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Diffstat (limited to 'src/os_kv.c')
| -rw-r--r-- | src/os_kv.c | 979 |
1 files changed, 979 insertions, 0 deletions
diff --git a/src/os_kv.c b/src/os_kv.c new file mode 100644 index 0000000..5e0ea49 --- /dev/null +++ b/src/os_kv.c @@ -0,0 +1,979 @@ +/* +** 2022-09-06 +** +** 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 experimental VFS layer that operates on a +** Key/Value storage engine where both keys and values must be pure +** text. +*/ +#include <sqliteInt.h> +#if SQLITE_OS_KV || (SQLITE_OS_UNIX && defined(SQLITE_OS_KV_OPTIONAL)) + +/***************************************************************************** +** Debugging logic +*/ + +/* SQLITE_KV_TRACE() is used for tracing calls to kvstorage routines. */ +#if 0 +#define SQLITE_KV_TRACE(X) printf X +#else +#define SQLITE_KV_TRACE(X) +#endif + +/* SQLITE_KV_LOG() is used for tracing calls to the VFS interface */ +#if 0 +#define SQLITE_KV_LOG(X) printf X +#else +#define SQLITE_KV_LOG(X) +#endif + + +/* +** Forward declaration of objects used by this VFS implementation +*/ +typedef struct KVVfsFile KVVfsFile; + +/* A single open file. There are only two files represented by this +** VFS - the database and the rollback journal. +*/ +struct KVVfsFile { + sqlite3_file base; /* IO methods */ + const char *zClass; /* Storage class */ + int isJournal; /* True if this is a journal file */ + unsigned int nJrnl; /* Space allocated for aJrnl[] */ + char *aJrnl; /* Journal content */ + int szPage; /* Last known page size */ + sqlite3_int64 szDb; /* Database file size. -1 means unknown */ + char *aData; /* Buffer to hold page data */ +}; +#define SQLITE_KVOS_SZ 133073 + +/* +** Methods for KVVfsFile +*/ +static int kvvfsClose(sqlite3_file*); +static int kvvfsReadDb(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); +static int kvvfsReadJrnl(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); +static int kvvfsWriteDb(sqlite3_file*,const void*,int iAmt, sqlite3_int64); +static int kvvfsWriteJrnl(sqlite3_file*,const void*,int iAmt, sqlite3_int64); +static int kvvfsTruncateDb(sqlite3_file*, sqlite3_int64 size); +static int kvvfsTruncateJrnl(sqlite3_file*, sqlite3_int64 size); +static int kvvfsSyncDb(sqlite3_file*, int flags); +static int kvvfsSyncJrnl(sqlite3_file*, int flags); +static int kvvfsFileSizeDb(sqlite3_file*, sqlite3_int64 *pSize); +static int kvvfsFileSizeJrnl(sqlite3_file*, sqlite3_int64 *pSize); +static int kvvfsLock(sqlite3_file*, int); +static int kvvfsUnlock(sqlite3_file*, int); +static int kvvfsCheckReservedLock(sqlite3_file*, int *pResOut); +static int kvvfsFileControlDb(sqlite3_file*, int op, void *pArg); +static int kvvfsFileControlJrnl(sqlite3_file*, int op, void *pArg); +static int kvvfsSectorSize(sqlite3_file*); +static int kvvfsDeviceCharacteristics(sqlite3_file*); + +/* +** Methods for sqlite3_vfs +*/ +static int kvvfsOpen(sqlite3_vfs*, const char *, sqlite3_file*, int , int *); +static int kvvfsDelete(sqlite3_vfs*, const char *zName, int syncDir); +static int kvvfsAccess(sqlite3_vfs*, const char *zName, int flags, int *); +static int kvvfsFullPathname(sqlite3_vfs*, const char *zName, int, char *zOut); +static void *kvvfsDlOpen(sqlite3_vfs*, const char *zFilename); +static int kvvfsRandomness(sqlite3_vfs*, int nByte, char *zOut); +static int kvvfsSleep(sqlite3_vfs*, int microseconds); +static int kvvfsCurrentTime(sqlite3_vfs*, double*); +static