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Diffstat (limited to 'database/sqlite/dbdata.c')
| -rw-r--r-- | database/sqlite/dbdata.c | 959 |
1 files changed, 0 insertions, 959 deletions
diff --git a/database/sqlite/dbdata.c b/database/sqlite/dbdata.c deleted file mode 100644 index 1ad742e0..00000000 --- a/database/sqlite/dbdata.c +++ /dev/null @@ -1,959 +0,0 @@ -/* -** 2019-04-17 -** -** 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 file contains an implementation of two eponymous virtual tables, -** "sqlite_dbdata" and "sqlite_dbptr". Both modules require that the -** "sqlite_dbpage" eponymous virtual table be available. -** -** SQLITE_DBDATA: -** sqlite_dbdata is used to extract data directly from a database b-tree -** page and its associated overflow pages, bypassing the b-tree layer. -** The table schema is equivalent to: -** -** CREATE TABLE sqlite_dbdata( -** pgno INTEGER, -** cell INTEGER, -** field INTEGER, -** value ANY, -** schema TEXT HIDDEN -** ); -** -** IMPORTANT: THE VIRTUAL TABLE SCHEMA ABOVE IS SUBJECT TO CHANGE. IN THE -** FUTURE NEW NON-HIDDEN COLUMNS MAY BE ADDED BETWEEN "value" AND -** "schema". -** -** Each page of the database is inspected. If it cannot be interpreted as -** a b-tree page, or if it is a b-tree page containing 0 entries, the -** sqlite_dbdata table contains no rows for that page. Otherwise, the -** table contains one row for each field in the record associated with -** each cell on the page. For intkey b-trees, the key value is stored in -** field -1. -** -** For example, for the database: -** -** CREATE TABLE t1(a, b); -- root page is page 2 -** INSERT INTO t1(rowid, a, b) VALUES(5, 'v', 'five'); -** INSERT INTO t1(rowid, a, b) VALUES(10, 'x', 'ten'); -** -** the sqlite_dbdata table contains, as well as from entries related to -** page 1, content equivalent to: -** -** INSERT INTO sqlite_dbdata(pgno, cell, field, value) VALUES -** (2, 0, -1, 5 ), -** (2, 0, 0, 'v' ), -** (2, 0, 1, 'five'), -** (2, 1, -1, 10 ), -** (2, 1, 0, 'x' ), -** (2, 1, 1, 'ten' ); -** -** If database corruption is encountered, this module does not report an -** error. Instead, it attempts to extract as much data as possible and -** ignores the corruption. -** -** SQLITE_DBPTR: -** The sqlite_dbptr table has the following schema: -** -** CREATE TABLE sqlite_dbptr( -** pgno INTEGER, -** child INTEGER, -** schema TEXT HIDDEN -** ); -** -** It contains one entry for each b-tree pointer between a parent and -** child page in the database. -*/ - -#pragma GCC diagnostic push -#pragma GCC diagnostic ignored "-Wimplicit-fallthrough" -#pragma GCC diagnostic ignored "-Wunused-parameter" -#if !defined(SQLITEINT_H) -#include "sqlite3.h" - -typedef unsigned char u8; -typedef unsigned int u32; - -#endif -#include <string.h> -#include <assert.h> - -#ifndef SQLITE_OMIT_VIRTUALTABLE - -#define DBDATA_PADDING_BYTES 100 - -typedef struct DbdataTable DbdataTable; -typedef struct DbdataCursor DbdataCursor; - -/* Cursor object */ -struct DbdataCursor { - sqlite3_vtab_cursor