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Diffstat (limited to '')
| -rw-r--r-- | ext/misc/appendvfs.c | 672 |
1 files changed, 672 insertions, 0 deletions
diff --git a/ext/misc/appendvfs.c b/ext/misc/appendvfs.c new file mode 100644 index 0000000..eb9ed01 --- /dev/null +++ b/ext/misc/appendvfs.c @@ -0,0 +1,672 @@ +/* +** 2017-10-20 +** +** 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 implements a VFS shim that allows an SQLite database to be +** appended onto the end of some other file, such as an executable. +** +** A special record must appear at the end of the file that identifies the +** file as an appended database and provides the offset to the first page +** of the exposed content. (Or, it is the length of the content prefix.) +** For best performance page 1 should be located at a disk page boundary, +** though that is not required. +** +** When opening a database using this VFS, the connection might treat +** the file as an ordinary SQLite database, or it might treat it as a +** database appended onto some other file. The decision is made by +** applying the following rules in order: +** +** (1) An empty file is an ordinary database. +** +** (2) If the file ends with the appendvfs trailer string +** "Start-Of-SQLite3-NNNNNNNN" that file is an appended database. +** +** (3) If the file begins with the standard SQLite prefix string +** "SQLite format 3", that file is an ordinary database. +** +** (4) If none of the above apply and the SQLITE_OPEN_CREATE flag is +** set, then a new database is appended to the already existing file. +** +** (5) Otherwise, SQLITE_CANTOPEN is returned. +** +** To avoid unnecessary complications with the PENDING_BYTE, the size of +** the file containing the database is limited to 1GiB. (1073741824 bytes) +** This VFS will not read or write past the 1GiB mark. This restriction +** might be lifted in future versions. For now, if you need a larger +** database, then keep it in a separate file. +** +** If the file being opened is a plain database (not an appended one), then +** this shim is a pass-through into the default underlying VFS. (rule 3) +**/ +#include "sqlite3ext.h" +SQLITE_EXTENSION_INIT1 +#include <string.h> +#include <assert.h> + +/* The append mark at the end of the database is: +** +** Start-Of-SQLite3-NNNNNNNN +** 123456789 123456789 12345 +** +** The NNNNNNNN represents a 64-bit big-endian unsigned integer which is +** the offset to page 1, and also the length of the prefix content. +*/ +#define APND_MARK_PREFIX "Start-Of-SQLite3-" +#define APND_MARK_PREFIX_SZ 17 +#define APND_MARK_FOS_SZ 8 +#define APND_MARK_SIZE (APND_MARK_PREFIX_SZ+APND_MARK_FOS_SZ) + +/* +** Maximum size of the combined prefix + database + append-mark. This +** must be less than 0x40000000 to avoid locking issues on Windows. +*/ +#define APND_MAX_SIZE (0x40000000) + +/* +** Try to align the database to an even multiple of APND_ROUNDUP bytes. +*/ +#ifndef APND_ROUNDUP +#define APND_ROUNDUP 4096 +#endif +#define APND_ALIGN_MASK ((sqlite3_int64)(APND_ROUNDUP-1)) +#define APND_START_ROUNDUP(fsz) (((fsz)+APND_ALIGN_MASK) & ~APND_ALIGN_MASK) + +/* +** Forward