+++ /dev/null
-/*
-** 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 is an in-memory VFS implementation. The application supplies
-** a chunk of memory to hold the database file.
-**
-** Because there is place to store a rollback or wal journal, the database
-** must use one of journal_mode=MEMORY or journal_mode=NONE.
-**
-** USAGE:
-**
-** sqlite3_open_v2("file:/whatever?ptr=0xf05538&sz=14336&max=65536", &db,
-** SQLITE_OPEN_READWRITE | SQLITE_OPEN_URI,
-** "memvfs");
-**
-** These are the query parameters:
-**
-** ptr= The address of the memory buffer that holds the database.
-**
-** sz= The current size the database file
-**
-** maxsz= The maximum size of the database. In other words, the
-** amount of space allocated for the ptr= buffer.
-**
-** freeonclose= If true, then sqlite3_free() is called on the ptr=
-** value when the connection closes.
-**
-** The ptr= and sz= query parameters are required. If maxsz= is omitted,
-** then it defaults to the sz= value. Parameter values can be in either
-** decimal or hexadecimal. The filename in the URI is ignored.
-*/
-
-/*************************************************************************
-** WARNING: THIS FILE CONTAINS UNTESTED CODE. The code in this file is for
-** demonstration purposes only. It has been tested informally only and is
-** not considered production ready.
-*************************************************************************/
-
-#include <sqlite3ext.h>
-SQLITE_EXTENSION_INIT1
-#include <string.h>
-#include <assert.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 bFreeOnClose; /* Invoke sqlite3_free() on aData at close */
-};
-
-/*
-** Methods for MemFile
-*/
-static int memClose(sqlite3_file*);
-static int memRead(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
-static int memWrite(sqlite3_file*,const void*,int iAmt, sqlite3_int64 iOfst);
-static int memTruncate(sqlite3_file*, sqlite3_int64 size);
-static int memSync(sqlite3_file*, int flags);
-static int memFileSize(sqlite3_file*, sqlite3_int64 *pSize);
-static int memLock(sqlite3_file*, int);
-static int memUnlock(sqlite3_file*, int);
-static int memCheckReservedLock(sqlite3_file*, int *pResOut);
-static int memFileControl(sqlite3_file*, int op, void *pArg);
-static int memSectorSize(sqlite3_file*);
-static int memDeviceCharacteristics(sqlite3_file*);
-static int memShmMap(sqlite3_file*, int iPg, int pgsz, int, void volatile**);
-static int memShmLock(sqlite3_file*, int offset, int n, int flags);
-static void memShmBarrier(sqlite3_file*);
-static int memShmUnmap(sqlite3_file*, int deleteFlag);
-static int memFetch(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp);
-static int memUnfetch(sqlite3_file*, sqlite3_int64 iOfst, void *p);
-
-/*
-** Methods for MemVfs
-*/
-static int memOpen(sqlite3_vfs*, const char *, sqlite3_file*, int , int *);
-static int memDelete(sqlite3_vfs*, const char *zName, int syncDir);
-static int memAccess(sqlite3_vfs*, const char *zName, int flags, int *);
-static int memFullPathname(sqlite3_vfs*, const char *zName, int, char *zOut);
-static void *memDlOpen(sqlite3_vfs*, const char *zFilename);
-static void memDlError(sqlite3_vfs*, int nByte, char *zErrMsg);
-static void (*memDlSym(sqlite3_vfs *pVfs, void *p, const char*zSym))(void);
-static void memDlClose(sqlite3_vfs*, void*);
-static int memRandomness(sqlite3_vfs*, int nByte, char *zOut);
-static int memSleep(sqlite3_vfs*, int microseconds);
-static int memCurrentTime(sqlite3_vfs*, double*);
-static int memGetLastError(sqlite3_vfs*, int, char *);
-static int memCurrentTimeInt64(sqlite3_vfs*, sqlite3_int64*);
-
-static sqlite3_vfs mem_vfs = {
- 2, /* iVersion */
- 0, /* szOsFile (set when registered) */
- 1024, /* mxPathname */
- 0, /* pNext */
- "memvfs", /* zName */
- 0, /* pAppData (set when registered) */
- memOpen, /* xOpen */
- memDelete, /* xDelete */
- memAccess, /* xAccess */
- memFullPathname, /* xFullPathname */
- memDlOpen, /* xDlOpen */
- memDlError, /* xDlError */
- memDlSym, /* xDlSym */
- memDlClose, /* xDlClose */
- memRandomness, /* xRandomness */
- memSleep, /* xSleep */
- memCurrentTime, /* xCurrentTime */
- memGetLastError, /* xGetLastError */
- memCurrentTimeInt64 /* xCurrentTimeInt64 */
-};
-
-static const sqlite3_io_methods mem_io_methods = {
- 3, /* iVersion */
- memClose, /* xClose */
- memRead, /* xRead */
- memWrite, /* xWrite */
- memTruncate, /* xTruncate */
- memSync, /* xSync */
- memFileSize, /* xFileSize */
- memLock, /* xLock */
- memUnlock, /* xUnlock */
- memCheckReservedLock, /* xCheckReservedLock */
- memFileControl, /* xFileControl */
- memSectorSize, /* xSectorSize */
- memDeviceCharacteristics, /* xDeviceCharacteristics */
- memShmMap, /* xShmMap */
- memShmLock, /* xShmLock */
- memShmBarrier, /* xShmBarrier */
- memShmUnmap, /* xShmUnmap */
- memFetch, /* xFetch */
- memUnfetch /* xUnfetch */
-};
-
-
-
-/*
-** Close an mem-file.
