+/************** Begin file memdb.c *******************************************/
+/*
+** 2016-09-07
+**
+** 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 an in-memory VFS. A database is held as a contiguous
+** block of memory.
+**
+** This file also implements interface sqlite3_serialize() and
+** sqlite3_deserialize().
+*/
+#ifdef SQLITE_ENABLE_DESERIALIZE
+/* #include "sqliteInt.h" */
+
+/*
+** Forward declaration of objects used by this utility
+*/
+typedef struct sqlite3_vfs MemVfs;
+typedef struct MemFile MemFile;
+
+/* Access to a lower-level VFS that (might) implement dynamic loading,
+** access to randomness, etc.
+*/
+#define ORIGVFS(p) ((sqlite3_vfs*)((p)->pAppData))
+
+/* An open file */
+struct MemFile {
+ sqlite3_file base; /* IO methods */
+ sqlite3_int64 sz; /* Size of the file */
+ sqlite3_int64 szMax; /* Space allocated to aData */
+ unsigned char *aData; /* content of the file */
+ int nMmap; /* Number of memory mapped pages */
+ unsigned mFlags; /* Flags */
+ int eLock; /* Most recent lock against this file */
+};
+
+/*
+** Methods for MemFile
+*/
+static int memdbClose(sqlite3_file*);
+static int memdbRead(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
+static int memdbWrite(sqlite3_file*,const void*,int iAmt, sqlite3_int64 iOfst);
+static int memdbTruncate(sqlite3_file*, sqlite3_int64 size);
+static int memdbSync(sqlite3_file*, int flags);
+static int memdbFileSize(sqlite3_file*, sqlite3_int64 *pSize);
+static int memdbLock(sqlite3_file*, int);
+/* static int memdbCheckReservedLock(sqlite3_file*, int *pResOut);// not used */
+static int memdbFileControl(sqlite3_file*, int op, void *pArg);
+/* static int memdbSectorSize(sqlite3_file*); // not used */
+static int memdbDeviceCharacteristics(sqlite3_file*);
+static int memdbFetch(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp);
+static int memdbUnfetch(sqlite3_file*, sqlite3_int64 iOfst, void *p);
+
+/*
+** Methods for MemVfs
+*/
+static int memdbOpen(sqlite3_vfs*, const char *, sqlite3_file*, int , int *);
+/* static int memdbDelete(sqlite3_vfs*, const char *zName, int syncDir); */
+static int memdbAccess(sqlite3_vfs*, const char *zName, int flags, int *);
+static int memdbFullPathname(sqlite3_vfs*, const char *zName, int, char *zOut);
+static void *memdbDlOpen(sqlite3_vfs*, const char *zFilename);
+static void memdbDlError(sqlite3_vfs*, int nByte, char *zErrMsg);
+static void (*memdbDlSym(sqlite3_vfs *pVfs, void *p, const char*zSym))(void);
+static void memdbDlClose(sqlite3_vfs*, void*);
+static int memdbRandomness(sqlite3_vfs*, int nByte, char *zOut);
+static int memdbSleep(sqlite3_vfs*, int microseconds);
+/* static int memdbCurrentTime(sqlite3_vfs*, double*); */
+static int memdbGetLastError(sqlite3_vfs*, int, char *);
+static int memdbCurrentTimeInt64(sqlite3_vfs*, sqlite3_int64*);
+
+static sqlite3_vfs memdb_vfs = {
+ 2, /* iVersion */
+ 0, /* szOsFile (set when registered) */
+ 1024, /* mxPathname */
+ 0, /* pNext */
+ "memdb", /* zName */
+ 0, /* pAppData (set when registered) */
+ memdbOpen, /* xOpen */
+ 0, /* memdbDelete, */ /* xDelete */
+ memdbAccess, /* xAccess */
+ memdbFullPathname, /* xFullPathname */
+ memdbDlOpen, /* xDlOpen */
+ memdbDlError, /* xDlError */
+ memdbDlSym, /* xDlSym */
+ memdbDlClose, /* xDlClose */
+ memdbRandomness, /* xRandomness */
+ memdbSleep, /* xSleep */
+ 0, /* memdbCurrentTime, */ /* xCurrentTime */
+ memdbGetLastError, /* xGetLastError */
+ memdbCurrentTimeInt64 /* xCurrentTimeInt64 */
+};
+
+static const sqlite3_io_methods memdb_io_methods = {
+ 3, /* iVersion */
+ memdbClose, /* xClose */
+ memdbRead, /* xRead */
+ memdbWrite, /* xWrite */
+ memdbTruncate, /* xTruncate */
+ memdbSync, /* xSync */
+ memdbFileSize, /* xFileSize */
+ memdbLock, /* xLock */
+ memdbLock, /* xUnlock - same as xLock in this case */
+ 0, /* memdbCheckReservedLock, */ /* xCheckReservedLock */
+ memdbFileControl, /* xFileControl */
+ 0, /* memdbSectorSize,*/ /* xSectorSize */
+ memdbDeviceCharacteristics, /* xDeviceCharacteristics */
+ 0, /* xShmMap */
+ 0, /* xShmLock */
+ 0, /* xShmBarrier */
+ 0, /* xShmUnmap */
+ memdbFetch, /* xFetch */
+ memdbUnfetch /* xUnfetch */
+};
+
+
+
+/*
+** Close an memdb-file.