int kvvfsCurrentTimeInt64(sqlite3_vfs*, sqlite3_int64*); + +static sqlite3_vfs sqlite3OsKvvfsObject = { + 1, /* iVersion */ + sizeof(KVVfsFile), /* szOsFile */ + 1024, /* mxPathname */ + 0, /* pNext */ + "kvvfs", /* zName */ + 0, /* pAppData */ + kvvfsOpen, /* xOpen */ + kvvfsDelete, /* xDelete */ + kvvfsAccess, /* xAccess */ + kvvfsFullPathname, /* xFullPathname */ + kvvfsDlOpen, /* xDlOpen */ + 0, /* xDlError */ + 0, /* xDlSym */ + 0, /* xDlClose */ + kvvfsRandomness, /* xRandomness */ + kvvfsSleep, /* xSleep */ + kvvfsCurrentTime, /* xCurrentTime */ + 0, /* xGetLastError */ + kvvfsCurrentTimeInt64 /* xCurrentTimeInt64 */ +}; + +/* Methods for sqlite3_file objects referencing a database file +*/ +static sqlite3_io_methods kvvfs_db_io_methods = { + 1, /* iVersion */ + kvvfsClose, /* xClose */ + kvvfsReadDb, /* xRead */ + kvvfsWriteDb, /* xWrite */ + kvvfsTruncateDb, /* xTruncate */ + kvvfsSyncDb, /* xSync */ + kvvfsFileSizeDb, /* xFileSize */ + kvvfsLock, /* xLock */ + kvvfsUnlock, /* xUnlock */ + kvvfsCheckReservedLock, /* xCheckReservedLock */ + kvvfsFileControlDb, /* xFileControl */ + kvvfsSectorSize, /* xSectorSize */ + kvvfsDeviceCharacteristics, /* xDeviceCharacteristics */ + 0, /* xShmMap */ + 0, /* xShmLock */ + 0, /* xShmBarrier */ + 0, /* xShmUnmap */ + 0, /* xFetch */ + 0 /* xUnfetch */ +}; + +/* Methods for sqlite3_file objects referencing a rollback journal +*/ +static sqlite3_io_methods kvvfs_jrnl_io_methods = { + 1, /* iVersion */ + kvvfsClose, /* xClose */ + kvvfsReadJrnl, /* xRead */ + kvvfsWriteJrnl, /* xWrite */ + kvvfsTruncateJrnl, /* xTruncate */ + kvvfsSyncJrnl, /* xSync */ + kvvfsFileSizeJrnl, /* xFileSize */ + kvvfsLock, /* xLock */ + kvvfsUnlock, /* xUnlock */ + kvvfsCheckReservedLock, /* xCheckReservedLock */ + kvvfsFileControlJrnl, /* xFileControl */ + kvvfsSectorSize, /* xSectorSize */ + kvvfsDeviceCharacteristics, /* xDeviceCharacteristics */ + 0, /* xShmMap */ + 0, /* xShmLock */ + 0, /* xShmBarrier */ + 0, /* xShmUnmap */ + 0, /* xFetch */ + 0 /* xUnfetch */ +}; + +/****** Storage subsystem **************************************************/ +#include <sys/types.h> +#include <sys/stat.h> +#include <unistd.h> + +/* Forward declarations for the low-level storage engine +*/ +static int kvstorageWrite(const char*, const char *zKey, const char *zData); +static int kvstorageDelete(const char*, const char *zKey); +static int kvstorageRead(const char*, const char *zKey, char *zBuf, int nBuf); +#define KVSTORAGE_KEY_SZ 32 + +/* Expand the key name with an appropriate prefix and put the result +** zKeyOut[]. The zKeyOut[] buffer is assumed to hold at least +** KVSTORAGE_KEY_SZ bytes. +*/ +static void kvstorageMakeKey( + const char *zClass, + const char *zKeyIn, + char *zKeyOut +){ + sqlite3_snprintf(KVSTORAGE_KEY_SZ, zKeyOut, "kvvfs-%s-%s", zClass, zKeyIn); +} + +/* Write content into a key. zClass is the particular namespace of the +** underlying key/value store to use - either "local" or "session". +** +** Both zKey and zData are zero-terminated pure text strings. +** +** Return the number of errors. +*/ +static int kvstorageWrite( + const char *zClass, + const char *zKey, + const char *zData +){ + FILE *fd; + char zXKey[KVSTORAGE_KEY_SZ]; + kvstorageMakeKey(zClass, zKey, zXKey); + fd = fopen(zXKey, "wb"); + if( fd ){ + SQLITE_KV_TRACE(("KVVFS-WRITE %-15s (%d) %.50s%s\n", zXKey, + (int)strlen(zData), zData, + strlen(zData)>50 ? "..." : "")); + fputs(zData, fd); + fclose(fd); + return 0; + }else{ + return 1; + } +} + +/* Delete a key (with its corresponding data) from the key/value +** namespace given by zClass. If the key does not previously exist, +** this routine is a no-op. +*/ +static int kvstorageDelete(const char *zClass, const char *zKey){ + char zXKey[KVSTORAGE_KEY_SZ]; + kvstorageMakeKey(zClass, zKey, zXKey); + unlink(zXKey); + SQLITE_KV_TRACE(("KVVFS-DELETE %-15s\n", zXKey)); + return 0; +} + +/* Read the value associated with a zKey from the key/value namespace given +** by zClass and put the text data associated with that key in the first +** nBuf bytes of zBuf[]. The value might be truncated if zBuf is not large +** enough to hold it all. The value put into zBuf must always be zero +** terminated, even if it gets truncated because nBuf is not large enough. +** +** Return the total number of bytes in the data, without truncation, and +** not counting the final zero terminator. Return -1 if the key does +** not exist. +** +** If nBuf<=0 then this routine simply returns the size of the data without +** actually reading it. +*/ +static int kvstorageRead( + const char *zClass, + const char *zKey, + char *zBuf, + int nBuf +){ + FILE *fd; + struct stat buf; + char zXKey[KVSTORAGE_KEY_SZ]; + kvstorageMakeKey(zClass, zKey, zXKey); + if( access(zXKey, R_OK)!=0 + || stat(zXKey, &buf)!=0 + || !S_ISREG(buf.st_mode) + ){ + SQLITE_KV_TRACE(("KVVFS-READ %-15s (-1)\n", zXKey)); + return -1; + } + if( nBuf<=0 ){ + return (int)buf.st_size; + }else if( nBuf==1 ){ + zBuf[0] = 0; + SQLITE_KV_TRACE(("KVVFS-READ %-15s (%d)\n", zXKey, + (int)buf.st_size)); + return (int)buf.st_size; + } + if( nBuf > buf.st_size + 1 ){ + nBuf = buf.st_size + 1; + } + fd = fopen(zXKey, "rb"); + if( fd==0 ){ + SQLITE_KV_TRACE(("KVVFS-READ %-15s (-1)\n", zXKey)); + return -1; + }else{ + sqlite3_int64 n = fread(zBuf, 1, nBuf-1, fd); + fclose(fd); + zBuf[n] = 0; + SQLITE_KV_TRACE(("KVVFS-READ %-15s (%lld) %.50s%s\n", zXKey, + n, zBuf, n>50 ? "..." : "")); + return (int)n; + } +} + +/* +** An internal level of indirection which enables us to replace the +** kvvfs i/o methods with JavaScript implementations in WASM builds. +** Maintenance reminder: if this struct changes in any way, the JSON +** rendering of its structure must be updated in +** sqlite3_wasm_enum_json(). There are no binary compatibility +** concerns, so it does not need an iVersion member. This file is +** necessarily always compiled together with sqlite3_wasm_enum_json(), +** and JS code dynamically creates the mapping of members based on +** that JSON description. +*/ +typedef struct sqlite3_kvvfs_methods sqlite3_kvvfs_methods; +struct sqlite3_kvvfs_methods { + int (*xRead)(const char *zClass, const char *zKey, char *zBuf, int nBuf); + int (*xWrite)(const char *zClass, const char *zKey, const char *zData); + int (*xDelete)(const char *zClass, const char *zKey); + const int nKeySize; +}; + +/* +** This object holds the kvvfs I/O methods which may be swapped out +** for JavaScript-side implementations in WASM builds. In such builds +** it cannot be const, but in native builds it should be so that +** the compiler can hopefully optimize this level of indirection out. +** That said, kvvfs is intended primarily for use in WASM builds. +** +** Note that this is not explicitly flagged as static because the +** amalgamation build will tag it with SQLITE_PRIVATE. +*/ +#ifndef SQLITE_WASM +const +#endif +sqlite3_kvvfs_methods sqlite3KvvfsMethods = { +kvstorageRead, +kvstorageWrite, +kvstorageDelete, +KVSTORAGE_KEY_SZ +}; + +/****** Utility subroutines ************************************************/ + +/* +** Encode binary into the text encoded used to persist on disk. +** The output text is stored in aOut[], which must be at least +** nData+1 bytes in length. +** +** Return the actual length of the encoded text, not counting the +** zero terminator at the end. +** +** Encoding format +** --------------- +** +** * Non-zero bytes are encoded as upper-case hexadecimal +** +** * A sequence of one or more zero-bytes that are not at the +** beginning of the buffer are encoded as a little-endian +** base-26 number using a..z. "a" means 0. "b" means 1, +** "z" means 25. "ab" means 26. "ac" means 52. And so forth. +** +** * Because there is no overlap between the encoding characters +** of hexadecimal and base-26 numbers, it is always clear where +** one stops and the next begins. +*/ +static int kvvfsEncode(const char *aData, int nData, char *aOut){ + int i, j; + const unsigned char *a = (const unsigned char*)aData; + for(i=j=0; i<nData; i++){ + unsigned char c = a[i]; + if( c!=0 ){ + aOut[j++] = "0123456789ABCDEF"[c>>4]; + aOut[j++] = "0123456789ABCDEF"[c&0xf]; + }else{ + /* A sequence of 1 or more zeros is stored as a little-endian + ** base-26 number using a..z as the digits. So one zero is "b". + ** Two zeros is "c". 25 zeros is "z", 26 zeros is "ab", 27 is "bb", + ** and so forth. + */ + int k; + for(k=1; i+k<nData && a[i+k]==0; k++){} + i += k-1; + while( k>0 ){ + aOut[j++] = 'a'+(k%26); + k /= 26; + } + } + } + aOut[j] = 0; + return j; +} + +static const signed char kvvfsHexValue[256] = { + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, -1, -1, -1, -1, -1, -1, + -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 +}; + +/* +** Decode the text encoding back to binary. The binary content is +** written into pOut, which must be at least nOut bytes in length. +** +** The return value is the number of bytes actually written into aOut[]. +*/ +static int kvvfsDecode(const char *a, char *aOut, int nOut){ + int i, j; + int c; + const unsigned char *aIn = (const unsigned char*)a; + i = 0; + j = 0; + while( 1 ){ + c = kvvfsHexValue[aIn[i]]; + if( c<0 ){ + int n = 0; + int mult = 1; + c = aIn[i]; + if( c==0 ) break; + while( c>='a' && c<='z' ){ + n += (c - 'a')*mult; + mult *= 26; + c = aIn[++i]; + } + if( j+n>nOut ) return -1; + memset(&aOut[j], 0, n); + j += n; + if( c==0 || mult==1 ) break; /* progress stalled if mult==1 */ + }else{ + aOut[j] = c<<4; + c = kvvfsHexValue[aIn[++i]]; + if( c<0 ) break; + aOut[j++] += c; + i++; + } + } + return j; +} + +/* +** Decode a complete journal file. Allocate space in pFile->aJrnl +** and store the decoding there. Or leave pFile->aJrnl set to NULL +** if an error is encountered. +** +** The first few characters of the text encoding will be a little-endian +** base-26 number (digits a..z) that is the total number of bytes +** in the decoded journal file image. This base-26 number is followed +** by a single space, then the encoding of the journal. The space +** separator is required to act as a terminator for the base-26 number. +*/ +static void kvvfsDecodeJournal( + KVVfsFile *pFile, /* Store decoding in pFile->aJrnl */ + const char *zTxt, /* Text encoding. Zero-terminated */ + int nTxt /* Bytes in zTxt, excluding zero terminator */ +){ + unsigned int n = 0; + int c, i, mult; + i = 0; + mult = 1; + while( (c = zTxt[i++])>='a' && c<='z' ){ + n += (zTxt[i] - 'a')*mult; + mult *= 26; + } + sqlite3_free(pFile->aJrnl); + pFile->aJrnl = sqlite3_malloc64( n ); + if( pFile->aJrnl==0 ){ + pFile->nJrnl = 0; + return; + } + pFile->nJrnl = n; + n = kvvfsDecode(zTxt+i, pFile->aJrnl, pFile->nJrnl); + if( n<pFile->nJrnl ){ + sqlite3_free(pFile->aJrnl); + pFile->aJrnl = 0; + pFile->nJrnl = 0; + } +} + +/* +** Read or write the "sz" element, containing the database file size. +*/ +static sqlite3_int64 kvvfsReadFileSize(KVVfsFile *pFile){ + char zData[50]; + zData[0] = 0; + sqlite3KvvfsMethods.xRead(pFile->zClass, "sz", zData, sizeof(zData)-1); + return strtoll(zData, 0, 0); +} +static int kvvfsWriteFileSize(KVVfsFile *pFile, sqlite3_int64 sz){ + char zData[50]; + sqlite3_snprintf(sizeof(zData), zData, "%lld", sz); + return sqlite3KvvfsMethods.xWrite(pFile->zClass, "sz", zData); +} + +/****** sqlite3_io_methods methods ******************************************/ + +/* +** Close an kvvfs-file. +*/ +static int kvvfsClose(sqlite3_file *pProtoFile){ + KVVfsFile *pFile = (KVVfsFile *)pProtoFile; + + SQLITE_KV_LOG(("xClose %s %s\n", pFile->zClass, + pFile->isJournal ? "journal" : "db")); + sqlite3_free(pFile->aJrnl); + sqlite3_free(pFile->aData); + return SQLITE_OK; +} + +/* +** Read from the -journal file. +*/ +static int kvvfsReadJrnl( + sqlite3_file *pProtoFile, + void *zBuf, + int iAmt, + sqlite_int64 iOfst +){ + KVVfsFile *pFile = (KVVfsFile*)pProtoFile; + assert( pFile->isJournal ); + SQLITE_KV_LOG(("xRead('%s-journal',%d,%lld)\n", pFile->zClass, iAmt, iOfst)); + if( pFile->aJrnl==0 ){ + int szTxt = kvstorageRead(pFile->zClass, "jrnl", 0, 0); + char *aTxt; + if( szTxt<=4 ){ + return SQLITE_IOERR; + } + aTxt = sqlite3_malloc64( szTxt+1 ); + if( aTxt==0 ) return SQLITE_NOMEM; + kvstorageRead(pFile->zClass, "jrnl", aTxt, szTxt+1); + kvvfsDecodeJournal(pFile, aTxt, szTxt); + sqlite3_free(aTxt); + if( pFile->aJrnl==0 ) return SQLITE_IOERR; + } + if( iOfst+iAmt>pFile->nJrnl ){ + return SQLITE_IOERR_SHORT_READ; + } + memcpy(zBuf, pFile->aJrnl+iOfst, iAmt); + return SQLITE_OK; +} + +/* +** Read from the database file. +*/ +static int kvvfsReadDb( + sqlite3_file *pProtoFile, + void *zBuf, + int iAmt, + sqlite_int64 iOfst +){ + KVVfsFile *pFile = (KVVfsFile*)pProtoFile; + unsigned int pgno; + int got, n; + char zKey[30]; + char *aData = pFile->aData; + assert( iOfst>=0 ); + assert( iAmt>=0 ); + SQLITE_KV_LOG(("xRead('%s-db',%d,%lld)\n", pFile->zClass, iAmt, iOfst)); + if( iOfst+iAmt>=512 ){ + if( (iOfst % iAmt)!=0 ){ + return SQLITE_IOERR_READ; + } + if( (iAmt & (iAmt-1))!=0 || iAmt<512 || iAmt>65536 ){ + return SQLITE_IOERR_READ; + } + pFile->szPage = iAmt; + pgno = 1 + iOfst/iAmt; + }else{ + pgno = 1; + } + sqlite3_snprintf(sizeof(zKey), zKey, "%u", pgno); + got = sqlite3KvvfsMethods.xRead(pFile->zClass, zKey, + aData, SQLITE_KVOS_SZ-1); + if( got<0 ){ + n = 0; + }else{ + aData[got] = 0; + if( iOfst+iAmt<512 ){ + int k = iOfst+iAmt; + aData[k*2] = 0; + n = kvvfsDecode(aData, &aData[2000], SQLITE_KVOS_SZ-2000); + if( n>=iOfst+iAmt ){ + memcpy(zBuf, &aData[2000+iOfst], iAmt); + n = iAmt; + }else{ + n = 0; + } + }else{ + n = kvvfsDecode(aData, zBuf, iAmt); + } + } + if( n<iAmt ){ + memset(zBuf+n, 0, iAmt-n); + return SQLITE_IOERR_SHORT_READ; + } + return SQLITE_OK; +} + + +/* +** Write