declaration of objects used by this utility +*/ +typedef struct sqlite3_vfs ApndVfs; +typedef struct ApndFile ApndFile; + +/* Access to a lower-level VFS that (might) implement dynamic loading, +** access to randomness, etc. +*/ +#define ORIGVFS(p) ((sqlite3_vfs*)((p)->pAppData)) +#define ORIGFILE(p) ((sqlite3_file*)(((ApndFile*)(p))+1)) + +/* An open appendvfs file +** +** An instance of this structure describes the appended database file. +** A separate sqlite3_file object is always appended. The appended +** sqlite3_file object (which can be accessed using ORIGFILE()) describes +** the entire file, including the prefix, the database, and the +** append-mark. +** +** The structure of an AppendVFS database is like this: +** +** +-------------+---------+----------+-------------+ +** | prefix-file | padding | database | append-mark | +** +-------------+---------+----------+-------------+ +** ^ ^ +** | | +** iPgOne iMark +** +** +** "prefix file" - file onto which the database has been appended. +** "padding" - zero or more bytes inserted so that "database" +** starts on an APND_ROUNDUP boundary +** "database" - The SQLite database file +** "append-mark" - The 25-byte "Start-Of-SQLite3-NNNNNNNN" that indicates +** the offset from the start of prefix-file to the start +** of "database". +** +** The size of the database is iMark - iPgOne. +** +** The NNNNNNNN in the "Start-Of-SQLite3-NNNNNNNN" suffix is the value +** of iPgOne stored as a big-ending 64-bit integer. +** +** iMark will be the size of the underlying file minus 25 (APND_MARKSIZE). +** Or, iMark is -1 to indicate that it has not yet been written. +*/ +struct ApndFile { + sqlite3_file base; /* Subclass. MUST BE FIRST! */ + sqlite3_int64 iPgOne; /* Offset to the start of the database */ + sqlite3_int64 iMark; /* Offset of the append mark. -1 if unwritten */ + /* Always followed by another sqlite3_file that describes the whole file */ +}; + +/* +** Methods for ApndFile +*/ +static int apndClose(sqlite3_file*); +static int apndRead(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); +static int apndWrite(sqlite3_file*,const void*,int iAmt, sqlite3_int64 iOfst); +static int apndTruncate(sqlite3_file*, sqlite3_int64 size); +static int apndSync(sqlite3_file*, int flags); +static int apndFileSize(sqlite3_file*, sqlite3_int64 *pSize); +static int apndLock(sqlite3_file*, int); +static int apndUnlock(sqlite3_file*, int); +static int apndCheckReservedLock(sqlite3_file*, int *pResOut); +static int apndFileControl(sqlite3_file*, int op, void *pArg); +static int apndSectorSize(sqlite3_file*); +static int apndDeviceCharacteristics(sqlite3_file*); +static int apndShmMap(sqlite3_file*, int iPg, int pgsz, int, void volatile**); +static int apndShmLock(sqlite3_file*, int offset, int n, int flags); +static void apndShmBarrier(sqlite3_file*); +static int apndShmUnmap(sqlite3_file*, int deleteFlag); +static int apndFetch(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); +static int apndUnfetch(sqlite3_file*, sqlite3_int64 iOfst, void *p); + +/* +** Methods for ApndVfs +*/ +static int apndOpen(sqlite3_vfs*, const char *, sqlite3_file*, int , int *); +static int apndDelete(sqlite3_vfs*, const char *zName, int syncDir); +static int apndAccess(sqlite3_vfs*, const char *zName, int flags, int *); +static int apndFullPathname(sqlite3_vfs*, const char *zName, int, char *zOut); +static void *apndDlOpen(sqlite3_vfs*, const char *zFilename); +static void apndDlError(sqlite3_vfs*, int nByte, char *zErrMsg); +static void (*apndDlSym(sqlite3_vfs *pVfs, void *p, const char*zSym))(void); +static void apndDlClose(sqlite3_vfs*, void*); +static int apndRandomness(sqlite3_vfs*, int nByte, char *zOut); +static int apndSleep(sqlite3_vfs*, int microseconds); +static int apndCurrentTime(sqlite3_vfs*, double*); +static int apndGetLastError(sqlite3_vfs*, int, char *); +static int apndCurrentTimeInt64(sqlite3_vfs*, sqlite3_int64*); +static int apndSetSystemCall(sqlite3_vfs*, const char*,sqlite3_syscall_ptr); +static sqlite3_syscall_ptr apndGetSystemCall(sqlite3_vfs*, const char *z); +static const char *apndNextSystemCall(sqlite3_vfs*, const char *zName); + +static sqlite3_vfs apnd_vfs = { + 3, /* iVersion (set when registered) */ + 0, /* szOsFile (set when registered) */ + 1024, /* mxPathname */ + 0, /* pNext */ + "apndvfs", /* zName */ + 0, /* pAppData (set when registered) */ + apndOpen, /* xOpen */ + apndDelete, /* xDelete */ + apndAccess, /* xAccess */ + apndFullPathname, /* xFullPathname */ + apndDlOpen, /* xDlOpen */ + apndDlError, /* xDlError */ + apndDlSym, /* xDlSym */ + apndDlClose, /* xDlClose */ + apndRandomness, /* xRandomness */ + apndSleep, /* xSleep */ + apndCurrentTime, /* xCurrentTime */ + apndGetLastError, /* xGetLastError */ + apndCurrentTimeInt64, /* xCurrentTimeInt64 */ + apndSetSystemCall, /* xSetSystemCall */ + apndGetSystemCall, /* xGetSystemCall */ + apndNextSystemCall /* xNextSystemCall */ +}; + +static const sqlite3_io_methods apnd_io_methods = { + 3, /* iVersion */ + apndClose, /* xClose */ + apndRead, /* xRead */ + apndWrite, /* xWrite */ + apndTruncate, /* xTruncate */ + apndSync, /* xSync */ + apndFileSize, /* xFileSize */ + apndLock, /* xLock */ + apndUnlock, /* xUnlock */ + apndCheckReservedLock, /* xCheckReservedLock */ + apndFileControl, /* xFileControl */ + apndSectorSize, /* xSectorSize */ + apndDeviceCharacteristics, /* xDeviceCharacteristics */ + apndShmMap, /* xShmMap */ + apndShmLock, /* xShmLock */ + apndShmBarrier, /* xShmBarrier */ + apndShmUnmap, /* xShmUnmap */ + apndFetch, /* xFetch */ + apndUnfetch /* xUnfetch */ +}; + +/* +** Close an apnd-file. +*/ +static int apndClose(sqlite3_file *pFile){ + pFile = ORIGFILE(pFile); + return pFile->pMethods->xClose(pFile); +} + +/* +** Read data from an apnd-file. +*/ +static int apndRead( + sqlite3_file *pFile, + void *zBuf, + int iAmt, + sqlite_int64 iOfst +){ + ApndFile *paf = (ApndFile *)pFile; + pFile = ORIGFILE(pFile); + return pFile->pMethods->xRead(pFile, zBuf, iAmt, paf->iPgOne+iOfst); +} + +/* +** Add the append-mark onto what should become the end of the file. +* If and only if this succeeds, internal ApndFile.iMark is updated. +* Parameter iWriteEnd is the appendvfs-relative offset of the new mark. +*/ +static int