3Index) * nIndex);
+ if( zParam ){
+ const char *p = zParam;
+ int i;
+ for(i=1; i<nIndex; i++){
+ int nPrefix = 0;
+ if( fts3GobbleInt(&p, &nPrefix) ) return SQLITE_ERROR;
+ assert( nPrefix>=0 );
+ if( nPrefix==0 ){
+ nIndex--;
+ i--;
+ }else{
+ aIndex[i].nPrefix = nPrefix;
+ }
+ p++;
+ }
+ }
+
+ *pnIndex = nIndex;
+ return SQLITE_OK;
+}
+
+/*
+** This function is called when initializing an FTS4 table that uses the
+** content=xxx option. It determines the number of and names of the columns
+** of the new FTS4 table.
+**
+** The third argument passed to this function is the value passed to the
+** config=xxx option (i.e. "xxx"). This function queries the database for
+** a table of that name. If found, the output variables are populated
+** as follows:
+**
+** *pnCol: Set to the number of columns table xxx has,
+**
+** *pnStr: Set to the total amount of space required to store a copy
+** of each columns name, including the nul-terminator.
+**
+** *pazCol: Set to point to an array of *pnCol strings. Each string is
+** the name of the corresponding column in table xxx. The array
+** and its contents are allocated using a single allocation. It
+** is the responsibility of the caller to free this allocation
+** by eventually passing the *pazCol value to sqlite3_free().
+**
+** If the table cannot be found, an error code is returned and the output
+** variables are undefined. Or, if an OOM is encountered, SQLITE_NOMEM is
+** returned (and the output variables are undefined).
+*/
+static int fts3ContentColumns(
+ sqlite3 *db, /* Database handle */
+ const char *zDb, /* Name of db (i.e. "main", "temp" etc.) */
+ const char *zTbl, /* Name of content table */
+ const char ***pazCol, /* OUT: Malloc'd array of column names */
+ int *pnCol, /* OUT: Size of array *pazCol */
+ int *pnStr, /* OUT: Bytes of string content */
+ char **pzErr /* OUT: error message */
+){
+ int rc = SQLITE_OK; /* Return code */
+ char *zSql; /* "SELECT *" statement on zTbl */
+ sqlite3_stmt *pStmt = 0; /* Compiled version of zSql */
+
+ zSql = sqlite3_mprintf("SELECT * FROM %Q.%Q", zDb, zTbl);
+ if( !zSql ){
+ rc = SQLITE_NOMEM;
+ }else{
+ rc = sqlite3_prepare(db, zSql, -1, &pStmt, 0);
+ if( rc!=SQLITE_OK ){
+ sqlite3Fts3ErrMsg(pzErr, "%s", sqlite3_errmsg(db));
+ }
+ }
+ sqlite3_free(zSql);
+
+ if( rc==SQLITE_OK ){
+ const char **azCol; /* Output array */
+ sqlite3_int64 nStr = 0; /* Size of all column names (incl. 0x00) */
+ int nCol; /* Number of table columns */
+ int i; /* Used to iterate through columns */
+
+ /* Loop through the returned columns. Set nStr to the number of bytes of
+ ** space required to store a copy of each column name, including the
+ ** nul-terminator byte. */
+ nCol = sqlite3_column_count(pStmt);
+ for(i=0; i<nCol; i++){
+ const char *zCol = sqlite3_column_name(pStmt, i);
+ nStr += strlen(zCol) + 1;
+ }
+
+ /* Allocate and populate the array to return. */
+ azCol = (const char **)sqlite3_malloc64(sizeof(char *) * nCol + nStr);
+ if( azCol==0 ){
+ rc = SQLITE_NOMEM;
+ }else{
+ char *p = (char *)&azCol[nCol];
+ for(i=0; i<nCol; i++){
+ const char *zCol = sqlite3_column_name(pStmt, i);
+ int n = (int)strlen(zCol)+1;
+ memcpy(p, zCol, n);
+ azCol[i] = p;
+ p += n;
+ }
+ }
+ sqlite3_finalize(pStmt);
+
+ /* Set the output variables. */
+ *pnCol = nCol;
+ *pnStr = nStr;
+ *pazCol = azCol;
+ }
+
+ return rc;
+}
+
+/*
+** This function is the implementation of both the xConnect and xCreate
+** methods of the FTS3 virtual table.
+**
+** The argv[] array contains the following:
+**
+** argv[0] -> module name ("fts3" or "fts4")
+** argv[1] -> database name
+** argv[2] -> table name
+** argv[...] -> "column name" and other module argument fields.
+*/
+static int fts3InitVtab(
+ int isCreate, /* True for xCreate, false for xConnect */
+ sqlite3 *db, /* The SQLite database connection */
+ void *pAux, /* Hash table containing tokenizers */
+ int argc, /* Number of elements in argv array */
+ const char * const *argv, /* xCreate/xConnect argument array */
+ sqlite3_vtab **ppVTab, /* Write the resulting vtab structure here */
+ char **pzErr /* Write any error message here */
+){
+ Fts3Hash *pHash = &((Fts3HashWrapper*)pAux)->hash;
+ Fts3Table *p = 0; /* Pointer to allocated vtab */
+ int rc = SQLITE_OK; /* Return code */
+ int i; /* Iterator variable */
+ sqlite3_int64 nByte; /* Size of allocation used for *p */
+ int iCol; /* Column index */
+ int nString = 0; /* Bytes required to hold all column names */
+ int nCol = 0; /* Number of columns in the FTS table */
+ char *zCsr; /* Space for holding column names */
+ int nDb; /* Bytes required to hold database name */
+ int nName; /* Bytes required to hold table name */
+ int isFts4 = (argv[0][3]=='4'); /* True for FTS4, false for FTS3 */
+ const char **aCol; /* Array of column names */
+ sqlite3_tokenizer *pTokenizer = 0; /* Tokenizer for this table */
+
+ int nIndex = 0; /* Size of aIndex[] array */
+ struct Fts3Index *aIndex = 0; /* Array of indexes for this table */
+
+ /* The results of parsing supported FTS4 key=value options: */
+ int bNoDocsize = 0; /* True to omit %_docsize table */
+ int bDescIdx = 0; /* True to store descending indexes */
+ char *zPrefix = 0; /* Prefix parameter value (or NULL) */
+ char *zCompress = 0; /* compress=? parameter (or NULL) */
+ char *zUncompress = 0; /* uncompress=? parameter (or NULL) */
+ char *zContent = 0; /* content=? parameter (or NULL) */
+ char *zLanguageid = 0; /* languageid=? parameter (or NULL) */
+ char **azNotindexed = 0; /* The set of notindexed= columns */
+ int nNotindexed = 0; /* Size of azNotindexed[] array */
+
+ assert( strlen(argv[0])==4 );
+ assert( (sqlite3_strnicmp(argv[0], "fts4", 4)==0 && isFts4)
+ || (sqlite3_strnicmp(argv[0], "fts3", 4)==0 && !isFts4)
+ );
+
+ nDb = (int)strlen(argv[1]) + 1;
+ nName = (int)strlen(argv[2]) + 1;
+
+ nByte = sizeof(const char *) * (argc-2);
+ aCol = (const char **)sqlite3_malloc64(nByte);
+ if( aCol ){
+ memset((void*)aCol, 0, nByte);
+ azNotindexed = (char **)sqlite3_malloc64(nByte);
+ }
+ if( azNotindexed ){
+ memset(azNotindexed, 0, nByte);
+ }
+ if( !aCol || !azNotindexed ){
+ rc = SQLITE_NOMEM;
+ goto fts3_init_out;
+ }
+
+ /* Loop through all of the arguments passed by the user to the FTS3/4
+ ** module (i.e. all the column names and special arguments). This loop
+ ** does the following:
+ **
+ ** + Figures out the number of columns the FTSX table will have, and
+ ** the number of bytes of space that must be allocated to store copies
+ ** of the column names.
+ **
+ ** + If there is a tokenizer specification included in the arguments,
+ ** initializes the tokenizer pTokenizer.
+ */
+ for(i=3; rc==SQLITE_OK && i<argc; i++){
+ char const *z = argv[i];
+ int nKey;
+ char *zVal;
+
+ /* Check if this is a tokenizer specification */
+ if( !pTokenizer
+ && strlen(z)>8
+ && 0==sqlite3_strnicmp(z, "tokenize", 8)
+ && 0==sqlite3Fts3IsIdChar(z[8])
+ ){
+ rc = sqlite3Fts3InitTokenizer(pHash, &z[9], &pTokenizer, pzErr);
+ }
+
+ /* Check if it is an FTS4 special argument. */
+ else if( isFts4 && fts3IsSpecialColumn(z, &nKey, &zVal) ){
+ struct Fts4Option {
+ const char *zOpt;
+ int nOpt;
+ } aFts4Opt[] = {
+ { "matchinfo", 9 }, /* 0 -> MATCHINFO */
+ { "prefix", 6 }, /* 1 -> PREFIX */
+ { "compress", 8 }, /* 2 -> COMPRESS */
+ { "uncompress", 10 }, /* 3 -> UNCOMPRESS */
+ { "order", 5 }, /* 4 -> ORDER */
+ { "content", 7 }, /* 5 -> CONTENT */
+ { "languageid", 10 }, /* 6 -> LANGUAGEID */
+ { "notindexed", 10 } /* 7 -> NOTINDEXED */
+ };
+
+ int iOpt;
+ if( !zVal ){
+ rc = SQLITE_NOMEM;
+ }else{
+ for(iOpt=0; iOpt<SizeofArray(aFts4Opt); iOpt++){
+ struct Fts4Option *pOp = &aFts4Opt[iOpt];
+ if( nKey==pOp->nOpt && !sqlite3_strnicmp(z, pOp->zOpt, pOp->nOpt) ){
+ break;
+ }
+ }
+ switch( iOpt ){
+ case 0: /* MATCHINFO */
+ if( strlen(zVal)!=4 || sqlite3_strnicmp(zVal, "fts3", 4) ){
+ sqlite3Fts3ErrMsg(pzErr, "unrecognized matchinfo: %s", zVal);
+ rc = SQLITE_ERROR;
+ }
+ bNoDocsize = 1;
+ break;
+
+ case 1: /* PREFIX */
+ sqlite3_free(zPrefix);
+ zPrefix = zVal;
+ zVal = 0;
+ break;
+
+ case 2: /* COMPRESS */
+ sqlite3_free(zCompress);
+ zCompress = zVal;
+ zVal = 0;
+ break;
+
+ case 3: /* UNCOMPRESS */
+ sqlite3_free(zUncompress);
+ zUncompress = zVal;
+ zVal = 0;
+ break;
+
+ case 4: /* ORDER */
+ if( (strlen(zVal)!=3 || sqlite3_strnicmp(zVal, "asc", 3))
+ && (strlen(zVal)!=4 || sqlite3_strnicmp(zVal, "desc", 4))
+ ){
+ sqlite3Fts3ErrMsg(pzErr, "unrecognized order: %s", zVal);
+ rc = SQLITE_ERROR;
+ }
+ bDescIdx = (zVal[0]=='d' || zVal[0]=='D');
+ break;
+
+ case 5: /* CONTENT */
+ sqlite3_free(zContent);
+ zContent = zVal;
+ zVal = 0;
+ break;
+
+ case 6: /* LANGUAGEID */
+ assert( iOpt==6 );
+ sqlite3_free(zLanguageid);
+ zLanguageid = zVal;
+ zVal = 0;
+ break;
+
+ case 7: /* NOTINDEXED */
+ azNotindexed[nNotindexed++] = zVal;
+ zVal = 0;
+ break;
+
+ default:
+ assert( iOpt==SizeofArray(aFts4Opt) );
+ sqlite3Fts3ErrMsg(pzErr, "unrecognized parameter: %s", z);
+ rc = SQLITE_ERROR;
+ break;
+ }
+ sqlite3_free(zVal);
+ }
+ }
+
+ /* Otherwise, the argument is a column name. */
+ else {
+ nString += (int)(strlen(z) + 1);
+ aCol[nCol++] = z;
+ }
+ }
+
+ /* If a content=xxx option was specified, the following:
+ **
+ ** 1. Ignore any compress= and uncompress= options.
+ **
+ ** 2. If no column names were specified as part of the CREATE VIRTUAL
+ ** TABLE statement, use all columns from the content table.
+ */
+ if( rc==SQLITE_OK && zContent ){
+ sqlite3_free(zCompress);
+ sqlite3_free(zUncompress);
+ zCompress = 0;
+ zUncompress = 0;
+ if( nCol==0 ){
+ sqlite3_free((void*)aCol);
+ aCol = 0;
+ rc = fts3ContentColumns(db, argv[1], zContent,&aCol,&nCol,&nString,pzErr);
+
+ /* If a languageid= option was specified, remove the language id
+ ** column from the aCol[] array. */
+ if( rc==SQLITE_OK && zLanguageid ){
+ int j;
+ for(j=0; j<nCol; j++){
+ if( sqlite3_stricmp(zLanguageid, aCol[j])==0 ){
+ int k;
+ for(k=j; k<nCol; k++) aCol[k] = aCol[k+1];
+ nCol--;
+ break;
+ }
+ }
+ }
+ }
+ }
+ if( rc!=SQLITE_OK ) goto fts3_init_out;
+
+ if( nCol==0 ){
+ assert( nString==0 );
+ aCol[0] = "content";
+ nString = 8;
+ nCol = 1;
+ }
+
+ if( pTokenizer==0 ){
+ rc = sqlite3Fts3InitTokenizer(pHash, "simple", &pTokenizer, pzErr);
+ if( rc!=SQLITE_OK ) goto fts3_init_out;
+ }
+ assert( pTokenizer );
+
+ rc = fts3PrefixParameter(zPrefix, &nIndex, &aIndex);
+ if( rc==SQLITE_ERROR ){
+ assert( zPrefix );
+ sqlite3Fts3ErrMsg(pzErr, "error parsing prefix parameter: %s", zPrefix);
+ }
+ if( rc!=SQLITE_OK ) goto fts3_init_out;
+
+ /* Allocate and populate the Fts3Table structure. */
+ nByte = sizeof(Fts3Table) + /* Fts3Table */
+ nCol * sizeof(char *) + /* azColumn */
+ nIndex * sizeof(struct Fts3Index) + /* aIndex */
+ nCol * sizeof(u8) + /* abNotindexed */
+ nName + /* zName */
+ nDb + /* zDb */
+ nString; /* Space for azColumn strings */
+ p = (Fts3Table*)sqlite3_malloc64(nByte);
+ if( p==0 ){
+ rc = SQLITE_NOMEM;
+ goto fts3_init_out;
+ }
+ memset(p, 0, nByte);
+ p->db = db;
+ p->nColumn = nCol;
+ p->nPendingData = 0;
+ p->azColumn = (char **)&p[1];
+ p->pTokenizer = pTokenizer;
+ p->nMaxPendingData = FTS3_MAX_PENDING_DATA;
+ p->bHasDocsize = (isFts4 && bNoDocsize==0);
+ p->bHasStat = (u8)isFts4;
+ p->bFts4 = (u8)isFts4;
+ p->bDescIdx = (u8)bDescIdx;
+ p->nAutoincrmerge = 0xff; /* 0xff means setting unknown */
+ p->zContentTbl = zContent;
+ p->zLanguageid = zLanguageid;
+ zContent = 0;
+ zLanguageid = 0;
+ TESTONLY( p->inTransaction = -1 );
+ TESTONLY( p->mxSavepoint = -1 );
+
+ p->aIndex = (struct Fts3Index *)&p->azColumn[nCol];
+ memcpy(p->aIndex, aIndex, sizeof(struct Fts3Index) * nIndex);
+ p->nIndex = nIndex;
+ for(i=0; i<nIndex; i++){
+ fts3HashInit(&p->aIndex[i].hPending, FTS3_HASH_STRING, 1);
+ }
+ p->abNotindexed = (u8 *)&p->aIndex[nIndex];
+
+ /* Fill in the zName and zDb fields of the vtab structure. */
+ zCsr = (char *)&p->abNotindexed[nCol];
+ p->zName = zCsr;
+ memcpy(zCsr, argv[2], nName);
+ zCsr += nName;
+ p->zDb = zCsr;
+ memcpy(zCsr, argv[1], nDb);
+ zCsr += nDb;
+
+ /* Fill in the azColumn array */
+ for(iCol=0; iCol<nCol; iCol++){
+ char *z;
+ int n = 0;
+ z = (char *)sqlite3Fts3NextToken(aCol[iCol], &n);
+ if( n>0 ){
+ memcpy(zCsr, z, n);
+ }
+ zCsr[n] = '\0';
+ sqlite3Fts3Dequote(zCsr);
+ p->azColumn[iCol] = zCsr;
+ zCsr += n+1;
+ assert( zCsr <= &((char *)p)[nByte] );
+ }
+
+ /* Fill in the abNotindexed array */
+ for(iCol=0; iCol<nCol; iCol++){
+ int n = (int)strlen(p->azColumn[iCol]);
+ for(i=0; i<nNotindexed; i++){
+ char *zNot = azNotindexed[i];
+ if( zNot && n==(int)strlen(zNot)
+ && 0==sqlite3_strnicmp(p->azColumn[iCol], zNot, n)
+ ){
+ p->abNotindexed[iCol] = 1;
+ sqlite3_free(zNot);
+ azNotindexed[i] = 0;
+ }
+ }
+ }
+ for(i=0; i<nNotindexed; i++){
+ if( azNotindexed[i] ){
+ sqlite3Fts3ErrMsg(pzErr, "no such column: %s", azNotindexed[i]);
+ rc = SQLITE_ERROR;
+ }
+ }
+
+ if( rc==SQLITE_OK && (zCompress==0)!=(zUncompress==0) ){
+ char const *zMiss = (zCompress==0 ? "compress" : "uncompress");
+ rc = SQLITE_ERROR;
+ sqlite3Fts3ErrMsg(pzErr, "missing %s parameter in fts4 constructor", zMiss);
+ }
+ p->zReadExprlist = fts3ReadExprList(p, zUncompress, &rc);
+ p->zWriteExprlist = fts3WriteExprList(p, zCompress, &rc);
+ if( rc!=SQLITE_OK ) goto fts3_init_out;
+
+ /* If this is an xCreate call, create the underlying tables in the
+ ** database. TODO: For xConnect(), it could verify that said tables exist.
+ */
+ if( isCreate ){
+ rc = fts3CreateTables(p);
+ }
+
+ /* Check to see if a legacy fts3 table has been "upgraded" by the
+ ** addition of a %_stat table so that it can use incremental merge.
+ */
+ if( !isFts4 && !isCreate ){
+ p->bHasStat = 2;
+ }
+
+ /* Figure out the page-size for the database. This is required in order to
+ ** estimate the cost of loading large doclists from the database. */
+ fts3DatabasePageSize(&rc, p);
+ p->nNodeSize = p->nPgsz-35;
+
+#if defined(SQLITE_DEBUG)||defined(SQLITE_TEST)
+ p->nMergeCount = FTS3_MERGE_COUNT;
+#endif
+
+ /* Declare the table schema to SQLite. */
+ fts3DeclareVtab(&rc, p);
+
+fts3_init_out:
+ sqlite3_free(zPrefix);
+ sqlite3_free(aIndex);
+ sqlite3_free(zCompress);
+ sqlite3_free(zUncompress);
+ sqlite3_free(zContent);
+ sqlite3_free(zLanguageid);
+ for(i=0; i<nNotindexed; i++) sqlite3_free(azNotindexed[i]);
+ sqlite3_free((void *)aCol);
+ sqlite3_free((void *)azNotindexed);
+ if( rc!=SQLITE_OK ){
+ if( p ){
+ fts3DisconnectMethod((sqlite3_vtab *)p);
+ }else if( pTokenizer ){
+ pTokenizer->pModule->xDestroy(pTokenizer);
+ }
+ }else{
+ assert( p->pSegments==0 );
+ *ppVTab = &p->base;
+ }
+ return rc;
+}
+
+/*
+** The xConnect() and xCreate() methods for the virtual table. All the
+** work is done in function fts3InitVtab().
+*/
+static int fts3ConnectMethod(
+ sqlite3 *db, /* Database connection */
+ void *pAux, /* Pointer to tokenizer hash table */
+ int argc, /* Number of elements in argv array */
+ const char * const *argv, /* xCreate/xConnect argument array */
+ sqlite3_vtab **ppVtab, /* OUT: New sqlite3_vtab object */
+ char **pzErr /* OUT: sqlite3_malloc'd error message */
+){
+ return fts3InitVtab(0, db, pAux, argc, argv, ppVtab, pzErr);
+}
+static int fts3CreateMethod(
+ sqlite3 *db, /* Database connection */
+ void *pAux, /* Pointer to tokenizer hash table */
+ int argc, /* Number of elements in argv array */
+ const char * const *argv, /* xCreate/xConnect argument array */
+ sqlite3_vtab **ppVtab, /* OUT: New sqlite3_vtab object */
+ char **pzErr /* OUT: sqlite3_malloc'd error message */
+){
+ return fts3InitVtab(1, db, pAux, argc, argv, ppVtab, pzErr);
+}
+
+/*
+** Set the pIdxInfo->estimatedRows variable to nRow. Unless this
+** extension is currently being used by a version of SQLite too old to
+** support estimatedRows. In that case this function is a no-op.
+*/
+static void fts3SetEstimatedRows(sqlite3_index_info *pIdxInfo, i64 nRow){
+#if SQLITE_VERSION_NUMBER>=3008002
+ if( sqlite3_libversion_number()>=3008002 ){
+ pIdxInfo->estimatedRows = nRow;
+ }
+#endif
+}
+
+/*
+** Set the SQLITE_INDEX_SCAN_UNIQUE flag in pIdxInfo->flags. Unless this
+** extension is currently being used by a version of SQLite too old to
+** support index-info flags. In that case this function is a no-op.
+*/
+static void fts3SetUniqueFlag(sqlite3_index_info *pIdxInfo){
+#if SQLITE_VERSION_NUMBER>=3008012
+ if( sqlite3_libversion_number()>=3008012 ){
+ pIdxInfo->idxFlags |= SQLITE_INDEX_SCAN_UNIQUE;
+ }
+#endif
+}
+
+/*
+** Implementation of the xBestIndex method for FTS3 tables. There
+** are three possible strategies, in order of preference:
+**
+** 1. Direct lookup by rowid or docid.
+** 2. Full-text search using a MATCH operator on a non-docid column.
+** 3. Linear scan of %_content table.
+*/
+static int fts3BestIndexMethod(sqlite3_vtab *pVTab, sqlite3_index_info *pInfo){
+ Fts3Table *p = (Fts3Table *)pVTab;
+ int i; /* Iterator variable */
+ int iCons = -1; /* Index of constraint to use */
+
+ int iLangidCons = -1; /* Index of langid=x constraint, if present */
+ int iDocidGe = -1; /* Index of docid>=x constraint, if present */
+ int iDocidLe = -1; /* Index of docid<=x constraint, if present */
+ int iIdx;
+
+ if( p->bLock ){
+ return SQLITE_ERROR;
+ }
+
+ /* By default use a full table scan. This is an expensive option,
+ ** so search through the constraints to see if a more efficient
+ ** strategy is possible.
+ */
+ pInfo->idxNum = FTS3_FULLSCAN_SEARCH;
+ pInfo->estimatedCost = 5000000;
+ for(i=0; i<pInfo->nConstraint; i++){
+ int bDocid; /* True if this constraint is on docid */
+ struct sqlite3_index_constraint *pCons = &pInfo->aConstraint[i];
+ if( pCons->usable==0 ){
+ if( pCons->op==SQLITE_INDEX_CONSTRAINT_MATCH ){
+ /* There exists an unusable MATCH constraint. This means that if
+ ** the planner does elect to use the results of this call as part
+ ** of the overall query plan the user will see an "unable to use
+ ** function MATCH in the requested context" error. To discourage
+ ** this, return a very high cost here. */
+ pInfo->idxNum = FTS3_FULLSCAN_SEARCH;
+ pInfo->estimatedCost = 1e50;
+ fts3SetEstimatedRows(pInfo, ((sqlite3_int64)1) << 50);
+ return SQLITE_OK;
+ }
+ continue;
+ }
+
+ bDocid = (pCons->iColumn<0 || pCons->iColumn==p->nColumn+1);
+
+ /* A direct lookup on the rowid or docid column. Assign a cost of 1.0. */
+ if( iCons<0 && pCons->op==SQLITE_INDEX_CONSTRAINT_EQ && bDocid ){
+ pInfo->idxNum = FTS3_DOCID_SEARCH;
+ pInfo->estimatedCost = 1.0;
+ iCons = i;
+ }
+
+ /* A MATCH constraint. Use a full-text search.
+ **
+ ** If there is more than one MATCH constraint available, use the first
+ ** one encountered. If there is both a MATCH constraint and a direct
+ ** rowid/docid lookup, prefer the MATCH strategy. This is done even
+ ** though the rowid/docid lookup is faster than a MATCH query, selecting
+ ** it would lead to an "unable to use function MATCH in the requested
+ ** context" error.