+**
+** The pData pointer is owned by the application, so there is nothing
+** to free.
+*/
+static int memdbClose(sqlite3_file *pFile){
+ MemFile *p = (MemFile *)pFile;
+ if( p->mFlags & SQLITE_DESERIALIZE_FREEONCLOSE ) sqlite3_free(p->aData);
+ return SQLITE_OK;
+}
+
+/*
+** Read data from an memdb-file.
+*/
+static int memdbRead(
+ sqlite3_file *pFile,
+ void *zBuf,
+ int iAmt,
+ sqlite_int64 iOfst
+){
+ MemFile *p = (MemFile *)pFile;
+ if( iOfst+iAmt>p->sz ){
+ memset(zBuf, 0, iAmt);
+ if( iOfst<p->sz ) memcpy(zBuf, p->aData+iOfst, p->sz - iOfst);
+ return SQLITE_IOERR_SHORT_READ;
+ }
+ memcpy(zBuf, p->aData+iOfst, iAmt);
+ return SQLITE_OK;
+}
+
+/*
+** Try to enlarge the memory allocation to hold at least sz bytes
+*/
+static int memdbEnlarge(MemFile *p, sqlite3_int64 newSz){
+ unsigned char *pNew;
+ if( (p->mFlags & SQLITE_DESERIALIZE_RESIZEABLE)==0 || p->nMmap>0 ){
+ return SQLITE_FULL;
+ }
+ pNew = sqlite3_realloc64(p->aData, newSz);
+ if( pNew==0 ) return SQLITE_NOMEM;
+ p->aData = pNew;
+ p->szMax = newSz;
+ return SQLITE_OK;
+}
+
+/*
+** Write data to an memdb-file.
+*/
+static int memdbWrite(
+ sqlite3_file *pFile,
+ const void *z,
+ int iAmt,
+ sqlite_int64 iOfst
+){
+ MemFile *p = (MemFile *)pFile;
+ if( iOfst+iAmt>p->sz ){
+ int rc;
+ if( iOfst+iAmt>p->szMax
+ && (rc = memdbEnlarge(p, (iOfst+iAmt)*2))!=SQLITE_OK
+ ){
+ return rc;
+ }
+ if( iOfst>p->sz ) memset(p->aData+p->sz, 0, iOfst-p->sz);
+ p->sz = iOfst+iAmt;
+ }
+ memcpy(p->aData+iOfst, z, iAmt);
+ return SQLITE_OK;
+}
+
+/*
+** Truncate an memdb-file.
+**
+** In rollback mode (which is always the case for memdb, as it does not
+** support WAL mode) the truncate() method is only used to reduce
+** the size of a file, never to increase the size.
+*/
+static int memdbTruncate(sqlite3_file *pFile, sqlite_int64 size){
+ MemFile *p = (MemFile *)pFile;
+ if( NEVER(size>p->sz) ) return SQLITE_FULL;
+ p->sz = size;
+ return SQLITE_OK;
+}
+
+/*
+** Sync an memdb-file.
+*/
+static int memdbSync(sqlite3_file *pFile, int flags){
+ return SQLITE_OK;
+}
+
+/*
+** Return the current file-size of an memdb-file.
+*/
+static int memdbFileSize(sqlite3_file *pFile, sqlite_int64 *pSize){
+ MemFile *p = (MemFile *)pFile;
+ *pSize = p->sz;
+ return SQLITE_OK;
+}
+
+/*
+** Lock an memdb-file.
+*/
+static int memdbLock(sqlite3_file *pFile, int eLock){
+ MemFile *p = (MemFile *)pFile;
+ p->eLock = eLock;
+ return SQLITE_OK;
+}
+
+#if 0 /* Never used because memdbAccess() always returns false */
+/*
+** Check if another file-handle holds a RESERVED lock on an memdb-file.