apndWriteMark( + ApndFile *paf, + sqlite3_file *pFile, + sqlite_int64 iWriteEnd +){ + sqlite_int64 iPgOne = paf->iPgOne; + unsigned char a[APND_MARK_SIZE]; + int i = APND_MARK_FOS_SZ; + int rc; + assert(pFile == ORIGFILE(paf)); + memcpy(a, APND_MARK_PREFIX, APND_MARK_PREFIX_SZ); + while( --i >= 0 ){ + a[APND_MARK_PREFIX_SZ+i] = (unsigned char)(iPgOne & 0xff); + iPgOne >>= 8; + } + iWriteEnd += paf->iPgOne; + if( SQLITE_OK==(rc = pFile->pMethods->xWrite + (pFile, a, APND_MARK_SIZE, iWriteEnd)) ){ + paf->iMark = iWriteEnd; + } + return rc; +} + +/* +** Write data to an apnd-file. +*/ +static int apndWrite( + sqlite3_file *pFile, + const void *zBuf, + int iAmt, + sqlite_int64 iOfst +){ + ApndFile *paf = (ApndFile *)pFile; + sqlite_int64 iWriteEnd = iOfst + iAmt; + if( iWriteEnd>=APND_MAX_SIZE ) return SQLITE_FULL; + pFile = ORIGFILE(pFile); + /* If append-mark is absent or will be overwritten, write it. */ + if( paf->iMark < 0 || paf->iPgOne + iWriteEnd > paf->iMark ){ + int rc = apndWriteMark(paf, pFile, iWriteEnd); + if( SQLITE_OK!=rc ) return rc; + } + return pFile->pMethods->xWrite(pFile, zBuf, iAmt, paf->iPgOne+iOfst); +} + +/* +** Truncate an apnd-file. +*/ +static int apndTruncate(sqlite3_file *pFile, sqlite_int64 size){ + ApndFile *paf = (ApndFile *)pFile; + pFile = ORIGFILE(pFile); + /* The append mark goes out first so truncate failure does not lose it. */ + if( SQLITE_OK!=apndWriteMark(paf, pFile, size) ) return SQLITE_IOERR; + /* Truncate underlying file just past append mark */ + return pFile->pMethods->xTruncate(pFile, paf->iMark+APND_MARK_SIZE); +} + +/* +** Sync an apnd-file. +*/ +static int apndSync(sqlite3_file *pFile, int flags){ + pFile = ORIGFILE(pFile); + return pFile->pMethods->xSync(pFile, flags); +} + +/* +** Return the current file-size of an apnd-file. +** If the append mark is not yet there, the file-size is 0. +*/ +static int apndFileSize(sqlite3_file *pFile, sqlite_int64 *pSize){ + ApndFile *paf = (ApndFile *)pFile; + *pSize = ( paf->iMark >= 0 )? (paf->iMark - paf->iPgOne) : 0; + return SQLITE_OK; +} + +/* +** Lock an apnd-file. +*/ +static int apndLock(sqlite3_file *pFile, int eLock){ + pFile = ORIGFILE(pFile); + return pFile->pMethods->xLock(pFile, eLock); +} + +/* +** Unlock an apnd-file. +*/ +static int apndUnlock(sqlite3_file *pFile, int eLock){ + pFile = ORIGFILE(pFile); + return pFile->pMethods->xUnlock(pFile, eLock); +} + +/* +** Check if another file-handle holds a RESERVED lock on an apnd-file. +*/ +static int apndCheckReservedLock(sqlite3_file *pFile, int *pResOut){ + pFile = ORIGFILE(pFile); + return pFile->pMethods->xCheckReservedLock(pFile, pResOut); +} + +/* +** File control method. For custom operations on an apnd-file. +*/ +static int apndFileControl(sqlite3_file *pFile, int op, void *pArg){ + ApndFile *paf = (ApndFile *)pFile; + int rc; + pFile = ORIGFILE(pFile); + if( op==SQLITE_FCNTL_SIZE_HINT ) *(sqlite3_int64*)pArg += paf->iPgOne; + rc = pFile->pMethods->xFileControl(pFile, op, pArg); + if( rc==SQLITE_OK && op==SQLITE_FCNTL_VFSNAME ){ + *(char**)pArg = sqlite3_mprintf("apnd(%lld)/%z", paf->iPgOne,*(char**)pArg); + } + return