+ */
+ if( pCons->op==SQLITE_INDEX_CONSTRAINT_MATCH
+ && pCons->iColumn>=0 && pCons->iColumn<=p->nColumn
+ ){
+ pInfo->idxNum = FTS3_FULLTEXT_SEARCH + pCons->iColumn;
+ pInfo->estimatedCost = 2.0;
+ iCons = i;
+ }
+
+ /* Equality constraint on the langid column */
+ if( pCons->op==SQLITE_INDEX_CONSTRAINT_EQ
+ && pCons->iColumn==p->nColumn + 2
+ ){
+ iLangidCons = i;
+ }
+
+ if( bDocid ){
+ switch( pCons->op ){
+ case SQLITE_INDEX_CONSTRAINT_GE:
+ case SQLITE_INDEX_CONSTRAINT_GT:
+ iDocidGe = i;
+ break;
+
+ case SQLITE_INDEX_CONSTRAINT_LE:
+ case SQLITE_INDEX_CONSTRAINT_LT:
+ iDocidLe = i;
+ break;
+ }
+ }
+ }
+
+ /* If using a docid=? or rowid=? strategy, set the UNIQUE flag. */
+ if( pInfo->idxNum==FTS3_DOCID_SEARCH ) fts3SetUniqueFlag(pInfo);
+
+ iIdx = 1;
+ if( iCons>=0 ){
+ pInfo->aConstraintUsage[iCons].argvIndex = iIdx++;
+ pInfo->aConstraintUsage[iCons].omit = 1;
+ }
+ if( iLangidCons>=0 ){
+ pInfo->idxNum |= FTS3_HAVE_LANGID;
+ pInfo->aConstraintUsage[iLangidCons].argvIndex = iIdx++;
+ }
+ if( iDocidGe>=0 ){
+ pInfo->idxNum |= FTS3_HAVE_DOCID_GE;
+ pInfo->aConstraintUsage[iDocidGe].argvIndex = iIdx++;
+ }
+ if( iDocidLe>=0 ){
+ pInfo->idxNum |= FTS3_HAVE_DOCID_LE;
+ pInfo->aConstraintUsage[iDocidLe].argvIndex = iIdx++;
+ }
+
+ /* Regardless of the strategy selected, FTS can deliver rows in rowid (or
+ ** docid) order. Both ascending and descending are possible.
+ */
+ if( pInfo->nOrderBy==1 ){
+ struct sqlite3_index_orderby *pOrder = &pInfo->aOrderBy[0];
+ if( pOrder->iColumn<0 || pOrder->iColumn==p->nColumn+1 ){
+ if( pOrder->desc ){
+ pInfo->idxStr = "DESC";
+ }else{
+ pInfo->idxStr = "ASC";
+ }
+ pInfo->orderByConsumed = 1;
+ }
+ }
+
+ assert( p->pSegments==0 );
+ return SQLITE_OK;
+}
+
+/*
+** Implementation of xOpen method.
+*/
+static int fts3OpenMethod(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCsr){
+ sqlite3_vtab_cursor *pCsr; /* Allocated cursor */
+
+ UNUSED_PARAMETER(pVTab);
+
+ /* Allocate a buffer large enough for an Fts3Cursor structure. If the
+ ** allocation succeeds, zero it and return SQLITE_OK. Otherwise,
+ ** if the allocation fails, return SQLITE_NOMEM.
+ */
+ *ppCsr = pCsr = (sqlite3_vtab_cursor *)sqlite3_malloc(sizeof(Fts3Cursor));
+ if( !pCsr ){
+ return SQLITE_NOMEM;
+ }
+ memset(pCsr, 0, sizeof(Fts3Cursor));
+ return SQLITE_OK;
+}
+
+/*
+** Finalize the statement handle at pCsr->pStmt.
+**
+** Or, if that statement handle is one created by fts3CursorSeekStmt(),
+** and the Fts3Table.pSeekStmt slot is currently NULL, save the statement
+** pointer there instead of finalizing it.
+*/
+static void fts3CursorFinalizeStmt(Fts3Cursor *pCsr){
+ if( pCsr->bSeekStmt ){
+ Fts3Table *p = (Fts3Table *)pCsr->base.pVtab;
+ if( p->pSeekStmt==0 ){
+ p->pSeekStmt = pCsr->pStmt;
+ sqlite3_reset(pCsr->pStmt);
+ pCsr->pStmt = 0;
+ }
+ pCsr->bSeekStmt = 0;
+ }
+ sqlite3_finalize(pCsr->pStmt);
+}
+
+/*
+** Free all resources currently held by the cursor passed as the only
+** argument.
+*/
+static void fts3ClearCursor(Fts3Cursor *pCsr){
+ fts3CursorFinalizeStmt(pCsr);
+ sqlite3Fts3FreeDeferredTokens(pCsr);
+ sqlite3_free(pCsr->aDoclist);
+ sqlite3Fts3MIBufferFree(pCsr->pMIBuffer);
+ sqlite3Fts3ExprFree(pCsr->pExpr);
+ memset(&(&pCsr->base)[1], 0, sizeof(Fts3Cursor)-sizeof(sqlite3_vtab_cursor));
+}
+
+/*
+** Close the cursor. For additional information see the documentation
+** on the xClose method of the virtual table interface.
+*/
+static int fts3CloseMethod(sqlite3_vtab_cursor *pCursor){
+ Fts3Cursor *pCsr = (Fts3Cursor *)pCursor;
+ assert( ((Fts3Table *)pCsr->base.pVtab)->pSegments==0 );
+ fts3ClearCursor(pCsr);
+ assert( ((Fts3Table *)pCsr->base.pVtab)->pSegments==0 );
+ sqlite3_free(pCsr);
+ return SQLITE_OK;
+}
+
+/*
+** If pCsr->pStmt has not been prepared (i.e. if pCsr->pStmt==0), then
+** compose and prepare an SQL statement of the form:
+**
+** "SELECT <columns> FROM %_content WHERE rowid = ?"
+**
+** (or the equivalent for a content=xxx table) and set pCsr->pStmt to
+** it. If an error occurs, return an SQLite error code.
+*/
+static int fts3CursorSeekStmt(Fts3Cursor *pCsr){
+ int rc = SQLITE_OK;
+ if( pCsr->pStmt==0 ){
+ Fts3Table *p = (Fts3Table *)pCsr->base.pVtab;
+ char *zSql;
+ if( p->pSeekStmt ){
+ pCsr->pStmt = p->pSeekStmt;
+ p->pSeekStmt = 0;
+ }else{
+ zSql = sqlite3_mprintf("SELECT %s WHERE rowid = ?", p->zReadExprlist);
+ if( !zSql ) return SQLITE_NOMEM;
+ p->bLock++;
+ rc = sqlite3_prepare_v3(
+ p->db, zSql,-1,SQLITE_PREPARE_PERSISTENT,&pCsr->pStmt,0
+ );
+ p->bLock--;
+ sqlite3_free(zSql);
+ }
+ if( rc==SQLITE_OK ) pCsr->bSeekStmt = 1;
+ }
+ return rc;
+}
+
+/*
+** Position the pCsr->pStmt statement so that it is on the row
+** of the %_content table that contains the last match. Return
+** SQLITE_OK on success.
+*/
+static int fts3CursorSeek(sqlite3_context *pContext, Fts3Cursor *pCsr){
+ int rc = SQLITE_OK;
+ if( pCsr->isRequireSeek ){
+ rc = fts3CursorSeekStmt(pCsr);
+ if( rc==SQLITE_OK ){
+ Fts3Table *pTab = (Fts3Table*)pCsr->base.pVtab;
+ pTab->bLock++;
+ sqlite3_bind_int64(pCsr->pStmt, 1, pCsr->iPrevId);
+ pCsr->isRequireSeek = 0;
+ if( SQLITE_ROW==sqlite3_step(pCsr->pStmt) ){
+ pTab->bLock--;
+ return SQLITE_OK;
+ }else{
+ pTab->bLock--;
+ rc = sqlite3_reset(pCsr->pStmt);
+ if( rc==SQLITE_OK && ((Fts3Table *)pCsr->base.pVtab)->zContentTbl==0 ){
+ /* If no row was found and no error has occurred, then the %_content
+ ** table is missing a row that is present in the full-text index.
+ ** The data structures are corrupt. */
+ rc = FTS_CORRUPT_VTAB;
+ pCsr->isEof = 1;
+ }
+ }
+ }
+ }
+
+ if( rc!=SQLITE_OK && pContext ){
+ sqlite3_result_error_code(pContext, rc);
+ }
+ return rc;
+}
+
+/*
+** This function is used to process a single interior node when searching
+** a b-tree for a term or term prefix. The node data is passed to this
+** function via the zNode/nNode parameters. The term to search for is
+** passed in zTerm/nTerm.
+**
+** If piFirst is not NULL, then this function sets *piFirst to the blockid
+** of the child node that heads the sub-tree that may contain the term.
+**
+** If piLast is not NULL, then *piLast is set to the right-most child node
+** that heads a sub-tree that may contain a term for which zTerm/nTerm is
+** a prefix.
+**
+** If an OOM error occurs, SQLITE_NOMEM is returned. Otherwise, SQLITE_OK.
+*/
+static int fts3ScanInteriorNode(
+ const char *zTerm, /* Term to select leaves for */
+ int nTerm, /* Size of term zTerm in bytes */
+ const char *zNode, /* Buffer containing segment interior node */
+ int nNode, /* Size of buffer at zNode */
+ sqlite3_int64 *piFirst, /* OUT: Selected child node */
+ sqlite3_int64 *piLast /* OUT: Selected child node */
+){
+ int rc = SQLITE_OK; /* Return code */
+ const char *zCsr = zNode; /* Cursor to iterate through node */
+ const char *zEnd = &zCsr[nNode];/* End of interior node buffer */
+ char *zBuffer = 0; /* Buffer to load terms into */
+ i64 nAlloc = 0; /* Size of allocated buffer */
+ int isFirstTerm = 1; /* True when processing first term on page */
+ u64 iChild; /* Block id of child node to descend to */
+ int nBuffer = 0; /* Total term size */
+
+ /* Skip over the 'height' varint that occurs at the start of every
+ ** interior node. Then load the blockid of the left-child of the b-tree
+ ** node into variable iChild.
+ **
+ ** Even if the data structure on disk is corrupted, this (reading two
+ ** varints from the buffer) does not risk an overread. If zNode is a
+ ** root node, then the buffer comes from a SELECT statement. SQLite does
+ ** not make this guarantee explicitly, but in practice there are always
+ ** either more than 20 bytes of allocated space following the nNode bytes of
+ ** contents, or two zero bytes. Or, if the node is read from the %_segments
+ ** table, then there are always 20 bytes of zeroed padding following the
+ ** nNode bytes of content (see sqlite3Fts3ReadBlock() for details).
+ */
+ zCsr += sqlite3Fts3GetVarintU(zCsr, &iChild);
+ zCsr += sqlite3Fts3GetVarintU(zCsr, &iChild);
+ if( zCsr>zEnd ){
+ return FTS_CORRUPT_VTAB;
+ }
+
+ while( zCsr<zEnd && (piFirst || piLast) ){
+ int cmp; /* memcmp() result */
+ int nSuffix; /* Size of term suffix */
+ int nPrefix = 0; /* Size of term prefix */
+
+ /* Load the next term on the node into zBuffer. Use realloc() to expand
+ ** the size of zBuffer if required. */
+ if( !isFirstTerm ){
+ zCsr += fts3GetVarint32(zCsr, &nPrefix);
+ if( nPrefix>nBuffer ){
+ rc = FTS_CORRUPT_VTAB;
+ goto finish_scan;
+ }
+ }
+ isFirstTerm = 0;
+ zCsr += fts3GetVarint32(zCsr, &nSuffix);
+
+ assert( nPrefix>=0 && nSuffix>=0 );
+ if( nPrefix>zCsr-zNode || nSuffix>zEnd-zCsr || nSuffix==0 ){
+ rc = FTS_CORRUPT_VTAB;
+ goto finish_scan;
+ }
+ if( (i64)nPrefix+nSuffix>nAlloc ){
+ char *zNew;
+ nAlloc = ((i64)nPrefix+nSuffix) * 2;
+ zNew = (char *)sqlite3_realloc64(zBuffer, nAlloc);
+ if( !zNew ){
+ rc = SQLITE_NOMEM;
+ goto finish_scan;
+ }
+ zBuffer = zNew;
+ }
+ assert( zBuffer );
+ memcpy(&zBuffer[nPrefix], zCsr, nSuffix);
+ nBuffer = nPrefix + nSuffix;
+ zCsr += nSuffix;
+
+ /* Compare the term we are searching for with the term just loaded from
+ ** the interior node. If the specified term is greater than or equal
+ ** to the term from the interior node, then all terms on the sub-tree
+ ** headed by node iChild are smaller than zTerm. No need to search
+ ** iChild.
+ **
+ ** If the interior node term is larger than the specified term, then
+ ** the tree headed by iChild may contain the specified term.
+ */
+ cmp = memcmp(zTerm, zBuffer, (nBuffer>nTerm ? nTerm : nBuffer));
+ if( piFirst && (cmp<0 || (cmp==0 && nBuffer>nTerm)) ){
+ *piFirst = (i64)iChild;
+ piFirst = 0;
+ }
+
+ if( piLast && cmp<0 ){
+ *piLast = (i64)iChild;
+ piLast = 0;
+ }
+
+ iChild++;
+ };
+
+ if( piFirst ) *piFirst = (i64)iChild;
+ if( piLast ) *piLast = (i64)iChild;
+
+ finish_scan:
+ sqlite3_free(zBuffer);
+ return rc;
+}
+
+
+/*
+** The buffer pointed to by argument zNode (size nNode bytes) contains an
+** interior node of a b-tree segment. The zTerm buffer (size nTerm bytes)
+** contains a term. This function searches the sub-tree headed by the zNode
+** node for the range of leaf nodes that may contain the specified term
+** or terms for which the specified term is a prefix.
+**
+** If piLeaf is not NULL, then *piLeaf is set to the blockid of the
+** left-most leaf node in the tree that may contain the specified term.
+** If piLeaf2 is not NULL, then *piLeaf2 is set to the blockid of the
+** right-most leaf node that may contain a term for which the specified
+** term is a prefix.
+**
+** It is possible that the range of returned leaf nodes does not contain
+** the specified term or any terms for which it is a prefix. However, if the
+** segment does contain any such terms, they are stored within the identified
+** range. Because this function only inspects interior segment nodes (and
+** never loads leaf nodes into memory), it is not possible to be sure.
+**
+** If an error occurs, an error code other than SQLITE_OK is returned.
+*/
+static int fts3SelectLeaf(
+ Fts3Table *p, /* Virtual table handle */
+ const char *zTerm, /* Term to select leaves for */
+ int nTerm, /* Size of term zTerm in bytes */
+ const char *zNode, /* Buffer containing segment interior node */
+ int nNode, /* Size of buffer at zNode */
+ sqlite3_int64 *piLeaf, /* Selected leaf node */
+ sqlite3_int64 *piLeaf2 /* Selected leaf node */
+){
+ int rc = SQLITE_OK; /* Return code */
+ int iHeight; /* Height of this node in tree */
+
+ assert( piLeaf || piLeaf2 );
+
+ fts3GetVarint32(zNode, &iHeight);
+ rc = fts3ScanInteriorNode(zTerm, nTerm, zNode, nNode, piLeaf, piLeaf2);
+ assert_fts3_nc( !piLeaf2 || !piLeaf || rc!=SQLITE_OK || (*piLeaf<=*piLeaf2) );
+
+ if( rc==SQLITE_OK && iHeight>1 ){
+ char *zBlob = 0; /* Blob read from %_segments table */
+ int nBlob = 0; /* Size of zBlob in bytes */
+
+ if( piLeaf && piLeaf2 && (*piLeaf!=*piLeaf2) ){
+ rc = sqlite3Fts3ReadBlock(p, *piLeaf, &zBlob, &nBlob, 0);
+ if( rc==SQLITE_OK ){
+ rc = fts3SelectLeaf(p, zTerm, nTerm, zBlob, nBlob, piLeaf, 0);
+ }
+ sqlite3_free(zBlob);
+ piLeaf = 0;
+ zBlob = 0;
+ }
+
+ if( rc==SQLITE_OK ){
+ rc = sqlite3Fts3ReadBlock(p, piLeaf?*piLeaf:*piLeaf2, &zBlob, &nBlob, 0);
+ }
+ if( rc==SQLITE_OK ){
+ int iNewHeight = 0;
+ fts3GetVarint32(zBlob, &iNewHeight);
+ if( iNewHeight>=iHeight ){
+ rc = FTS_CORRUPT_VTAB;
+ }else{
+ rc = fts3SelectLeaf(p, zTerm, nTerm, zBlob, nBlob, piLeaf, piLeaf2);
+ }
+ }
+ sqlite3_free(zBlob);
+ }
+
+ return rc;
+}
+
+/*
+** This function is used to create delta-encoded serialized lists of FTS3
+** varints. Each call to this function appends a single varint to a list.
+*/
+static void fts3PutDeltaVarint(
+ char **pp, /* IN/OUT: Output pointer */
+ sqlite3_int64 *piPrev, /* IN/OUT: Previous value written to list */
+ sqlite3_int64 iVal /* Write this value to the list */
+){
+ assert_fts3_nc( iVal-*piPrev > 0 || (*piPrev==0 && iVal==0) );
+ *pp += sqlite3Fts3PutVarint(*pp, iVal-*piPrev);
+ *piPrev = iVal;
+}
+
+/*
+** When this function is called, *ppPoslist is assumed to point to the
+** start of a position-list. After it returns, *ppPoslist points to the
+** first byte after the position-list.
+**
+** A position list is list of positions (delta encoded) and columns for
+** a single document record of a doclist. So, in other words, this
+** routine advances *ppPoslist so that it points to the next docid in
+** the doclist, or to the first byte past the end of the doclist.
+**
+** If pp is not NULL, then the contents of the position list are copied
+** to *pp. *pp is set to point to the first byte past the last byte copied
+** before this function returns.
+*/
+static void fts3PoslistCopy(char **pp, char **ppPoslist){
+ char *pEnd = *ppPoslist;
+ char c = 0;
+
+ /* The end of a position list is marked by a zero encoded as an FTS3
+ ** varint. A single POS_END (0) byte. Except, if the 0 byte is preceded by
+ ** a byte with the 0x80 bit set, then it is not a varint 0, but the tail
+ ** of some other, multi-byte, value.
+ **
+ ** The following while-loop moves pEnd to point to the first byte that is not
+ ** immediately preceded by a byte with the 0x80 bit set. Then increments
+ ** pEnd once more so that it points to the byte immediately following the
+ ** last byte in the position-list.
+ */
+ while( *pEnd | c ){
+ c = *pEnd++ & 0x80;
+ testcase( c!=0 && (*pEnd)==0 );
+ }
+ pEnd++; /* Advance past the POS_END terminator byte */
+
+ if( pp ){
+ int n = (int)(pEnd - *ppPoslist);
+ char *p = *pp;
+ memcpy(p, *ppPoslist, n);
+ p += n;
+ *pp = p;
+ }
+ *ppPoslist = pEnd;
+}
+
+/*
+** When this function is called, *ppPoslist is assumed to point to the
+** start of a column-list. After it returns, *ppPoslist points to the
+** to the terminator (POS_COLUMN or POS_END) byte of the column-list.
+**
+** A column-list is list of delta-encoded positions for a single column
+** within a single document within a doclist.
+**
+** The column-list is terminated either by a POS_COLUMN varint (1) or
+** a POS_END varint (0). This routine leaves *ppPoslist pointing to
+** the POS_COLUMN or POS_END that terminates the column-list.
+**
+** If pp is not NULL, then the contents of the column-list are copied
+** to *pp. *pp is set to point to the first byte past the last byte copied
+** before this function returns. The POS_COLUMN or POS_END terminator
+** is not copied into *pp.
+*/
+static void fts3ColumnlistCopy(char **pp, char **ppPoslist){
+ char *pEnd = *ppPoslist;
+ char c = 0;
+
+ /* A column-list is terminated by either a 0x01 or 0x00 byte that is
+ ** not part of a multi-byte varint.
+ */
+ while( 0xFE & (*pEnd | c) ){
+ c = *pEnd++ & 0x80;
+ testcase( c!=0 && ((*pEnd)&0xfe)==0 );
+ }
+ if( pp ){
+ int n = (int)(pEnd - *ppPoslist);
+ char *p = *pp;
+ memcpy(p, *ppPoslist, n);
+ p += n;
+ *pp = p;
+ }
+ *ppPoslist = pEnd;
+}
+
+/*
+** Value used to signify the end of an position-list. This must be
+** as large or larger than any value that might appear on the
+** position-list, even a position list that has been corrupted.
+*/
+#define POSITION_LIST_END LARGEST_INT64
+
+/*
+** This function is used to help parse position-lists. When this function is
+** called, *pp may point to the start of the next varint in the position-list
+** being parsed, or it may point to 1 byte past the end of the position-list
+** (in which case **pp will be a terminator bytes POS_END (0) or
+** (1)).
+**
+** If *pp points past the end of the current position-list, set *pi to
+** POSITION_LIST_END and return. Otherwise, read the next varint from *pp,
+** increment the current value of *pi by the value read, and set *pp to
+** point to the next value before returning.
+**
+** Before calling this routine *pi must be initialized to the value of
+** the previous position, or zero if we are reading the first position
+** in the position-list. Because positions are delta-encoded, the value
+** of the previous position is needed in order to compute the value of
+** the next position.
+*/
+static void fts3ReadNextPos(
+ char **pp, /* IN/OUT: Pointer into position-list buffer */
+ sqlite3_int64 *pi /* IN/OUT: Value read from position-list */
+){
+ if( (**pp)&0xFE ){
+ int iVal;
+ *pp += fts3GetVarint32((*pp), &iVal);
+ *pi += iVal;
+ *pi -= 2;
+ }else{
+ *pi = POSITION_LIST_END;
+ }
+}
+
+/*
+** If parameter iCol is not 0, write an POS_COLUMN (1) byte followed by
+** the value of iCol encoded as a varint to *pp. This will start a new
+** column list.
+**
+** Set *pp to point to the byte just after the last byte written before
+** returning (do not modify it if iCol==0). Return the total number of bytes
+** written (0 if iCol==0).
+*/
+static int fts3PutColNumber(char **pp, int iCol){
+ int n = 0; /* Number of bytes written */
+ if( iCol ){
+ char *p = *pp; /* Output pointer */
+ n = 1 + sqlite3Fts3PutVarint(&p[1], iCol);
+ *p = 0x01;
+ *pp = &p[n];
+ }
+ return n;
+}
+
+/*
+** Compute the union of two position lists. The output written
+** into *pp contains all positions of both *pp1 and *pp2 in sorted
+** order and with any duplicates removed. All pointers are
+** updated appropriately. The caller is responsible for insuring
+** that there is enough space in *pp to hold the complete output.
+*/
+static int fts3PoslistMerge(
+ char **pp, /* Output buffer */
+ char **pp1, /* Left input list */
+ char **pp2 /* Right input list */
+){
+ char *p = *pp;
+ char *p1 = *pp1;
+ char *p2 = *pp2;
+
+ while( *p1 || *p2 ){
+ int iCol1; /* The current column index in pp1 */
+ int iCol2; /* The current column index in pp2 */
+
+ if( *p1==POS_COLUMN ){
+ fts3GetVarint32(&p1[1], &iCol1);
+ if( iCol1==0 ) return FTS_CORRUPT_VTAB;
+ }
+ else if( *p1==POS_END ) iCol1 = 0x7fffffff;
+ else iCol1 = 0;
+
+ if( *p2==POS_COLUMN ){
+ fts3GetVarint32(&p2[1], &iCol2);
+ if( iCol2==0 ) return FTS_CORRUPT_VTAB;
+ }
+ else if( *p2==POS_END ) iCol2 = 0x7fffffff;
+ else iCol2 = 0;
+
+ if( iCol1==iCol2 ){
+ sqlite3_int64 i1 = 0; /* Last position from pp1 */
+ sqlite3_int64 i2 = 0; /* Last position from pp2 */
+ sqlite3_int64 iPrev = 0;
+ int n = fts3PutColNumber(&p, iCol1);
+ p1 += n;
+ p2 += n;
+
+ /* At this point, both p1 and p2 point to the start of column-lists
+ ** for the same column (the column with index iCol1 and iCol2).
+ ** A column-list is a list of non-negative delta-encoded varints, each
+ ** incremented by 2 before being stored. Each list is terminated by a
+ ** POS_END (0) or POS_COLUMN (1). The following block merges the two lists
+ ** and writes the results to buffer p. p is left pointing to the byte
+ ** after the list written. No terminator (POS_END or POS_COLUMN) is
+ ** written to the output.
+ */
+ fts3GetDeltaVarint(&p1, &i1);
+ fts3GetDeltaVarint(&p2, &i2);
+ if( i1<2 || i2<2 ){
+ break;
+ }
+ do {
+ fts3PutDeltaVarint(&p, &iPrev, (i1<i2) ? i1 : i2);
+ iPrev -= 2;
+ if( i1==i2 ){
+ fts3ReadNextPos(&p1, &i1);
+ fts3ReadNextPos(&p2, &i2);
+ }else if( i1<i2 ){
+ fts3ReadNextPos(&p1, &i1);
+ }else{
+ fts3ReadNextPos(&p2, &i2);
+ }
+ }while( i1!=POSITION_LIST_END || i2!=POSITION_LIST_END );
+ }else if( iCol1<iCol2 ){
+ p1 += fts3PutColNumber(&p, iCol1);
+ fts3ColumnlistCopy(&p, &p1);
+ }else{
+ p2 += fts3PutColNumber(&p, iCol2);
+ fts3ColumnlistCopy(&p, &p2);
+ }
+ }
+
+ *p++ = POS_END;
+ *pp = p;
+ *pp1 = p1 + 1;
+ *pp2 = p2 + 1;
+ return SQLITE_OK;
+}
+
+/*
+** This function is used to merge two position lists into one. When it is
+** called, *pp1 and *pp2 must both point to position lists. A position-list is
+** the part of a doclist that follows each document id. For example, if a row
+** contains:
+**
+** 'a b c'|'x y z'|'a b b a'
+**
+** Then the position list for this row for token 'b' would consist of:
+**
+** 0x02 0x01 0x02 0x03 0x03 0x00
+**
+** When this function returns, both *pp1 and *pp2 are left pointing to the
+** byte following the 0x00 terminator of their respective position lists.
+**
+** If isSaveLeft is 0, an entry is added to the output position list for
+** each position in *pp2 for which there exists one or more positions in
+** *pp1 so that (pos(*pp2)>pos(*pp1) && pos(*pp2)-pos(*pp1)<=nToken). i.e.
+** when the *pp1 token appears before the *pp2 token, but not more than nToken
+** slots before it.
+**
+** e.g. nToken==1 searches for adjacent positions.