-**
-** The pData pointer is owned by the application, so there is nothing
-** to free.
-*/
-static int memClose(sqlite3_file *pFile){
- MemFile *p = (MemFile *)pFile;
- if( p->bFreeOnClose ) sqlite3_free(p->aData);
- return SQLITE_OK;
-}
-
-/*
-** Read data from an mem-file.
-*/
-static int memRead(
- sqlite3_file *pFile,
- void *zBuf,
- int iAmt,
- sqlite_int64 iOfst
-){
- MemFile *p = (MemFile *)pFile;
- int nCopy = iAmt;
- int rc = SQLITE_OK;
-
- if( iOfst+iAmt>p->szMax ){
- memset(zBuf, 0, iAmt);
- nCopy = (iOfst<p->szMax ? (p->szMax - iOfst) : 0);
- rc = SQLITE_IOERR_SHORT_READ;
- }
- if( nCopy>0 ){
- memcpy(zBuf, p->aData+iOfst, nCopy);
- }
-
- return rc;
-}
-
-/*
-** Write data to an mem-file.
-*/
-static int memWrite(
- sqlite3_file *pFile,
- const void *z,
- int iAmt,
- sqlite_int64 iOfst
-){
- MemFile *p = (MemFile *)pFile;
- if( iOfst+iAmt>p->sz ){
- if( iOfst+iAmt>p->szMax ) return SQLITE_FULL;
- 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 mem-file.
-*/
-static int memTruncate(sqlite3_file *pFile, sqlite_int64 size){
- MemFile *p = (MemFile *)pFile;
- if( size>p->sz ){
- if( size>p->szMax ) return SQLITE_FULL;
- memset(p->aData+p->sz, 0, size-p->sz);
- }
- p->sz = size;
- return SQLITE_OK;
-}
-
-/*
-** Sync an mem-file.
-*/
-static int memSync(sqlite3_file *pFile, int flags){
- return SQLITE_OK;
-}
-
-/*
-** Return the current file-size of an mem-file.
-*/
-static int memFileSize(sqlite3_file *pFile, sqlite_int64 *pSize){
- MemFile *p = (MemFile *)pFile;
- *pSize = p->sz;
- return SQLITE_OK;
-}
-
-/*
-** Lock an mem-file.
-*/
-static int memLock(sqlite3_file *pFile, int eLock){
- return SQLITE_OK;
-}
-
-/*
-** Unlock an mem-file.
-*/
-static int memUnlock(sqlite3_file *pFile, int eLock){
- return SQLITE_OK;
-}
-
-/*
-** Check if another file-handle holds a RESERVED lock on an mem-file.
-*/
-static int memCheckReservedLock(sqlite3_file *pFile, int *pResOut){
- *pResOut = 0;
- return SQLITE_OK;
-}
-
-/*
-** File control method. For custom operations on an mem-file.
-*/
-static int memFileControl(sqlite3_file *pFile, int op, void *pArg){
- MemFile *p = (MemFile *)pFile;
- int rc = SQLITE_NOTFOUND;
- if( op==SQLITE_FCNTL_VFSNAME ){
- *(char**)pArg = sqlite3_mprintf("mem(%p,%lld)", p->aData, p->sz);
- rc = SQLITE_OK;
- }
- return rc;
-}
-
-/*
-** Return the sector-size in bytes for an mem-file.
-*/
-static int memSectorSize(sqlite3_file *pFile){
- return 1024;
-}
-
-/*
-** Return the device characteristic flags supported by an mem-file.