rc; +} + +/* +** Return the sector-size in bytes for an apnd-file. +*/ +static int apndSectorSize(sqlite3_file *pFile){ + pFile = ORIGFILE(pFile); + return pFile->pMethods->xSectorSize(pFile); +} + +/* +** Return the device characteristic flags supported by an apnd-file. +*/ +static int apndDeviceCharacteristics(sqlite3_file *pFile){ + pFile = ORIGFILE(pFile); + return pFile->pMethods->xDeviceCharacteristics(pFile); +} + +/* Create a shared memory file mapping */ +static int apndShmMap( + sqlite3_file *pFile, + int iPg, + int pgsz, + int bExtend, + void volatile **pp +){ + pFile = ORIGFILE(pFile); + return pFile->pMethods->xShmMap(pFile,iPg,pgsz,bExtend,pp); +} + +/* Perform locking on a shared-memory segment */ +static int apndShmLock(sqlite3_file *pFile, int offset, int n, int flags){ + pFile = ORIGFILE(pFile); + return pFile->pMethods->xShmLock(pFile,offset,n,flags); +} + +/* Memory barrier operation on shared memory */ +static void apndShmBarrier(sqlite3_file *pFile){ + pFile = ORIGFILE(pFile); + pFile->pMethods->xShmBarrier(pFile); +} + +/* Unmap a shared memory segment */ +static int apndShmUnmap(sqlite3_file *pFile, int deleteFlag){ + pFile = ORIGFILE(pFile); + return pFile->pMethods->xShmUnmap(pFile,deleteFlag); +} + +/* Fetch a page of a memory-mapped file */ +static int apndFetch( + sqlite3_file *pFile, + sqlite3_int64 iOfst, + int iAmt, + void **pp +){ + ApndFile *p = (ApndFile *)pFile; + if( p->iMark < 0 || iOfst+iAmt > p->iMark ){ + return SQLITE_IOERR; /* Cannot read what is not yet there. */ + } + pFile = ORIGFILE(pFile); + return pFile->pMethods->xFetch(pFile, iOfst+p->iPgOne, iAmt, pp); +} + +/* Release a memory-mapped page */ +static int apndUnfetch(sqlite3_file *pFile, sqlite3_int64 iOfst, void *pPage){ + ApndFile *p = (ApndFile *)pFile; + pFile = ORIGFILE(pFile); + return pFile->pMethods->xUnfetch(pFile, iOfst+p->iPgOne, pPage); +} + +/* +** Try to read the append-mark off the end of a file. Return the +** start of the appended database if the append-mark is present. +** If there is no valid append-mark, return -1; +** +** An append-mark is only valid if the NNNNNNNN start-of-database offset +** indicates that the appended database contains at least one page. The +** start-of-database value must be a multiple of 512. +*/ +static sqlite3_int64 apndReadMark(sqlite3_int64 sz, sqlite3_file *pFile){ + int rc, i; + sqlite3_int64 iMark; + int msbs = 8 * (APND_MARK_FOS_SZ-1); + unsigned char a[APND_MARK_SIZE]; + + if( APND_MARK_SIZE!=(sz & 0x1ff) ) return -1; + rc = pFile->pMethods->xRead(pFile, a, APND_MARK_SIZE, sz-APND_MARK_SIZE); + if( rc ) return -1; + if( memcmp(a, APND_MARK_PREFIX, APND_MARK_PREFIX_SZ)!=0 ) return -1; + iMark = ((sqlite3_int64)(a[APND_MARK_PREFIX_SZ] & 0x7f)) << msbs; + for(i=1; i<8; i++){ + msbs -= 8; + iMark |= (sqlite3_int64)a[APND_MARK_PREFIX_SZ+i]<<msbs; + } + if( iMark > (sz - APND_MARK_SIZE - 512) ) return -1; + if( iMark & 0x1ff ) return -1; + return iMark; +} + +static const char apvfsSqliteHdr[] = "SQLite format 3"; +/* +** Check to see if the file is an appendvfs SQLite database file. +** Return true iff it is such. Parameter sz is the