+*/
+static int fts3PoslistPhraseMerge(
+ char **pp, /* IN/OUT: Preallocated output buffer */
+ int nToken, /* Maximum difference in token positions */
+ int isSaveLeft, /* Save the left position */
+ int isExact, /* If *pp1 is exactly nTokens before *pp2 */
+ char **pp1, /* IN/OUT: Left input list */
+ char **pp2 /* IN/OUT: Right input list */
+){
+ char *p = *pp;
+ char *p1 = *pp1;
+ char *p2 = *pp2;
+ int iCol1 = 0;
+ int iCol2 = 0;
+
+ /* Never set both isSaveLeft and isExact for the same invocation. */
+ assert( isSaveLeft==0 || isExact==0 );
+
+ assert_fts3_nc( p!=0 && *p1!=0 && *p2!=0 );
+ if( *p1==POS_COLUMN ){
+ p1++;
+ p1 += fts3GetVarint32(p1, &iCol1);
+ }
+ if( *p2==POS_COLUMN ){
+ p2++;
+ p2 += fts3GetVarint32(p2, &iCol2);
+ }
+
+ while( 1 ){
+ if( iCol1==iCol2 ){
+ char *pSave = p;
+ sqlite3_int64 iPrev = 0;
+ sqlite3_int64 iPos1 = 0;
+ sqlite3_int64 iPos2 = 0;
+
+ if( iCol1 ){
+ *p++ = POS_COLUMN;
+ p += sqlite3Fts3PutVarint(p, iCol1);
+ }
+
+ fts3GetDeltaVarint(&p1, &iPos1); iPos1 -= 2;
+ fts3GetDeltaVarint(&p2, &iPos2); iPos2 -= 2;
+ if( iPos1<0 || iPos2<0 ) break;
+
+ while( 1 ){
+ if( iPos2==iPos1+nToken
+ || (isExact==0 && iPos2>iPos1 && iPos2<=iPos1+nToken)
+ ){
+ sqlite3_int64 iSave;
+ iSave = isSaveLeft ? iPos1 : iPos2;
+ fts3PutDeltaVarint(&p, &iPrev, iSave+2); iPrev -= 2;
+ pSave = 0;
+ assert( p );
+ }
+ if( (!isSaveLeft && iPos2<=(iPos1+nToken)) || iPos2<=iPos1 ){
+ if( (*p2&0xFE)==0 ) break;
+ fts3GetDeltaVarint(&p2, &iPos2); iPos2 -= 2;
+ }else{
+ if( (*p1&0xFE)==0 ) break;
+ fts3GetDeltaVarint(&p1, &iPos1); iPos1 -= 2;
+ }
+ }
+
+ if( pSave ){
+ assert( pp && p );
+ p = pSave;
+ }
+
+ fts3ColumnlistCopy(0, &p1);
+ fts3ColumnlistCopy(0, &p2);
+ assert( (*p1&0xFE)==0 && (*p2&0xFE)==0 );
+ if( 0==*p1 || 0==*p2 ) break;
+
+ p1++;
+ p1 += fts3GetVarint32(p1, &iCol1);
+ p2++;
+ p2 += fts3GetVarint32(p2, &iCol2);
+ }
+
+ /* Advance pointer p1 or p2 (whichever corresponds to the smaller of
+ ** iCol1 and iCol2) so that it points to either the 0x00 that marks the
+ ** end of the position list, or the 0x01 that precedes the next
+ ** column-number in the position list.
+ */
+ else if( iCol1<iCol2 ){
+ fts3ColumnlistCopy(0, &p1);
+ if( 0==*p1 ) break;
+ p1++;
+ p1 += fts3GetVarint32(p1, &iCol1);
+ }else{
+ fts3ColumnlistCopy(0, &p2);
+ if( 0==*p2 ) break;
+ p2++;
+ p2 += fts3GetVarint32(p2, &iCol2);
+ }
+ }
+
+ fts3PoslistCopy(0, &p2);
+ fts3PoslistCopy(0, &p1);
+ *pp1 = p1;
+ *pp2 = p2;
+ if( *pp==p ){
+ return 0;
+ }
+ *p++ = 0x00;
+ *pp = p;
+ return 1;
+}
+
+/*
+** Merge two position-lists as required by the NEAR operator. The argument
+** position lists correspond to the left and right phrases of an expression
+** like:
+**
+** "phrase 1" NEAR "phrase number 2"
+**
+** Position list *pp1 corresponds to the left-hand side of the NEAR
+** expression and *pp2 to the right. As usual, the indexes in the position
+** lists are the offsets of the last token in each phrase (tokens "1" and "2"
+** in the example above).
+**
+** The output position list - written to *pp - is a copy of *pp2 with those
+** entries that are not sufficiently NEAR entries in *pp1 removed.
+*/
+static int fts3PoslistNearMerge(
+ char **pp, /* Output buffer */
+ char *aTmp, /* Temporary buffer space */
+ int nRight, /* Maximum difference in token positions */
+ int nLeft, /* Maximum difference in token positions */
+ char **pp1, /* IN/OUT: Left input list */
+ char **pp2 /* IN/OUT: Right input list */
+){
+ char *p1 = *pp1;
+ char *p2 = *pp2;
+
+ char *pTmp1 = aTmp;
+ char *pTmp2;
+ char *aTmp2;
+ int res = 1;
+
+ fts3PoslistPhraseMerge(&pTmp1, nRight, 0, 0, pp1, pp2);
+ aTmp2 = pTmp2 = pTmp1;
+ *pp1 = p1;
+ *pp2 = p2;
+ fts3PoslistPhraseMerge(&pTmp2, nLeft, 1, 0, pp2, pp1);
+ if( pTmp1!=aTmp && pTmp2!=aTmp2 ){
+ fts3PoslistMerge(pp, &aTmp, &aTmp2);
+ }else if( pTmp1!=aTmp ){
+ fts3PoslistCopy(pp, &aTmp);
+ }else if( pTmp2!=aTmp2 ){
+ fts3PoslistCopy(pp, &aTmp2);
+ }else{
+ res = 0;
+ }
+
+ return res;
+}
+
+/*
+** An instance of this function is used to merge together the (potentially
+** large number of) doclists for each term that matches a prefix query.
+** See function fts3TermSelectMerge() for details.
+*/
+typedef struct TermSelect TermSelect;
+struct TermSelect {
+ char *aaOutput[16]; /* Malloc'd output buffers */
+ int anOutput[16]; /* Size each output buffer in bytes */
+};
+
+/*
+** This function is used to read a single varint from a buffer. Parameter
+** pEnd points 1 byte past the end of the buffer. When this function is
+** called, if *pp points to pEnd or greater, then the end of the buffer
+** has been reached. In this case *pp is set to 0 and the function returns.
+**
+** If *pp does not point to or past pEnd, then a single varint is read
+** from *pp. *pp is then set to point 1 byte past the end of the read varint.
+**
+** If bDescIdx is false, the value read is added to *pVal before returning.
+** If it is true, the value read is subtracted from *pVal before this
+** function returns.
+*/
+static void fts3GetDeltaVarint3(
+ char **pp, /* IN/OUT: Point to read varint from */
+ char *pEnd, /* End of buffer */
+ int bDescIdx, /* True if docids are descending */
+ sqlite3_int64 *pVal /* IN/OUT: Integer value */
+){
+ if( *pp>=pEnd ){
+ *pp = 0;
+ }else{
+ u64 iVal;
+ *pp += sqlite3Fts3GetVarintU(*pp, &iVal);
+ if( bDescIdx ){
+ *pVal = (i64)((u64)*pVal - iVal);
+ }else{
+ *pVal = (i64)((u64)*pVal + iVal);
+ }
+ }
+}
+
+/*
+** This function is used to write a single varint to a buffer. The varint
+** is written to *pp. Before returning, *pp is set to point 1 byte past the
+** end of the value written.
+**
+** If *pbFirst is zero when this function is called, the value written to
+** the buffer is that of parameter iVal.
+**
+** If *pbFirst is non-zero when this function is called, then the value
+** written is either (iVal-*piPrev) (if bDescIdx is zero) or (*piPrev-iVal)
+** (if bDescIdx is non-zero).
+**
+** Before returning, this function always sets *pbFirst to 1 and *piPrev
+** to the value of parameter iVal.
+*/
+static void fts3PutDeltaVarint3(
+ char **pp, /* IN/OUT: Output pointer */
+ int bDescIdx, /* True for descending docids */
+ sqlite3_int64 *piPrev, /* IN/OUT: Previous value written to list */
+ int *pbFirst, /* IN/OUT: True after first int written */
+ sqlite3_int64 iVal /* Write this value to the list */
+){
+ sqlite3_uint64 iWrite;
+ if( bDescIdx==0 || *pbFirst==0 ){
+ assert_fts3_nc( *pbFirst==0 || iVal>=*piPrev );
+ iWrite = (u64)iVal - (u64)*piPrev;
+ }else{
+ assert_fts3_nc( *piPrev>=iVal );
+ iWrite = (u64)*piPrev - (u64)iVal;
+ }
+ assert( *pbFirst || *piPrev==0 );
+ assert_fts3_nc( *pbFirst==0 || iWrite>0 );
+ *pp += sqlite3Fts3PutVarint(*pp, iWrite);
+ *piPrev = iVal;
+ *pbFirst = 1;
+}
+
+
+/*
+** This macro is used by various functions that merge doclists. The two
+** arguments are 64-bit docid values. If the value of the stack variable
+** bDescDoclist is 0 when this macro is invoked, then it returns (i1-i2).
+** Otherwise, (i2-i1).
+**
+** Using this makes it easier to write code that can merge doclists that are
+** sorted in either ascending or descending order.
+*/
+/* #define DOCID_CMP(i1, i2) ((bDescDoclist?-1:1) * (i64)((u64)i1-i2)) */
+#define DOCID_CMP(i1, i2) ((bDescDoclist?-1:1) * (i1>i2?1:((i1==i2)?0:-1)))
+
+/*
+** This function does an "OR" merge of two doclists (output contains all
+** positions contained in either argument doclist). If the docids in the
+** input doclists are sorted in ascending order, parameter bDescDoclist
+** should be false. If they are sorted in ascending order, it should be
+** passed a non-zero value.
+**
+** If no error occurs, *paOut is set to point at an sqlite3_malloc'd buffer
+** containing the output doclist and SQLITE_OK is returned. In this case
+** *pnOut is set to the number of bytes in the output doclist.
+**
+** If an error occurs, an SQLite error code is returned. The output values
+** are undefined in this case.
+*/
+static int fts3DoclistOrMerge(
+ int bDescDoclist, /* True if arguments are desc */
+ char *a1, int n1, /* First doclist */
+ char *a2, int n2, /* Second doclist */
+ char **paOut, int *pnOut /* OUT: Malloc'd doclist */
+){
+ int rc = SQLITE_OK;
+ sqlite3_int64 i1 = 0;
+ sqlite3_int64 i2 = 0;
+ sqlite3_int64 iPrev = 0;
+ char *pEnd1 = &a1[n1];
+ char *pEnd2 = &a2[n2];
+ char *p1 = a1;
+ char *p2 = a2;
+ char *p;
+ char *aOut;
+ int bFirstOut = 0;
+
+ *paOut = 0;
+ *pnOut = 0;
+
+ /* Allocate space for the output. Both the input and output doclists
+ ** are delta encoded. If they are in ascending order (bDescDoclist==0),
+ ** then the first docid in each list is simply encoded as a varint. For
+ ** each subsequent docid, the varint stored is the difference between the
+ ** current and previous docid (a positive number - since the list is in
+ ** ascending order).
+ **
+ ** The first docid written to the output is therefore encoded using the
+ ** same number of bytes as it is in whichever of the input lists it is
+ ** read from. And each subsequent docid read from the same input list
+ ** consumes either the same or less bytes as it did in the input (since
+ ** the difference between it and the previous value in the output must
+ ** be a positive value less than or equal to the delta value read from
+ ** the input list). The same argument applies to all but the first docid
+ ** read from the 'other' list. And to the contents of all position lists
+ ** that will be copied and merged from the input to the output.
+ **
+ ** However, if the first docid copied to the output is a negative number,
+ ** then the encoding of the first docid from the 'other' input list may
+ ** be larger in the output than it was in the input (since the delta value
+ ** may be a larger positive integer than the actual docid).
+ **
+ ** The space required to store the output is therefore the sum of the
+ ** sizes of the two inputs, plus enough space for exactly one of the input
+ ** docids to grow.
+ **
+ ** A symetric argument may be made if the doclists are in descending
+ ** order.
+ */
+ aOut = sqlite3_malloc64((i64)n1+n2+FTS3_VARINT_MAX-1+FTS3_BUFFER_PADDING);
+ if( !aOut ) return SQLITE_NOMEM;
+
+ p = aOut;
+ fts3GetDeltaVarint3(&p1, pEnd1, 0, &i1);
+ fts3GetDeltaVarint3(&p2, pEnd2, 0, &i2);
+ while( p1 || p2 ){
+ sqlite3_int64 iDiff = DOCID_CMP(i1, i2);
+
+ if( p2 && p1 && iDiff==0 ){
+ fts3PutDeltaVarint3(&p, bDescDoclist, &iPrev, &bFirstOut, i1);
+ rc = fts3PoslistMerge(&p, &p1, &p2);
+ if( rc ) break;
+ fts3GetDeltaVarint3(&p1, pEnd1, bDescDoclist, &i1);
+ fts3GetDeltaVarint3(&p2, pEnd2, bDescDoclist, &i2);
+ }else if( !p2 || (p1 && iDiff<0) ){
+ fts3PutDeltaVarint3(&p, bDescDoclist, &iPrev, &bFirstOut, i1);
+ fts3PoslistCopy(&p, &p1);
+ fts3GetDeltaVarint3(&p1, pEnd1, bDescDoclist, &i1);
+ }else{
+ fts3PutDeltaVarint3(&p, bDescDoclist, &iPrev, &bFirstOut, i2);
+ fts3PoslistCopy(&p, &p2);
+ fts3GetDeltaVarint3(&p2, pEnd2, bDescDoclist, &i2);
+ }
+
+ assert( (p-aOut)<=((p1?(p1-a1):n1)+(p2?(p2-a2):n2)+FTS3_VARINT_MAX-1) );
+ }
+
+ if( rc!=SQLITE_OK ){
+ sqlite3_free(aOut);
+ p = aOut = 0;
+ }else{
+ assert( (p-aOut)<=n1+n2+FTS3_VARINT_MAX-1 );
+ memset(&aOut[(p-aOut)], 0, FTS3_BUFFER_PADDING);
+ }
+ *paOut = aOut;
+ *pnOut = (int)(p-aOut);
+ return rc;
+}
+
+/*
+** This function does a "phrase" merge of two doclists. In a phrase merge,
+** the output contains a copy of each position from the right-hand input
+** doclist for which there is a position in the left-hand input doclist
+** exactly nDist tokens before it.
+**
+** If the docids in the input doclists are sorted in ascending order,
+** parameter bDescDoclist should be false. If they are sorted in ascending
+** order, it should be passed a non-zero value.
+**
+** The right-hand input doclist is overwritten by this function.
+*/
+static int fts3DoclistPhraseMerge(
+ int bDescDoclist, /* True if arguments are desc */
+ int nDist, /* Distance from left to right (1=adjacent) */
+ char *aLeft, int nLeft, /* Left doclist */
+ char **paRight, int *pnRight /* IN/OUT: Right/output doclist */
+){
+ sqlite3_int64 i1 = 0;
+ sqlite3_int64 i2 = 0;
+ sqlite3_int64 iPrev = 0;
+ char *aRight = *paRight;
+ char *pEnd1 = &aLeft[nLeft];
+ char *pEnd2 = &aRight[*pnRight];
+ char *p1 = aLeft;
+ char *p2 = aRight;
+ char *p;
+ int bFirstOut = 0;
+ char *aOut;
+
+ assert( nDist>0 );
+ if( bDescDoclist ){
+ aOut = sqlite3_malloc64((sqlite3_int64)*pnRight + FTS3_VARINT_MAX);
+ if( aOut==0 ) return SQLITE_NOMEM;
+ }else{
+ aOut = aRight;
+ }
+ p = aOut;
+
+ fts3GetDeltaVarint3(&p1, pEnd1, 0, &i1);
+ fts3GetDeltaVarint3(&p2, pEnd2, 0, &i2);
+
+ while( p1 && p2 ){
+ sqlite3_int64 iDiff = DOCID_CMP(i1, i2);
+ if( iDiff==0 ){
+ char *pSave = p;
+ sqlite3_int64 iPrevSave = iPrev;
+ int bFirstOutSave = bFirstOut;
+
+ fts3PutDeltaVarint3(&p, bDescDoclist, &iPrev, &bFirstOut, i1);
+ if( 0==fts3PoslistPhraseMerge(&p, nDist, 0, 1, &p1, &p2) ){
+ p = pSave;
+ iPrev = iPrevSave;
+ bFirstOut = bFirstOutSave;
+ }
+ fts3GetDeltaVarint3(&p1, pEnd1, bDescDoclist, &i1);
+ fts3GetDeltaVarint3(&p2, pEnd2, bDescDoclist, &i2);
+ }else if( iDiff<0 ){
+ fts3PoslistCopy(0, &p1);
+ fts3GetDeltaVarint3(&p1, pEnd1, bDescDoclist, &i1);
+ }else{
+ fts3PoslistCopy(0, &p2);
+ fts3GetDeltaVarint3(&p2, pEnd2, bDescDoclist, &i2);
+ }
+ }
+
+ *pnRight = (int)(p - aOut);
+ if( bDescDoclist ){
+ sqlite3_free(aRight);
+ *paRight = aOut;
+ }
+
+ return SQLITE_OK;
+}
+
+/*
+** Argument pList points to a position list nList bytes in size. This
+** function checks to see if the position list contains any entries for
+** a token in position 0 (of any column). If so, it writes argument iDelta
+** to the output buffer pOut, followed by a position list consisting only
+** of the entries from pList at position 0, and terminated by an 0x00 byte.
+** The value returned is the number of bytes written to pOut (if any).
+*/
+int sqlite3Fts3FirstFilter(
+ sqlite3_int64 iDelta, /* Varint that may be written to pOut */
+ char *pList, /* Position list (no 0x00 term) */
+ int nList, /* Size of pList in bytes */
+ char *pOut /* Write output here */
+){
+ int nOut = 0;
+ int bWritten = 0; /* True once iDelta has been written */
+ char *p = pList;
+ char *pEnd = &pList[nList];
+
+ if( *p!=0x01 ){
+ if( *p==0x02 ){
+ nOut += sqlite3Fts3PutVarint(&pOut[nOut], iDelta);
+ pOut[nOut++] = 0x02;
+ bWritten = 1;
+ }
+ fts3ColumnlistCopy(0, &p);
+ }
+
+ while( p<pEnd ){
+ sqlite3_int64 iCol;
+ p++;
+ p += sqlite3Fts3GetVarint(p, &iCol);
+ if( *p==0x02 ){
+ if( bWritten==0 ){
+ nOut += sqlite3Fts3PutVarint(&pOut[nOut], iDelta);
+ bWritten = 1;
+ }
+ pOut[nOut++] = 0x01;
+ nOut += sqlite3Fts3PutVarint(&pOut[nOut], iCol);
+ pOut[nOut++] = 0x02;
+ }
+ fts3ColumnlistCopy(0, &p);
+ }
+ if( bWritten ){
+ pOut[nOut++] = 0x00;
+ }
+
+ return nOut;
+}
+
+
+/*
+** Merge all doclists in the TermSelect.aaOutput[] array into a single
+** doclist stored in TermSelect.aaOutput[0]. If successful, delete all
+** other doclists (except the aaOutput[0] one) and return SQLITE_OK.
+**
+** If an OOM error occurs, return SQLITE_NOMEM. In this case it is
+** the responsibility of the caller to free any doclists left in the
+** TermSelect.aaOutput[] array.
+*/
+static int fts3TermSelectFinishMerge(Fts3Table *p, TermSelect *pTS){
+ char *aOut = 0;
+ int nOut = 0;
+ int i;
+
+ /* Loop through the doclists in the aaOutput[] array. Merge them all
+ ** into a single doclist.
+ */
+ for(i=0; i<SizeofArray(pTS->aaOutput); i++){
+ if( pTS->aaOutput[i] ){
+ if( !aOut ){
+ aOut = pTS->aaOutput[i];
+ nOut = pTS->anOutput[i];
+ pTS->aaOutput[i] = 0;
+ }else{
+ int nNew;
+ char *aNew;
+
+ int rc = fts3DoclistOrMerge(p->bDescIdx,
+ pTS->aaOutput[i], pTS->anOutput[i], aOut, nOut, &aNew, &nNew
+ );
+ if( rc!=SQLITE_OK ){
+ sqlite3_free(aOut);
+ return rc;
+ }
+
+ sqlite3_free(pTS->aaOutput[i]);
+ sqlite3_free(aOut);
+ pTS->aaOutput[i] = 0;
+ aOut = aNew;
+ nOut = nNew;
+ }
+ }
+ }
+
+ pTS->aaOutput[0] = aOut;
+ pTS->anOutput[0] = nOut;
+ return SQLITE_OK;
+}
+
+/*
+** Merge the doclist aDoclist/nDoclist into the TermSelect object passed
+** as the first argument. The merge is an "OR" merge (see function
+** fts3DoclistOrMerge() for details).
+**
+** This function is called with the doclist for each term that matches
+** a queried prefix. It merges all these doclists into one, the doclist
+** for the specified prefix. Since there can be a very large number of
+** doclists to merge, the merging is done pair-wise using the TermSelect
+** object.
+**
+** This function returns SQLITE_OK if the merge is successful, or an
+** SQLite error code (SQLITE_NOMEM) if an error occurs.
+*/
+static int fts3TermSelectMerge(
+ Fts3Table *p, /* FTS table handle */
+ TermSelect *pTS, /* TermSelect object to merge into */
+ char *aDoclist, /* Pointer to doclist */
+ int nDoclist /* Size of aDoclist in bytes */
+){
+ if( pTS->aaOutput[0]==0 ){
+ /* If this is the first term selected, copy the doclist to the output
+ ** buffer using memcpy().
+ **
+ ** Add FTS3_VARINT_MAX bytes of unused space to the end of the
+ ** allocation. This is so as to ensure that the buffer is big enough
+ ** to hold the current doclist AND'd with any other doclist. If the
+ ** doclists are stored in order=ASC order, this padding would not be
+ ** required (since the size of [doclistA AND doclistB] is always less
+ ** than or equal to the size of [doclistA] in that case). But this is
+ ** not true for order=DESC. For example, a doclist containing (1, -1)
+ ** may be smaller than (-1), as in the first example the -1 may be stored
+ ** as a single-byte delta, whereas in the second it must be stored as a
+ ** FTS3_VARINT_MAX byte varint.
+ **
+ ** Similar padding is added in the fts3DoclistOrMerge() function.
+ */
+ pTS->aaOutput[0] = sqlite3_malloc64((i64)nDoclist + FTS3_VARINT_MAX + 1);
+ pTS->anOutput[0] = nDoclist;
+ if( pTS->aaOutput[0] ){
+ memcpy(pTS->aaOutput[0], aDoclist, nDoclist);
+ memset(&pTS->aaOutput[0][nDoclist], 0, FTS3_VARINT_MAX);
+ }else{
+ return SQLITE_NOMEM;
+ }
+ }else{
+ char *aMerge = aDoclist;
+ int nMerge = nDoclist;
+ int iOut;
+
+ for(iOut=0; iOut<SizeofArray(pTS->aaOutput); iOut++){
+ if( pTS->aaOutput[iOut]==0 ){
+ assert( iOut>0 );
+ pTS->aaOutput[iOut] = aMerge;
+ pTS->anOutput[iOut] = nMerge;
+ break;
+ }else{
+ char *aNew;
+ int nNew;
+
+ int rc = fts3DoclistOrMerge(p->bDescIdx, aMerge, nMerge,
+ pTS->aaOutput[iOut], pTS->anOutput[iOut], &aNew, &nNew
+ );
+ if( rc!=SQLITE_OK ){
+ if( aMerge!=aDoclist ) sqlite3_free(aMerge);
+ return rc;
+ }
+
+ if( aMerge!=aDoclist ) sqlite3_free(aMerge);
+ sqlite3_free(pTS->aaOutput[iOut]);
+ pTS->aaOutput[iOut] = 0;
+
+ aMerge = aNew;
+ nMerge = nNew;
+ if( (iOut+1)==SizeofArray(pTS->aaOutput) ){
+ pTS->aaOutput[iOut] = aMerge;
+ pTS->anOutput[iOut] = nMerge;
+ }
+ }
+ }
+ }
+ return SQLITE_OK;
+}
+
+/*
+** Append SegReader object pNew to the end of the pCsr->apSegment[] array.
+*/
+static int fts3SegReaderCursorAppend(
+ Fts3MultiSegReader *pCsr,
+ Fts3SegReader *pNew
+){
+ if( (pCsr->nSegment%16)==0 ){
+ Fts3SegReader **apNew;
+ sqlite3_int64 nByte = (pCsr->nSegment + 16)*sizeof(Fts3SegReader*);
+ apNew = (Fts3SegReader **)sqlite3_realloc64(pCsr->apSegment, nByte);
+ if( !apNew ){
+ sqlite3Fts3SegReaderFree(pNew);
+ return SQLITE_NOMEM;
+ }
+ pCsr->apSegment = apNew;
+ }
+ pCsr->apSegment[pCsr->nSegment++] = pNew;
+ return SQLITE_OK;
+}
+
+/*
+** Add seg-reader objects to the Fts3MultiSegReader object passed as the
+** 8th argument.
+**
+** This function returns SQLITE_OK if successful, or an SQLite error code
+** otherwise.