into the -journal file. +*/ +static int kvvfsWriteJrnl( + sqlite3_file *pProtoFile, + const void *zBuf, + int iAmt, + sqlite_int64 iOfst +){ + KVVfsFile *pFile = (KVVfsFile*)pProtoFile; + sqlite3_int64 iEnd = iOfst+iAmt; + SQLITE_KV_LOG(("xWrite('%s-journal',%d,%lld)\n", pFile->zClass, iAmt, iOfst)); + if( iEnd>=0x10000000 ) return SQLITE_FULL; + if( pFile->aJrnl==0 || pFile->nJrnl<iEnd ){ + char *aNew = sqlite3_realloc(pFile->aJrnl, iEnd); + if( aNew==0 ){ + return SQLITE_IOERR_NOMEM; + } + pFile->aJrnl = aNew; + if( pFile->nJrnl<iOfst ){ + memset(pFile->aJrnl+pFile->nJrnl, 0, iOfst-pFile->nJrnl); + } + pFile->nJrnl = iEnd; + } + memcpy(pFile->aJrnl+iOfst, zBuf, iAmt); + return SQLITE_OK; +} + +/* +** Write into the database file. +*/ +static int kvvfsWriteDb( + sqlite3_file *pProtoFile, + const void *zBuf, + int iAmt, + sqlite_int64 iOfst +){ + KVVfsFile *pFile = (KVVfsFile*)pProtoFile; + unsigned int pgno; + char zKey[30]; + char *aData = pFile->aData; + SQLITE_KV_LOG(("xWrite('%s-db',%d,%lld)\n", pFile->zClass, iAmt, iOfst)); + assert( iAmt>=512 && iAmt<=65536 ); + assert( (iAmt & (iAmt-1))==0 ); + assert( pFile->szPage<0 || pFile->szPage==iAmt ); + pFile->szPage = iAmt; + pgno = 1 + iOfst/iAmt; + sqlite3_snprintf(sizeof(zKey), zKey, "%u", pgno); + kvvfsEncode(zBuf, iAmt, aData); + if( sqlite3KvvfsMethods.xWrite(pFile->zClass, zKey, aData) ){ + return SQLITE_IOERR; + } + if( iOfst+iAmt > pFile->szDb ){ + pFile->szDb = iOfst + iAmt; + } + return SQLITE_OK; +} + +/* +** Truncate an kvvfs-file. +*/ +static int kvvfsTruncateJrnl(sqlite3_file *pProtoFile, sqlite_int64 size){ + KVVfsFile *pFile = (KVVfsFile *)pProtoFile; + SQLITE_KV_LOG(("xTruncate('%s-journal',%lld)\n", pFile->zClass, size)); + assert( size==0 ); + sqlite3KvvfsMethods.xDelete(pFile->zClass, "jrnl"); + sqlite3_free(pFile->aJrnl); + pFile->aJrnl = 0; + pFile->nJrnl = 0; + return SQLITE_OK; +} +static int kvvfsTruncateDb(sqlite3_file *pProtoFile, sqlite_int64 size){ + KVVfsFile *pFile = (KVVfsFile *)pProtoFile; + if( pFile->szDb>size + && pFile->szPage>0 + && (size % pFile->szPage)==0 + ){ + char zKey[50]; + unsigned int pgno, pgnoMax; + SQLITE_KV_LOG(("xTruncate('%s-db',%lld)\n", pFile->zClass, size)); + pgno = 1 + size/pFile->szPage; + pgnoMax = 2 + pFile->szDb/pFile->szPage; + while( pgno<=pgnoMax ){ + sqlite3_snprintf(sizeof(zKey), zKey, "%u", pgno); + sqlite3KvvfsMethods.xDelete(pFile->zClass, zKey); + pgno++; + } + pFile->szDb = size; + return kvvfsWriteFileSize(pFile, size) ? SQLITE_IOERR : SQLITE_OK; + } + return SQLITE_IOERR; +} + +/* +** Sync an kvvfs-file. +*/ +static int kvvfsSyncJrnl(sqlite3_file *pProtoFile, int flags){ + int i, n; + KVVfsFile *pFile = (KVVfsFile *)pProtoFile; + char *zOut; + SQLITE_KV_LOG(("xSync('%s-journal')\n", pFile->zClass)); + if( pFile->nJrnl<=0 ){ + return kvvfsTruncateJrnl(pProtoFile, 0); + } + zOut = sqlite3_malloc64( pFile->nJrnl*2 + 50 ); + if( zOut==0 ){ + return SQLITE_IOERR_NOMEM; + } + n = pFile->nJrnl; + i = 0; + do{ + zOut[i++] = 'a' + (n%26); + n /= 26; + }while( n>0 ); + zOut[i++] = ' '; + kvvfsEncode(pFile->aJrnl, pFile->nJrnl, &zOut[i]); + i = sqlite3KvvfsMethods.xWrite(pFile->zClass, "jrnl", zOut); + sqlite3_free(zOut); + return i ? SQLITE_IOERR : SQLITE_OK; +} +static int kvvfsSyncDb(sqlite3_file *pProtoFile, int flags){ + return SQLITE_OK; +} + +/* +** Return the current file-size of an kvvfs-file. +*/ +static int kvvfsFileSizeJrnl(sqlite3_file *pProtoFile, sqlite_int64 *pSize){ + KVVfsFile *pFile = (KVVfsFile *)pProtoFile; + SQLITE_KV_LOG(("xFileSize('%s-journal')\n", pFile->zClass)); + *pSize = pFile->nJrnl; + return SQLITE_OK; +} +static int kvvfsFileSizeDb(sqlite3_file *pProtoFile, sqlite_int64 *pSize){ + KVVfsFile *pFile = (KVVfsFile *)pProtoFile; + SQLITE_KV_LOG(("xFileSize('%s-db')\n", pFile->zClass)); + if( pFile->szDb>=0 ){ + *pSize = pFile->szDb; + }else{ + *pSize = kvvfsReadFileSize(pFile); + } + return SQLITE_OK; +} + +/* +** Lock an kvvfs-file. +*/ +static int kvvfsLock(sqlite3_file *pProtoFile, int eLock){ + KVVfsFile *pFile = (KVVfsFile *)pProtoFile; + assert( !pFile->isJournal ); + SQLITE_KV_LOG(("xLock(%s,%d)\n", pFile->zClass, eLock)); + + if( eLock!=SQLITE_LOCK_NONE ){ + pFile->szDb = kvvfsReadFileSize(pFile); + } + return SQLITE_OK; +} + +/* +** Unlock an kvvfs-file. +*/ +static int kvvfsUnlock(sqlite3_file *pProtoFile, int eLock){ + KVVfsFile *pFile = (KVVfsFile *)pProtoFile; + assert( !pFile->isJournal ); + SQLITE_KV_LOG(("xUnlock(%s,%d)\n", pFile->zClass, eLock)); + if( eLock==SQLITE_LOCK_NONE ){ + pFile->szDb = -1; + } + return SQLITE_OK; +} + +/* +** Check if another file-handle holds a RESERVED lock on an kvvfs-file. +*/ +static int kvvfsCheckReservedLock(sqlite3_file *pProtoFile, int *pResOut){ + SQLITE_KV_LOG(("xCheckReservedLock\n")); + *pResOut = 0; + return SQLITE_OK; +} + +/* +** File control method. For custom operations on an kvvfs-file. +*/ +static int kvvfsFileControlJrnl(sqlite3_file *pProtoFile, int op, void *pArg){ + SQLITE_KV_LOG(("xFileControl(%d) on journal\n", op)); + return SQLITE_NOTFOUND; +} +static int kvvfsFileControlDb(sqlite3_file *pProtoFile, int op, void *pArg){ + SQLITE_KV_LOG(("xFileControl(%d) on database\n", op)); + if( op==SQLITE_FCNTL_SYNC ){ + KVVfsFile *pFile = (KVVfsFile *)pProtoFile; + int rc = SQLITE_OK; + SQLITE_KV_LOG(("xSync('%s-db')\n", pFile->zClass)); + if( pFile->szDb>0 && 0!=kvvfsWriteFileSize(pFile, pFile->szDb) ){ + rc = SQLITE_IOERR; + } + return rc; + } + return SQLITE_NOTFOUND; +} + +/* +** Return the sector-size in bytes for an kvvfs-file. +*/ +static int kvvfsSectorSize(sqlite3_file *pFile){ + return 512; +} + +/* +** Return the device characteristic flags supported by an kvvfs-file. +*/ +static int kvvfsDeviceCharacteristics(sqlite3_file *pProtoFile){ + return 0; +} + +/****** sqlite3_vfs methods *************************************************/ + +/* +** Open an kvvfs file handle. +*/ +static int kvvfsOpen( + sqlite3_vfs *pProtoVfs, + const char *zName, + sqlite3_file *pProtoFile, + int flags, + int *pOutFlags +){ + KVVfsFile *pFile = (KVVfsFile*)pProtoFile; + if( zName==0 ) zName = ""; + SQLITE_KV_LOG(("xOpen(\"%s\")\n", zName)); + if( strcmp(zName, "local")==0 + || strcmp(zName, "session")==0 + ){ + pFile->isJournal = 0; + pFile->base.pMethods = &kvvfs_db_io_methods; + }else + if( strcmp(zName, "local-journal")==0 + || strcmp(zName, "session-journal")==0 + ){ + pFile->isJournal = 1; + pFile->base.pMethods = &kvvfs_jrnl_io_methods; + }else{ + return SQLITE_CANTOPEN; + } + if( zName[0]=='s' ){ + pFile->zClass = "session"; + }else{ + pFile->zClass = "local"; + } + pFile->aData = sqlite3_malloc64(SQLITE_KVOS_SZ); + if( pFile->aData==0 ){ + return SQLITE_NOMEM; + } + pFile->aJrnl = 0; + pFile->nJrnl = 0; + pFile->szPage = -1; + pFile->szDb = -1; + return SQLITE_OK; +} + +/* +** Delete the file located at zPath. If the dirSync