+*/
+static int memdbCheckReservedLock(sqlite3_file *pFile, int *pResOut){
+ *pResOut = 0;
+ return SQLITE_OK;
+}
+#endif
+
+/*
+** File control method. For custom operations on an memdb-file.
+*/
+static int memdbFileControl(sqlite3_file *pFile, int op, void *pArg){
+ MemFile *p = (MemFile *)pFile;
+ int rc = SQLITE_NOTFOUND;
+ if( op==SQLITE_FCNTL_VFSNAME ){
+ *(char**)pArg = sqlite3_mprintf("memdb(%p,%lld)", p->aData, p->sz);
+ rc = SQLITE_OK;
+ }
+ return rc;
+}
+
+#if 0 /* Not used because of SQLITE_IOCAP_POWERSAFE_OVERWRITE */
+/*
+** Return the sector-size in bytes for an memdb-file.
+*/
+static int memdbSectorSize(sqlite3_file *pFile){
+ return 1024;
+}
+#endif
+
+/*
+** Return the device characteristic flags supported by an memdb-file.
+*/
+static int memdbDeviceCharacteristics(sqlite3_file *pFile){
+ return SQLITE_IOCAP_ATOMIC |
+ SQLITE_IOCAP_POWERSAFE_OVERWRITE |
+ SQLITE_IOCAP_SAFE_APPEND |
+ SQLITE_IOCAP_SEQUENTIAL;
+}
+
+/* Fetch a page of a memory-mapped file */
+static int memdbFetch(
+ sqlite3_file *pFile,
+ sqlite3_int64 iOfst,
+ int iAmt,
+ void **pp
+){
+ MemFile *p = (MemFile *)pFile;
+ p->nMmap++;
+ *pp = (void*)(p->aData + iOfst);
+ return SQLITE_OK;
+}
+
+/* Release a memory-mapped page */
+static int memdbUnfetch(sqlite3_file *pFile, sqlite3_int64 iOfst, void *pPage){
+ MemFile *p = (MemFile *)pFile;
+ p->nMmap--;
+ return SQLITE_OK;
+}
+
+/*
+** Open an mem file handle.
+*/
+static int memdbOpen(
+ sqlite3_vfs *pVfs,
+ const char *zName,
+ sqlite3_file *pFile,
+ int flags,
+ int *pOutFlags
+){
+ MemFile *p = (MemFile*)pFile;
+ if( (flags & SQLITE_OPEN_MAIN_DB)==0 ){
+ return ORIGVFS(pVfs)->xOpen(ORIGVFS(pVfs), zName, pFile, flags, pOutFlags);
+ }
+ memset(p, 0, sizeof(*p));
+ p->mFlags = SQLITE_DESERIALIZE_RESIZEABLE | SQLITE_DESERIALIZE_FREEONCLOSE;
+ assert( pOutFlags!=0 ); /* True because flags==SQLITE_OPEN_MAIN_DB */
+ *pOutFlags = flags | SQLITE_OPEN_MEMORY;
+ p->base.pMethods = &memdb_io_methods;
+ return SQLITE_OK;
+}
+
+#if 0 /* Only used to delete rollback journals, master journals, and WAL
+ ** files, none of which exist in memdb. So this routine is never used */
+/*
+** 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 memdbDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){
+ return SQLITE_IOERR_DELETE;
+}
+#endif
+
+/*
+** Test for access permissions. Return true if the requested permission
+** is available, or false otherwise.
+**
+** With memdb, no files ever exist on disk. So always return false.
+*/
+static int memdbAccess(
+ sqlite3_vfs *pVfs,
+ const char *zPath,
+ int flags,
+ int *pResOut
+){
+ *pResOut = 0;
+ 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 memdbFullPathname(
+ sqlite3_vfs *pVfs,
+ const char *zPath,
+ int nOut,
+ char *zOut
+){
+ sqlite3_snprintf(nOut, zOut, "%s", zPath);
+ return SQLITE_OK;
+}
+
+/*
+** Open the dynamic library located at zPath and return a handle.
+*/
+static void *memdbDlOpen(sqlite3_vfs *pVfs, const char *zPath){
+ return ORIGVFS(pVfs)->xDlOpen(ORIGVFS(pVfs), zPath);
+}
+
+/*
+** Populate the buffer zErrMsg (size nByte bytes) with a human readable
+** utf-8 string describing the most recent error encountered associated
+** with dynamic libraries.