+*/
+static int fts3SegReaderCursor(
+ Fts3Table *p, /* FTS3 table handle */
+ int iLangid, /* Language id */
+ int iIndex, /* Index to search (from 0 to p->nIndex-1) */
+ int iLevel, /* Level of segments to scan */
+ const char *zTerm, /* Term to query for */
+ int nTerm, /* Size of zTerm in bytes */
+ int isPrefix, /* True for a prefix search */
+ int isScan, /* True to scan from zTerm to EOF */
+ Fts3MultiSegReader *pCsr /* Cursor object to populate */
+){
+ int rc = SQLITE_OK; /* Error code */
+ sqlite3_stmt *pStmt = 0; /* Statement to iterate through segments */
+ int rc2; /* Result of sqlite3_reset() */
+
+ /* If iLevel is less than 0 and this is not a scan, include a seg-reader
+ ** for the pending-terms. If this is a scan, then this call must be being
+ ** made by an fts4aux module, not an FTS table. In this case calling
+ ** Fts3SegReaderPending might segfault, as the data structures used by
+ ** fts4aux are not completely populated. So it's easiest to filter these
+ ** calls out here. */
+ if( iLevel<0 && p->aIndex && p->iPrevLangid==iLangid ){
+ Fts3SegReader *pSeg = 0;
+ rc = sqlite3Fts3SegReaderPending(p, iIndex, zTerm, nTerm, isPrefix||isScan, &pSeg);
+ if( rc==SQLITE_OK && pSeg ){
+ rc = fts3SegReaderCursorAppend(pCsr, pSeg);
+ }
+ }
+
+ if( iLevel!=FTS3_SEGCURSOR_PENDING ){
+ if( rc==SQLITE_OK ){
+ rc = sqlite3Fts3AllSegdirs(p, iLangid, iIndex, iLevel, &pStmt);
+ }
+
+ while( rc==SQLITE_OK && SQLITE_ROW==(rc = sqlite3_step(pStmt)) ){
+ Fts3SegReader *pSeg = 0;
+
+ /* Read the values returned by the SELECT into local variables. */
+ sqlite3_int64 iStartBlock = sqlite3_column_int64(pStmt, 1);
+ sqlite3_int64 iLeavesEndBlock = sqlite3_column_int64(pStmt, 2);
+ sqlite3_int64 iEndBlock = sqlite3_column_int64(pStmt, 3);
+ int nRoot = sqlite3_column_bytes(pStmt, 4);
+ char const *zRoot = sqlite3_column_blob(pStmt, 4);
+
+ /* If zTerm is not NULL, and this segment is not stored entirely on its
+ ** root node, the range of leaves scanned can be reduced. Do this. */
+ if( iStartBlock && zTerm && zRoot ){
+ sqlite3_int64 *pi = (isPrefix ? &iLeavesEndBlock : 0);
+ rc = fts3SelectLeaf(p, zTerm, nTerm, zRoot, nRoot, &iStartBlock, pi);
+ if( rc!=SQLITE_OK ) goto finished;
+ if( isPrefix==0 && isScan==0 ) iLeavesEndBlock = iStartBlock;
+ }
+
+ rc = sqlite3Fts3SegReaderNew(pCsr->nSegment+1,
+ (isPrefix==0 && isScan==0),
+ iStartBlock, iLeavesEndBlock,
+ iEndBlock, zRoot, nRoot, &pSeg
+ );
+ if( rc!=SQLITE_OK ) goto finished;
+ rc = fts3SegReaderCursorAppend(pCsr, pSeg);
+ }
+ }
+
+ finished:
+ rc2 = sqlite3_reset(pStmt);
+ if( rc==SQLITE_DONE ) rc = rc2;
+
+ return rc;
+}
+
+/*
+** Set up a cursor object for iterating through a full-text index or a
+** single level therein.
+*/
+int sqlite3Fts3SegReaderCursor(
+ Fts3Table *p, /* FTS3 table handle */
+ int iLangid, /* Language-id to search */
+ int iIndex, /* Index to search (from 0 to p->nIndex-1) */
+ int iLevel, /* Level of segments to scan */
+ const char *zTerm, /* Term to query for */
+ int nTerm, /* Size of zTerm in bytes */
+ int isPrefix, /* True for a prefix search */
+ int isScan, /* True to scan from zTerm to EOF */
+ Fts3MultiSegReader *pCsr /* Cursor object to populate */
+){
+ assert( iIndex>=0 && iIndex<p->nIndex );
+ assert( iLevel==FTS3_SEGCURSOR_ALL
+ || iLevel==FTS3_SEGCURSOR_PENDING
+ || iLevel>=0
+ );
+ assert( iLevel<FTS3_SEGDIR_MAXLEVEL );
+ assert( FTS3_SEGCURSOR_ALL<0 && FTS3_SEGCURSOR_PENDING<0 );
+ assert( isPrefix==0 || isScan==0 );
+
+ memset(pCsr, 0, sizeof(Fts3MultiSegReader));
+ return fts3SegReaderCursor(
+ p, iLangid, iIndex, iLevel, zTerm, nTerm, isPrefix, isScan, pCsr
+ );
+}
+
+/*
+** In addition to its current configuration, have the Fts3MultiSegReader
+** passed as the 4th argument also scan the doclist for term zTerm/nTerm.
+**
+** SQLITE_OK is returned if no error occurs, otherwise an SQLite error code.
+*/
+static int fts3SegReaderCursorAddZero(
+ Fts3Table *p, /* FTS virtual table handle */
+ int iLangid,
+ const char *zTerm, /* Term to scan doclist of */
+ int nTerm, /* Number of bytes in zTerm */
+ Fts3MultiSegReader *pCsr /* Fts3MultiSegReader to modify */
+){
+ return fts3SegReaderCursor(p,
+ iLangid, 0, FTS3_SEGCURSOR_ALL, zTerm, nTerm, 0, 0,pCsr
+ );
+}
+
+/*
+** Open an Fts3MultiSegReader to scan the doclist for term zTerm/nTerm. Or,
+** if isPrefix is true, to scan the doclist for all terms for which
+** zTerm/nTerm is a prefix. If successful, return SQLITE_OK and write
+** a pointer to the new Fts3MultiSegReader to *ppSegcsr. Otherwise, return
+** an SQLite error code.
+**
+** It is the responsibility of the caller to free this object by eventually
+** passing it to fts3SegReaderCursorFree()
+**
+** SQLITE_OK is returned if no error occurs, otherwise an SQLite error code.
+** Output parameter *ppSegcsr is set to 0 if an error occurs.
+*/
+static int fts3TermSegReaderCursor(
+ Fts3Cursor *pCsr, /* Virtual table cursor handle */
+ const char *zTerm, /* Term to query for */
+ int nTerm, /* Size of zTerm in bytes */
+ int isPrefix, /* True for a prefix search */
+ Fts3MultiSegReader **ppSegcsr /* OUT: Allocated seg-reader cursor */
+){
+ Fts3MultiSegReader *pSegcsr; /* Object to allocate and return */
+ int rc = SQLITE_NOMEM; /* Return code */
+
+ pSegcsr = sqlite3_malloc(sizeof(Fts3MultiSegReader));
+ if( pSegcsr ){
+ int i;
+ int bFound = 0; /* True once an index has been found */
+ Fts3Table *p = (Fts3Table *)pCsr->base.pVtab;
+
+ if( isPrefix ){
+ for(i=1; bFound==0 && i<p->nIndex; i++){
+ if( p->aIndex[i].nPrefix==nTerm ){
+ bFound = 1;
+ rc = sqlite3Fts3SegReaderCursor(p, pCsr->iLangid,
+ i, FTS3_SEGCURSOR_ALL, zTerm, nTerm, 0, 0, pSegcsr
+ );
+ pSegcsr->bLookup = 1;
+ }
+ }
+
+ for(i=1; bFound==0 && i<p->nIndex; i++){
+ if( p->aIndex[i].nPrefix==nTerm+1 ){
+ bFound = 1;
+ rc = sqlite3Fts3SegReaderCursor(p, pCsr->iLangid,
+ i, FTS3_SEGCURSOR_ALL, zTerm, nTerm, 1, 0, pSegcsr
+ );
+ if( rc==SQLITE_OK ){
+ rc = fts3SegReaderCursorAddZero(
+ p, pCsr->iLangid, zTerm, nTerm, pSegcsr
+ );
+ }
+ }
+ }
+ }
+
+ if( bFound==0 ){
+ rc = sqlite3Fts3SegReaderCursor(p, pCsr->iLangid,
+ 0, FTS3_SEGCURSOR_ALL, zTerm, nTerm, isPrefix, 0, pSegcsr
+ );
+ pSegcsr->bLookup = !isPrefix;
+ }
+ }
+
+ *ppSegcsr = pSegcsr;
+ return rc;
+}
+
+/*
+** Free an Fts3MultiSegReader allocated by fts3TermSegReaderCursor().
+*/
+static void fts3SegReaderCursorFree(Fts3MultiSegReader *pSegcsr){
+ sqlite3Fts3SegReaderFinish(pSegcsr);
+ sqlite3_free(pSegcsr);
+}
+
+/*
+** This function retrieves the doclist for the specified term (or term
+** prefix) from the database.
+*/
+static int fts3TermSelect(
+ Fts3Table *p, /* Virtual table handle */
+ Fts3PhraseToken *pTok, /* Token to query for */
+ int iColumn, /* Column to query (or -ve for all columns) */
+ int *pnOut, /* OUT: Size of buffer at *ppOut */
+ char **ppOut /* OUT: Malloced result buffer */
+){
+ int rc; /* Return code */
+ Fts3MultiSegReader *pSegcsr; /* Seg-reader cursor for this term */
+ TermSelect tsc; /* Object for pair-wise doclist merging */
+ Fts3SegFilter filter; /* Segment term filter configuration */
+
+ pSegcsr = pTok->pSegcsr;
+ memset(&tsc, 0, sizeof(TermSelect));
+
+ filter.flags = FTS3_SEGMENT_IGNORE_EMPTY | FTS3_SEGMENT_REQUIRE_POS
+ | (pTok->isPrefix ? FTS3_SEGMENT_PREFIX : 0)
+ | (pTok->bFirst ? FTS3_SEGMENT_FIRST : 0)
+ | (iColumn<p->nColumn ? FTS3_SEGMENT_COLUMN_FILTER : 0);
+ filter.iCol = iColumn;
+ filter.zTerm = pTok->z;
+ filter.nTerm = pTok->n;
+
+ rc = sqlite3Fts3SegReaderStart(p, pSegcsr, &filter);
+ while( SQLITE_OK==rc
+ && SQLITE_ROW==(rc = sqlite3Fts3SegReaderStep(p, pSegcsr))
+ ){
+ rc = fts3TermSelectMerge(p, &tsc, pSegcsr->aDoclist, pSegcsr->nDoclist);
+ }
+
+ if( rc==SQLITE_OK ){
+ rc = fts3TermSelectFinishMerge(p, &tsc);
+ }
+ if( rc==SQLITE_OK ){
+ *ppOut = tsc.aaOutput[0];
+ *pnOut = tsc.anOutput[0];
+ }else{
+ int i;
+ for(i=0; i<SizeofArray(tsc.aaOutput); i++){
+ sqlite3_free(tsc.aaOutput[i]);
+ }
+ }
+
+ fts3SegReaderCursorFree(pSegcsr);
+ pTok->pSegcsr = 0;
+ return rc;
+}
+
+/*
+** This function counts the total number of docids in the doclist stored
+** in buffer aList[], size nList bytes.
+**
+** If the isPoslist argument is true, then it is assumed that the doclist
+** contains a position-list following each docid. Otherwise, it is assumed
+** that the doclist is simply a list of docids stored as delta encoded
+** varints.
+*/
+static int fts3DoclistCountDocids(char *aList, int nList){
+ int nDoc = 0; /* Return value */
+ if( aList ){
+ char *aEnd = &aList[nList]; /* Pointer to one byte after EOF */
+ char *p = aList; /* Cursor */
+ while( p<aEnd ){
+ nDoc++;
+ while( (*p++)&0x80 ); /* Skip docid varint */
+ fts3PoslistCopy(0, &p); /* Skip over position list */
+ }
+ }
+
+ return nDoc;
+}
+
+/*
+** Advance the cursor to the next row in the %_content table that
+** matches the search criteria. For a MATCH search, this will be
+** the next row that matches. For a full-table scan, this will be
+** simply the next row in the %_content table. For a docid lookup,
+** this routine simply sets the EOF flag.
+**
+** Return SQLITE_OK if nothing goes wrong. SQLITE_OK is returned
+** even if we reach end-of-file. The fts3EofMethod() will be called
+** subsequently to determine whether or not an EOF was hit.
+*/
+static int fts3NextMethod(sqlite3_vtab_cursor *pCursor){
+ int rc;
+ Fts3Cursor *pCsr = (Fts3Cursor *)pCursor;
+ if( pCsr->eSearch==FTS3_DOCID_SEARCH || pCsr->eSearch==FTS3_FULLSCAN_SEARCH ){
+ Fts3Table *pTab = (Fts3Table*)pCursor->pVtab;
+ pTab->bLock++;
+ if( SQLITE_ROW!=sqlite3_step(pCsr->pStmt) ){
+ pCsr->isEof = 1;
+ rc = sqlite3_reset(pCsr->pStmt);
+ }else{
+ pCsr->iPrevId = sqlite3_column_int64(pCsr->pStmt, 0);
+ rc = SQLITE_OK;
+ }
+ pTab->bLock--;
+ }else{
+ rc = fts3EvalNext((Fts3Cursor *)pCursor);
+ }
+ assert( ((Fts3Table *)pCsr->base.pVtab)->pSegments==0 );
+ return rc;
+}
+
+/*
+** If the numeric type of argument pVal is "integer", then return it
+** converted to a 64-bit signed integer. Otherwise, return a copy of
+** the second parameter, iDefault.
+*/
+static sqlite3_int64 fts3DocidRange(sqlite3_value *pVal, i64 iDefault){
+ if( pVal ){
+ int eType = sqlite3_value_numeric_type(pVal);
+ if( eType==SQLITE_INTEGER ){
+ return sqlite3_value_int64(pVal);
+ }
+ }
+ return iDefault;
+}
+
+/*
+** This is the xFilter interface for the virtual table. See
+** the virtual table xFilter method documentation for additional
+** information.
+**
+** If idxNum==FTS3_FULLSCAN_SEARCH then do a full table scan against
+** the %_content table.
+**
+** If idxNum==FTS3_DOCID_SEARCH then do a docid lookup for a single entry
+** in the %_content table.
+**
+** If idxNum>=FTS3_FULLTEXT_SEARCH then use the full text index. The
+** column on the left-hand side of the MATCH operator is column
+** number idxNum-FTS3_FULLTEXT_SEARCH, 0 indexed. argv[0] is the right-hand
+** side of the MATCH operator.
+*/
+static int fts3FilterMethod(
+ sqlite3_vtab_cursor *pCursor, /* The cursor used for this query */
+ int idxNum, /* Strategy index */
+ const char *idxStr, /* Unused */
+ int nVal, /* Number of elements in apVal */
+ sqlite3_value **apVal /* Arguments for the indexing scheme */
+){
+ int rc = SQLITE_OK;
+ char *zSql; /* SQL statement used to access %_content */
+ int eSearch;
+ Fts3Table *p = (Fts3Table *)pCursor->pVtab;
+ Fts3Cursor *pCsr = (Fts3Cursor *)pCursor;
+
+ sqlite3_value *pCons = 0; /* The MATCH or rowid constraint, if any */
+ sqlite3_value *pLangid = 0; /* The "langid = ?" constraint, if any */
+ sqlite3_value *pDocidGe = 0; /* The "docid >= ?" constraint, if any */
+ sqlite3_value *pDocidLe = 0; /* The "docid <= ?" constraint, if any */
+ int iIdx;
+
+ UNUSED_PARAMETER(idxStr);
+ UNUSED_PARAMETER(nVal);
+
+ if( p->bLock ){
+ return SQLITE_ERROR;
+ }
+
+ eSearch = (idxNum & 0x0000FFFF);
+ assert( eSearch>=0 && eSearch<=(FTS3_FULLTEXT_SEARCH+p->nColumn) );
+ assert( p->pSegments==0 );
+
+ /* Collect arguments into local variables */
+ iIdx = 0;
+ if( eSearch!=FTS3_FULLSCAN_SEARCH ) pCons = apVal[iIdx++];
+ if( idxNum & FTS3_HAVE_LANGID ) pLangid = apVal[iIdx++];
+ if( idxNum & FTS3_HAVE_DOCID_GE ) pDocidGe = apVal[iIdx++];
+ if( idxNum & FTS3_HAVE_DOCID_LE ) pDocidLe = apVal[iIdx++];
+ assert( iIdx==nVal );
+
+ /* In case the cursor has been used before, clear it now. */
+ fts3ClearCursor(pCsr);
+
+ /* Set the lower and upper bounds on docids to return */
+ pCsr->iMinDocid = fts3DocidRange(pDocidGe, SMALLEST_INT64);
+ pCsr->iMaxDocid = fts3DocidRange(pDocidLe, LARGEST_INT64);
+
+ if( idxStr ){
+ pCsr->bDesc = (idxStr[0]=='D');
+ }else{
+ pCsr->bDesc = p->bDescIdx;
+ }
+ pCsr->eSearch = (i16)eSearch;
+
+ if( eSearch!=FTS3_DOCID_SEARCH && eSearch!=FTS3_FULLSCAN_SEARCH ){
+ int iCol = eSearch-FTS3_FULLTEXT_SEARCH;
+ const char *zQuery = (const char *)sqlite3_value_text(pCons);
+
+ if( zQuery==0 && sqlite3_value_type(pCons)!=SQLITE_NULL ){
+ return SQLITE_NOMEM;
+ }
+
+ pCsr->iLangid = 0;
+ if( pLangid ) pCsr->iLangid = sqlite3_value_int(pLangid);
+
+ assert( p->base.zErrMsg==0 );
+ rc = sqlite3Fts3ExprParse(p->pTokenizer, pCsr->iLangid,
+ p->azColumn, p->bFts4, p->nColumn, iCol, zQuery, -1, &pCsr->pExpr,
+ &p->base.zErrMsg
+ );
+ if( rc!=SQLITE_OK ){
+ return rc;
+ }
+
+ rc = fts3EvalStart(pCsr);
+ sqlite3Fts3SegmentsClose(p);
+ if( rc!=SQLITE_OK ) return rc;
+ pCsr->pNextId = pCsr->aDoclist;
+ pCsr->iPrevId = 0;
+ }
+
+ /* Compile a SELECT statement for this cursor. For a full-table-scan, the
+ ** statement loops through all rows of the %_content table. For a
+ ** full-text query or docid lookup, the statement retrieves a single
+ ** row by docid.
+ */
+ if( eSearch==FTS3_FULLSCAN_SEARCH ){
+ if( pDocidGe || pDocidLe ){
+ zSql = sqlite3_mprintf(
+ "SELECT %s WHERE rowid BETWEEN %lld AND %lld ORDER BY rowid %s",
+ p->zReadExprlist, pCsr->iMinDocid, pCsr->iMaxDocid,
+ (pCsr->bDesc ? "DESC" : "ASC")
+ );
+ }else{
+ zSql = sqlite3_mprintf("SELECT %s ORDER BY rowid %s",
+ p->zReadExprlist, (pCsr->bDesc ? "DESC" : "ASC")
+ );
+ }
+ if( zSql ){
+ p->bLock++;
+ rc = sqlite3_prepare_v3(
+ p->db,zSql,-1,SQLITE_PREPARE_PERSISTENT,&pCsr->pStmt,0
+ );
+ p->bLock--;
+ sqlite3_free(zSql);
+ }else{
+ rc = SQLITE_NOMEM;
+ }
+ }else if( eSearch==FTS3_DOCID_SEARCH ){
+ rc = fts3CursorSeekStmt(pCsr);
+ if( rc==SQLITE_OK ){
+ rc = sqlite3_bind_value(pCsr->pStmt, 1, pCons);
+ }
+ }
+ if( rc!=SQLITE_OK ) return rc;
+
+ return fts3NextMethod(pCursor);
+}
+
+/*
+** This is the xEof method of the virtual table. SQLite calls this
+** routine to find out if it has reached the end of a result set.
+*/
+static int fts3EofMethod(sqlite3_vtab_cursor *pCursor){
+ Fts3Cursor *pCsr = (Fts3Cursor*)pCursor;
+ if( pCsr->isEof ){
+ fts3ClearCursor(pCsr);
+ pCsr->isEof = 1;
+ }
+ return pCsr->isEof;
+}
+
+/*
+** This is the xRowid method. The SQLite core calls this routine to
+** retrieve the rowid for the current row of the result set. fts3
+** exposes %_content.docid as the rowid for the virtual table. The
+** rowid should be written to *pRowid.
+*/
+static int fts3RowidMethod(sqlite3_vtab_cursor *pCursor, sqlite_int64 *pRowid){
+ Fts3Cursor *pCsr = (Fts3Cursor *) pCursor;
+ *pRowid = pCsr->iPrevId;
+ return SQLITE_OK;
+}
+
+/*
+** This is the xColumn method, called by SQLite to request a value from
+** the row that the supplied cursor currently points to.
+**
+** If:
+**
+** (iCol < p->nColumn) -> The value of the iCol'th user column.
+** (iCol == p->nColumn) -> Magic column with the same name as the table.
+** (iCol == p->nColumn+1) -> Docid column
+** (iCol == p->nColumn+2) -> Langid column
+*/
+static int fts3ColumnMethod(
+ sqlite3_vtab_cursor *pCursor, /* Cursor to retrieve value from */
+ sqlite3_context *pCtx, /* Context for sqlite3_result_xxx() calls */
+ int iCol /* Index of column to read value from */
+){
+ int rc = SQLITE_OK; /* Return Code */
+ Fts3Cursor *pCsr = (Fts3Cursor *) pCursor;
+ Fts3Table *p = (Fts3Table *)pCursor->pVtab;
+
+ /* The column value supplied by SQLite must be in range. */
+ assert( iCol>=0 && iCol<=p->nColumn+2 );
+
+ switch( iCol-p->nColumn ){
+ case 0:
+ /* The special 'table-name' column */
+ sqlite3_result_pointer(pCtx, pCsr, "fts3cursor", 0);
+ break;
+
+ case 1:
+ /* The docid column */
+ sqlite3_result_int64(pCtx, pCsr->iPrevId);
+ break;
+
+ case 2:
+ if( pCsr->pExpr ){
+ sqlite3_result_int64(pCtx, pCsr->iLangid);
+ break;
+ }else if( p->zLanguageid==0 ){
+ sqlite3_result_int(pCtx, 0);
+ break;
+ }else{
+ iCol = p->nColumn;
+ /* no break */ deliberate_fall_through
+ }
+
+ default:
+ /* A user column. Or, if this is a full-table scan, possibly the
+ ** language-id column. Seek the cursor. */
+ rc = fts3CursorSeek(0, pCsr);
+ if( rc==SQLITE_OK && sqlite3_data_count(pCsr->pStmt)-1>iCol ){
+ sqlite3_result_value(pCtx, sqlite3_column_value(pCsr->pStmt, iCol+1));
+ }
+ break;
+ }
+
+ assert( ((Fts3Table *)pCsr->base.pVtab)->pSegments==0 );
+ return rc;
+}
+
+/*
+** This function is the implementation of the xUpdate callback used by
+** FTS3 virtual tables. It is invoked by SQLite each time a row is to be
+** inserted, updated or deleted.
+*/
+static int fts3UpdateMethod(
+ sqlite3_vtab *pVtab, /* Virtual table handle */
+ int nArg, /* Size of argument array */
+ sqlite3_value **apVal, /* Array of arguments */
+ sqlite_int64 *pRowid /* OUT: The affected (or effected) rowid */
+){
+ return sqlite3Fts3UpdateMethod(pVtab, nArg, apVal, pRowid);
+}
+
+/*
+** Implementation of xSync() method. Flush the contents of the pending-terms
+** hash-table to the database.
+*/
+static int fts3SyncMethod(sqlite3_vtab *pVtab){
+
+ /* Following an incremental-merge operation, assuming that the input
+ ** segments are not completely consumed (the usual case), they are updated
+ ** in place to remove the entries that have already been merged. This
+ ** involves updating the leaf block that contains the smallest unmerged
+ ** entry and each block (if any) between the leaf and the root node. So
+ ** if the height of the input segment b-trees is N, and input segments
+ ** are merged eight at a time, updating the input segments at the end
+ ** of an incremental-merge requires writing (8*(1+N)) blocks. N is usually
+ ** small - often between 0 and 2. So the overhead of the incremental
+ ** merge is somewhere between 8 and 24 blocks. To avoid this overhead
+ ** dwarfing the actual productive work accomplished, the incremental merge
+ ** is only attempted if it will write at least 64 leaf blocks. Hence
+ ** nMinMerge.
+ **
+ ** Of course, updating the input segments also involves deleting a bunch
+ ** of blocks from the segments table. But this is not considered overhead
+ ** as it would also be required by a crisis-merge that used the same input
+ ** segments.
+ */
+ const u32 nMinMerge = 64; /* Minimum amount of incr-merge work to do */
+
+ Fts3Table *p = (Fts3Table*)pVtab;
+ int rc;
+ i64 iLastRowid = sqlite3_last_insert_rowid(p->db);
+
+ rc = sqlite3Fts3PendingTermsFlush(p);
+ if( rc==SQLITE_OK
+ && p->nLeafAdd>(nMinMerge/16)
+ && p->nAutoincrmerge && p->nAutoincrmerge!=0xff
+ ){
+ int mxLevel = 0; /* Maximum relative level value in db */
+ int A; /* Incr-merge parameter A */
+
+ rc = sqlite3Fts3MaxLevel(p, &mxLevel);
+ assert( rc==SQLITE_OK || mxLevel==0 );
+ A = p->nLeafAdd * mxLevel;
+ A += (A/2);
+ if( A>(int)nMinMerge ) rc = sqlite3Fts3Incrmerge(p, A, p->nAutoincrmerge);
+ }
+ sqlite3Fts3SegmentsClose(p);
+ sqlite3_set_last_insert_rowid(p->db, iLastRowid);
+ return rc;
+}
+
+/*
+** If it is currently unknown whether or not the FTS table has an %_stat
+** table (if p->bHasStat==2), attempt to determine this (set p->bHasStat
+** to 0 or 1). Return SQLITE_OK if successful, or an SQLite error code
+** if an error occurs.