file's size. +*/ +static int apndIsAppendvfsDatabase(sqlite3_int64 sz, sqlite3_file *pFile){ + int rc; + char zHdr[16]; + sqlite3_int64 iMark = apndReadMark(sz, pFile); + if( iMark>=0 ){ + /* If file has the correct end-marker, the expected odd size, and the + ** SQLite DB type marker where the end-marker puts it, then it + ** is an appendvfs database. + */ + rc = pFile->pMethods->xRead(pFile, zHdr, sizeof(zHdr), iMark); + if( SQLITE_OK==rc + && memcmp(zHdr, apvfsSqliteHdr, sizeof(zHdr))==0 + && (sz & 0x1ff) == APND_MARK_SIZE + && sz>=512+APND_MARK_SIZE + ){ + return 1; /* It's an appendvfs database */ + } + } + return 0; +} + +/* +** Check to see if the file is an ordinary SQLite database file. +** Return true iff so. Parameter sz is the file's size. +*/ +static int apndIsOrdinaryDatabaseFile(sqlite3_int64 sz, sqlite3_file *pFile){ + char zHdr[16]; + if( apndIsAppendvfsDatabase(sz, pFile) /* rule 2 */ + || (sz & 0x1ff) != 0 + || SQLITE_OK!=pFile->pMethods->xRead(pFile, zHdr, sizeof(zHdr), 0) + || memcmp(zHdr, apvfsSqliteHdr, sizeof(zHdr))!=0 + ){ + return 0; + }else{ + return 1; + } +} + +/* +** Open an apnd file handle. +*/ +static int apndOpen( + sqlite3_vfs *pApndVfs, + const char *zName, + sqlite3_file *pFile, + int flags, + int *pOutFlags +){ + ApndFile *pApndFile = (ApndFile*)pFile; + sqlite3_file *pBaseFile = ORIGFILE(pFile); + sqlite3_vfs *pBaseVfs = ORIGVFS(pApndVfs); + int rc; + sqlite3_int64 sz = 0; + if( (flags & SQLITE_OPEN_MAIN_DB)==0 ){ + /* The appendvfs is not to be used for transient or temporary databases. + ** Just use the base VFS open to initialize the given file object and + ** open the underlying file. (Appendvfs is then unused for this file.) + */ + return pBaseVfs->xOpen(pBaseVfs, zName, pFile, flags, pOutFlags); + } + memset(pApndFile, 0, sizeof(ApndFile)); + pFile->pMethods = &apnd_io_methods; + pApndFile->iMark = -1; /* Append mark not yet written */ + + rc = pBaseVfs->xOpen(pBaseVfs, zName, pBaseFile, flags, pOutFlags); + if( rc==SQLITE_OK ){ + rc = pBaseFile->pMethods->xFileSize(pBaseFile, &sz); + if( rc ){ + pBaseFile->pMethods->xClose(pBaseFile); + } + } + if( rc ){ + pFile->pMethods = 0; + return rc; + } + if( apndIsOrdinaryDatabaseFile(sz, pBaseFile) ){ + /* The file being opened appears to be just an ordinary DB. Copy + ** the base dispatch-table so this instance mimics the base VFS. + */ + memmove(pApndFile, pBaseFile, pBaseVfs->szOsFile); + return SQLITE_OK; + } + pApndFile->iPgOne = apndReadMark(sz, pFile); + if( pApndFile->iPgOne>=0 ){ + pApndFile->iMark = sz - APND_MARK_SIZE; /* Append mark found */ + return SQLITE_OK; + } + if( (flags & SQLITE_OPEN_CREATE)==0 ){ + pBaseFile->pMethods->xClose(pBaseFile); + rc = SQLITE_CANTOPEN; + pFile->pMethods = 0; + }else{ + /* Round newly added appendvfs location to #define'd page boundary. + ** Note that nothing has yet been written to the underlying file. + ** The append mark will be written along with first content write. + ** Until then, paf->iMark value indicates it is not yet written. + */ + pApndFile->iPgOne = APND_START_ROUNDUP(sz); + } + return rc; +} + +/* +** Delete an apnd file. +** For an