+*/
+static void memdbDlError(sqlite3_vfs *pVfs, int nByte, char *zErrMsg){
+ ORIGVFS(pVfs)->xDlError(ORIGVFS(pVfs), nByte, zErrMsg);
+}
+
+/*
+** Return a pointer to the symbol zSymbol in the dynamic library pHandle.
+*/
+static void (*memdbDlSym(sqlite3_vfs *pVfs, void *p, const char *zSym))(void){
+ return ORIGVFS(pVfs)->xDlSym(ORIGVFS(pVfs), p, zSym);
+}
+
+/*
+** Close the dynamic library handle pHandle.
+*/
+static void memdbDlClose(sqlite3_vfs *pVfs, void *pHandle){
+ ORIGVFS(pVfs)->xDlClose(ORIGVFS(pVfs), pHandle);
+}
+
+/*
+** Populate the buffer pointed to by zBufOut with nByte bytes of
+** random data.
+*/
+static int memdbRandomness(sqlite3_vfs *pVfs, int nByte, char *zBufOut){
+ return ORIGVFS(pVfs)->xRandomness(ORIGVFS(pVfs), nByte, zBufOut);
+}
+
+/*
+** Sleep for nMicro microseconds. Return the number of microseconds
+** actually slept.
+*/
+static int memdbSleep(sqlite3_vfs *pVfs, int nMicro){
+ return ORIGVFS(pVfs)->xSleep(ORIGVFS(pVfs), nMicro);
+}
+
+#if 0 /* Never used. Modern cores only call xCurrentTimeInt64() */
+/*
+** Return the current time as a Julian Day number in *pTimeOut.
+*/
+static int memdbCurrentTime(sqlite3_vfs *pVfs, double *pTimeOut){
+ return ORIGVFS(pVfs)->xCurrentTime(ORIGVFS(pVfs), pTimeOut);
+}
+#endif
+
+static int memdbGetLastError(sqlite3_vfs *pVfs, int a, char *b){
+ return ORIGVFS(pVfs)->xGetLastError(ORIGVFS(pVfs), a, b);
+}
+static int memdbCurrentTimeInt64(sqlite3_vfs *pVfs, sqlite3_int64 *p){
+ return ORIGVFS(pVfs)->xCurrentTimeInt64(ORIGVFS(pVfs), p);
+}
+
+/*
+** Translate a database connection pointer and schema name into a
+** MemFile pointer.
+*/
+static MemFile *memdbFromDbSchema(sqlite3 *db, const char *zSchema){
+ MemFile *p = 0;
+ int rc = sqlite3_file_control(db, zSchema, SQLITE_FCNTL_FILE_POINTER, &p);
+ if( rc ) return 0;
+ if( p->base.pMethods!=&memdb_io_methods ) return 0;
+ return p;
+}
+
+/*
+** Return the serialization of a database
+*/
+SQLITE_API unsigned char *sqlite3_serialize(
+ sqlite3 *db, /* The database connection */
+ const char *zSchema, /* Which database within the connection */
+ sqlite3_int64 *piSize, /* Write size here, if not NULL */
+ unsigned int mFlags /* Maybe SQLITE_SERIALIZE_NOCOPY */
+){
+ MemFile *p;
+ int iDb;
+ Btree *pBt;
+ sqlite3_int64 sz;
+ int szPage = 0;
+ sqlite3_stmt *pStmt = 0;
+ unsigned char *pOut;
+ char *zSql;
+ int rc;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+ if( !sqlite3SafetyCheckOk(db) ){
+ (void)SQLITE_MISUSE_BKPT;
+ return 0;
+ }
+#endif
+
+ if( zSchema==0 ) zSchema = db->aDb[0].zDbSName;
+ p = memdbFromDbSchema(db, zSchema);
+ iDb = sqlite3FindDbName(db, zSchema);
+ if( piSize ) *piSize = -1;
+ if( iDb<0 ) return 0;
+ if( p ){
+ if( piSize ) *piSize = p->sz;
+ if( mFlags & SQLITE_SERIALIZE_NOCOPY ){
+ pOut = p->aData;
+ }else{
+ pOut = sqlite3_malloc64( p->sz );
+ if( pOut ) memcpy(pOut, p->aData, p->sz);
+ }
+ return pOut;
+ }
+ pBt = db->aDb[iDb].pBt;
+ if( pBt==0 ) return 0;
+ szPage = sqlite3BtreeGetPageSize(pBt);
+ zSql = sqlite3_mprintf("PRAGMA \"%w\".page_count", zSchema);
+ rc = zSql ? sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0) : SQLITE_NOMEM;