+*/
+static int fts3SetHasStat(Fts3Table *p){
+ int rc = SQLITE_OK;
+ if( p->bHasStat==2 ){
+ char *zTbl = sqlite3_mprintf("%s_stat", p->zName);
+ if( zTbl ){
+ int res = sqlite3_table_column_metadata(p->db, p->zDb, zTbl, 0,0,0,0,0,0);
+ sqlite3_free(zTbl);
+ p->bHasStat = (res==SQLITE_OK);
+ }else{
+ rc = SQLITE_NOMEM;
+ }
+ }
+ return rc;
+}
+
+/*
+** Implementation of xBegin() method.
+*/
+static int fts3BeginMethod(sqlite3_vtab *pVtab){
+ Fts3Table *p = (Fts3Table*)pVtab;
+ int rc;
+ UNUSED_PARAMETER(pVtab);
+ assert( p->pSegments==0 );
+ assert( p->nPendingData==0 );
+ assert( p->inTransaction!=1 );
+ p->nLeafAdd = 0;
+ rc = fts3SetHasStat(p);
+#ifdef SQLITE_DEBUG
+ if( rc==SQLITE_OK ){
+ p->inTransaction = 1;
+ p->mxSavepoint = -1;
+ }
+#endif
+ return rc;
+}
+
+/*
+** Implementation of xCommit() method. This is a no-op. The contents of
+** the pending-terms hash-table have already been flushed into the database
+** by fts3SyncMethod().
+*/
+static int fts3CommitMethod(sqlite3_vtab *pVtab){
+ TESTONLY( Fts3Table *p = (Fts3Table*)pVtab );
+ UNUSED_PARAMETER(pVtab);
+ assert( p->nPendingData==0 );
+ assert( p->inTransaction!=0 );
+ assert( p->pSegments==0 );
+ TESTONLY( p->inTransaction = 0 );
+ TESTONLY( p->mxSavepoint = -1; );
+ return SQLITE_OK;
+}
+
+/*
+** Implementation of xRollback(). Discard the contents of the pending-terms
+** hash-table. Any changes made to the database are reverted by SQLite.
+*/
+static int fts3RollbackMethod(sqlite3_vtab *pVtab){
+ Fts3Table *p = (Fts3Table*)pVtab;
+ sqlite3Fts3PendingTermsClear(p);
+ assert( p->inTransaction!=0 );
+ TESTONLY( p->inTransaction = 0 );
+ TESTONLY( p->mxSavepoint = -1; );
+ return SQLITE_OK;
+}
+
+/*
+** When called, *ppPoslist must point to the byte immediately following the
+** end of a position-list. i.e. ( (*ppPoslist)[-1]==POS_END ). This function
+** moves *ppPoslist so that it instead points to the first byte of the
+** same position list.
+*/
+static void fts3ReversePoslist(char *pStart, char **ppPoslist){
+ char *p = &(*ppPoslist)[-2];
+ char c = 0;
+
+ /* Skip backwards passed any trailing 0x00 bytes added by NearTrim() */
+ while( p>pStart && (c=*p--)==0 );
+
+ /* Search backwards for a varint with value zero (the end of the previous
+ ** poslist). This is an 0x00 byte preceded by some byte that does not
+ ** have the 0x80 bit set. */
+ while( p>pStart && (*p & 0x80) | c ){
+ c = *p--;
+ }
+ assert( p==pStart || c==0 );
+
+ /* At this point p points to that preceding byte without the 0x80 bit
+ ** set. So to find the start of the poslist, skip forward 2 bytes then
+ ** over a varint.
+ **
+ ** Normally. The other case is that p==pStart and the poslist to return
+ ** is the first in the doclist. In this case do not skip forward 2 bytes.
+ ** The second part of the if condition (c==0 && *ppPoslist>&p[2])
+ ** is required for cases where the first byte of a doclist and the
+ ** doclist is empty. For example, if the first docid is 10, a doclist
+ ** that begins with:
+ **
+ ** 0x0A 0x00 <next docid delta varint>
+ */
+ if( p>pStart || (c==0 && *ppPoslist>&p[2]) ){ p = &p[2]; }
+ while( *p++&0x80 );
+ *ppPoslist = p;
+}
+
+/*
+** Helper function used by the implementation of the overloaded snippet(),
+** offsets() and optimize() SQL functions.
+**
+** If the value passed as the third argument is a blob of size
+** sizeof(Fts3Cursor*), then the blob contents are copied to the
+** output variable *ppCsr and SQLITE_OK is returned. Otherwise, an error
+** message is written to context pContext and SQLITE_ERROR returned. The
+** string passed via zFunc is used as part of the error message.
+*/
+static int fts3FunctionArg(
+ sqlite3_context *pContext, /* SQL function call context */
+ const char *zFunc, /* Function name */
+ sqlite3_value *pVal, /* argv[0] passed to function */
+ Fts3Cursor **ppCsr /* OUT: Store cursor handle here */
+){
+ int rc;
+ *ppCsr = (Fts3Cursor*)sqlite3_value_pointer(pVal, "fts3cursor");
+ if( (*ppCsr)!=0 ){
+ rc = SQLITE_OK;
+ }else{
+ char *zErr = sqlite3_mprintf("illegal first argument to %s", zFunc);
+ sqlite3_result_error(pContext, zErr, -1);
+ sqlite3_free(zErr);
+ rc = SQLITE_ERROR;
+ }
+ return rc;
+}
+
+/*
+** Implementation of the snippet() function for FTS3
+*/
+static void fts3SnippetFunc(
+ sqlite3_context *pContext, /* SQLite function call context */
+ int nVal, /* Size of apVal[] array */
+ sqlite3_value **apVal /* Array of arguments */
+){
+ Fts3Cursor *pCsr; /* Cursor handle passed through apVal[0] */
+ const char *zStart = "<b>";
+ const char *zEnd = "</b>";
+ const char *zEllipsis = "<b>...</b>";
+ int iCol = -1;
+ int nToken = 15; /* Default number of tokens in snippet */
+
+ /* There must be at least one argument passed to this function (otherwise
+ ** the non-overloaded version would have been called instead of this one).
+ */
+ assert( nVal>=1 );
+
+ if( nVal>6 ){
+ sqlite3_result_error(pContext,
+ "wrong number of arguments to function snippet()", -1);
+ return;
+ }
+ if( fts3FunctionArg(pContext, "snippet", apVal[0], &pCsr) ) return;
+
+ switch( nVal ){
+ case 6: nToken = sqlite3_value_int(apVal[5]);
+ /* no break */ deliberate_fall_through
+ case 5: iCol = sqlite3_value_int(apVal[4]);
+ /* no break */ deliberate_fall_through
+ case 4: zEllipsis = (const char*)sqlite3_value_text(apVal[3]);
+ /* no break */ deliberate_fall_through
+ case 3: zEnd = (const char*)sqlite3_value_text(apVal[2]);
+ /* no break */ deliberate_fall_through
+ case 2: zStart = (const char*)sqlite3_value_text(apVal[1]);
+ }
+ if( !zEllipsis || !zEnd || !zStart ){
+ sqlite3_result_error_nomem(pContext);
+ }else if( nToken==0 ){
+ sqlite3_result_text(pContext, "", -1, SQLITE_STATIC);
+ }else if( SQLITE_OK==fts3CursorSeek(pContext, pCsr) ){
+ sqlite3Fts3Snippet(pContext, pCsr, zStart, zEnd, zEllipsis, iCol, nToken);
+ }
+}
+
+/*
+** Implementation of the offsets() function for FTS3
+*/
+static void fts3OffsetsFunc(
+ sqlite3_context *pContext, /* SQLite function call context */
+ int nVal, /* Size of argument array */
+ sqlite3_value **apVal /* Array of arguments */
+){
+ Fts3Cursor *pCsr; /* Cursor handle passed through apVal[0] */
+
+ UNUSED_PARAMETER(nVal);
+
+ assert( nVal==1 );
+ if( fts3FunctionArg(pContext, "offsets", apVal[0], &pCsr) ) return;
+ assert( pCsr );
+ if( SQLITE_OK==fts3CursorSeek(pContext, pCsr) ){
+ sqlite3Fts3Offsets(pContext, pCsr);
+ }
+}
+
+/*
+** Implementation of the special optimize() function for FTS3. This
+** function merges all segments in the database to a single segment.
+** Example usage is:
+**
+** SELECT optimize(t) FROM t LIMIT 1;
+**
+** where 't' is the name of an FTS3 table.
+*/
+static void fts3OptimizeFunc(
+ sqlite3_context *pContext, /* SQLite function call context */
+ int nVal, /* Size of argument array */
+ sqlite3_value **apVal /* Array of arguments */
+){
+ int rc; /* Return code */
+ Fts3Table *p; /* Virtual table handle */
+ Fts3Cursor *pCursor; /* Cursor handle passed through apVal[0] */
+
+ UNUSED_PARAMETER(nVal);
+
+ assert( nVal==1 );
+ if( fts3FunctionArg(pContext, "optimize", apVal[0], &pCursor) ) return;
+ p = (Fts3Table *)pCursor->base.pVtab;
+ assert( p );
+
+ rc = sqlite3Fts3Optimize(p);
+
+ switch( rc ){
+ case SQLITE_OK:
+ sqlite3_result_text(pContext, "Index optimized", -1, SQLITE_STATIC);
+ break;
+ case SQLITE_DONE:
+ sqlite3_result_text(pContext, "Index already optimal", -1, SQLITE_STATIC);
+ break;
+ default:
+ sqlite3_result_error_code(pContext, rc);
+ break;
+ }
+}
+
+/*
+** Implementation of the matchinfo() function for FTS3
+*/
+static void fts3MatchinfoFunc(
+ sqlite3_context *pContext, /* SQLite function call context */
+ int nVal, /* Size of argument array */
+ sqlite3_value **apVal /* Array of arguments */
+){
+ Fts3Cursor *pCsr; /* Cursor handle passed through apVal[0] */
+ assert( nVal==1 || nVal==2 );
+ if( SQLITE_OK==fts3FunctionArg(pContext, "matchinfo", apVal[0], &pCsr) ){
+ const char *zArg = 0;
+ if( nVal>1 ){
+ zArg = (const char *)sqlite3_value_text(apVal[1]);
+ }
+ sqlite3Fts3Matchinfo(pContext, pCsr, zArg);
+ }
+}
+
+/*
+** This routine implements the xFindFunction method for the FTS3
+** virtual table.
+*/
+static int fts3FindFunctionMethod(
+ sqlite3_vtab *pVtab, /* Virtual table handle */
+ int nArg, /* Number of SQL function arguments */
+ const char *zName, /* Name of SQL function */
+ void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), /* OUT: Result */
+ void **ppArg /* Unused */
+){
+ struct Overloaded {
+ const char *zName;
+ void (*xFunc)(sqlite3_context*,int,sqlite3_value**);
+ } aOverload[] = {
+ { "snippet", fts3SnippetFunc },
+ { "offsets", fts3OffsetsFunc },
+ { "optimize", fts3OptimizeFunc },
+ { "matchinfo", fts3MatchinfoFunc },
+ };
+ int i; /* Iterator variable */
+
+ UNUSED_PARAMETER(pVtab);
+ UNUSED_PARAMETER(nArg);
+ UNUSED_PARAMETER(ppArg);
+
+ for(i=0; i<SizeofArray(aOverload); i++){
+ if( strcmp(zName, aOverload[i].zName)==0 ){
+ *pxFunc = aOverload[i].xFunc;
+ return 1;
+ }
+ }
+
+ /* No function of the specified name was found. Return 0. */
+ return 0;
+}
+
+/*
+** Implementation of FTS3 xRename method. Rename an fts3 table.
+*/
+static int fts3RenameMethod(
+ sqlite3_vtab *pVtab, /* Virtual table handle */
+ const char *zName /* New name of table */
+){
+ Fts3Table *p = (Fts3Table *)pVtab;
+ sqlite3 *db = p->db; /* Database connection */
+ int rc; /* Return Code */
+
+ /* At this point it must be known if the %_stat table exists or not.
+ ** So bHasStat may not be 2. */
+ rc = fts3SetHasStat(p);
+
+ /* As it happens, the pending terms table is always empty here. This is
+ ** because an "ALTER TABLE RENAME TABLE" statement inside a transaction
+ ** always opens a savepoint transaction. And the xSavepoint() method
+ ** flushes the pending terms table. But leave the (no-op) call to
+ ** PendingTermsFlush() in in case that changes.
+ */
+ assert( p->nPendingData==0 );
+ if( rc==SQLITE_OK ){
+ rc = sqlite3Fts3PendingTermsFlush(p);
+ }
+
+ if( p->zContentTbl==0 ){
+ fts3DbExec(&rc, db,
+ "ALTER TABLE %Q.'%q_content' RENAME TO '%q_content';",
+ p->zDb, p->zName, zName
+ );
+ }
+
+ if( p->bHasDocsize ){
+ fts3DbExec(&rc, db,
+ "ALTER TABLE %Q.'%q_docsize' RENAME TO '%q_docsize';",
+ p->zDb, p->zName, zName
+ );
+ }
+ if( p->bHasStat ){
+ fts3DbExec(&rc, db,
+ "ALTER TABLE %Q.'%q_stat' RENAME TO '%q_stat';",
+ p->zDb, p->zName, zName
+ );
+ }
+ fts3DbExec(&rc, db,
+ "ALTER TABLE %Q.'%q_segments' RENAME TO '%q_segments';",
+ p->zDb, p->zName, zName
+ );
+ fts3DbExec(&rc, db,
+ "ALTER TABLE %Q.'%q_segdir' RENAME TO '%q_segdir';",
+ p->zDb, p->zName, zName
+ );
+ return rc;
+}
+
+/*
+** The xSavepoint() method.
+**
+** Flush the contents of the pending-terms table to disk.
+*/
+static int fts3SavepointMethod(sqlite3_vtab *pVtab, int iSavepoint){
+ int rc = SQLITE_OK;
+ UNUSED_PARAMETER(iSavepoint);
+ assert( ((Fts3Table *)pVtab)->inTransaction );
+ assert( ((Fts3Table *)pVtab)->mxSavepoint <= iSavepoint );
+ TESTONLY( ((Fts3Table *)pVtab)->mxSavepoint = iSavepoint );
+ if( ((Fts3Table *)pVtab)->bIgnoreSavepoint==0 ){
+ rc = fts3SyncMethod(pVtab);
+ }
+ return rc;
+}
+
+/*
+** The xRelease() method.
+**
+** This is a no-op.
+*/
+static int fts3ReleaseMethod(sqlite3_vtab *pVtab, int iSavepoint){
+ TESTONLY( Fts3Table *p = (Fts3Table*)pVtab );
+ UNUSED_PARAMETER(iSavepoint);
+ UNUSED_PARAMETER(pVtab);
+ assert( p->inTransaction );
+ assert( p->mxSavepoint >= iSavepoint );
+ TESTONLY( p->mxSavepoint = iSavepoint-1 );
+ return SQLITE_OK;
+}
+
+/*
+** The xRollbackTo() method.
+**
+** Discard the contents of the pending terms table.
+*/
+static int fts3RollbackToMethod(sqlite3_vtab *pVtab, int iSavepoint){
+ Fts3Table *p = (Fts3Table*)pVtab;
+ UNUSED_PARAMETER(iSavepoint);
+ assert( p->inTransaction );
+ TESTONLY( p->mxSavepoint = iSavepoint );
+ sqlite3Fts3PendingTermsClear(p);
+ return SQLITE_OK;
+}
+
+/*
+** Return true if zName is the extension on one of the shadow tables used
+** by this module.
+*/
+static int fts3ShadowName(const char *zName){
+ static const char *azName[] = {
+ "content", "docsize", "segdir", "segments", "stat",
+ };
+ unsigned int i;
+ for(i=0; i<sizeof(azName)/sizeof(azName[0]); i++){
+ if( sqlite3_stricmp(zName, azName[i])==0 ) return 1;
+ }
+ return 0;
+}
+
+static const sqlite3_module fts3Module = {
+ /* iVersion */ 3,
+ /* xCreate */ fts3CreateMethod,
+ /* xConnect */ fts3ConnectMethod,
+ /* xBestIndex */ fts3BestIndexMethod,
+ /* xDisconnect */ fts3DisconnectMethod,
+ /* xDestroy */ fts3DestroyMethod,
+ /* xOpen */ fts3OpenMethod,
+ /* xClose */ fts3CloseMethod,
+ /* xFilter */ fts3FilterMethod,
+ /* xNext */ fts3NextMethod,
+ /* xEof */ fts3EofMethod,
+ /* xColumn */ fts3ColumnMethod,
+ /* xRowid */ fts3RowidMethod,
+ /* xUpdate */ fts3UpdateMethod,
+ /* xBegin */ fts3BeginMethod,
+ /* xSync */ fts3SyncMethod,
+ /* xCommit */ fts3CommitMethod,
+ /* xRollback */ fts3RollbackMethod,
+ /* xFindFunction */ fts3FindFunctionMethod,
+ /* xRename */ fts3RenameMethod,
+ /* xSavepoint */ fts3SavepointMethod,
+ /* xRelease */ fts3ReleaseMethod,
+ /* xRollbackTo */ fts3RollbackToMethod,
+ /* xShadowName */ fts3ShadowName,
+};
+
+/*
+** This function is registered as the module destructor (called when an
+** FTS3 enabled database connection is closed). It frees the memory
+** allocated for the tokenizer hash table.
+*/
+static void hashDestroy(void *p){
+ Fts3HashWrapper *pHash = (Fts3HashWrapper *)p;
+ pHash->nRef--;
+ if( pHash->nRef<=0 ){
+ sqlite3Fts3HashClear(&pHash->hash);
+ sqlite3_free(pHash);
+ }
+}
+
+/*
+** The fts3 built-in tokenizers - "simple", "porter" and "icu"- are
+** implemented in files fts3_tokenizer1.c, fts3_porter.c and fts3_icu.c
+** respectively. The following three forward declarations are for functions
+** declared in these files used to retrieve the respective implementations.
+**
+** Calling sqlite3Fts3SimpleTokenizerModule() sets the value pointed
+** to by the argument to point to the "simple" tokenizer implementation.
+** And so on.
+*/
+void sqlite3Fts3SimpleTokenizerModule(sqlite3_tokenizer_module const**ppModule);
+void sqlite3Fts3PorterTokenizerModule(sqlite3_tokenizer_module const**ppModule);
+#ifndef SQLITE_DISABLE_FTS3_UNICODE
+void sqlite3Fts3UnicodeTokenizer(sqlite3_tokenizer_module const**ppModule);
+#endif
+#ifdef SQLITE_ENABLE_ICU
+void sqlite3Fts3IcuTokenizerModule(sqlite3_tokenizer_module const**ppModule);
+#endif
+
+/*
+** Initialize the fts3 extension. If this extension is built as part
+** of the sqlite library, then this function is called directly by
+** SQLite. If fts3 is built as a dynamically loadable extension, this
+** function is called by the sqlite3_extension_init() entry point.
+*/
+int sqlite3Fts3Init(sqlite3 *db){
+ int rc = SQLITE_OK;
+ Fts3HashWrapper *pHash = 0;
+ const sqlite3_tokenizer_module *pSimple = 0;
+ const sqlite3_tokenizer_module *pPorter = 0;
+#ifndef SQLITE_DISABLE_FTS3_UNICODE
+ const sqlite3_tokenizer_module *pUnicode = 0;
+#endif
+
+#ifdef SQLITE_ENABLE_ICU
+ const sqlite3_tokenizer_module *pIcu = 0;
+ sqlite3Fts3IcuTokenizerModule(&pIcu);
+#endif
+
+#ifndef SQLITE_DISABLE_FTS3_UNICODE
+ sqlite3Fts3UnicodeTokenizer(&pUnicode);
+#endif
+
+#ifdef SQLITE_TEST
+ rc = sqlite3Fts3InitTerm(db);
+ if( rc!=SQLITE_OK ) return rc;
+#endif
+
+ rc = sqlite3Fts3InitAux(db);
+ if( rc!=SQLITE_OK ) return rc;
+
+ sqlite3Fts3SimpleTokenizerModule(&pSimple);
+ sqlite3Fts3PorterTokenizerModule(&pPorter);
+
+ /* Allocate and initialize the hash-table used to store tokenizers. */
+ pHash = sqlite3_malloc(sizeof(Fts3HashWrapper));
+ if( !pHash ){
+ rc = SQLITE_NOMEM;
+ }else{
+ sqlite3Fts3HashInit(&pHash->hash, FTS3_HASH_STRING, 1);
+ pHash->nRef = 0;
+ }
+
+ /* Load the built-in tokenizers into the hash table */
+ if( rc==SQLITE_OK ){
+ if( sqlite3Fts3HashInsert(&pHash->hash, "simple", 7, (void *)pSimple)
+ || sqlite3Fts3HashInsert(&pHash->hash, "porter", 7, (void *)pPorter)
+
+#ifndef SQLITE_DISABLE_FTS3_UNICODE
+ || sqlite3Fts3HashInsert(&pHash->hash, "unicode61", 10, (void *)pUnicode)
+#endif
+#ifdef SQLITE_ENABLE_ICU
+ || (pIcu && sqlite3Fts3HashInsert(&pHash->hash, "icu", 4, (void *)pIcu))
+#endif
+ ){
+ rc = SQLITE_NOMEM;
+ }
+ }
+
+#ifdef SQLITE_TEST
+ if( rc==SQLITE_OK ){
+ rc = sqlite3Fts3ExprInitTestInterface(db, &pHash->hash);
+ }
+#endif
+
+ /* Create the virtual table wrapper around the hash-table and overload
+ ** the four scalar functions. If this is successful, register the
+ ** module with sqlite.
+ */
+ if( SQLITE_OK==rc
+ && SQLITE_OK==(rc=sqlite3Fts3InitHashTable(db,&pHash->hash,"fts3_tokenizer"))
+ && SQLITE_OK==(rc = sqlite3_overload_function(db, "snippet", -1))
+ && SQLITE_OK==(rc = sqlite3_overload_function(db, "offsets", 1))
+ && SQLITE_OK==(rc = sqlite3_overload_function(db, "matchinfo", 1))
+ && SQLITE_OK==(rc = sqlite3_overload_function(db, "matchinfo", 2))
+ && SQLITE_OK==(rc = sqlite3_overload_function(db, "optimize", 1))
+ ){
+ pHash->nRef++;
+ rc = sqlite3_create_module_v2(
+ db, "fts3", &fts3Module, (void *)pHash, hashDestroy
+ );
+ if( rc==SQLITE_OK ){
+ pHash->nRef++;
+ rc = sqlite3_create_module_v2(
+ db, "fts4", &fts3Module, (void *)pHash, hashDestroy
+ );
+ }
+ if( rc==SQLITE_OK ){
+ pHash->nRef++;
+ rc = sqlite3Fts3InitTok(db, (void *)pHash, hashDestroy);
+ }
+ return rc;
+ }
+
+
+ /* An error has occurred. Delete the hash table and return the error code. */
+ assert( rc!=SQLITE_OK );
+ if( pHash ){
+ sqlite3Fts3HashClear(&pHash->hash);
+ sqlite3_free(pHash);
+ }
+ return rc;
+}
+
+/*
+** Allocate an Fts3MultiSegReader for each token in the expression headed
+** by pExpr.
+**
+** An Fts3SegReader object is a cursor that can seek or scan a range of
+** entries within a single segment b-tree. An Fts3MultiSegReader uses multiple
+** Fts3SegReader objects internally to provide an interface to seek or scan
+** within the union of all segments of a b-tree. Hence the name.
+**
+** If the allocated Fts3MultiSegReader just seeks to a single entry in a
+** segment b-tree (if the term is not a prefix or it is a prefix for which
+** there exists prefix b-tree of the right length) then it may be traversed
+** and merged incrementally. Otherwise, it has to be merged into an in-memory
+** doclist and then traversed.
+*/
+static void fts3EvalAllocateReaders(
+ Fts3Cursor *pCsr, /* FTS cursor handle */
+ Fts3Expr *pExpr, /* Allocate readers for this expression */
+ int *pnToken, /* OUT: Total number of tokens in phrase. */
+ int *pnOr, /* OUT: Total number of OR nodes in expr. */
+ int *pRc /* IN/OUT: Error code */
+){
+ if( pExpr && SQLITE_OK==*pRc ){
+ if( pExpr->eType==FTSQUERY_PHRASE ){
+ int i;
+ int nToken = pExpr->pPhrase->nToken;
+ *pnToken += nToken;
+ for(i=0; i<nToken; i++){
+ Fts3PhraseToken *pToken = &pExpr->pPhrase->aToken[i];
+ int rc = fts3TermSegReaderCursor(pCsr,
+ pToken->z, pToken->n, pToken->isPrefix, &pToken->pSegcsr
+ );
+ if( rc!=SQLITE_OK ){
+ *pRc = rc;
+ return;
+ }
+ }
+ assert( pExpr->pPhrase->iDoclistToken==0 );
+ pExpr->pPhrase->iDoclistToken = -1;
+ }else{
+ *pnOr += (pExpr->eType==FTSQUERY_OR);
+ fts3EvalAllocateReaders(pCsr, pExpr->pLeft, pnToken, pnOr, pRc);
+ fts3EvalAllocateReaders(pCsr, pExpr->pRight, pnToken, pnOr, pRc);
+ }
+ }
+}
+
+/*
+** Arguments pList/nList contain the doclist for token iToken of phrase p.
+** It is merged into the main doclist stored in p->doclist.aAll/nAll.
+**
+** This function assumes that pList points to a buffer allocated using
+** sqlite3_malloc(). This function takes responsibility for eventually
+** freeing the buffer.
+**
+** SQLITE_OK is returned if successful, or SQLITE_NOMEM if an error occurs.
