SQLite

**
*************************************************************************
** Utility functions used throughout sqlite.
**
** This file contains functions for allocating memory, comparing
** strings, and stuff like that.
**
** $Id: util.c,v 1.166 2006/01/10 15:18:28 drh Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <stdarg.h>
#include <ctype.h>

/*

** This is the test layer's wrapper around sqlite3OsMalloc().
*/
static void * OSMALLOC(int n){
#ifndef SQLITE_OMIT_MEMORY_MANAGEMENT
  ThreadData *pTsd = sqlite3ThreadData();
  pTsd->nMaxAlloc = MAX(pTsd->nMaxAlloc, pTsd->nAlloc);
#endif

  if( !failMalloc() ){
    u32 *p;
    p = (u32 *)sqlite3OsMalloc(n + TESTALLOC_OVERHEAD);
    assert(p);
    sqlite3_nMalloc++;
    applyGuards(p);
    linkAlloc(p);

** This is the test layer's wrapper around sqlite3OsRealloc().
*/
static void * OSREALLOC(void *pRealloc, int n){
#ifndef SQLITE_OMIT_MEMORY_MANAGEMENT
  ThreadData *pTsd = sqlite3ThreadData();
  pTsd->nMaxAlloc = MAX(pTsd->nMaxAlloc, pTsd->nAlloc);
#endif

  if( !failMalloc() ){
    u32 *p = (u32 *)getOsPointer(pRealloc);
    checkGuards(p);
    p = sqlite3OsRealloc(p, n + TESTALLOC_OVERHEAD);
    applyGuards(p);
    relinkAlloc(p);
    return (void *)(&p[TESTALLOC_NGUARD + 2*sizeof(void *)/sizeof(u32)]);

**
*************************************************************************
** This file contains code used to implement the VACUUM command.
**
** Most of the code in this file may be omitted by defining the
** SQLITE_OMIT_VACUUM macro.
**
** $Id: vacuum.c,v 1.55 2006/01/09 06:29:49 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "vdbeInt.h"
#include "os.h"

#ifndef SQLITE_OMIT_VACUUM
/*

  int nFilename;          /* number of characters  in zFilename[] */
  char *zTemp = 0;        /* a temporary file in same directory as zFilename */
  Btree *pMain;           /* The database being vacuumed */
  Btree *pTemp;
  char *zSql = 0;
  int rc2;  
  int saved_flags;       /* Saved value of the db->flags */
  sqlite3_stmt *pDetach = 0;

  /* Save the current value of the write-schema flag before setting it. */
  saved_flags = db->flags;
  db->flags |= SQLITE_WriteSchema | SQLITE_IgnoreChecks;

  if( !db->autoCommit ){
    sqlite3SetString(pzErrMsg, "cannot VACUUM from within a transaction", 

  ** that we don't even bother to set a maximum loop count.
  */
  do {
    zTemp[nFilename] = '-';
    randomName((unsigned char*)&zTemp[nFilename+1]);
  } while( sqlite3OsFileExists(zTemp) );

  /* Before we even attach it, compile a DETACH statement for vacuum_db. This
  ** way, if malloc() fails we can detach the database without needing to
  ** dynamically allocate memory.
  */ 
  rc = sqlite3_prepare(db, "DETACH vacuum_db", -1, &pDetach, 0);
  if( rc!=SQLITE_OK ){
    goto end_of_vacuum;
  }

  /* Attach the temporary database as 'vacuum_db'. The synchronous pragma
  ** can be set to 'off' for this file, as it is not recovered if a crash
  ** occurs anyway. The integrity of the database is maintained by a
  ** (possibly synchronous) transaction opened on the main database before
  ** sqlite3BtreeCopyFile() is called.
  **
  ** An optimisation would be to use a non-journaled pager.
  */
  zSql = sqlite3MPrintf("ATTACH '%q' AS vacuum_db;", zTemp);
  if( !zSql ){
    rc = SQLITE_NOMEM;
    goto end_of_vacuum;
  }
  rc = execSql(db, zSql);
  sqliteFree(zSql);
  zSql = 0;
  if( rc!=SQLITE_OK ) goto end_of_vacuum;

  assert( strcmp(db->aDb[db->nDb-1].zName,"vacuum_db")==0 );
  pTemp = db->aDb[db->nDb-1].pBt;
  sqlite3BtreeSetPageSize(pTemp, sqlite3BtreeGetPageSize(pMain),
     sqlite3BtreeGetReserve(pMain));
  assert( sqlite3BtreeGetPageSize(pTemp)==sqlite3BtreeGetPageSize(pMain) );
  rc = execSql(db, "PRAGMA vacuum_db.synchronous=OFF");
  if( rc!=SQLITE_OK ){

  ** was committed at the btree level). So it safe to end the transaction
  ** by manually setting the autoCommit flag to true and detaching the
  ** vacuum database. The vacuum_db journal file is deleted when the pager
  ** is closed by the DETACH.
  */
  db->autoCommit = 1;

  if( pDetach ){
    int mf = sqlite3ThreadData()->mallocFailed;
    sqlite3ThreadData()->mallocFailed = 0;
    sqlite3MallocDisallow();
    ((Vdbe *)pDetach)->expired = 0;
    sqlite3_step(pDetach);
    rc2 = sqlite3_finalize(pDetach);
    if( rc==SQLITE_OK ){
      rc = rc2;
    }
    sqlite3MallocAllow();
    sqlite3ThreadData()->mallocFailed = mf;

  }

  /* If one of the execSql() calls above returned SQLITE_NOMEM, then the
  ** mallocFailed flag will be clear (because execSql() calls sqlite3_exec()).
  ** Fix this so the flag and return code match.
  */
  if( rc==SQLITE_NOMEM ){