+ sqlite3_free(zSql);
+ if( rc ) return 0;
+ rc = sqlite3_step(pStmt);
+ if( rc!=SQLITE_ROW ){
+ pOut = 0;
+ }else{
+ sz = sqlite3_column_int64(pStmt, 0)*szPage;
+ if( piSize ) *piSize = sz;
+ if( mFlags & SQLITE_SERIALIZE_NOCOPY ){
+ pOut = 0;
+ }else{
+ pOut = sqlite3_malloc64( sz );
+ if( pOut ){
+ int nPage = sqlite3_column_int(pStmt, 0);
+ Pager *pPager = sqlite3BtreePager(pBt);
+ int pgno;
+ for(pgno=1; pgno<=nPage; pgno++){
+ DbPage *pPage = 0;
+ unsigned char *pTo = pOut + szPage*(sqlite3_int64)(pgno-1);
+ rc = sqlite3PagerGet(pPager, pgno, (DbPage**)&pPage, 0);
+ if( rc==SQLITE_OK ){
+ memcpy(pTo, sqlite3PagerGetData(pPage), szPage);
+ }else{
+ memset(pTo, 0, szPage);
+ }
+ sqlite3PagerUnref(pPage);
+ }
+ }
+ }
+ }
+ sqlite3_finalize(pStmt);
+ return pOut;
+}
+
+/* Convert zSchema to a MemDB and initialize its content.
+*/
+SQLITE_API int sqlite3_deserialize(
+ sqlite3 *db, /* The database connection */
+ const char *zSchema, /* Which DB to reopen with the deserialization */
+ unsigned char *pData, /* The serialized database content */
+ sqlite3_int64 szDb, /* Number bytes in the deserialization */
+ sqlite3_int64 szBuf, /* Total size of buffer pData[] */
+ unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */
+){
+ MemFile *p;
+ char *zSql;
+ sqlite3_stmt *pStmt = 0;
+ int rc;
+ int iDb;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+ if( !sqlite3SafetyCheckOk(db) ){
+ return SQLITE_MISUSE_BKPT;
+ }
+ if( szDb<0 ) return SQLITE_MISUSE_BKPT;
+ if( szBuf<0 ) return SQLITE_MISUSE_BKPT;
+#endif
+
+ sqlite3_mutex_enter(db->mutex);
+ if( zSchema==0 ) zSchema = db->aDb[0].zDbSName;
+ iDb = sqlite3FindDbName(db, zSchema);
+ if( iDb<0 ){
+ rc = SQLITE_ERROR;
+ goto end_deserialize;
+ }
+ zSql = sqlite3_mprintf("ATTACH x AS %Q", zSchema);
+ rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0);
+ sqlite3_free(zSql);
+ if( rc ) goto end_deserialize;
+ db->init.iDb = (u8)iDb;
+ db->init.reopenMemdb = 1;
+ rc = sqlite3_step(pStmt);
+ db->init.reopenMemdb = 0;
+ if( rc!=SQLITE_DONE ){
+ rc = SQLITE_ERROR;
+ goto end_deserialize;
+ }
+ p = memdbFromDbSchema(db, zSchema);
+ if( p==0 ){
+ rc = SQLITE_ERROR;
+ }else{
+ p->aData = pData;
+ p->sz = szDb;
+ p->szMax = szBuf;
+ p->mFlags = mFlags;
+ rc = SQLITE_OK;
+ }
+
+end_deserialize:
+ sqlite3_finalize(pStmt);
+ sqlite3_mutex_leave(db->mutex);
+ return rc;
+}
+
+/*
+** This routine is called when the extension is loaded.
+** Register the new VFS.
+*/
+SQLITE_PRIVATE int sqlite3MemdbInit(void){
+ sqlite3_vfs *pLower = sqlite3_vfs_find(0);
+ int sz = pLower->szOsFile;
+ memdb_vfs.pAppData = pLower;
+ /* In all known configurations of SQLite, the size of a default
+ ** sqlite3_file is greater than the size of a memdb sqlite3_file.
+ ** Should that ever change, remove the following NEVER() */
+ if( NEVER(sz<sizeof(MemFile)) ) sz = sizeof(MemFile);
+ memdb_vfs.szOsFile = sz;
+ return sqlite3_vfs_register(&memdb_vfs, 0);
+}
+#endif /* SQLITE_ENABLE_DESERIALIZE */
+
+/************** End of memdb.c ***********************************************/
projects / sqlite3-cmake.git / commitdiff