AryaWu/sqlite

1/*2** 2016 September 103**4** The author disclaims copyright to this source code.  In place of5** a legal notice, here is a blessing:6**7**    May you do good and not evil.8**    May you find forgiveness for yourself and forgive others.9**    May you share freely, never taking more than you give.10**11*************************************************************************12** This file contains test code to delete an SQLite database and all13** of its associated files. Associated files include:14**15**   * The journal file.16**   * The wal file.17**   * The SQLITE_ENABLE_8_3_NAMES version of the db, journal or wal files.18**   * Files created by the test_multiplex.c module to extend any of the 19**     above.20*/21 22#ifndef SQLITE_OS_WIN23#  include <unistd.h>24#  include <errno.h>25#endif26#include <string.h>27#include <assert.h>28#include "sqlite3.h"29 30/* The following #defines are copied from test_multiplex.c */31#ifndef MX_CHUNK_NUMBER 32# define MX_CHUNK_NUMBER 29933#endif34#ifndef SQLITE_MULTIPLEX_JOURNAL_8_3_OFFSET35# define SQLITE_MULTIPLEX_JOURNAL_8_3_OFFSET 40036#endif37#ifndef SQLITE_MULTIPLEX_WAL_8_3_OFFSET38# define SQLITE_MULTIPLEX_WAL_8_3_OFFSET 70039#endif40 41/*42** This routine is a copy of (most of) the code from SQLite function43** sqlite3FileSuffix3(). It modifies the filename in buffer z in the44** same way as SQLite does when in 8.3 filenames mode.45*/46static void sqlite3Delete83Name(char *z){47  int i, sz;48  sz = (int)strlen(z);49  for(i=sz-1; i>0 && z[i]!='/' && z[i]!='.'; i--){}50  if( z[i]=='.' && (sz>i+4) ) memmove(&z[i+1], &z[sz-3], 4);51}52 53/*54** zFile is a filename. Assuming no error occurs, if this file exists, 55** set *pbExists to true and unlink it. Or, if the file does not exist,56** set *pbExists to false before returning.57**58** If an error occurs, non-zero is returned. Or, if no error occurs, zero.59*/60static int sqlite3DeleteUnlinkIfExists(61  sqlite3_vfs *pVfs,62  const char *zFile, 63  int *pbExists64){65  int rc = SQLITE_ERROR;66#ifdef _WIN3267  if( pVfs ){68    if( pbExists ) *pbExists = 1;69    rc = pVfs->xDelete(pVfs, zFile, 0);70    if( rc==SQLITE_IOERR_DELETE_NOENT ){71      if( pbExists ) *pbExists = 0;72      rc = SQLITE_OK;73    }74  }75#else76  assert( pVfs==0 );77  rc = access(zFile, F_OK);78  if( rc ){79    if( errno==ENOENT ){ 80      if( pbExists ) *pbExists = 0;81      rc = SQLITE_OK; 82    }83  }else{84    if( pbExists ) *pbExists = 1;85    rc = unlink(zFile);86  }87#endif88  return rc;89}90 91/*92** Delete the database file identified by the string argument passed to this93** function. The string must contain a filename, not an SQLite URI.94*/95SQLITE_API int sqlite3_delete_database(96  const char *zFile               /* File to delete */97){98  char *zBuf;                     /* Buffer to sprintf() filenames to */99  int nBuf;                       /* Size of buffer in bytes */100  int rc = 0;                     /* System error code */101  int i;                          /* Iterate through azFmt[] and aMFile[] */102 103  const char *azFmt[] = { "%s", "%s-journal", "%s-wal", "%s-shm" };104 105  struct MFile {106    const char *zFmt;107    int iOffset;108    int b83;109  } aMFile[] = {110    { "%s%03d",         0,   0 },111    { "%s-journal%03d", 0,   0 },112    { "%s-wal%03d",     0,   0 },113    { "%s%03d",         0,   1 },114    { "%s-journal%03d", SQLITE_MULTIPLEX_JOURNAL_8_3_OFFSET, 1 },115    { "%s-wal%03d",     SQLITE_MULTIPLEX_WAL_8_3_OFFSET, 1 },116  };117 118#ifdef _WIN32119  sqlite3_vfs *pVfs = sqlite3_vfs_find("win32");120#else121  sqlite3_vfs *pVfs = 0;122#endif123 124  /* Allocate a buffer large enough for any of the files that need to be125  ** deleted.  */126  nBuf = (int)strlen(zFile) + 100;127  zBuf = (char*)sqlite3_malloc(nBuf);128  if( zBuf==0 ) return SQLITE_NOMEM;129 130  /* Delete both the regular and 8.3 filenames versions of the database,131  ** journal, wal and shm files.  */132  for(i=0; rc==0 && i<sizeof(azFmt)/sizeof(azFmt[0]); i++){133    sqlite3_snprintf(nBuf, zBuf, azFmt[i], zFile);134    rc = sqlite3DeleteUnlinkIfExists(pVfs, zBuf, 0);135    if( rc==0 && i!=0 ){136      sqlite3Delete83Name(zBuf);137      rc = sqlite3DeleteUnlinkIfExists(pVfs, zBuf, 0);138    }139  }140 141  /* Delete any multiplexor files */142  for(i=0; rc==0 && i<sizeof(aMFile)/sizeof(aMFile[0]); i++){143    struct MFile *p = &aMFile[i];144    int iChunk;145    for(iChunk=1; iChunk<=MX_CHUNK_NUMBER; iChunk++){146      int bExists;147      sqlite3_snprintf(nBuf, zBuf, p->zFmt, zFile, iChunk+p->iOffset);148      if( p->b83 ) sqlite3Delete83Name(zBuf);149      rc = sqlite3DeleteUnlinkIfExists(pVfs, zBuf, &bExists);150      if( bExists==0 || rc!=0 ) break;151    }152  }153 154  sqlite3_free(zBuf);155  return (rc ? SQLITE_ERROR : SQLITE_OK);156}157