base; /* Base class. Must be first */ - sqlite3_stmt *pStmt; /* For fetching database pages */ - - int iPgno; /* Current page number */ - u8 *aPage; /* Buffer containing page */ - int nPage; /* Size of aPage[] in bytes */ - int nCell; /* Number of cells on aPage[] */ - int iCell; /* Current cell number */ - int bOnePage; /* True to stop after one page */ - int szDb; - sqlite3_int64 iRowid; - - /* Only for the sqlite_dbdata table */ - u8 *pRec; /* Buffer containing current record */ - sqlite3_int64 nRec; /* Size of pRec[] in bytes */ - sqlite3_int64 nHdr; /* Size of header in bytes */ - int iField; /* Current field number */ - u8 *pHdrPtr; - u8 *pPtr; - u32 enc; /* Text encoding */ - - sqlite3_int64 iIntkey; /* Integer key value */ -}; - -/* Table object */ -struct DbdataTable { - sqlite3_vtab base; /* Base class. Must be first */ - sqlite3 *db; /* The database connection */ - sqlite3_stmt *pStmt; /* For fetching database pages */ - int bPtr; /* True for sqlite3_dbptr table */ -}; - -/* Column and schema definitions for sqlite_dbdata */ -#define DBDATA_COLUMN_PGNO 0 -#define DBDATA_COLUMN_CELL 1 -#define DBDATA_COLUMN_FIELD 2 -#define DBDATA_COLUMN_VALUE 3 -#define DBDATA_COLUMN_SCHEMA 4 -#define DBDATA_SCHEMA \ - "CREATE TABLE x(" \ - " pgno INTEGER," \ - " cell INTEGER," \ - " field INTEGER," \ - " value ANY," \ - " schema TEXT HIDDEN" \ - ")" - -/* Column and schema definitions for sqlite_dbptr */ -#define DBPTR_COLUMN_PGNO 0 -#define DBPTR_COLUMN_CHILD 1 -#define DBPTR_COLUMN_SCHEMA 2 -#define DBPTR_SCHEMA \ - "CREATE TABLE x(" \ - " pgno INTEGER," \ - " child INTEGER," \ - " schema TEXT HIDDEN" \ - ")" - -/* -** Connect to an sqlite_dbdata (pAux==0) or sqlite_dbptr (pAux!=0) virtual -** table. -*/ -static int dbdataConnect( - sqlite3 *db, - void *pAux, - int argc, const char *const*argv, - sqlite3_vtab **ppVtab, - char **pzErr -){ - DbdataTable *pTab = 0; - int rc = sqlite3_declare_vtab(db, pAux ? DBPTR_SCHEMA : DBDATA_SCHEMA); - - (void)argc; - (void)argv; - (void)pzErr; - sqlite3_vtab_config(db, SQLITE_VTAB_USES_ALL_SCHEMAS); - if( rc==SQLITE_OK ){ - pTab = (DbdataTable*)sqlite3_malloc64(sizeof(DbdataTable)); - if( pTab==0 ){ - rc = SQLITE_NOMEM; - }else{ - memset(pTab, 0, sizeof(DbdataTable)); - pTab->db = db; - pTab->bPtr = (pAux!=0); - } - } - - *ppVtab = (sqlite3_vtab*)pTab; - return rc; -} - -/* -** Disconnect from or destroy a sqlite_dbdata or sqlite_dbptr virtual table. -*/ -static int dbdataDisconnect(sqlite3_vtab *pVtab){ - DbdataTable *pTab = (DbdataTable*)pVtab; - if( pTab ){ - sqlite3_finalize(pTab->pStmt); - sqlite3_free(pVtab); - } - return SQLITE_OK; -} - -/* -** This function interprets two types of constraints: -** -** schema=? -** pgno=? -** -** If neither are present, idxNum is set to 0. If schema=? is present, -** the 0x01 bit in idxNum is set. If pgno=? is present, the 0x02 bit -** in idxNum is set. -** -** If both parameters are present, schema is in position 0 and pgno in -** position 1. -*/ -static int dbdataBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdx){ - DbdataTable *pTab = (DbdataTable*)tab; - int i; - int iSchema = -1; - int iPgno = -1; - int colSchema = (pTab->bPtr ? DBPTR_COLUMN_SCHEMA : DBDATA_COLUMN_SCHEMA); - - for(i=0; i<pIdx->nConstraint; i++){ - struct sqlite3_index_constraint *p = &pIdx->aConstraint[i]; - if( p->op==SQLITE_INDEX_CONSTRAINT_EQ ){ - if( p->iColumn==colSchema ){ - if( p->usable==0 ) return SQLITE_CONSTRAINT; - iSchema = i; - } - if( p->iColumn==DBDATA_COLUMN_PGNO && p->usable ){ - iPgno = i; - } - } - } - - if( iSchema>=0 ){ - pIdx->aConstraintUsage[iSchema].argvIndex = 1; - pIdx->aConstraintUsage[iSchema].omit = 1; - } - if( iPgno>=0 ){ - pIdx->aConstraintUsage[iPgno].argvIndex = 1 + (iSchema>=0); - pIdx->aConstraintUsage[iPgno].omit = 1; - pIdx->estimatedCost = 100; - pIdx->estimatedRows = 50; - - if( pTab->bPtr==0 && pIdx->nOrderBy && pIdx->aOrderBy[0].desc==0 ){ - int iCol = pIdx->aOrderBy[0].iColumn; - if( pIdx->nOrderBy==1 ){ - pIdx->orderByConsumed = (iCol==0 || iCol==1); - }else if( pIdx->nOrderBy==2 && pIdx->aOrderBy[1].desc==0 && iCol==0 ){ - pIdx->orderByConsumed = (pIdx->aOrderBy[1].iColumn==1); - } - } - - }else{ - pIdx->estimatedCost = 100000000; - pIdx->estimatedRows = 1000000000; - } - pIdx->idxNum = (iSchema>=0 ? 0x01 : 0x00) | (iPgno>=0 ? 0x02 : 0x00); - return SQLITE_OK; -} - -/* -** Open a new sqlite_dbdata or sqlite_dbptr cursor. -*/ -static int dbdataOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){ - DbdataCursor *pCsr; - - pCsr = (DbdataCursor*)sqlite3_malloc64(sizeof(DbdataCursor)); - if( pCsr==0 ){ - return SQLITE_NOMEM; - }else{ - memset(pCsr, 0, sizeof(DbdataCursor)); - pCsr->base.pVtab = pVTab; - } - - *ppCursor = (sqlite3_vtab_cursor *)pCsr; - return SQLITE_OK; -} - -/* -** Restore a cursor object to the state it was in when first allocated -** by dbdataOpen(). -*/ -static void dbdataResetCursor(DbdataCursor *pCsr){ - DbdataTable *pTab = (DbdataTable*)(pCsr->base.pVtab); - if( pTab->pStmt==0 ){ - pTab->pStmt = pCsr->pStmt; - }else{ - sqlite3_finalize(pCsr->pStmt); - } - pCsr->pStmt = 0; - pCsr->iPgno = 1; - pCsr->iCell = 0; - pCsr->iField = 0; - pCsr->bOnePage = 0; - sqlite3_free(pCsr->aPage); - sqlite3_free(pCsr->pRec); - pCsr->pRec = 0; - pCsr->aPage = 0; -} - -/* -** Close an sqlite_dbdata or sqlite_dbptr cursor. -*/ -static int dbdataClose(sqlite3_vtab_cursor *pCursor){ - DbdataCursor *pCsr = (DbdataCursor*)pCursor; - dbdataResetCursor(pCsr); - sqlite3_free(pCsr); - return SQLITE_OK; -} - -/* -** Utility methods to decode 16 and 32-bit big-endian unsigned integers. -*/ -static u32 get_uint16(unsigned char *a){ - return (a[0]<<8)|a[1]; -} -static u32 get_uint32(unsigned char *a){ - return ((u32)a[0]<<24) - | ((u32)a[1]<<16) - | ((u32)a[2]<<8) - | ((u32)a[3]); -} - -/* -** Load page pgno from the database via the sqlite_dbpage virtual table. -** If successful, set (*ppPage) to point to a buffer containing the page -** data, (*pnPage) to the size of that buffer in bytes and return -** SQLITE_OK. In this case it is the