-*/
-static int memDeviceCharacteristics(sqlite3_file *pFile){
- return SQLITE_IOCAP_ATOMIC |
- SQLITE_IOCAP_POWERSAFE_OVERWRITE |
- SQLITE_IOCAP_SAFE_APPEND |
- SQLITE_IOCAP_SEQUENTIAL;
-}
-
-/* Create a shared memory file mapping */
-static int memShmMap(
- sqlite3_file *pFile,
- int iPg,
- int pgsz,
- int bExtend,
- void volatile **pp
-){
- return SQLITE_IOERR_SHMMAP;
-}
-
-/* Perform locking on a shared-memory segment */
-static int memShmLock(sqlite3_file *pFile, int offset, int n, int flags){
- return SQLITE_IOERR_SHMLOCK;
-}
-
-/* Memory barrier operation on shared memory */
-static void memShmBarrier(sqlite3_file *pFile){
- return;
-}
-
-/* Unmap a shared memory segment */
-static int memShmUnmap(sqlite3_file *pFile, int deleteFlag){
- return SQLITE_OK;
-}
-
-/* Fetch a page of a memory-mapped file */
-static int memFetch(
- sqlite3_file *pFile,
- sqlite3_int64 iOfst,
- int iAmt,
- void **pp
-){
- MemFile *p = (MemFile *)pFile;
- *pp = (void*)(p->aData + iOfst);
- return SQLITE_OK;
-}
-
-/* Release a memory-mapped page */
-static int memUnfetch(sqlite3_file *pFile, sqlite3_int64 iOfst, void *pPage){
- return SQLITE_OK;
-}
-
-/*
-** Open an mem file handle.
-*/
-static int memOpen(
- sqlite3_vfs *pVfs,
- const char *zName,
- sqlite3_file *pFile,
- int flags,
- int *pOutFlags
-){
- MemFile *p = (MemFile*)pFile;
- memset(p, 0, sizeof(*p));
- if( (flags & SQLITE_OPEN_MAIN_DB)==0 ) return SQLITE_CANTOPEN;
- p->aData = (unsigned char*)sqlite3_uri_int64(zName,"ptr",0);
- if( p->aData==0 ) return SQLITE_CANTOPEN;
- p->sz = sqlite3_uri_int64(zName,"sz",0);
- if( p->sz<0 ) return SQLITE_CANTOPEN;
- p->szMax = sqlite3_uri_int64(zName,"max",p->sz);
- if( p->szMax<p->sz ) return SQLITE_CANTOPEN;
- p->bFreeOnClose = sqlite3_uri_boolean(zName,"freeonclose",0);
- pFile->pMethods = &mem_io_methods;
- 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 memDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){
- return SQLITE_IOERR_DELETE;
-}
-
-/*
-** Test for access permissions. Return true if the requested permission
-** is available, or false otherwise.
-*/
-static int memAccess(
- 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 memFullPathname(
- 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 *memDlOpen(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 memDlError(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 (*memDlSym(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 memDlClose(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 memRandomness(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 memSleep(sqlite3_vfs *pVfs, int nMicro){
- return ORIGVFS(pVfs)->xSleep(ORIGVFS(pVfs), nMicro);
-}
-
-/*
-** Return the current time as a Julian Day number in *pTimeOut.
-*/
-static int memCurrentTime(sqlite3_vfs *pVfs, double *pTimeOut){
- return ORIGVFS(pVfs)->xCurrentTime(ORIGVFS(pVfs), pTimeOut);
-}
-
-static int memGetLastError(sqlite3_vfs *pVfs, int a, char *b){
- return ORIGVFS(pVfs)->xGetLastError(ORIGVFS(pVfs), a, b);
-}
-static int memCurrentTimeInt64(sqlite3_vfs *pVfs, sqlite3_int64 *p){
- return ORIGVFS(pVfs)->xCurrentTimeInt64(ORIGVFS(pVfs), p);
-}
-
-#ifdef MEMVFS_TEST
-/*
-** memvfs_from_file(FILENAME, MAXSIZE)
-**
-** This an SQL function used to help in testing the memvfs VFS. The
-** function reads the content of a file into memory and then returns
-** a URI that can be handed to ATTACH to attach the memory buffer as
-** a database. Example:
-**
-** ATTACH memvfs_from_file('test.db',1048576) AS inmem;
-**
-** The optional MAXSIZE argument gives the size of the memory allocation
-** used to hold the database. If omitted, it defaults to the size of the
-** file on disk.