+*/
+static int fts3EvalPhraseMergeToken(
+ Fts3Table *pTab, /* FTS Table pointer */
+ Fts3Phrase *p, /* Phrase to merge pList/nList into */
+ int iToken, /* Token pList/nList corresponds to */
+ char *pList, /* Pointer to doclist */
+ int nList /* Number of bytes in pList */
+){
+ int rc = SQLITE_OK;
+ assert( iToken!=p->iDoclistToken );
+
+ if( pList==0 ){
+ sqlite3_free(p->doclist.aAll);
+ p->doclist.aAll = 0;
+ p->doclist.nAll = 0;
+ }
+
+ else if( p->iDoclistToken<0 ){
+ p->doclist.aAll = pList;
+ p->doclist.nAll = nList;
+ }
+
+ else if( p->doclist.aAll==0 ){
+ sqlite3_free(pList);
+ }
+
+ else {
+ char *pLeft;
+ char *pRight;
+ int nLeft;
+ int nRight;
+ int nDiff;
+
+ if( p->iDoclistToken<iToken ){
+ pLeft = p->doclist.aAll;
+ nLeft = p->doclist.nAll;
+ pRight = pList;
+ nRight = nList;
+ nDiff = iToken - p->iDoclistToken;
+ }else{
+ pRight = p->doclist.aAll;
+ nRight = p->doclist.nAll;
+ pLeft = pList;
+ nLeft = nList;
+ nDiff = p->iDoclistToken - iToken;
+ }
+
+ rc = fts3DoclistPhraseMerge(
+ pTab->bDescIdx, nDiff, pLeft, nLeft, &pRight, &nRight
+ );
+ sqlite3_free(pLeft);
+ p->doclist.aAll = pRight;
+ p->doclist.nAll = nRight;
+ }
+
+ if( iToken>p->iDoclistToken ) p->iDoclistToken = iToken;
+ return rc;
+}
+
+/*
+** Load the doclist for phrase p into p->doclist.aAll/nAll. The loaded doclist
+** does not take deferred tokens into account.
+**
+** SQLITE_OK is returned if no error occurs, otherwise an SQLite error code.
+*/
+static int fts3EvalPhraseLoad(
+ Fts3Cursor *pCsr, /* FTS Cursor handle */
+ Fts3Phrase *p /* Phrase object */
+){
+ Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;
+ int iToken;
+ int rc = SQLITE_OK;
+
+ for(iToken=0; rc==SQLITE_OK && iToken<p->nToken; iToken++){
+ Fts3PhraseToken *pToken = &p->aToken[iToken];
+ assert( pToken->pDeferred==0 || pToken->pSegcsr==0 );
+
+ if( pToken->pSegcsr ){
+ int nThis = 0;
+ char *pThis = 0;
+ rc = fts3TermSelect(pTab, pToken, p->iColumn, &nThis, &pThis);
+ if( rc==SQLITE_OK ){
+ rc = fts3EvalPhraseMergeToken(pTab, p, iToken, pThis, nThis);
+ }
+ }
+ assert( pToken->pSegcsr==0 );
+ }
+
+ return rc;
+}
+
+#ifndef SQLITE_DISABLE_FTS4_DEFERRED
+/*
+** This function is called on each phrase after the position lists for
+** any deferred tokens have been loaded into memory. It updates the phrases
+** current position list to include only those positions that are really
+** instances of the phrase (after considering deferred tokens). If this
+** means that the phrase does not appear in the current row, doclist.pList
+** and doclist.nList are both zeroed.
+**
+** SQLITE_OK is returned if no error occurs, otherwise an SQLite error code.
+*/
+static int fts3EvalDeferredPhrase(Fts3Cursor *pCsr, Fts3Phrase *pPhrase){
+ int iToken; /* Used to iterate through phrase tokens */
+ char *aPoslist = 0; /* Position list for deferred tokens */
+ int nPoslist = 0; /* Number of bytes in aPoslist */
+ int iPrev = -1; /* Token number of previous deferred token */
+ char *aFree = (pPhrase->doclist.bFreeList ? pPhrase->doclist.pList : 0);
+
+ for(iToken=0; iToken<pPhrase->nToken; iToken++){
+ Fts3PhraseToken *pToken = &pPhrase->aToken[iToken];
+ Fts3DeferredToken *pDeferred = pToken->pDeferred;
+
+ if( pDeferred ){
+ char *pList;
+ int nList;
+ int rc = sqlite3Fts3DeferredTokenList(pDeferred, &pList, &nList);
+ if( rc!=SQLITE_OK ) return rc;
+
+ if( pList==0 ){
+ sqlite3_free(aPoslist);
+ sqlite3_free(aFree);
+ pPhrase->doclist.pList = 0;
+ pPhrase->doclist.nList = 0;
+ return SQLITE_OK;
+
+ }else if( aPoslist==0 ){
+ aPoslist = pList;
+ nPoslist = nList;
+
+ }else{
+ char *aOut = pList;
+ char *p1 = aPoslist;
+ char *p2 = aOut;
+
+ assert( iPrev>=0 );
+ fts3PoslistPhraseMerge(&aOut, iToken-iPrev, 0, 1, &p1, &p2);
+ sqlite3_free(aPoslist);
+ aPoslist = pList;
+ nPoslist = (int)(aOut - aPoslist);
+ if( nPoslist==0 ){
+ sqlite3_free(aPoslist);
+ sqlite3_free(aFree);
+ pPhrase->doclist.pList = 0;
+ pPhrase->doclist.nList = 0;
+ return SQLITE_OK;
+ }
+ }
+ iPrev = iToken;
+ }
+ }
+
+ if( iPrev>=0 ){
+ int nMaxUndeferred = pPhrase->iDoclistToken;
+ if( nMaxUndeferred<0 ){
+ pPhrase->doclist.pList = aPoslist;
+ pPhrase->doclist.nList = nPoslist;
+ pPhrase->doclist.iDocid = pCsr->iPrevId;
+ pPhrase->doclist.bFreeList = 1;
+ }else{
+ int nDistance;
+ char *p1;
+ char *p2;
+ char *aOut;
+
+ if( nMaxUndeferred>iPrev ){
+ p1 = aPoslist;
+ p2 = pPhrase->doclist.pList;
+ nDistance = nMaxUndeferred - iPrev;
+ }else{
+ p1 = pPhrase->doclist.pList;
+ p2 = aPoslist;
+ nDistance = iPrev - nMaxUndeferred;
+ }
+
+ aOut = (char *)sqlite3Fts3MallocZero(nPoslist+FTS3_BUFFER_PADDING);
+ if( !aOut ){
+ sqlite3_free(aPoslist);
+ return SQLITE_NOMEM;
+ }
+
+ pPhrase->doclist.pList = aOut;
+ assert( p1 && p2 );
+ if( fts3PoslistPhraseMerge(&aOut, nDistance, 0, 1, &p1, &p2) ){
+ pPhrase->doclist.bFreeList = 1;
+ pPhrase->doclist.nList = (int)(aOut - pPhrase->doclist.pList);
+ }else{
+ sqlite3_free(aOut);
+ pPhrase->doclist.pList = 0;
+ pPhrase->doclist.nList = 0;
+ }
+ sqlite3_free(aPoslist);
+ }
+ }
+
+ if( pPhrase->doclist.pList!=aFree ) sqlite3_free(aFree);
+ return SQLITE_OK;
+}
+#endif /* SQLITE_DISABLE_FTS4_DEFERRED */
+
+/*
+** Maximum number of tokens a phrase may have to be considered for the
+** incremental doclists strategy.
+*/
+#define MAX_INCR_PHRASE_TOKENS 4
+
+/*
+** This function is called for each Fts3Phrase in a full-text query
+** expression to initialize the mechanism for returning rows. Once this
+** function has been called successfully on an Fts3Phrase, it may be
+** used with fts3EvalPhraseNext() to iterate through the matching docids.
+**
+** If parameter bOptOk is true, then the phrase may (or may not) use the
+** incremental loading strategy. Otherwise, the entire doclist is loaded into
+** memory within this call.
+**
+** SQLITE_OK is returned if no error occurs, otherwise an SQLite error code.
+*/
+static int fts3EvalPhraseStart(Fts3Cursor *pCsr, int bOptOk, Fts3Phrase *p){
+ Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;
+ int rc = SQLITE_OK; /* Error code */
+ int i;
+
+ /* Determine if doclists may be loaded from disk incrementally. This is
+ ** possible if the bOptOk argument is true, the FTS doclists will be
+ ** scanned in forward order, and the phrase consists of
+ ** MAX_INCR_PHRASE_TOKENS or fewer tokens, none of which are are "^first"
+ ** tokens or prefix tokens that cannot use a prefix-index. */
+ int bHaveIncr = 0;
+ int bIncrOk = (bOptOk
+ && pCsr->bDesc==pTab->bDescIdx
+ && p->nToken<=MAX_INCR_PHRASE_TOKENS && p->nToken>0
+#if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)
+ && pTab->bNoIncrDoclist==0
+#endif
+ );
+ for(i=0; bIncrOk==1 && i<p->nToken; i++){
+ Fts3PhraseToken *pToken = &p->aToken[i];
+ if( pToken->bFirst || (pToken->pSegcsr!=0 && !pToken->pSegcsr->bLookup) ){
+ bIncrOk = 0;
+ }
+ if( pToken->pSegcsr ) bHaveIncr = 1;
+ }
+
+ if( bIncrOk && bHaveIncr ){
+ /* Use the incremental approach. */
+ int iCol = (p->iColumn >= pTab->nColumn ? -1 : p->iColumn);
+ for(i=0; rc==SQLITE_OK && i<p->nToken; i++){
+ Fts3PhraseToken *pToken = &p->aToken[i];
+ Fts3MultiSegReader *pSegcsr = pToken->pSegcsr;
+ if( pSegcsr ){
+ rc = sqlite3Fts3MsrIncrStart(pTab, pSegcsr, iCol, pToken->z, pToken->n);
+ }
+ }
+ p->bIncr = 1;
+ }else{
+ /* Load the full doclist for the phrase into memory. */
+ rc = fts3EvalPhraseLoad(pCsr, p);
+ p->bIncr = 0;
+ }
+
+ assert( rc!=SQLITE_OK || p->nToken<1 || p->aToken[0].pSegcsr==0 || p->bIncr );
+ return rc;
+}
+
+/*
+** This function is used to iterate backwards (from the end to start)
+** through doclists. It is used by this module to iterate through phrase
+** doclists in reverse and by the fts3_write.c module to iterate through
+** pending-terms lists when writing to databases with "order=desc".
+**
+** The doclist may be sorted in ascending (parameter bDescIdx==0) or
+** descending (parameter bDescIdx==1) order of docid. Regardless, this
+** function iterates from the end of the doclist to the beginning.
+*/
+void sqlite3Fts3DoclistPrev(
+ int bDescIdx, /* True if the doclist is desc */
+ char *aDoclist, /* Pointer to entire doclist */
+ int nDoclist, /* Length of aDoclist in bytes */
+ char **ppIter, /* IN/OUT: Iterator pointer */
+ sqlite3_int64 *piDocid, /* IN/OUT: Docid pointer */
+ int *pnList, /* OUT: List length pointer */
+ u8 *pbEof /* OUT: End-of-file flag */
+){
+ char *p = *ppIter;
+
+ assert( nDoclist>0 );
+ assert( *pbEof==0 );
+ assert_fts3_nc( p || *piDocid==0 );
+ assert( !p || (p>aDoclist && p<&aDoclist[nDoclist]) );
+
+ if( p==0 ){
+ sqlite3_int64 iDocid = 0;
+ char *pNext = 0;
+ char *pDocid = aDoclist;
+ char *pEnd = &aDoclist[nDoclist];
+ int iMul = 1;
+
+ while( pDocid<pEnd ){
+ sqlite3_int64 iDelta;
+ pDocid += sqlite3Fts3GetVarint(pDocid, &iDelta);
+ iDocid += (iMul * iDelta);
+ pNext = pDocid;
+ fts3PoslistCopy(0, &pDocid);
+ while( pDocid<pEnd && *pDocid==0 ) pDocid++;
+ iMul = (bDescIdx ? -1 : 1);
+ }
+
+ *pnList = (int)(pEnd - pNext);
+ *ppIter = pNext;
+ *piDocid = iDocid;
+ }else{
+ int iMul = (bDescIdx ? -1 : 1);
+ sqlite3_int64 iDelta;
+ fts3GetReverseVarint(&p, aDoclist, &iDelta);
+ *piDocid -= (iMul * iDelta);
+
+ if( p==aDoclist ){
+ *pbEof = 1;
+ }else{
+ char *pSave = p;
+ fts3ReversePoslist(aDoclist, &p);
+ *pnList = (int)(pSave - p);
+ }
+ *ppIter = p;
+ }
+}
+
+/*
+** Iterate forwards through a doclist.
+*/
+void sqlite3Fts3DoclistNext(
+ int bDescIdx, /* True if the doclist is desc */
+ char *aDoclist, /* Pointer to entire doclist */
+ int nDoclist, /* Length of aDoclist in bytes */
+ char **ppIter, /* IN/OUT: Iterator pointer */
+ sqlite3_int64 *piDocid, /* IN/OUT: Docid pointer */
+ u8 *pbEof /* OUT: End-of-file flag */
+){
+ char *p = *ppIter;
+
+ assert( nDoclist>0 );
+ assert( *pbEof==0 );
+ assert_fts3_nc( p || *piDocid==0 );
+ assert( !p || (p>=aDoclist && p<=&aDoclist[nDoclist]) );
+
+ if( p==0 ){
+ p = aDoclist;
+ p += sqlite3Fts3GetVarint(p, piDocid);
+ }else{
+ fts3PoslistCopy(0, &p);
+ while( p<&aDoclist[nDoclist] && *p==0 ) p++;
+ if( p>=&aDoclist[nDoclist] ){
+ *pbEof = 1;
+ }else{
+ sqlite3_int64 iVar;
+ p += sqlite3Fts3GetVarint(p, &iVar);
+ *piDocid += ((bDescIdx ? -1 : 1) * iVar);
+ }
+ }
+
+ *ppIter = p;
+}
+
+/*
+** Advance the iterator pDL to the next entry in pDL->aAll/nAll. Set *pbEof
+** to true if EOF is reached.
+*/
+static void fts3EvalDlPhraseNext(
+ Fts3Table *pTab,
+ Fts3Doclist *pDL,
+ u8 *pbEof
+){
+ char *pIter; /* Used to iterate through aAll */
+ char *pEnd; /* 1 byte past end of aAll */
+
+ if( pDL->pNextDocid ){
+ pIter = pDL->pNextDocid;
+ assert( pDL->aAll!=0 || pIter==0 );
+ }else{
+ pIter = pDL->aAll;
+ }
+
+ if( pIter==0 || pIter>=(pEnd = pDL->aAll + pDL->nAll) ){
+ /* We have already reached the end of this doclist. EOF. */
+ *pbEof = 1;
+ }else{
+ sqlite3_int64 iDelta;
+ pIter += sqlite3Fts3GetVarint(pIter, &iDelta);
+ if( pTab->bDescIdx==0 || pDL->pNextDocid==0 ){
+ pDL->iDocid += iDelta;
+ }else{
+ pDL->iDocid -= iDelta;
+ }
+ pDL->pList = pIter;
+ fts3PoslistCopy(0, &pIter);
+ pDL->nList = (int)(pIter - pDL->pList);
+
+ /* pIter now points just past the 0x00 that terminates the position-
+ ** list for document pDL->iDocid. However, if this position-list was
+ ** edited in place by fts3EvalNearTrim(), then pIter may not actually
+ ** point to the start of the next docid value. The following line deals
+ ** with this case by advancing pIter past the zero-padding added by
+ ** fts3EvalNearTrim(). */
+ while( pIter<pEnd && *pIter==0 ) pIter++;
+
+ pDL->pNextDocid = pIter;
+ assert( pIter>=&pDL->aAll[pDL->nAll] || *pIter );
+ *pbEof = 0;
+ }
+}
+
+/*
+** Helper type used by fts3EvalIncrPhraseNext() and incrPhraseTokenNext().
+*/
+typedef struct TokenDoclist TokenDoclist;
+struct TokenDoclist {
+ int bIgnore;
+ sqlite3_int64 iDocid;
+ char *pList;
+ int nList;
+};
+
+/*
+** Token pToken is an incrementally loaded token that is part of a
+** multi-token phrase. Advance it to the next matching document in the
+** database and populate output variable *p with the details of the new
+** entry. Or, if the iterator has reached EOF, set *pbEof to true.
+**
+** If an error occurs, return an SQLite error code. Otherwise, return
+** SQLITE_OK.
+*/
+static int incrPhraseTokenNext(
+ Fts3Table *pTab, /* Virtual table handle */
+ Fts3Phrase *pPhrase, /* Phrase to advance token of */
+ int iToken, /* Specific token to advance */
+ TokenDoclist *p, /* OUT: Docid and doclist for new entry */
+ u8 *pbEof /* OUT: True if iterator is at EOF */
+){
+ int rc = SQLITE_OK;
+
+ if( pPhrase->iDoclistToken==iToken ){
+ assert( p->bIgnore==0 );
+ assert( pPhrase->aToken[iToken].pSegcsr==0 );
+ fts3EvalDlPhraseNext(pTab, &pPhrase->doclist, pbEof);
+ p->pList = pPhrase->doclist.pList;
+ p->nList = pPhrase->doclist.nList;
+ p->iDocid = pPhrase->doclist.iDocid;
+ }else{
+ Fts3PhraseToken *pToken = &pPhrase->aToken[iToken];
+ assert( pToken->pDeferred==0 );
+ assert( pToken->pSegcsr || pPhrase->iDoclistToken>=0 );
+ if( pToken->pSegcsr ){
+ assert( p->bIgnore==0 );
+ rc = sqlite3Fts3MsrIncrNext(
+ pTab, pToken->pSegcsr, &p->iDocid, &p->pList, &p->nList
+ );
+ if( p->pList==0 ) *pbEof = 1;
+ }else{
+ p->bIgnore = 1;
+ }
+ }
+
+ return rc;
+}
+
+
+/*
+** The phrase iterator passed as the second argument:
+**
+** * features at least one token that uses an incremental doclist, and
+**
+** * does not contain any deferred tokens.
+**
+** Advance it to the next matching documnent in the database and populate
+** the Fts3Doclist.pList and nList fields.
+**
+** If there is no "next" entry and no error occurs, then *pbEof is set to
+** 1 before returning. Otherwise, if no error occurs and the iterator is
+** successfully advanced, *pbEof is set to 0.
+**
+** If an error occurs, return an SQLite error code. Otherwise, return
+** SQLITE_OK.
+*/
+static int fts3EvalIncrPhraseNext(
+ Fts3Cursor *pCsr, /* FTS Cursor handle */
+ Fts3Phrase *p, /* Phrase object to advance to next docid */
+ u8 *pbEof /* OUT: Set to 1 if EOF */
+){
+ int rc = SQLITE_OK;
+ Fts3Doclist *pDL = &p->doclist;
+ Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;
+ u8 bEof = 0;
+
+ /* This is only called if it is guaranteed that the phrase has at least
+ ** one incremental token. In which case the bIncr flag is set. */
+ assert( p->bIncr==1 );
+
+ if( p->nToken==1 ){
+ rc = sqlite3Fts3MsrIncrNext(pTab, p->aToken[0].pSegcsr,
+ &pDL->iDocid, &pDL->pList, &pDL->nList
+ );
+ if( pDL->pList==0 ) bEof = 1;
+ }else{
+ int bDescDoclist = pCsr->bDesc;
+ struct TokenDoclist a[MAX_INCR_PHRASE_TOKENS];
+
+ memset(a, 0, sizeof(a));
+ assert( p->nToken<=MAX_INCR_PHRASE_TOKENS );
+ assert( p->iDoclistToken<MAX_INCR_PHRASE_TOKENS );
+
+ while( bEof==0 ){
+ int bMaxSet = 0;
+ sqlite3_int64 iMax = 0; /* Largest docid for all iterators */
+ int i; /* Used to iterate through tokens */
+
+ /* Advance the iterator for each token in the phrase once. */
+ for(i=0; rc==SQLITE_OK && i<p->nToken && bEof==0; i++){
+ rc = incrPhraseTokenNext(pTab, p, i, &a[i], &bEof);
+ if( a[i].bIgnore==0 && (bMaxSet==0 || DOCID_CMP(iMax, a[i].iDocid)<0) ){
+ iMax = a[i].iDocid;
+ bMaxSet = 1;
+ }
+ }
+ assert( rc!=SQLITE_OK || (p->nToken>=1 && a[p->nToken-1].bIgnore==0) );
+ assert( rc!=SQLITE_OK || bMaxSet );
+
+ /* Keep advancing iterators until they all point to the same document */
+ for(i=0; i<p->nToken; i++){
+ while( rc==SQLITE_OK && bEof==0
+ && a[i].bIgnore==0 && DOCID_CMP(a[i].iDocid, iMax)<0
+ ){
+ rc = incrPhraseTokenNext(pTab, p, i, &a[i], &bEof);
+ if( DOCID_CMP(a[i].iDocid, iMax)>0 ){
+ iMax = a[i].iDocid;
+ i = 0;
+ }
+ }
+ }
+
+ /* Check if the current entries really are a phrase match */
+ if( bEof==0 ){
+ int nList = 0;
+ int nByte = a[p->nToken-1].nList;
+ char *aDoclist = sqlite3_malloc64((i64)nByte+FTS3_BUFFER_PADDING);
+ if( !aDoclist ) return SQLITE_NOMEM;
+ memcpy(aDoclist, a[p->nToken-1].pList, nByte+1);
+ memset(&aDoclist[nByte], 0, FTS3_BUFFER_PADDING);
+
+ for(i=0; i<(p->nToken-1); i++){
+ if( a[i].bIgnore==0 ){
+ char *pL = a[i].pList;
+ char *pR = aDoclist;
+ char *pOut = aDoclist;
+ int nDist = p->nToken-1-i;
+ int res = fts3PoslistPhraseMerge(&pOut, nDist, 0, 1, &pL, &pR);
+ if( res==0 ) break;
+ nList = (int)(pOut - aDoclist);
+ }
+ }
+ if( i==(p->nToken-1) ){
+ pDL->iDocid = iMax;
+ pDL->pList = aDoclist;
+ pDL->nList = nList;
+ pDL->bFreeList = 1;
+ break;
+ }
+ sqlite3_free(aDoclist);
+ }
+ }
+ }
+
+ *pbEof = bEof;
+ return rc;
+}
+
+/*
+** Attempt to move the phrase iterator to point to the next matching docid.
+** If an error occurs, return an SQLite error code. Otherwise, return
+** SQLITE_OK.
+**
+** If there is no "next" entry and no error occurs, then *pbEof is set to
+** 1 before returning. Otherwise, if no error occurs and the iterator is
+** successfully advanced, *pbEof is set to 0.
+*/
+static int fts3EvalPhraseNext(
+ Fts3Cursor *pCsr, /* FTS Cursor handle */
+ Fts3Phrase *p, /* Phrase object to advance to next docid */
+ u8 *pbEof /* OUT: Set to 1 if EOF */
+){
+ int rc = SQLITE_OK;
+ Fts3Doclist *pDL = &p->doclist;
+ Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;
+
+ if( p->bIncr ){
+ rc = fts3EvalIncrPhraseNext(pCsr, p, pbEof);
+ }else if( pCsr->bDesc!=pTab->bDescIdx && pDL->nAll ){
+ sqlite3Fts3DoclistPrev(pTab->bDescIdx, pDL->aAll, pDL->nAll,
+ &pDL->pNextDocid, &pDL->iDocid, &pDL->nList, pbEof
+ );
+ pDL->pList = pDL->pNextDocid;
+ }else{
+ fts3EvalDlPhraseNext(pTab, pDL, pbEof);
+ }
+
+ return rc;
+}
+
+/*
+**
+** If *pRc is not SQLITE_OK when this function is called, it is a no-op.
+** Otherwise, fts3EvalPhraseStart() is called on all phrases within the
+** expression. Also the Fts3Expr.bDeferred variable is set to true for any
+** expressions for which all descendent tokens are deferred.
+**
+** If parameter bOptOk is zero, then it is guaranteed that the
+** Fts3Phrase.doclist.aAll/nAll variables contain the entire doclist for
+** each phrase in the expression (subject to deferred token processing).
+** Or, if bOptOk is non-zero, then one or more tokens within the expression
+** may be loaded incrementally, meaning doclist.aAll/nAll is not available.
+**
+** If an error occurs within this function, *pRc is set to an SQLite error
+** code before returning.
+*/
+static void fts3EvalStartReaders(
+ Fts3Cursor *pCsr, /* FTS Cursor handle */
+ Fts3Expr *pExpr, /* Expression to initialize phrases in */
+ int *pRc /* IN/OUT: Error code */
+){
+ if( pExpr && SQLITE_OK==*pRc ){
+ if( pExpr->eType==FTSQUERY_PHRASE ){
+ int nToken = pExpr->pPhrase->nToken;
+ if( nToken ){
+ int i;
+ for(i=0; i<nToken; i++){
+ if( pExpr->pPhrase->aToken[i].pDeferred==0 ) break;
+ }
+ pExpr->bDeferred = (i==nToken);
+ }
+ *pRc = fts3EvalPhraseStart(pCsr, 1, pExpr->pPhrase);
+ }else{
+ fts3EvalStartReaders(pCsr, pExpr->pLeft, pRc);
+ fts3EvalStartReaders(pCsr, pExpr->pRight, pRc);
+ pExpr->bDeferred = (pExpr->pLeft->bDeferred && pExpr->pRight->bDeferred);
+ }
+ }
+}
+
+/*
+** An array of the following structures is assembled as part of the process
+** of selecting tokens to defer before the query starts executing (as part
+** of the xFilter() method). There is one element in the array for each
+** token in the FTS expression.
+**
+** Tokens are divided into AND/NEAR clusters. All tokens in a cluster belong
+** to phrases that are connected only by AND and NEAR operators (not OR or
+** NOT). When determining tokens to defer, each AND/NEAR cluster is considered
+** separately. The root of a tokens AND/NEAR cluster is stored in
+** Fts3TokenAndCost.pRoot.