responsibility of the caller to -** eventually free the buffer using sqlite3_free(). -** -** Or, if an error occurs, set both (*ppPage) and (*pnPage) to 0 and -** return an SQLite error code. -*/ -static int dbdataLoadPage( - DbdataCursor *pCsr, /* Cursor object */ - u32 pgno, /* Page number of page to load */ - u8 **ppPage, /* OUT: pointer to page buffer */ - int *pnPage /* OUT: Size of (*ppPage) in bytes */ -){ - int rc2; - int rc = SQLITE_OK; - sqlite3_stmt *pStmt = pCsr->pStmt; - - *ppPage = 0; - *pnPage = 0; - if( pgno>0 ){ - sqlite3_bind_int64(pStmt, 2, pgno); - if( SQLITE_ROW==sqlite3_step(pStmt) ){ - int nCopy = sqlite3_column_bytes(pStmt, 0); - if( nCopy>0 ){ - u8 *pPage; - pPage = (u8*)sqlite3_malloc64(nCopy + DBDATA_PADDING_BYTES); - if( pPage==0 ){ - rc = SQLITE_NOMEM; - }else{ - const u8 *pCopy = sqlite3_column_blob(pStmt, 0); - memcpy(pPage, pCopy, nCopy); - memset(&pPage[nCopy], 0, DBDATA_PADDING_BYTES); - } - *ppPage = pPage; - *pnPage = nCopy; - } - } - rc2 = sqlite3_reset(pStmt); - if( rc==SQLITE_OK ) rc = rc2; - } - - return rc; -} - -/* -** Read a varint. Put the value in *pVal and return the number of bytes. -*/ -static int dbdataGetVarint(const u8 *z, sqlite3_int64 *pVal){ - sqlite3_uint64 u = 0; - int i; - for(i=0; i<8; i++){ - u = (u<<7) + (z[i]&0x7f); - if( (z[i]&0x80)==0 ){ *pVal = (sqlite3_int64)u; return i+1; } - } - u = (u<<8) + (z[i]&0xff); - *pVal = (sqlite3_int64)u; - return 9; -} - -/* -** Like dbdataGetVarint(), but set the output to 0 if it is less than 0 -** or greater than 0xFFFFFFFF. This can be used for all varints in an -** SQLite database except for key values in intkey tables. -*/ -static int dbdataGetVarintU32(const u8 *z, sqlite3_int64 *pVal){ - sqlite3_int64 val; - int nRet = dbdataGetVarint(z, &val); - if( val<0 || val>0xFFFFFFFF ) val = 0; - *pVal = val; - return nRet; -} - -/* -** Return the number of bytes of space used by an SQLite value of type -** eType. -*/ -static int dbdataValueBytes(int eType){ - switch( eType ){ - case 0: case 8: case 9: - case 10: case 11: - return 0; - case 1: - return 1; - case 2: - return 2; - case 3: - return 3; - case 4: - return 4; - case 5: - return 6; - case 6: - case 7: - return 8; - default: - if( eType>0 ){ - return ((eType-12) / 2); - } - return 0; - } -} - -/* -** Load a value of type eType from buffer pData and use it to set the -** result of context object pCtx. -*/ -static void dbdataValue( - sqlite3_context *pCtx, - u32 enc, - int eType, - u8 *pData, - sqlite3_int64 nData -){ - if( eType>=0 && dbdataValueBytes(eType)<=nData ){ - switch( eType ){ - case 0: - case 10: - case 11: - sqlite3_result_null(pCtx); - break; - - case 8: - sqlite3_result_int(pCtx, 0); - break; - case 9: - sqlite3_result_int(pCtx, 1); - break; - - case 1: case 2: case 3: case 4: case 5: case 6: case 7: { - sqlite3_uint64 v = (signed char)pData[0]; - pData++; - switch( eType ){ - case 7: - case 6: v = (v<<16) + (pData[0]<<8) + pData[1]; pData += 2; - case 5: v = (v<<16) + (pData[0]<<8) + pData[1]; pData += 