-*/
-#include <stdio.h>
-static void memvfsFromFileFunc(
- sqlite3_context *context,
- int argc,
- sqlite3_value **argv
-){
- unsigned char *p;
- sqlite3_int64 sz;
- sqlite3_int64 szMax;
- FILE *in;
- const char *zFilename = (const char*)sqlite3_value_text(argv[0]);
- char *zUri;
-
- if( zFilename==0 ) return;
- in = fopen(zFilename, "rb");
- if( in==0 ) return;
- fseek(in, 0, SEEK_END);
- szMax = sz = ftell(in);
- rewind(in);
- if( argc>=2 ){
- szMax = sqlite3_value_int64(argv[1]);
- if( szMax<sz ) szMax = sz;
- }
- p = sqlite3_malloc64( szMax );
- if( p==0 ){
- fclose(in);
- sqlite3_result_error_nomem(context);
- return;
- }
- fread(p, sz, 1, in);
- fclose(in);
- zUri = sqlite3_mprintf(
- "file:/mem?vfs=memvfs&ptr=%lld&sz=%lld&max=%lld&freeonclose=1",
- (sqlite3_int64)p, sz, szMax);
- sqlite3_result_text(context, zUri, -1, sqlite3_free);
-}
-#endif /* MEMVFS_TEST */
-
-#ifdef MEMVFS_TEST
-/*
-** memvfs_to_file(SCHEMA, FILENAME)
-**
-** The schema identified by SCHEMA must be a memvfs database. Write
-** the content of this database into FILENAME.
-*/
-static void memvfsToFileFunc(
- sqlite3_context *context,
- int argc,
- sqlite3_value **argv
-){
- MemFile *p = 0;
- FILE *out;
- int rc;
- sqlite3 *db = sqlite3_context_db_handle(context);
- sqlite3_vfs *pVfs = 0;
- const char *zSchema = (const char*)sqlite3_value_text(argv[0]);
- const char *zFilename = (const char*)sqlite3_value_text(argv[1]);
-
- if( zFilename==0 ) return;
- out = fopen(zFilename, "wb");
- if( out==0 ) return;
- rc = sqlite3_file_control(db, zSchema, SQLITE_FCNTL_VFS_POINTER, &pVfs);
- if( rc || pVfs==0 ) return;
- if( strcmp(pVfs->zName,"memvfs")!=0 ) return;
- rc = sqlite3_file_control(db, zSchema, SQLITE_FCNTL_FILE_POINTER, &p);
- if( rc ) return;
- fwrite(p->aData, 1, (size_t)p->sz, out);
- fclose(out);
-}
-#endif /* MEMVFS_TEST */
-
-#ifdef MEMVFS_TEST
-/* Called for each new database connection */
-static int memvfsRegister(
- sqlite3 *db,
- char **pzErrMsg,
- const struct sqlite3_api_routines *pThunk
-){
- sqlite3_create_function(db, "memvfs_from_file", 1, SQLITE_UTF8, 0,
- memvfsFromFileFunc, 0, 0);
- sqlite3_create_function(db, "memvfs_from_file", 2, SQLITE_UTF8, 0,
- memvfsFromFileFunc, 0, 0);
- sqlite3_create_function(db, "memvfs_to_file", 2, SQLITE_UTF8, 0,
- memvfsToFileFunc, 0, 0);
- return SQLITE_OK;
-}
-#endif /* MEMVFS_TEST */
-
-
-#ifdef _WIN32
-__declspec(dllexport)
-#endif
-/*
-** This routine is called when the extension is loaded.
-** Register the new VFS.
-*/
-int sqlite3_memvfs_init(
- sqlite3 *db,
- char **pzErrMsg,
- const sqlite3_api_routines *pApi
-){
- int rc = SQLITE_OK;
- SQLITE_EXTENSION_INIT2(pApi);
- mem_vfs.pAppData = sqlite3_vfs_find(0);
- if( mem_vfs.pAppData==0 ) return SQLITE_ERROR;
- mem_vfs.szOsFile = sizeof(MemFile);
- rc = sqlite3_vfs_register(&mem_vfs, 1);
-#ifdef MEMVFS_TEST
- if( rc==SQLITE_OK ){
- rc = sqlite3_auto_extension((void(*)(void))memvfsRegister);
- }
- if( rc==SQLITE_OK ){
- rc = memvfsRegister(db, pzErrMsg, pApi);
- }
-#endif
- if( rc==SQLITE_OK ) rc = SQLITE_OK_LOAD_PERMANENTLY;
- return rc;
-}
projects / thirdparty / sqlite.git / commitdiff