+*/
+typedef struct Fts3TokenAndCost Fts3TokenAndCost;
+struct Fts3TokenAndCost {
+ Fts3Phrase *pPhrase; /* The phrase the token belongs to */
+ int iToken; /* Position of token in phrase */
+ Fts3PhraseToken *pToken; /* The token itself */
+ Fts3Expr *pRoot; /* Root of NEAR/AND cluster */
+ int nOvfl; /* Number of overflow pages to load doclist */
+ int iCol; /* The column the token must match */
+};
+
+/*
+** This function is used to populate an allocated Fts3TokenAndCost array.
+**
+** If *pRc is not SQLITE_OK when this function is called, it is a no-op.
+** Otherwise, if an error occurs during execution, *pRc is set to an
+** SQLite error code.
+*/
+static void fts3EvalTokenCosts(
+ Fts3Cursor *pCsr, /* FTS Cursor handle */
+ Fts3Expr *pRoot, /* Root of current AND/NEAR cluster */
+ Fts3Expr *pExpr, /* Expression to consider */
+ Fts3TokenAndCost **ppTC, /* Write new entries to *(*ppTC)++ */
+ Fts3Expr ***ppOr, /* Write new OR root to *(*ppOr)++ */
+ int *pRc /* IN/OUT: Error code */
+){
+ if( *pRc==SQLITE_OK ){
+ if( pExpr->eType==FTSQUERY_PHRASE ){
+ Fts3Phrase *pPhrase = pExpr->pPhrase;
+ int i;
+ for(i=0; *pRc==SQLITE_OK && i<pPhrase->nToken; i++){
+ Fts3TokenAndCost *pTC = (*ppTC)++;
+ pTC->pPhrase = pPhrase;
+ pTC->iToken = i;
+ pTC->pRoot = pRoot;
+ pTC->pToken = &pPhrase->aToken[i];
+ pTC->iCol = pPhrase->iColumn;
+ *pRc = sqlite3Fts3MsrOvfl(pCsr, pTC->pToken->pSegcsr, &pTC->nOvfl);
+ }
+ }else if( pExpr->eType!=FTSQUERY_NOT ){
+ assert( pExpr->eType==FTSQUERY_OR
+ || pExpr->eType==FTSQUERY_AND
+ || pExpr->eType==FTSQUERY_NEAR
+ );
+ assert( pExpr->pLeft && pExpr->pRight );
+ if( pExpr->eType==FTSQUERY_OR ){
+ pRoot = pExpr->pLeft;
+ **ppOr = pRoot;
+ (*ppOr)++;
+ }
+ fts3EvalTokenCosts(pCsr, pRoot, pExpr->pLeft, ppTC, ppOr, pRc);
+ if( pExpr->eType==FTSQUERY_OR ){
+ pRoot = pExpr->pRight;
+ **ppOr = pRoot;
+ (*ppOr)++;
+ }
+ fts3EvalTokenCosts(pCsr, pRoot, pExpr->pRight, ppTC, ppOr, pRc);
+ }
+ }
+}
+
+/*
+** Determine the average document (row) size in pages. If successful,
+** write this value to *pnPage and return SQLITE_OK. Otherwise, return
+** an SQLite error code.
+**
+** The average document size in pages is calculated by first calculating
+** determining the average size in bytes, B. If B is less than the amount
+** of data that will fit on a single leaf page of an intkey table in
+** this database, then the average docsize is 1. Otherwise, it is 1 plus
+** the number of overflow pages consumed by a record B bytes in size.
+*/
+static int fts3EvalAverageDocsize(Fts3Cursor *pCsr, int *pnPage){
+ int rc = SQLITE_OK;
+ if( pCsr->nRowAvg==0 ){
+ /* The average document size, which is required to calculate the cost
+ ** of each doclist, has not yet been determined. Read the required
+ ** data from the %_stat table to calculate it.
+ **
+ ** Entry 0 of the %_stat table is a blob containing (nCol+1) FTS3
+ ** varints, where nCol is the number of columns in the FTS3 table.
+ ** The first varint is the number of documents currently stored in
+ ** the table. The following nCol varints contain the total amount of
+ ** data stored in all rows of each column of the table, from left
+ ** to right.
+ */
+ Fts3Table *p = (Fts3Table*)pCsr->base.pVtab;
+ sqlite3_stmt *pStmt;
+ sqlite3_int64 nDoc = 0;
+ sqlite3_int64 nByte = 0;
+ const char *pEnd;
+ const char *a;
+
+ rc = sqlite3Fts3SelectDoctotal(p, &pStmt);
+ if( rc!=SQLITE_OK ) return rc;
+ a = sqlite3_column_blob(pStmt, 0);
+ testcase( a==0 ); /* If %_stat.value set to X'' */
+ if( a ){
+ pEnd = &a[sqlite3_column_bytes(pStmt, 0)];
+ a += sqlite3Fts3GetVarintBounded(a, pEnd, &nDoc);
+ while( a<pEnd ){
+ a += sqlite3Fts3GetVarintBounded(a, pEnd, &nByte);
+ }
+ }
+ if( nDoc==0 || nByte==0 ){
+ sqlite3_reset(pStmt);
+ return FTS_CORRUPT_VTAB;
+ }
+
+ pCsr->nDoc = nDoc;
+ pCsr->nRowAvg = (int)(((nByte / nDoc) + p->nPgsz) / p->nPgsz);
+ assert( pCsr->nRowAvg>0 );
+ rc = sqlite3_reset(pStmt);
+ }
+
+ *pnPage = pCsr->nRowAvg;
+ return rc;
+}
+
+/*
+** This function is called to select the tokens (if any) that will be
+** deferred. The array aTC[] has already been populated when this is
+** called.
+**
+** This function is called once for each AND/NEAR cluster in the
+** expression. Each invocation determines which tokens to defer within
+** the cluster with root node pRoot. See comments above the definition
+** of struct Fts3TokenAndCost for more details.
+**
+** If no error occurs, SQLITE_OK is returned and sqlite3Fts3DeferToken()
+** called on each token to defer. Otherwise, an SQLite error code is
+** returned.
+*/
+static int fts3EvalSelectDeferred(
+ Fts3Cursor *pCsr, /* FTS Cursor handle */
+ Fts3Expr *pRoot, /* Consider tokens with this root node */
+ Fts3TokenAndCost *aTC, /* Array of expression tokens and costs */
+ int nTC /* Number of entries in aTC[] */
+){
+ Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;
+ int nDocSize = 0; /* Number of pages per doc loaded */
+ int rc = SQLITE_OK; /* Return code */
+ int ii; /* Iterator variable for various purposes */
+ int nOvfl = 0; /* Total overflow pages used by doclists */
+ int nToken = 0; /* Total number of tokens in cluster */
+
+ int nMinEst = 0; /* The minimum count for any phrase so far. */
+ int nLoad4 = 1; /* (Phrases that will be loaded)^4. */
+
+ /* Tokens are never deferred for FTS tables created using the content=xxx
+ ** option. The reason being that it is not guaranteed that the content
+ ** table actually contains the same data as the index. To prevent this from
+ ** causing any problems, the deferred token optimization is completely
+ ** disabled for content=xxx tables. */
+ if( pTab->zContentTbl ){
+ return SQLITE_OK;
+ }
+
+ /* Count the tokens in this AND/NEAR cluster. If none of the doclists
+ ** associated with the tokens spill onto overflow pages, or if there is
+ ** only 1 token, exit early. No tokens to defer in this case. */
+ for(ii=0; ii<nTC; ii++){
+ if( aTC[ii].pRoot==pRoot ){
+ nOvfl += aTC[ii].nOvfl;
+ nToken++;
+ }
+ }
+ if( nOvfl==0 || nToken<2 ) return SQLITE_OK;
+
+ /* Obtain the average docsize (in pages). */
+ rc = fts3EvalAverageDocsize(pCsr, &nDocSize);
+ assert( rc!=SQLITE_OK || nDocSize>0 );
+
+
+ /* Iterate through all tokens in this AND/NEAR cluster, in ascending order
+ ** of the number of overflow pages that will be loaded by the pager layer
+ ** to retrieve the entire doclist for the token from the full-text index.
+ ** Load the doclists for tokens that are either:
+ **
+ ** a. The cheapest token in the entire query (i.e. the one visited by the
+ ** first iteration of this loop), or
+ **
+ ** b. Part of a multi-token phrase.
+ **
+ ** After each token doclist is loaded, merge it with the others from the
+ ** same phrase and count the number of documents that the merged doclist
+ ** contains. Set variable "nMinEst" to the smallest number of documents in
+ ** any phrase doclist for which 1 or more token doclists have been loaded.
+ ** Let nOther be the number of other phrases for which it is certain that
+ ** one or more tokens will not be deferred.
+ **
+ ** Then, for each token, defer it if loading the doclist would result in
+ ** loading N or more overflow pages into memory, where N is computed as:
+ **
+ ** (nMinEst + 4^nOther - 1) / (4^nOther)
+ */
+ for(ii=0; ii<nToken && rc==SQLITE_OK; ii++){
+ int iTC; /* Used to iterate through aTC[] array. */
+ Fts3TokenAndCost *pTC = 0; /* Set to cheapest remaining token. */
+
+ /* Set pTC to point to the cheapest remaining token. */
+ for(iTC=0; iTC<nTC; iTC++){
+ if( aTC[iTC].pToken && aTC[iTC].pRoot==pRoot
+ && (!pTC || aTC[iTC].nOvfl<pTC->nOvfl)
+ ){
+ pTC = &aTC[iTC];
+ }
+ }
+ assert( pTC );
+
+ if( ii && pTC->nOvfl>=((nMinEst+(nLoad4/4)-1)/(nLoad4/4))*nDocSize ){
+ /* The number of overflow pages to load for this (and therefore all
+ ** subsequent) tokens is greater than the estimated number of pages
+ ** that will be loaded if all subsequent tokens are deferred.
+ */
+ Fts3PhraseToken *pToken = pTC->pToken;
+ rc = sqlite3Fts3DeferToken(pCsr, pToken, pTC->iCol);
+ fts3SegReaderCursorFree(pToken->pSegcsr);
+ pToken->pSegcsr = 0;
+ }else{
+ /* Set nLoad4 to the value of (4^nOther) for the next iteration of the
+ ** for-loop. Except, limit the value to 2^24 to prevent it from
+ ** overflowing the 32-bit integer it is stored in. */
+ if( ii<12 ) nLoad4 = nLoad4*4;
+
+ if( ii==0 || (pTC->pPhrase->nToken>1 && ii!=nToken-1) ){
+ /* Either this is the cheapest token in the entire query, or it is
+ ** part of a multi-token phrase. Either way, the entire doclist will
+ ** (eventually) be loaded into memory. It may as well be now. */
+ Fts3PhraseToken *pToken = pTC->pToken;
+ int nList = 0;
+ char *pList = 0;
+ rc = fts3TermSelect(pTab, pToken, pTC->iCol, &nList, &pList);
+ assert( rc==SQLITE_OK || pList==0 );
+ if( rc==SQLITE_OK ){
+ rc = fts3EvalPhraseMergeToken(
+ pTab, pTC->pPhrase, pTC->iToken,pList,nList
+ );
+ }
+ if( rc==SQLITE_OK ){
+ int nCount;
+ nCount = fts3DoclistCountDocids(
+ pTC->pPhrase->doclist.aAll, pTC->pPhrase->doclist.nAll
+ );
+ if( ii==0 || nCount<nMinEst ) nMinEst = nCount;
+ }
+ }
+ }
+ pTC->pToken = 0;
+ }
+
+ return rc;
+}
+
+/*
+** This function is called from within the xFilter method. It initializes
+** the full-text query currently stored in pCsr->pExpr. To iterate through
+** the results of a query, the caller does:
+**
+** fts3EvalStart(pCsr);
+** while( 1 ){
+** fts3EvalNext(pCsr);
+** if( pCsr->bEof ) break;
+** ... return row pCsr->iPrevId to the caller ...
+** }
+*/
+static int fts3EvalStart(Fts3Cursor *pCsr){
+ Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;
+ int rc = SQLITE_OK;
+ int nToken = 0;
+ int nOr = 0;
+
+ /* Allocate a MultiSegReader for each token in the expression. */
+ fts3EvalAllocateReaders(pCsr, pCsr->pExpr, &nToken, &nOr, &rc);
+
+ /* Determine which, if any, tokens in the expression should be deferred. */
+#ifndef SQLITE_DISABLE_FTS4_DEFERRED
+ if( rc==SQLITE_OK && nToken>1 && pTab->bFts4 ){
+ Fts3TokenAndCost *aTC;
+ aTC = (Fts3TokenAndCost *)sqlite3_malloc64(
+ sizeof(Fts3TokenAndCost) * nToken
+ + sizeof(Fts3Expr *) * nOr * 2
+ );
+
+ if( !aTC ){
+ rc = SQLITE_NOMEM;
+ }else{
+ Fts3Expr **apOr = (Fts3Expr **)&aTC[nToken];
+ int ii;
+ Fts3TokenAndCost *pTC = aTC;
+ Fts3Expr **ppOr = apOr;
+
+ fts3EvalTokenCosts(pCsr, 0, pCsr->pExpr, &pTC, &ppOr, &rc);
+ nToken = (int)(pTC-aTC);
+ nOr = (int)(ppOr-apOr);
+
+ if( rc==SQLITE_OK ){
+ rc = fts3EvalSelectDeferred(pCsr, 0, aTC, nToken);
+ for(ii=0; rc==SQLITE_OK && ii<nOr; ii++){
+ rc = fts3EvalSelectDeferred(pCsr, apOr[ii], aTC, nToken);
+ }
+ }
+
+ sqlite3_free(aTC);
+ }
+ }
+#endif
+
+ fts3EvalStartReaders(pCsr, pCsr->pExpr, &rc);
+ return rc;
+}
+
+/*
+** Invalidate the current position list for phrase pPhrase.
+*/
+static void fts3EvalInvalidatePoslist(Fts3Phrase *pPhrase){
+ if( pPhrase->doclist.bFreeList ){
+ sqlite3_free(pPhrase->doclist.pList);
+ }
+ pPhrase->doclist.pList = 0;
+ pPhrase->doclist.nList = 0;
+ pPhrase->doclist.bFreeList = 0;
+}
+
+/*
+** This function is called to edit the position list associated with
+** the phrase object passed as the fifth argument according to a NEAR
+** condition. For example:
+**
+** abc NEAR/5 "def ghi"
+**
+** Parameter nNear is passed the NEAR distance of the expression (5 in
+** the example above). When this function is called, *paPoslist points to
+** the position list, and *pnToken is the number of phrase tokens in the
+** phrase on the other side of the NEAR operator to pPhrase. For example,
+** if pPhrase refers to the "def ghi" phrase, then *paPoslist points to
+** the position list associated with phrase "abc".
+**
+** All positions in the pPhrase position list that are not sufficiently
+** close to a position in the *paPoslist position list are removed. If this
+** leaves 0 positions, zero is returned. Otherwise, non-zero.
+**
+** Before returning, *paPoslist is set to point to the position lsit
+** associated with pPhrase. And *pnToken is set to the number of tokens in
+** pPhrase.
+*/
+static int fts3EvalNearTrim(
+ int nNear, /* NEAR distance. As in "NEAR/nNear". */
+ char *aTmp, /* Temporary space to use */
+ char **paPoslist, /* IN/OUT: Position list */
+ int *pnToken, /* IN/OUT: Tokens in phrase of *paPoslist */
+ Fts3Phrase *pPhrase /* The phrase object to trim the doclist of */
+){
+ int nParam1 = nNear + pPhrase->nToken;
+ int nParam2 = nNear + *pnToken;
+ int nNew;
+ char *p2;
+ char *pOut;
+ int res;
+
+ assert( pPhrase->doclist.pList );
+
+ p2 = pOut = pPhrase->doclist.pList;
+ res = fts3PoslistNearMerge(
+ &pOut, aTmp, nParam1, nParam2, paPoslist, &p2
+ );
+ if( res ){
+ nNew = (int)(pOut - pPhrase->doclist.pList) - 1;
+ assert_fts3_nc( nNew<=pPhrase->doclist.nList && nNew>0 );
+ if( nNew>=0 && nNew<=pPhrase->doclist.nList ){
+ assert( pPhrase->doclist.pList[nNew]=='\0' );
+ memset(&pPhrase->doclist.pList[nNew], 0, pPhrase->doclist.nList - nNew);
+ pPhrase->doclist.nList = nNew;
+ }
+ *paPoslist = pPhrase->doclist.pList;
+ *pnToken = pPhrase->nToken;
+ }
+
+ return res;
+}
+
+/*
+** This function is a no-op if *pRc is other than SQLITE_OK when it is called.
+** Otherwise, it advances the expression passed as the second argument to
+** point to the next matching row in the database. Expressions iterate through
+** matching rows in docid order. Ascending order if Fts3Cursor.bDesc is zero,
+** or descending if it is non-zero.
+**
+** If an error occurs, *pRc is set to an SQLite error code. Otherwise, if
+** successful, the following variables in pExpr are set:
+**
+** Fts3Expr.bEof (non-zero if EOF - there is no next row)
+** Fts3Expr.iDocid (valid if bEof==0. The docid of the next row)
+**
+** If the expression is of type FTSQUERY_PHRASE, and the expression is not
+** at EOF, then the following variables are populated with the position list
+** for the phrase for the visited row:
+**
+** FTs3Expr.pPhrase->doclist.nList (length of pList in bytes)
+** FTs3Expr.pPhrase->doclist.pList (pointer to position list)
+**
+** It says above that this function advances the expression to the next
+** matching row. This is usually true, but there are the following exceptions:
+**
+** 1. Deferred tokens are not taken into account. If a phrase consists
+** entirely of deferred tokens, it is assumed to match every row in
+** the db. In this case the position-list is not populated at all.
+**
+** Or, if a phrase contains one or more deferred tokens and one or
+** more non-deferred tokens, then the expression is advanced to the
+** next possible match, considering only non-deferred tokens. In other
+** words, if the phrase is "A B C", and "B" is deferred, the expression
+** is advanced to the next row that contains an instance of "A * C",
+** where "*" may match any single token. The position list in this case
+** is populated as for "A * C" before returning.
+**
+** 2. NEAR is treated as AND. If the expression is "x NEAR y", it is
+** advanced to point to the next row that matches "x AND y".
+**
+** See sqlite3Fts3EvalTestDeferred() for details on testing if a row is
+** really a match, taking into account deferred tokens and NEAR operators.
+*/
+static void fts3EvalNextRow(
+ Fts3Cursor *pCsr, /* FTS Cursor handle */
+ Fts3Expr *pExpr, /* Expr. to advance to next matching row */
+ int *pRc /* IN/OUT: Error code */
+){
+ if( *pRc==SQLITE_OK ){
+ int bDescDoclist = pCsr->bDesc; /* Used by DOCID_CMP() macro */
+ assert( pExpr->bEof==0 );
+ pExpr->bStart = 1;
+
+ switch( pExpr->eType ){
+ case FTSQUERY_NEAR:
+ case FTSQUERY_AND: {
+ Fts3Expr *pLeft = pExpr->pLeft;
+ Fts3Expr *pRight = pExpr->pRight;
+ assert( !pLeft->bDeferred || !pRight->bDeferred );
+
+ if( pLeft->bDeferred ){
+ /* LHS is entirely deferred. So we assume it matches every row.
+ ** Advance the RHS iterator to find the next row visited. */
+ fts3EvalNextRow(pCsr, pRight, pRc);
+ pExpr->iDocid = pRight->iDocid;
+ pExpr->bEof = pRight->bEof;
+ }else if( pRight->bDeferred ){
+ /* RHS is entirely deferred. So we assume it matches every row.
+ ** Advance the LHS iterator to find the next row visited. */
+ fts3EvalNextRow(pCsr, pLeft, pRc);
+ pExpr->iDocid = pLeft->iDocid;
+ pExpr->bEof = pLeft->bEof;
+ }else{
+ /* Neither the RHS or LHS are deferred. */
+ fts3EvalNextRow(pCsr, pLeft, pRc);
+ fts3EvalNextRow(pCsr, pRight, pRc);
+ while( !pLeft->bEof && !pRight->bEof && *pRc==SQLITE_OK ){
+ sqlite3_int64 iDiff = DOCID_CMP(pLeft->iDocid, pRight->iDocid);
+ if( iDiff==0 ) break;
+ if( iDiff<0 ){
+ fts3EvalNextRow(pCsr, pLeft, pRc);
+ }else{
+ fts3EvalNextRow(pCsr, pRight, pRc);
+ }
+ }
+ pExpr->iDocid = pLeft->iDocid;
+ pExpr->bEof = (pLeft->bEof || pRight->bEof);
+ if( pExpr->eType==FTSQUERY_NEAR && pExpr->bEof ){
+ assert( pRight->eType==FTSQUERY_PHRASE );
+ if( pRight->pPhrase->doclist.aAll ){
+ Fts3Doclist *pDl = &pRight->pPhrase->doclist;
+ while( *pRc==SQLITE_OK && pRight->bEof==0 ){
+ memset(pDl->pList, 0, pDl->nList);
+ fts3EvalNextRow(pCsr, pRight, pRc);
+ }
+ }
+ if( pLeft->pPhrase && pLeft->pPhrase->doclist.aAll ){
+ Fts3Doclist *pDl = &pLeft->pPhrase->doclist;
+ while( *pRc==SQLITE_OK && pLeft->bEof==0 ){
+ memset(pDl->pList, 0, pDl->nList);
+ fts3EvalNextRow(pCsr, pLeft, pRc);
+ }
+ }
+ pRight->bEof = pLeft->bEof = 1;
+ }
+ }
+ break;
+ }
+
+ case FTSQUERY_OR: {
+ Fts3Expr *pLeft = pExpr->pLeft;
+ Fts3Expr *pRight = pExpr->pRight;
+ sqlite3_int64 iCmp = DOCID_CMP(pLeft->iDocid, pRight->iDocid);
+
+ assert_fts3_nc( pLeft->bStart || pLeft->iDocid==pRight->iDocid );
+ assert_fts3_nc( pRight->bStart || pLeft->iDocid==pRight->iDocid );
+
+ if( pRight->bEof || (pLeft->bEof==0 && iCmp<0) ){
+ fts3EvalNextRow(pCsr, pLeft, pRc);
+ }else if( pLeft->bEof || iCmp>0 ){
+ fts3EvalNextRow(pCsr, pRight, pRc);
+ }else{
+ fts3EvalNextRow(pCsr, pLeft, pRc);
+ fts3EvalNextRow(pCsr, pRight, pRc);
+ }
+
+ pExpr->bEof = (pLeft->bEof && pRight->bEof);
+ iCmp = DOCID_CMP(pLeft->iDocid, pRight->iDocid);
+ if( pRight->bEof || (pLeft->bEof==0 && iCmp<0) ){
+ pExpr->iDocid = pLeft->iDocid;
+ }else{
+ pExpr->iDocid = pRight->iDocid;
+ }
+
+ break;
+ }
+
+ case FTSQUERY_NOT: {
+ Fts3Expr *pLeft = pExpr->pLeft;
+ Fts3Expr *pRight = pExpr->pRight;
+
+ if( pRight->bStart==0 ){
+ fts3EvalNextRow(pCsr, pRight, pRc);
+ assert( *pRc!=SQLITE_OK || pRight->bStart );
+ }
+
+ fts3EvalNextRow(pCsr, pLeft, pRc);
+ if( pLeft->bEof==0 ){
+ while( !*pRc
+ && !pRight->bEof
+ && DOCID_CMP(pLeft->iDocid, pRight->iDocid)>0
+ ){
+ fts3EvalNextRow(pCsr, pRight, pRc);
+ }
+ }
+ pExpr->iDocid = pLeft->iDocid;
+ pExpr->bEof = pLeft->bEof;
+ break;
+ }
+
+ default: {
+ Fts3Phrase *pPhrase = pExpr->pPhrase;
+ fts3EvalInvalidatePoslist(pPhrase);
+ *pRc = fts3EvalPhraseNext(pCsr, pPhrase, &pExpr->bEof);
+ pExpr->iDocid = pPhrase->doclist.iDocid;
+ break;
+ }
+ }
+ }
+}
+
+/*
+** If *pRc is not SQLITE_OK, or if pExpr is not the root node of a NEAR
+** cluster, then this function returns 1 immediately.
+**
+** Otherwise, it checks if the current row really does match the NEAR
+** expression, using the data currently stored in the position lists
+** (Fts3Expr->pPhrase.doclist.pList/nList) for each phrase in the expression.
+**
+** If the current row is a match, the position list associated with each
+** phrase in the NEAR expression is edited in place to contain only those
+** phrase instances sufficiently close to their peers to satisfy all NEAR
+** constraints. In this case it returns 1. If the NEAR expression does not
+** match the current row, 0 is returned. The position lists may or may not
+** be edited if 0 is returned.
+*/
+static int fts3EvalNearTest(Fts3Expr *pExpr, int *pRc){
+ int res = 1;
+
+ /* The following block runs if pExpr is the root of a NEAR query.
+ ** For example, the query:
+ **
+ ** "w" NEAR "x" NEAR "y" NEAR "z"
+ **
+ ** which is represented in tree form as:
+ **
+ ** |
+ ** +--NEAR--+ <-- root of NEAR query
+ ** | |
+ ** +--NEAR--+ "z"
+ ** | |
+ ** +--NEAR--+ "y"
+ ** | |
+ ** "w" "x"
+ **
+ ** The right-hand child of a NEAR node is always a phrase. The
+ ** left-hand child may be either a phrase or a NEAR node. There are
+ ** no exceptions to this - it's the way the parser in fts3_expr.c works.