appendvfs, this could mean delete the appendvfs portion, +** leaving the appendee as it was before it gained an appendvfs. +** For now, this code deletes the underlying file too. +*/ +static int apndDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){ + return ORIGVFS(pVfs)->xDelete(ORIGVFS(pVfs), zPath, dirSync); +} + +/* +** All other VFS methods are pass-thrus. +*/ +static int apndAccess( + sqlite3_vfs *pVfs, + const char *zPath, + int flags, + int *pResOut +){ + return ORIGVFS(pVfs)->xAccess(ORIGVFS(pVfs), zPath, flags, pResOut); +} +static int apndFullPathname( + sqlite3_vfs *pVfs, + const char *zPath, + int nOut, + char *zOut +){ + return ORIGVFS(pVfs)->xFullPathname(ORIGVFS(pVfs),zPath,nOut,zOut); +} +static void *apndDlOpen(sqlite3_vfs *pVfs, const char *zPath){ + return ORIGVFS(pVfs)->xDlOpen(ORIGVFS(pVfs), zPath); +} +static void apndDlError(sqlite3_vfs *pVfs, int nByte, char *zErrMsg){ + ORIGVFS(pVfs)->xDlError(ORIGVFS(pVfs), nByte, zErrMsg); +} +static void (*apndDlSym(sqlite3_vfs *pVfs, void *p, const char *zSym))(void){ + return ORIGVFS(pVfs)->xDlSym(ORIGVFS(pVfs), p, zSym); +} +static void apndDlClose(sqlite3_vfs *pVfs, void *pHandle){ + ORIGVFS(pVfs)->xDlClose(ORIGVFS(pVfs), pHandle); +} +static int apndRandomness(sqlite3_vfs *pVfs, int nByte, char *zBufOut){ + return ORIGVFS(pVfs)->xRandomness(ORIGVFS(pVfs), nByte, zBufOut); +} +static int apndSleep(sqlite3_vfs *pVfs, int nMicro){ + return ORIGVFS(pVfs)->xSleep(ORIGVFS(pVfs), nMicro); +} +static int apndCurrentTime(sqlite3_vfs *pVfs, double *pTimeOut){ + return ORIGVFS(pVfs)->xCurrentTime(ORIGVFS(pVfs), pTimeOut); +} +static int apndGetLastError(sqlite3_vfs *pVfs, int a, char *b){ + return ORIGVFS(pVfs)->xGetLastError(ORIGVFS(pVfs), a, b); +} +static int apndCurrentTimeInt64(sqlite3_vfs *pVfs, sqlite3_int64 *p){ + return ORIGVFS(pVfs)->xCurrentTimeInt64(ORIGVFS(pVfs), p); +} +static int apndSetSystemCall( + sqlite3_vfs *pVfs, + const char *zName, + sqlite3_syscall_ptr pCall +){ + return ORIGVFS(pVfs)->xSetSystemCall(ORIGVFS(pVfs),zName,pCall); +} +static sqlite3_syscall_ptr apndGetSystemCall( + sqlite3_vfs *pVfs, + const char *zName +){ + return ORIGVFS(pVfs)->xGetSystemCall(ORIGVFS(pVfs),zName); +} +static const char *apndNextSystemCall(sqlite3_vfs *pVfs, const char *zName){ + return ORIGVFS(pVfs)->xNextSystemCall(ORIGVFS(pVfs), zName); +} + + +#ifdef _WIN32 +__declspec(dllexport) +#endif +/* +** This routine is called when the extension is loaded. +** Register the new VFS. +*/ +int sqlite3_appendvfs_init( + sqlite3 *db, + char **pzErrMsg, + const sqlite3_api_routines *pApi +){ + int rc = SQLITE_OK; + sqlite3_vfs *pOrig; + SQLITE_EXTENSION_INIT2(pApi); + (void)pzErrMsg; + (void)db; + pOrig = sqlite3_vfs_find(0); + if( pOrig==0 ) return SQLITE_ERROR; + apnd_vfs.iVersion = pOrig->iVersion; + apnd_vfs.pAppData = pOrig; + apnd_vfs.szOsFile = pOrig->szOsFile + sizeof(ApndFile); + rc = sqlite3_vfs_register(&apnd_vfs, 0); +#ifdef APPENDVFS_TEST + if( rc==SQLITE_OK ){ + rc = sqlite3_auto_extension((void(*)(void))apndvfsRegister); + } +#endif + if( rc==SQLITE_OK ) rc = SQLITE_OK_LOAD_PERMANENTLY; + return rc; +} |