2; - case 4: v = (v<<8) + pData[0]; pData++; - case 3: v = (v<<8) + pData[0]; pData++; - case 2: v = (v<<8) + pData[0]; pData++; - } - - if( eType==7 ){ - double r; - memcpy(&r, &v, sizeof(r)); - sqlite3_result_double(pCtx, r); - }else{ - sqlite3_result_int64(pCtx, (sqlite3_int64)v); - } - break; - } - - default: { - int n = ((eType-12) / 2); - if( eType % 2 ){ - switch( enc ){ -#ifndef SQLITE_OMIT_UTF16 - case SQLITE_UTF16BE: - sqlite3_result_text16be(pCtx, (void*)pData, n, SQLITE_TRANSIENT); - break; - case SQLITE_UTF16LE: - sqlite3_result_text16le(pCtx, (void*)pData, n, SQLITE_TRANSIENT); - break; -#endif - default: - sqlite3_result_text(pCtx, (char*)pData, n, SQLITE_TRANSIENT); - break; - } - }else{ - sqlite3_result_blob(pCtx, pData, n, SQLITE_TRANSIENT); - } - } - } - } -} - -/* -** Move an sqlite_dbdata or sqlite_dbptr cursor to the next entry. -*/ -static int dbdataNext(sqlite3_vtab_cursor *pCursor){ - DbdataCursor *pCsr = (DbdataCursor*)pCursor; - DbdataTable *pTab = (DbdataTable*)pCursor->pVtab; - - pCsr->iRowid++; - while( 1 ){ - int rc; - int iOff = (pCsr->iPgno==1 ? 100 : 0); - int bNextPage = 0; - - if( pCsr->aPage==0 ){ - while( 1 ){ - if( pCsr->bOnePage==0 && pCsr->iPgno>pCsr->szDb ) return SQLITE_OK; - rc = dbdataLoadPage(pCsr, pCsr->iPgno, &pCsr->aPage, &pCsr->nPage); - if( rc!=SQLITE_OK ) return rc; - if( pCsr->aPage && pCsr->nPage>=256 ) break; - sqlite3_free(pCsr->aPage); - pCsr->aPage = 0; - if( pCsr->bOnePage ) return SQLITE_OK; - pCsr->iPgno++; - } - - assert( iOff+3+2<=pCsr->nPage ); - pCsr->iCell = pTab->bPtr ? -2 : 0; - pCsr->nCell = get_uint16(&pCsr->aPage[iOff+3]); - } - - if( pTab->bPtr ){ - if( pCsr->aPage[iOff]!=0x02 && pCsr->aPage[iOff]!=0x05 ){ - pCsr->iCell = pCsr->nCell; - } - pCsr->iCell++; - if( pCsr->iCell>=pCsr->nCell ){ - sqlite3_free(pCsr->aPage); - pCsr->aPage = 0; - if( pCsr->bOnePage ) return SQLITE_OK; - pCsr->iPgno++; - }else{ - return SQLITE_OK; - } - }else{ - /* If there is no record loaded, load it now. */ - if( pCsr->pRec==0 ){ - int bHasRowid = 0; - int nPointer = 0; - sqlite3_int64 nPayload = 0; - sqlite3_int64 nHdr = 0; - int iHdr; - int U, X; - int nLocal; - - switch( pCsr->aPage[iOff] ){ - case 0x02: - nPointer = 4; - break; - case 0x0a: - break; - case 0x0d: - bHasRowid = 1; - break; - default: - /* This is not a b-tree page with records on it. Continue. */ - pCsr->iCell = pCsr->nCell; - break; - } - - if( pCsr->iCell>=pCsr->nCell ){ - bNextPage = 1; - }else{ - - iOff += 8 + nPointer + pCsr->iCell*2; - if( iOff>pCsr->nPage ){ - bNextPage = 1; - }else{ - iOff = get_uint16(&pCsr->aPage[iOff]); - } - - /* For an interior node cell, skip past the child-page number */ - iOff += nPointer; - - /* Load the "byte of payload including overflow" field */ - if( bNextPage || iOff>pCsr->nPage ){ - bNextPage = 1; - }else{ - iOff += dbdataGetVarintU32(&pCsr->aPage[iOff], &nPayload); - } - - /* If this is a leaf intkey cell, load the rowid */ - if( bHasRowid && !bNextPage && iOff<pCsr->nPage ){ - iOff += dbdataGetVarint(&pCsr->aPage[iOff], &pCsr->iIntkey); - } - - /* Figure out how much data to read from the local page */ - U = pCsr->nPage; - if( bHasRowid ){ - X = U-35; - }else{ - X = ((U-12)*64/255)-23; - } - if( nPayload<=X ){ - nLocal = nPayload; - }else{ - int M, K; - M = ((U-12)*32/255)-23; - K = M+((nPayload-M)%(U-4)); - if( K<=X ){ - nLocal = K; - }else{ - nLocal = M; - } - } - - if( bNextPage || nLocal+iOff>pCsr->nPage ){ - bNextPage = 1; - }else{ - - /* Allocate space for payload. And a bit more to catch small buffer - ** overruns caused by attempting to read a varint or similar from - ** near the end of a corrupt record. */ - pCsr->pRec = (u8*)sqlite3_malloc64(nPayload+DBDATA_PADDING_BYTES); - if( pCsr->pRec==0 ) return SQLITE_NOMEM; - memset(pCsr->pRec, 0, nPayload+DBDATA_PADDING_BYTES); - pCsr->nRec = nPayload; - - /* Load the nLocal bytes of payload */ - memcpy(pCsr->pRec, &pCsr->aPage[iOff], nLocal); - iOff += nLocal; - - /* Load content from overflow pages */ - if( nPayload>nLocal ){ - sqlite3_int64 nRem = nPayload - nLocal; - u32 pgnoOvfl = get_uint32(&pCsr->aPage[iOff]); - while( nRem>0 ){ - u8 *aOvfl = 0; - int nOvfl = 0; - int nCopy; - rc = dbdataLoadPage(pCsr, pgnoOvfl, &aOvfl, &nOvfl); - assert( rc!=SQLITE_OK || aOvfl==0 || nOvfl==pCsr->nPage ); - if( rc!=SQLITE_OK ) return rc; - if( aOvfl==0 ) break; - - nCopy = U-4; - if( nCopy>nRem ) nCopy = nRem; - memcpy(&pCsr->pRec[nPayload-nRem], &aOvfl[4], nCopy); - nRem -= nCopy; - - pgnoOvfl = get_uint32(aOvfl); - sqlite3_free(aOvfl); - } - } - - iHdr = dbdataGetVarintU32(pCsr->pRec, &nHdr); - if( nHdr>nPayload ) nHdr = 0; - pCsr->nHdr = nHdr; - pCsr->pHdrPtr = &pCsr->pRec[iHdr]; - pCsr->pPtr = &pCsr->pRec[pCsr->nHdr]; - pCsr->iField = (bHasRowid ? -1 : 0); - } - } - }else{ - pCsr->iField++; - if( pCsr->iField>0 ){ - sqlite3_int64 iType; - if( pCsr->pHdrPtr>&pCsr->pRec[pCsr->nRec] ){ - bNextPage = 1; - }else{ - int szField = 0; - pCsr->pHdrPtr += dbdataGetVarintU32(pCsr->pHdrPtr, &iType); - szField = dbdataValueBytes(iType); - if( (pCsr->nRec - (pCsr->pPtr - pCsr->pRec))<szField ){ - pCsr->pPtr = &pCsr->pRec[pCsr->nRec]; - }else{ - pCsr->pPtr += szField; - } - } - } - } - - if( bNextPage ){ - sqlite3_free(pCsr->aPage); - sqlite3_free(pCsr->pRec); - pCsr->aPage = 0; - pCsr->pRec = 0; - if( pCsr->bOnePage ) return SQLITE_OK; - pCsr->iPgno++; - }else{ - if( pCsr->iField<0 || pCsr->pHdrPtr<&pCsr->pRec[pCsr->nHdr] ){ - return SQLITE_OK; - } - - /* Advance to the next cell. The next iteration of the loop will load - ** the record and so on. */ - sqlite3_free(pCsr->pRec); - pCsr->pRec = 0; - pCsr->iCell++; - } - } - } - - assert( !"can't get here" ); - return SQLITE_OK; -} - -/* -** Return true if the cursor is at EOF. -*/ -static int dbdataEof(sqlite3_vtab_cursor *pCursor){ - DbdataCursor *pCsr = (DbdataCursor*)pCursor; - return pCsr->aPage==0; -} - -/* -** Return true if nul-terminated string zSchema ends in "()". Or false -** otherwise. -*/ -static int dbdataIsFunction(const char *zSchema){ - size_t n = strlen(zSchema); - if( n>2 && zSchema[n-2]=='(' && zSchema[n-1]==')' ){ - return (int)n-2; - } - return 0; -} - -/* -** Determine the size in pages of database zSchema (where zSchema is -** "main", "temp" or the name of an attached database) and set -** pCsr->szDb accordingly. If successful, return SQLITE_OK. Otherwise, -** an SQLite error code. -*/ -static int dbdataDbsize(DbdataCursor *pCsr, const char *zSchema){ - DbdataTable *pTab = (DbdataTable*)pCsr->base.pVtab; - char *zSql = 0; - int rc, rc2; - int nFunc = 0; - sqlite3_stmt *pStmt = 0; - - if( (nFunc = dbdataIsFunction(zSchema))>0 ){ - zSql = sqlite3_mprintf("SELECT %.*s(0)", nFunc, zSchema); - }else{ - zSql = sqlite3_mprintf("PRAGMA %Q.page_count", zSchema); - } - if( zSql==0 ) return SQLITE_NOMEM; - - rc = sqlite3_prepare_v2(pTab->db, zSql, -1, &pStmt, 0); - sqlite3_free(zSql); - if( rc==SQLITE_OK && sqlite3_step(pStmt)==SQLITE_ROW ){ - pCsr->szDb = sqlite3_column_int(pStmt, 0); - } - rc2 = sqlite3_finalize(pStmt); - if( rc==SQLITE_OK ) rc = rc2; - return rc; -} - -/* -** Attempt to figure out the encoding of the database by retrieving page 1 -** and inspecting the header field. If successful, set the pCsr->enc variable -** and return SQLITE_OK. Otherwise, return an SQLite error code. -*/ -static int dbdataGetEncoding(DbdataCursor *pCsr){ - int rc = SQLITE_OK; - int nPg1 = 0; - u8 *aPg1 = 0; - rc = dbdataLoadPage(pCsr, 1, &aPg1, &nPg1); - if( rc==SQLITE_OK && nPg1>=(56+4) ){ - pCsr->enc = get_uint32(&aPg1[56]); - } - sqlite3_free(aPg1); - return rc; -} - - -/* -** xFilter method for sqlite_dbdata and sqlite_dbptr. -*/ -static int dbdataFilter( - sqlite3_vtab_cursor *pCursor, - int idxNum, const char *idxStr, - int argc, sqlite3_value **argv -){ - DbdataCursor *pCsr = (DbdataCursor*)pCursor; - DbdataTable *pTab = (DbdataTable*)pCursor->pVtab; - int rc = SQLITE_OK; - const char *zSchema = "main"; - (void)idxStr; - (void)argc; - - dbdataResetCursor(pCsr); - assert( pCsr->iPgno==1 ); - if( idxNum & 0x01 ){ - zSchema = (const char*)sqlite3_value_text(argv[0]); - if( zSchema==0 ) zSchema = ""; - } - if( idxNum & 0x02 ){ - pCsr->iPgno = sqlite3_value_int(argv[(idxNum & 0x01)]); - pCsr->bOnePage = 1; - }else{ - rc = dbdataDbsize(pCsr, zSchema); - } - - if( rc==SQLITE_OK ){ - int nFunc = 0; - if( pTab->pStmt ){ - pCsr->pStmt = pTab->pStmt; - pTab->pStmt = 0; - }else if( (nFunc = dbdataIsFunction(zSchema))>0 ){ - char *zSql = sqlite3_mprintf("SELECT %.*s(?2)", nFunc, zSchema); - if( zSql==0 ){ - rc = SQLITE_NOMEM; - }else{ - rc = sqlite3_prepare_v2(pTab->db, zSql, -1, &pCsr->pStmt, 0); - sqlite3_free(zSql); - } - }else{ - rc = sqlite3_prepare_v2(pTab->db, - "SELECT data FROM sqlite_dbpage(?) WHERE pgno=?", -1, - &pCsr->pStmt, 0 - ); - } - } - if( rc==SQLITE_OK ){ - rc = sqlite3_bind_text(pCsr->pStmt, 1, zSchema, -1, SQLITE_TRANSIENT); - } - - /* Try to determine the encoding of the db by inspecting the header - ** field on page 1. */ - if( rc==SQLITE_OK ){ - rc = dbdataGetEncoding(pCsr); - } - - if( rc!