argument is true, +** ensure the file-system modifications are synced to disk before +** returning. +*/ +static int kvvfsDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){ + if( strcmp(zPath, "local-journal")==0 ){ + sqlite3KvvfsMethods.xDelete("local", "jrnl"); + }else + if( strcmp(zPath, "session-journal")==0 ){ + sqlite3KvvfsMethods.xDelete("session", "jrnl"); + } + return SQLITE_OK; +} + +/* +** Test for access permissions. Return true if the requested permission +** is available, or false otherwise. +*/ +static int kvvfsAccess( + sqlite3_vfs *pProtoVfs, + const char *zPath, + int flags, + int *pResOut +){ + SQLITE_KV_LOG(("xAccess(\"%s\")\n", zPath)); + if( strcmp(zPath, "local-journal")==0 ){ + *pResOut = sqlite3KvvfsMethods.xRead("local", "jrnl", 0, 0)>0; + }else + if( strcmp(zPath, "session-journal")==0 ){ + *pResOut = sqlite3KvvfsMethods.xRead("session", "jrnl", 0, 0)>0; + }else + if( strcmp(zPath, "local")==0 ){ + *pResOut = sqlite3KvvfsMethods.xRead("local", "sz", 0, 0)>0; + }else + if( strcmp(zPath, "session")==0 ){ + *pResOut = sqlite3KvvfsMethods.xRead("session", "sz", 0, 0)>0; + }else + { + *pResOut = 0; + } + SQLITE_KV_LOG(("xAccess returns %d\n",*pResOut)); + return SQLITE_OK; +} + +/* +** Populate buffer zOut with the full canonical pathname corresponding +** to the pathname in zPath. zOut is guaranteed to point to a buffer +** of at least (INST_MAX_PATHNAME+1) bytes. +*/ +static int kvvfsFullPathname( + sqlite3_vfs *pVfs, + const char *zPath, + int nOut, + char *zOut +){ + size_t nPath; +#ifdef SQLITE_OS_KV_ALWAYS_LOCAL + zPath = "local"; +#endif + nPath = strlen(zPath); + SQLITE_KV_LOG(("xFullPathname(\"%s\")\n", zPath)); + if( nOut<nPath+1 ) nPath = nOut - 1; + memcpy(zOut, zPath, nPath); + zOut[nPath] = 0; + return SQLITE_OK; +} + +/* +** Open the dynamic library located at zPath and return a handle. +*/ +static void *kvvfsDlOpen(sqlite3_vfs *pVfs, const char *zPath){ + return 0; +} + +/* +** Populate the buffer pointed to by zBufOut with nByte bytes of +** random data. +*/ +static int kvvfsRandomness(sqlite3_vfs *pVfs, int nByte, char *zBufOut){ + memset(zBufOut, 0, nByte); + return nByte; +} + +/* +** Sleep for nMicro microseconds. Return the number of microseconds +** actually slept. +*/ +static int kvvfsSleep(sqlite3_vfs *pVfs, int nMicro){ + return SQLITE_OK; +} + +/* +** Return the current time as a Julian Day number in *pTimeOut. +*/ +static int kvvfsCurrentTime(sqlite3_vfs *pVfs, double *pTimeOut){ + sqlite3_int64 i = 0; + int rc; + rc = kvvfsCurrentTimeInt64(0, &i); + *pTimeOut = i/86400000.0; + return rc; +} +#include <sys/time.h> +static int kvvfsCurrentTimeInt64(sqlite3_vfs *pVfs, sqlite3_int64 *pTimeOut){ + static const sqlite3_int64 unixEpoch = 24405875*(sqlite3_int64)8640000; + struct timeval sNow; + (void)gettimeofday(&sNow, 0); /* Cannot fail given valid arguments */ + *pTimeOut = unixEpoch + 1000*(sqlite3_int64)sNow.tv_sec + sNow.tv_usec/1000; + return SQLITE_OK; +} +#endif /* SQLITE_OS_KV || SQLITE_OS_UNIX */ + +#if SQLITE_OS_KV +/* +** This routine is called initialize the KV-vfs as the default VFS. +*/ +int sqlite3_os_init(void){ + return sqlite3_vfs_register(&sqlite3OsKvvfsObject, 1); +} +int sqlite3_os_end(void){ + return SQLITE_OK; +} +#endif /* SQLITE_OS_KV */ + +#if SQLITE_OS_UNIX && defined(SQLITE_OS_KV_OPTIONAL) +int sqlite3KvvfsInit(void){ + return sqlite3_vfs_register(&sqlite3OsKvvfsObject, 0); +} +#endif |