[sql] Import SQLite 3.17.0.

third_party/sqlite/src/src/test_delete.c

+/*
+** 2016 September 10
+**
+** 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 contains test code to delete an SQLite database and all
+** of its associated files. Associated files include:
+**
+**   * The journal file.
+**   * The wal file.
+**   * The SQLITE_ENABLE_8_3_NAMES version of the db, journal or wal files.
+**   * Files created by the test_multiplex.c module to extend any of the 
+**     above.
+*/
+
+#if SQLITE_OS_WIN
+#  include <io.h>
+#  define F_OK 0
+#else
+#  include <unistd.h>
+#endif
+#include <string.h>
+#include <errno.h>
+#include "sqlite3.h"
+
+/* The following #defines are copied from test_multiplex.c */
+#ifndef MX_CHUNK_NUMBER 
+# define MX_CHUNK_NUMBER 299
+#endif
+#ifndef SQLITE_MULTIPLEX_JOURNAL_8_3_OFFSET
+# define SQLITE_MULTIPLEX_JOURNAL_8_3_OFFSET 400
+#endif
+#ifndef SQLITE_MULTIPLEX_WAL_8_3_OFFSET
+# define SQLITE_MULTIPLEX_WAL_8_3_OFFSET 700
+#endif
+
+/*
+** This routine is a copy of (most of) the code from SQLite function
+** sqlite3FileSuffix3(). It modifies the filename in buffer z in the
+** same way as SQLite does when in 8.3 filenames mode.
+*/
+static void sqlite3Delete83Name(char *z){
+  int i, sz;
+  sz = (int)strlen(z);
+  for(i=sz-1; i>0 && z[i]!='/' && z[i]!='.'; i--){}
+  if( z[i]=='.' && (sz>i+4) ) memmove(&z[i+1], &z[sz-3], 4);
+}
+
+/*
+** zFile is a filename. Assuming no error occurs, if this file exists, 
+** set *pbExists to true and unlink it. Or, if the file does not exist,
+** set *pbExists to false before returning.
+**
+** If an error occurs, the value of errno is returned. Or, if no error
+** occurs, zero is returned.
+*/
+static int sqlite3DeleteUnlinkIfExists(const char *zFile, int *pbExists){
+  int rc;
+  rc = access(zFile, F_OK);
+  if( rc ){
+    if( errno==ENOENT ){ 
+      if( pbExists ) *pbExists = 0;
+      return 0; 
+    }
+    return errno;
+  }
+  if( pbExists ) *pbExists = 1;
+  rc = unlink(zFile);
+  if( rc ) return errno;
+  return 0;
+}
+
+/*
+** Delete the database file identified by the string argument passed to this
+** function. The string must contain a filename, not an SQLite URI.
+*/
+SQLITE_API int sqlite3_delete_database(
+  const char *zFile               /* File to delete */
+){
+  char *zBuf;                     /* Buffer to sprintf() filenames to */
+  int nBuf;                       /* Size of buffer in bytes */
+  int rc = 0;                     /* System error code */
+  int i;                          /* Iterate through azFmt[] and aMFile[] */
+
+  const char *azFmt[] = { "%s", "%s-journal", "%s-wal", "%s-shm" };
+
+  struct MFile {
+    const char *zFmt;
+    int iOffset;
+    int b83;
+  } aMFile[] = {
+    { "%s%03d",         0,   0 },
+    { "%s-journal%03d", 0,   0 },
+    { "%s-wal%03d",     0,   0 },
+    { "%s%03d",         0,   1 },
+    { "%s-journal%03d", SQLITE_MULTIPLEX_JOURNAL_8_3_OFFSET, 1 },
+    { "%s-wal%03d",     SQLITE_MULTIPLEX_WAL_8_3_OFFSET, 1 },
+  };
+
+  /* Allocate a buffer large enough for any of the files that need to be
+  ** deleted.  */
+  nBuf = (int)strlen(zFile) + 100;
+  zBuf = (char*)sqlite3_malloc(nBuf);
+  if( zBuf==0 ) return SQLITE_NOMEM;
+
+  /* Delete both the regular and 8.3 filenames versions of the database,
+  ** journal, wal and shm files.  */
+  for(i=0; rc==0 && i<sizeof(azFmt)/sizeof(azFmt[0]); i++){
+    sqlite3_snprintf(nBuf, zBuf, azFmt[i], zFile);
+    rc = sqlite3DeleteUnlinkIfExists(zBuf, 0);
+    if( rc==0 && i!=0 ){
+      sqlite3Delete83Name(zBuf);
+      rc = sqlite3DeleteUnlinkIfExists(zBuf, 0);
+    }
+  }
+
+  /* Delete any multiplexor files */
+  for(i=0; rc==0 && i<sizeof(aMFile)/sizeof(aMFile[0]); i++){
+    struct MFile *p = &aMFile[i];
+    int iChunk;
+    for(iChunk=1; iChunk<=MX_CHUNK_NUMBER; iChunk++){
+      int bExists;
+      sqlite3_snprintf(nBuf, zBuf, p->zFmt, zFile, iChunk+p->iOffset);
+      if( p->b83 ) sqlite3Delete83Name(zBuf);
+      rc = sqlite3DeleteUnlinkIfExists(zBuf, &bExists);
+      if( bExists==0 || rc!=0 ) break;
+    }
+  }
+
+  sqlite3_free(zBuf);
+  return (rc ? SQLITE_ERROR : SQLITE_OK);
+}