=SQLITE_OK ){ - pTab->base.zErrMsg = sqlite3_mprintf("%s", sqlite3_errmsg(pTab->db)); - } - - if( rc==SQLITE_OK ){ - rc = dbdataNext(pCursor); - } - return rc; -} - -/* -** Return a column for the sqlite_dbdata or sqlite_dbptr table. -*/ -static int dbdataColumn( - sqlite3_vtab_cursor *pCursor, - sqlite3_context *ctx, - int i -){ - DbdataCursor *pCsr = (DbdataCursor*)pCursor; - DbdataTable *pTab = (DbdataTable*)pCursor->pVtab; - if( pTab->bPtr ){ - switch( i ){ - case DBPTR_COLUMN_PGNO: - sqlite3_result_int64(ctx, pCsr->iPgno); - break; - case DBPTR_COLUMN_CHILD: { - int iOff = pCsr->iPgno==1 ? 100 : 0; - if( pCsr->iCell<0 ){ - iOff += 8; - }else{ - iOff += 12 + pCsr->iCell*2; - if( iOff>pCsr->nPage ) return SQLITE_OK; - iOff = get_uint16(&pCsr->aPage[iOff]); - } - if( iOff<=pCsr->nPage ){ - sqlite3_result_int64(ctx, get_uint32(&pCsr->aPage[iOff])); - } - break; - } - } - }else{ - switch( i ){ - case DBDATA_COLUMN_PGNO: - sqlite3_result_int64(ctx, pCsr->iPgno); - break; - case DBDATA_COLUMN_CELL: - sqlite3_result_int(ctx, pCsr->iCell); - break; - case DBDATA_COLUMN_FIELD: - sqlite3_result_int(ctx, pCsr->iField); - break; - case DBDATA_COLUMN_VALUE: { - if( pCsr->iField<0 ){ - sqlite3_result_int64(ctx, pCsr->iIntkey); - }else if( &pCsr->pRec[pCsr->nRec] >= pCsr->pPtr ){ - sqlite3_int64 iType; - dbdataGetVarintU32(pCsr->pHdrPtr, &iType); - dbdataValue( - ctx, pCsr->enc, iType, pCsr->pPtr, - &pCsr->pRec[pCsr->nRec] - pCsr->pPtr - ); - } - break; - } - } - } - return SQLITE_OK; -} - -/* -** Return the rowid for an sqlite_dbdata or sqlite_dptr table. -*/ -static int dbdataRowid(sqlite3_vtab_cursor *pCursor, sqlite_int64 *pRowid){ - DbdataCursor *pCsr = (DbdataCursor*)pCursor; - *pRowid = pCsr->iRowid; - return SQLITE_OK; -} - - -/* -** Invoke this routine to register the "sqlite_dbdata" virtual table module -*/ -static int sqlite3DbdataRegister(sqlite3 *db){ - static sqlite3_module dbdata_module = { - 0, /* iVersion */ - 0, /* xCreate */ - dbdataConnect, /* xConnect */ - dbdataBestIndex, /* xBestIndex */ - dbdataDisconnect, /* xDisconnect */ - 0, /* xDestroy */ - dbdataOpen, /* xOpen - open a cursor */ - dbdataClose, /* xClose - close a cursor */ - dbdataFilter, /* xFilter - configure scan constraints */ - dbdataNext, /* xNext - advance a cursor */ - dbdataEof, /* xEof - check for end of scan */ - dbdataColumn, /* xColumn - read data */ - dbdataRowid, /* xRowid - read data */ - 0, /* xUpdate */ - 0, /* xBegin */ - 0, /* xSync */ - 0, /* xCommit */ - 0, /* xRollback */ - 0, /* xFindMethod */ - 0, /* xRename */ - 0, /* xSavepoint */ - 0, /* xRelease */ - 0, /* xRollbackTo */ - 0 /* xShadowName */ - }; - - int rc = sqlite3_create_module(db, "sqlite_dbdata", &dbdata_module, 0); - if( rc==SQLITE_OK ){ - rc = sqlite3_create_module(db, "sqlite_dbptr", &dbdata_module, (void*)1); - } - return rc; -} - -int sqlite3_dbdata_init( - sqlite3 *db, - char **pzErrMsg, - const sqlite3_api_routines *pApi -){ - (void)pzErrMsg; - return sqlite3DbdataRegister(db); -} - -#endif /* ifndef SQLITE_OMIT_VIRTUALTABLE */ -#pragma GCC diagnostic pop |