+ */
+ if( *pRc==SQLITE_OK
+ && pExpr->eType==FTSQUERY_NEAR
+ && (pExpr->pParent==0 || pExpr->pParent->eType!=FTSQUERY_NEAR)
+ ){
+ Fts3Expr *p;
+ sqlite3_int64 nTmp = 0; /* Bytes of temp space */
+ char *aTmp; /* Temp space for PoslistNearMerge() */
+
+ /* Allocate temporary working space. */
+ for(p=pExpr; p->pLeft; p=p->pLeft){
+ assert( p->pRight->pPhrase->doclist.nList>0 );
+ nTmp += p->pRight->pPhrase->doclist.nList;
+ }
+ nTmp += p->pPhrase->doclist.nList;
+ aTmp = sqlite3_malloc64(nTmp*2);
+ if( !aTmp ){
+ *pRc = SQLITE_NOMEM;
+ res = 0;
+ }else{
+ char *aPoslist = p->pPhrase->doclist.pList;
+ int nToken = p->pPhrase->nToken;
+
+ for(p=p->pParent;res && p && p->eType==FTSQUERY_NEAR; p=p->pParent){
+ Fts3Phrase *pPhrase = p->pRight->pPhrase;
+ int nNear = p->nNear;
+ res = fts3EvalNearTrim(nNear, aTmp, &aPoslist, &nToken, pPhrase);
+ }
+
+ aPoslist = pExpr->pRight->pPhrase->doclist.pList;
+ nToken = pExpr->pRight->pPhrase->nToken;
+ for(p=pExpr->pLeft; p && res; p=p->pLeft){
+ int nNear;
+ Fts3Phrase *pPhrase;
+ assert( p->pParent && p->pParent->pLeft==p );
+ nNear = p->pParent->nNear;
+ pPhrase = (
+ p->eType==FTSQUERY_NEAR ? p->pRight->pPhrase : p->pPhrase
+ );
+ res = fts3EvalNearTrim(nNear, aTmp, &aPoslist, &nToken, pPhrase);
+ }
+ }
+
+ sqlite3_free(aTmp);
+ }
+
+ return res;
+}
+
+/*
+** This function is a helper function for sqlite3Fts3EvalTestDeferred().
+** Assuming no error occurs or has occurred, It returns non-zero if the
+** expression passed as the second argument matches the row that pCsr
+** currently points to, or zero if it does not.
+**
+** If *pRc is not SQLITE_OK when this function is called, it is a no-op.
+** If an error occurs during execution of this function, *pRc is set to
+** the appropriate SQLite error code. In this case the returned value is
+** undefined.
+*/
+static int fts3EvalTestExpr(
+ Fts3Cursor *pCsr, /* FTS cursor handle */
+ Fts3Expr *pExpr, /* Expr to test. May or may not be root. */
+ int *pRc /* IN/OUT: Error code */
+){
+ int bHit = 1; /* Return value */
+ if( *pRc==SQLITE_OK ){
+ switch( pExpr->eType ){
+ case FTSQUERY_NEAR:
+ case FTSQUERY_AND:
+ bHit = (
+ fts3EvalTestExpr(pCsr, pExpr->pLeft, pRc)
+ && fts3EvalTestExpr(pCsr, pExpr->pRight, pRc)
+ && fts3EvalNearTest(pExpr, pRc)
+ );
+
+ /* If the NEAR expression does not match any rows, zero the doclist for
+ ** all phrases involved in the NEAR. This is because the snippet(),
+ ** offsets() and matchinfo() functions are not supposed to recognize
+ ** any instances of phrases that are part of unmatched NEAR queries.
+ ** For example if this expression:
+ **
+ ** ... MATCH 'a OR (b NEAR c)'
+ **
+ ** is matched against a row containing:
+ **
+ ** 'a b d e'
+ **
+ ** then any snippet() should ony highlight the "a" term, not the "b"
+ ** (as "b" is part of a non-matching NEAR clause).
+ */
+ if( bHit==0
+ && pExpr->eType==FTSQUERY_NEAR
+ && (pExpr->pParent==0 || pExpr->pParent->eType!=FTSQUERY_NEAR)
+ ){
+ Fts3Expr *p;
+ for(p=pExpr; p->pPhrase==0; p=p->pLeft){
+ if( p->pRight->iDocid==pCsr->iPrevId ){
+ fts3EvalInvalidatePoslist(p->pRight->pPhrase);
+ }
+ }
+ if( p->iDocid==pCsr->iPrevId ){
+ fts3EvalInvalidatePoslist(p->pPhrase);
+ }
+ }
+
+ break;
+
+ case FTSQUERY_OR: {
+ int bHit1 = fts3EvalTestExpr(pCsr, pExpr->pLeft, pRc);
+ int bHit2 = fts3EvalTestExpr(pCsr, pExpr->pRight, pRc);
+ bHit = bHit1 || bHit2;
+ break;
+ }
+
+ case FTSQUERY_NOT:
+ bHit = (
+ fts3EvalTestExpr(pCsr, pExpr->pLeft, pRc)
+ && !fts3EvalTestExpr(pCsr, pExpr->pRight, pRc)
+ );
+ break;
+
+ default: {
+#ifndef SQLITE_DISABLE_FTS4_DEFERRED
+ if( pCsr->pDeferred && (pExpr->bDeferred || (
+ pExpr->iDocid==pCsr->iPrevId && pExpr->pPhrase->doclist.pList
+ ))){
+ Fts3Phrase *pPhrase = pExpr->pPhrase;
+ if( pExpr->bDeferred ){
+ fts3EvalInvalidatePoslist(pPhrase);
+ }
+ *pRc = fts3EvalDeferredPhrase(pCsr, pPhrase);
+ bHit = (pPhrase->doclist.pList!=0);
+ pExpr->iDocid = pCsr->iPrevId;
+ }else
+#endif
+ {
+ bHit = (
+ pExpr->bEof==0 && pExpr->iDocid==pCsr->iPrevId
+ && pExpr->pPhrase->doclist.nList>0
+ );
+ }
+ break;
+ }
+ }
+ }
+ return bHit;
+}
+
+/*
+** This function is called as the second part of each xNext operation when
+** iterating through the results of a full-text query. At this point the
+** cursor points to a row that matches the query expression, with the
+** following caveats:
+**
+** * Up until this point, "NEAR" operators in the expression have been
+** treated as "AND".
+**
+** * Deferred tokens have not yet been considered.
+**
+** If *pRc is not SQLITE_OK when this function is called, it immediately
+** returns 0. Otherwise, it tests whether or not after considering NEAR
+** operators and deferred tokens the current row is still a match for the
+** expression. It returns 1 if both of the following are true:
+**
+** 1. *pRc is SQLITE_OK when this function returns, and
+**
+** 2. After scanning the current FTS table row for the deferred tokens,
+** it is determined that the row does *not* match the query.
+**
+** Or, if no error occurs and it seems the current row does match the FTS
+** query, return 0.
+*/
+int sqlite3Fts3EvalTestDeferred(Fts3Cursor *pCsr, int *pRc){
+ int rc = *pRc;
+ int bMiss = 0;
+ if( rc==SQLITE_OK ){
+
+ /* If there are one or more deferred tokens, load the current row into
+ ** memory and scan it to determine the position list for each deferred
+ ** token. Then, see if this row is really a match, considering deferred
+ ** tokens and NEAR operators (neither of which were taken into account
+ ** earlier, by fts3EvalNextRow()).
+ */
+ if( pCsr->pDeferred ){
+ rc = fts3CursorSeek(0, pCsr);
+ if( rc==SQLITE_OK ){
+ rc = sqlite3Fts3CacheDeferredDoclists(pCsr);
+ }
+ }
+ bMiss = (0==fts3EvalTestExpr(pCsr, pCsr->pExpr, &rc));
+
+ /* Free the position-lists accumulated for each deferred token above. */
+ sqlite3Fts3FreeDeferredDoclists(pCsr);
+ *pRc = rc;
+ }
+ return (rc==SQLITE_OK && bMiss);
+}
+
+/*
+** Advance to the next document that matches the FTS expression in
+** Fts3Cursor.pExpr.
+*/
+static int fts3EvalNext(Fts3Cursor *pCsr){
+ int rc = SQLITE_OK; /* Return Code */
+ Fts3Expr *pExpr = pCsr->pExpr;
+ assert( pCsr->isEof==0 );
+ if( pExpr==0 ){
+ pCsr->isEof = 1;
+ }else{
+ do {
+ if( pCsr->isRequireSeek==0 ){
+ sqlite3_reset(pCsr->pStmt);
+ }
+ assert( sqlite3_data_count(pCsr->pStmt)==0 );
+ fts3EvalNextRow(pCsr, pExpr, &rc);
+ pCsr->isEof = pExpr->bEof;
+ pCsr->isRequireSeek = 1;
+ pCsr->isMatchinfoNeeded = 1;
+ pCsr->iPrevId = pExpr->iDocid;
+ }while( pCsr->isEof==0 && sqlite3Fts3EvalTestDeferred(pCsr, &rc) );
+ }
+
+ /* Check if the cursor is past the end of the docid range specified
+ ** by Fts3Cursor.iMinDocid/iMaxDocid. If so, set the EOF flag. */
+ if( rc==SQLITE_OK && (
+ (pCsr->bDesc==0 && pCsr->iPrevId>pCsr->iMaxDocid)
+ || (pCsr->bDesc!=0 && pCsr->iPrevId<pCsr->iMinDocid)
+ )){
+ pCsr->isEof = 1;
+ }
+
+ return rc;
+}
+
+/*
+** Restart interation for expression pExpr so that the next call to
+** fts3EvalNext() visits the first row. Do not allow incremental
+** loading or merging of phrase doclists for this iteration.
+**
+** If *pRc is other than SQLITE_OK when this function is called, it is
+** a no-op. If an error occurs within this function, *pRc is set to an
+** SQLite error code before returning.
+*/
+static void fts3EvalRestart(
+ Fts3Cursor *pCsr,
+ Fts3Expr *pExpr,
+ int *pRc
+){
+ if( pExpr && *pRc==SQLITE_OK ){
+ Fts3Phrase *pPhrase = pExpr->pPhrase;
+
+ if( pPhrase ){
+ fts3EvalInvalidatePoslist(pPhrase);
+ if( pPhrase->bIncr ){
+ int i;
+ for(i=0; i<pPhrase->nToken; i++){
+ Fts3PhraseToken *pToken = &pPhrase->aToken[i];
+ assert( pToken->pDeferred==0 );
+ if( pToken->pSegcsr ){
+ sqlite3Fts3MsrIncrRestart(pToken->pSegcsr);
+ }
+ }
+ *pRc = fts3EvalPhraseStart(pCsr, 0, pPhrase);
+ }
+ pPhrase->doclist.pNextDocid = 0;
+ pPhrase->doclist.iDocid = 0;
+ pPhrase->pOrPoslist = 0;
+ }
+
+ pExpr->iDocid = 0;
+ pExpr->bEof = 0;
+ pExpr->bStart = 0;
+
+ fts3EvalRestart(pCsr, pExpr->pLeft, pRc);
+ fts3EvalRestart(pCsr, pExpr->pRight, pRc);
+ }
+}
+
+/*
+** After allocating the Fts3Expr.aMI[] array for each phrase in the
+** expression rooted at pExpr, the cursor iterates through all rows matched
+** by pExpr, calling this function for each row. This function increments
+** the values in Fts3Expr.aMI[] according to the position-list currently
+** found in Fts3Expr.pPhrase->doclist.pList for each of the phrase
+** expression nodes.
+*/
+static void fts3EvalUpdateCounts(Fts3Expr *pExpr, int nCol){
+ if( pExpr ){
+ Fts3Phrase *pPhrase = pExpr->pPhrase;
+ if( pPhrase && pPhrase->doclist.pList ){
+ int iCol = 0;
+ char *p = pPhrase->doclist.pList;
+
+ do{
+ u8 c = 0;
+ int iCnt = 0;
+ while( 0xFE & (*p | c) ){
+ if( (c&0x80)==0 ) iCnt++;
+ c = *p++ & 0x80;
+ }
+
+ /* aMI[iCol*3 + 1] = Number of occurrences
+ ** aMI[iCol*3 + 2] = Number of rows containing at least one instance
+ */
+ pExpr->aMI[iCol*3 + 1] += iCnt;
+ pExpr->aMI[iCol*3 + 2] += (iCnt>0);
+ if( *p==0x00 ) break;
+ p++;
+ p += fts3GetVarint32(p, &iCol);
+ }while( iCol<nCol );
+ }
+
+ fts3EvalUpdateCounts(pExpr->pLeft, nCol);
+ fts3EvalUpdateCounts(pExpr->pRight, nCol);
+ }
+}
+
+/*
+** Expression pExpr must be of type FTSQUERY_PHRASE.
+**
+** If it is not already allocated and populated, this function allocates and
+** populates the Fts3Expr.aMI[] array for expression pExpr. If pExpr is part
+** of a NEAR expression, then it also allocates and populates the same array
+** for all other phrases that are part of the NEAR expression.
+**
+** SQLITE_OK is returned if the aMI[] array is successfully allocated and
+** populated. Otherwise, if an error occurs, an SQLite error code is returned.
+*/
+static int fts3EvalGatherStats(
+ Fts3Cursor *pCsr, /* Cursor object */
+ Fts3Expr *pExpr /* FTSQUERY_PHRASE expression */
+){
+ int rc = SQLITE_OK; /* Return code */
+
+ assert( pExpr->eType==FTSQUERY_PHRASE );
+ if( pExpr->aMI==0 ){
+ Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;
+ Fts3Expr *pRoot; /* Root of NEAR expression */
+ Fts3Expr *p; /* Iterator used for several purposes */
+
+ sqlite3_int64 iPrevId = pCsr->iPrevId;
+ sqlite3_int64 iDocid;
+ u8 bEof;
+
+ /* Find the root of the NEAR expression */
+ pRoot = pExpr;
+ while( pRoot->pParent && pRoot->pParent->eType==FTSQUERY_NEAR ){
+ pRoot = pRoot->pParent;
+ }
+ iDocid = pRoot->iDocid;
+ bEof = pRoot->bEof;
+ assert( pRoot->bStart );
+
+ /* Allocate space for the aMSI[] array of each FTSQUERY_PHRASE node */
+ for(p=pRoot; p; p=p->pLeft){
+ Fts3Expr *pE = (p->eType==FTSQUERY_PHRASE?p:p->pRight);
+ assert( pE->aMI==0 );
+ pE->aMI = (u32 *)sqlite3_malloc64(pTab->nColumn * 3 * sizeof(u32));
+ if( !pE->aMI ) return SQLITE_NOMEM;
+ memset(pE->aMI, 0, pTab->nColumn * 3 * sizeof(u32));
+ }
+
+ fts3EvalRestart(pCsr, pRoot, &rc);
+
+ while( pCsr->isEof==0 && rc==SQLITE_OK ){
+
+ do {
+ /* Ensure the %_content statement is reset. */
+ if( pCsr->isRequireSeek==0 ) sqlite3_reset(pCsr->pStmt);
+ assert( sqlite3_data_count(pCsr->pStmt)==0 );
+
+ /* Advance to the next document */
+ fts3EvalNextRow(pCsr, pRoot, &rc);
+ pCsr->isEof = pRoot->bEof;
+ pCsr->isRequireSeek = 1;
+ pCsr->isMatchinfoNeeded = 1;
+ pCsr->iPrevId = pRoot->iDocid;
+ }while( pCsr->isEof==0
+ && pRoot->eType==FTSQUERY_NEAR
+ && sqlite3Fts3EvalTestDeferred(pCsr, &rc)
+ );
+
+ if( rc==SQLITE_OK && pCsr->isEof==0 ){
+ fts3EvalUpdateCounts(pRoot, pTab->nColumn);
+ }
+ }
+
+ pCsr->isEof = 0;
+ pCsr->iPrevId = iPrevId;
+
+ if( bEof ){
+ pRoot->bEof = bEof;
+ }else{
+ /* Caution: pRoot may iterate through docids in ascending or descending
+ ** order. For this reason, even though it seems more defensive, the
+ ** do loop can not be written:
+ **
+ ** do {...} while( pRoot->iDocid<iDocid && rc==SQLITE_OK );
+ */
+ fts3EvalRestart(pCsr, pRoot, &rc);
+ do {
+ fts3EvalNextRow(pCsr, pRoot, &rc);
+ assert_fts3_nc( pRoot->bEof==0 );
+ if( pRoot->bEof ) rc = FTS_CORRUPT_VTAB;
+ }while( pRoot->iDocid!=iDocid && rc==SQLITE_OK );
+ }
+ }
+ return rc;
+}
+
+/*
+** This function is used by the matchinfo() module to query a phrase
+** expression node for the following information:
+**
+** 1. The total number of occurrences of the phrase in each column of
+** the FTS table (considering all rows), and
+**
+** 2. For each column, the number of rows in the table for which the
+** column contains at least one instance of the phrase.
+**
+** If no error occurs, SQLITE_OK is returned and the values for each column
+** written into the array aiOut as follows:
+**
+** aiOut[iCol*3 + 1] = Number of occurrences
+** aiOut[iCol*3 + 2] = Number of rows containing at least one instance
+**
+** Caveats:
+**
+** * If a phrase consists entirely of deferred tokens, then all output
+** values are set to the number of documents in the table. In other
+** words we assume that very common tokens occur exactly once in each
+** column of each row of the table.
+**
+** * If a phrase contains some deferred tokens (and some non-deferred
+** tokens), count the potential occurrence identified by considering
+** the non-deferred tokens instead of actual phrase occurrences.
+**
+** * If the phrase is part of a NEAR expression, then only phrase instances
+** that meet the NEAR constraint are included in the counts.
+*/
+int sqlite3Fts3EvalPhraseStats(
+ Fts3Cursor *pCsr, /* FTS cursor handle */
+ Fts3Expr *pExpr, /* Phrase expression */
+ u32 *aiOut /* Array to write results into (see above) */
+){
+ Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;
+ int rc = SQLITE_OK;
+ int iCol;
+
+ if( pExpr->bDeferred && pExpr->pParent->eType!=FTSQUERY_NEAR ){
+ assert( pCsr->nDoc>0 );
+ for(iCol=0; iCol<pTab->nColumn; iCol++){
+ aiOut[iCol*3 + 1] = (u32)pCsr->nDoc;
+ aiOut[iCol*3 + 2] = (u32)pCsr->nDoc;
+ }
+ }else{
+ rc = fts3EvalGatherStats(pCsr, pExpr);
+ if( rc==SQLITE_OK ){
+ assert( pExpr->aMI );
+ for(iCol=0; iCol<pTab->nColumn; iCol++){
+ aiOut[iCol*3 + 1] = pExpr->aMI[iCol*3 + 1];
+ aiOut[iCol*3 + 2] = pExpr->aMI[iCol*3 + 2];
+ }
+ }
+ }
+
+ return rc;
+}
+
+/*
+** The expression pExpr passed as the second argument to this function
+** must be of type FTSQUERY_PHRASE.
+**
+** The returned value is either NULL or a pointer to a buffer containing
+** a position-list indicating the occurrences of the phrase in column iCol
+** of the current row.
+**
+** More specifically, the returned buffer contains 1 varint for each
+** occurrence of the phrase in the column, stored using the normal (delta+2)
+** compression and is terminated by either an 0x01 or 0x00 byte. For example,
+** if the requested column contains "a b X c d X X" and the position-list
+** for 'X' is requested, the buffer returned may contain:
+**
+** 0x04 0x05 0x03 0x01 or 0x04 0x05 0x03 0x00
+**
+** This function works regardless of whether or not the phrase is deferred,
+** incremental, or neither.
+*/
+int sqlite3Fts3EvalPhrasePoslist(
+ Fts3Cursor *pCsr, /* FTS3 cursor object */
+ Fts3Expr *pExpr, /* Phrase to return doclist for */
+ int iCol, /* Column to return position list for */
+ char **ppOut /* OUT: Pointer to position list */
+){
+ Fts3Phrase *pPhrase = pExpr->pPhrase;
+ Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;
+ char *pIter;
+ int iThis;
+ sqlite3_int64 iDocid;
+
+ /* If this phrase is applies specifically to some column other than
+ ** column iCol, return a NULL pointer. */
+ *ppOut = 0;
+ assert( iCol>=0 && iCol<pTab->nColumn );
+ if( (pPhrase->iColumn<pTab->nColumn && pPhrase->iColumn!=iCol) ){
+ return SQLITE_OK;
+ }
+
+ iDocid = pExpr->iDocid;
+ pIter = pPhrase->doclist.pList;
+ if( iDocid!=pCsr->iPrevId || pExpr->bEof ){
+ int rc = SQLITE_OK;
+ int bDescDoclist = pTab->bDescIdx; /* For DOCID_CMP macro */
+ int bOr = 0;
+ u8 bTreeEof = 0;
+ Fts3Expr *p; /* Used to iterate from pExpr to root */
+ Fts3Expr *pNear; /* Most senior NEAR ancestor (or pExpr) */
+ int bMatch;
+
+ /* Check if this phrase descends from an OR expression node. If not,
+ ** return NULL. Otherwise, the entry that corresponds to docid
+ ** pCsr->iPrevId may lie earlier in the doclist buffer. Or, if the
+ ** tree that the node is part of has been marked as EOF, but the node
+ ** itself is not EOF, then it may point to an earlier entry. */
+ pNear = pExpr;
+ for(p=pExpr->pParent; p; p=p->pParent){
+ if( p->eType==FTSQUERY_OR ) bOr = 1;
+ if( p->eType==FTSQUERY_NEAR ) pNear = p;
+ if( p->bEof ) bTreeEof = 1;
+ }
+ if( bOr==0 ) return SQLITE_OK;
+
+ /* This is the descendent of an OR node. In this case we cannot use
+ ** an incremental phrase. Load the entire doclist for the phrase
+ ** into memory in this case. */
+ if( pPhrase->bIncr ){
+ int bEofSave = pNear->bEof;
+ fts3EvalRestart(pCsr, pNear, &rc);
+ while( rc==SQLITE_OK && !pNear->bEof ){
+ fts3EvalNextRow(pCsr, pNear, &rc);
+ if( bEofSave==0 && pNear->iDocid==iDocid ) break;
+ }
+ assert( rc!=SQLITE_OK || pPhrase->bIncr==0 );
+ if( rc==SQLITE_OK && pNear->bEof!=bEofSave ){
+ rc = FTS_CORRUPT_VTAB;
+ }
+ }
+ if( bTreeEof ){
+ while( rc==SQLITE_OK && !pNear->bEof ){
+ fts3EvalNextRow(pCsr, pNear, &rc);
+ }
+ }
+ if( rc!=SQLITE_OK ) return rc;
+
+ bMatch = 1;
+ for(p=pNear; p; p=p->pLeft){
+ u8 bEof = 0;
+ Fts3Expr *pTest = p;
+ Fts3Phrase *pPh;
+ assert( pTest->eType==FTSQUERY_NEAR || pTest->eType==FTSQUERY_PHRASE );
+ if( pTest->eType==FTSQUERY_NEAR ) pTest = pTest->pRight;
+ assert( pTest->eType==FTSQUERY_PHRASE );
+ pPh = pTest->pPhrase;
+
+ pIter = pPh->pOrPoslist;
+ iDocid = pPh->iOrDocid;
+ if( pCsr->bDesc==bDescDoclist ){
+ bEof = !pPh->doclist.nAll ||
+ (pIter >= (pPh->doclist.aAll + pPh->doclist.nAll));
+ while( (pIter==0 || DOCID_CMP(iDocid, pCsr->iPrevId)<0 ) && bEof==0 ){
+ sqlite3Fts3DoclistNext(
+ bDescDoclist, pPh->doclist.aAll, pPh->doclist.nAll,
+ &pIter, &iDocid, &bEof
+ );
+ }
+ }else{
+ bEof = !pPh->doclist.nAll || (pIter && pIter<=pPh->doclist.aAll);
+ while( (pIter==0 || DOCID_CMP(iDocid, pCsr->iPrevId)>0 ) && bEof==0 ){
+ int dummy;
+ sqlite3Fts3DoclistPrev(
+ bDescDoclist, pPh->doclist.aAll, pPh->doclist.nAll,
+ &pIter, &iDocid, &dummy, &bEof
+ );
+ }
+ }
+ pPh->pOrPoslist = pIter;
+ pPh->iOrDocid = iDocid;
+ if( bEof || iDocid!=pCsr->iPrevId ) bMatch = 0;
+ }
+
+ if( bMatch ){
+ pIter = pPhrase->pOrPoslist;
+ }else{
+ pIter = 0;
+ }
+ }
+ if( pIter==0 ) return SQLITE_OK;
+
+ if( *pIter==0x01 ){
+ pIter++;
+ pIter += fts3GetVarint32(pIter, &iThis);
+ }else{
+ iThis = 0;
+ }
+ while( iThis<iCol ){
+ fts3ColumnlistCopy(0, &pIter);
+ if( *pIter==0x00 ) return SQLITE_OK;
+ pIter++;
+ pIter += fts3GetVarint32(pIter, &iThis);
+ }
+ if( *pIter==0x00 ){
+ pIter = 0;
+ }
+
+ *ppOut = ((iCol==iThis)?pIter:0);
+ return SQLITE_OK;
+}
+
+/*
+** Free all components of the Fts3Phrase structure that were allocated by
+** the eval module. Specifically, this means to free:
+**
+** * the contents of pPhrase->doclist, and
+** * any Fts3MultiSegReader objects held by phrase tokens.
+*/
+void sqlite3Fts3EvalPhraseCleanup(Fts3Phrase *pPhrase){
+ if( pPhrase ){
+ int i;
+ sqlite3_free(pPhrase->doclist.aAll);
+ fts3EvalInvalidatePoslist(pPhrase);
+ memset(&pPhrase->doclist, 0, sizeof(Fts3Doclist));
+ for(i=0; i<pPhrase->nToken; i++){
+ fts3SegReaderCursorFree(pPhrase->aToken[i].pSegcsr);
+ pPhrase->aToken[i].pSegcsr = 0;
+ }
+ }
+}
+
+
+/*
+** Return SQLITE_CORRUPT_VTAB.
+*/
+#ifdef SQLITE_DEBUG
+int sqlite3Fts3Corrupt(){
+ return SQLITE_CORRUPT_VTAB;
+}
+#endif
+
+#if !SQLITE_CORE
+/*
+** Initialize API pointer table, if required.
+*/
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+int sqlite3_fts3_init(
+ sqlite3 *db,
+ char **pzErrMsg,
+ const sqlite3_api_routines *pApi
+){
+ SQLITE_EXTENSION_INIT2(pApi)
+ return sqlite3Fts3Init(db);
+}
+#endif
+
+#endif
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-26 23:01:17 +0000