src/test_delete.c

   1 /*
   2 ** 2016 September 10
   3 **
   4 ** The author disclaims copyright to this source code.  In place of
   5 ** 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 all
  13 ** 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_WIN
  23 #  include <unistd.h>
  24 #  include <errno.h>
  25 #endif
  26 #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 299
  33 #endif
  34 #ifndef SQLITE_MULTIPLEX_JOURNAL_8_3_OFFSET
  35 # define SQLITE_MULTIPLEX_JOURNAL_8_3_OFFSET 400
  36 #endif
  37 #ifndef SQLITE_MULTIPLEX_WAL_8_3_OFFSET
  38 # define SQLITE_MULTIPLEX_WAL_8_3_OFFSET 700
  39 #endif
  40
  41 /*
  42 ** This routine is a copy of (most of) the code from SQLite function
  43 ** sqlite3FileSuffix3(). It modifies the filename in buffer z in the
  44 ** same way as SQLite does when in 8.3 filenames mode.
  45 */
  46 static 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 */
  60 static int sqlite3DeleteUnlinkIfExists(
  61   sqlite3_vfs *pVfs,
  62   const char *zFile,
  63   int *pbExists
  64 ){
  65   int rc = SQLITE_ERROR;
  66 #if SQLITE_OS_WIN
  67   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 #else
  76   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 #endif
  88   return rc;
  89 }
  90
  91 /*
  92 ** Delete the database file identified by the string argument passed to this
  93 ** function. The string must contain a filename, not an SQLite URI.
  94 */
  95 SQLITE_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 SQLITE_OS_WIN
 119   sqlite3_vfs *pVfs = sqlite3_vfs_find("win32");
 120 #else
 121   sqlite3_vfs *pVfs = 0;
 122 #endif
 123
 124   /* Allocate a buffer large enough for any of the files that need to be
 125   ** 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 }