SQLite

**     DROP INDEX
**     creating ID lists
**     BEGIN TRANSACTION
**     COMMIT
**     ROLLBACK
**     PRAGMA
**
** $Id: build.c,v 1.165 2004/02/11 09:46:31 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** This routine is called when a new SQL statement is beginning to
** be parsed.  Check to see if the schema for the database needs

** the schema to change multiple times and for the cookie to be
** set back to prior value.  But schema changes are infrequent
** and the probability of hitting the same cookie value is only
** 1 chance in 2^32.  So we're safe enough.
*/
void sqliteChangeCookie(sqlite *db, Vdbe *v){
  if( db->next_cookie==db->aDb[0].schema_cookie ){
    unsigned char r;
    sqliteRandomness(1, &r);
    db->next_cookie = db->aDb[0].schema_cookie + r + 1;
    db->flags |= SQLITE_InternChanges;
    sqliteVdbeAddOp(v, OP_Integer, db->next_cookie, 0);
    sqliteVdbeAddOp(v, OP_SetCookie, 0, 0);
  }
}

/*

** This file contains the C functions that implement various SQL
** functions of SQLite.  
**
** There is only one exported symbol in this file - the function
** sqliteRegisterBuildinFunctions() found at the bottom of the file.
** All other code has file scope.
**
** $Id: func.c,v 1.39 2004/02/11 09:46:32 drh Exp $
*/
#include <ctype.h>
#include <math.h>
#include <stdlib.h>
#include <assert.h>
#include "sqliteInt.h"
#include "os.h"

  }
}

/*
** Implementation of random().  Return a random integer.  
*/
static void randomFunc(sqlite_func *context, int argc, const char **argv){
  int r;
  sqliteRandomness(sizeof(r), &r);
  sqlite_set_result_int(context, r);
}

/*
** Implementation of the last_insert_rowid() SQL function.  The return
** value is the same as the sqlite_last_insert_rowid() API function.
*/
static void last_insert_rowid(sqlite_func *context, int arg, const char **argv){

#ifdef SQLITE_TEST
/*
** This function generates a string of random characters.  Used for
** generating test data.
*/
static void randStr(sqlite_func *context, int argc, const char **argv){
  static const unsigned char zSrc[] = 
     "abcdefghijklmnopqrstuvwxyz"
     "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
     "0123456789"
     ".-!,:*^+=_|?/<> ";
  int iMin, iMax, n, r, i;
  unsigned char zBuf[1000];
  if( argc>=1 ){
    iMin = atoi(argv[0]);
    if( iMin<0 ) iMin = 0;
    if( iMin>=sizeof(zBuf) ) iMin = sizeof(zBuf)-1;
  }else{
    iMin = 1;
  }
  if( argc>=2 ){
    iMax = atoi(argv[1]);
    if( iMax<iMin ) iMax = iMin;
    if( iMax>=sizeof(zBuf) ) iMax = sizeof(zBuf)-1;
  }else{
    iMax = 50;
  }
  n = iMin;
  if( iMax>iMin ){
    sqliteRandomness(sizeof(r), &r);
    r &= 0x7fffffff;
    n += r%(iMax + 1 - iMin);
  }
  assert( n<sizeof(zBuf) );
  sqliteRandomness(n, zBuf);
  for(i=0; i<n; i++){

    zBuf[i] = zSrc[zBuf[i]%(sizeof(zSrc)-1)];
  }
  zBuf[n] = 0;
  sqlite_set_result_string(context, zBuf, n);
}
#endif

/*

#if OS_UNIX
  static const char *azDirs[] = {
     "/var/tmp",
     "/usr/tmp",
     "/tmp",
     ".",
  };
  static unsigned char zChars[] =
    "abcdefghijklmnopqrstuvwxyz"
    "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
    "0123456789";
  int i, j;
  struct stat buf;
  const char *zDir = ".";
  for(i=0; i<sizeof(azDirs)/sizeof(azDirs[0]); i++){
    if( stat(azDirs[i], &buf) ) continue;
    if( !S_ISDIR(buf.st_mode) ) continue;
    if( access(azDirs[i], 07) ) continue;
    zDir = azDirs[i];
    break;
  }
  do{
    sprintf(zBuf, "%s/"TEMP_FILE_PREFIX, zDir);
    j = strlen(zBuf);
    sqliteRandomness(15, &zBuf[j]);
    for(i=0; i<15; i++, j++){
      zBuf[j] = (char)zChars[ ((unsigned char)zBuf[j])%(sizeof(zChars)-1) ];

    }
    zBuf[j] = 0;
  }while( access(zBuf,0)==0 );
#endif
#if OS_WIN
  static char zChars[] =
    "abcdefghijklmnopqrstuvwxyz"
    "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
    "0123456789";
  int i, j;
  char zTempPath[SQLITE_TEMPNAME_SIZE];
  GetTempPath(SQLITE_TEMPNAME_SIZE-30, zTempPath);
  for(i=strlen(zTempPath); i>0 && zTempPath[i-1]=='\\'; i--){}
  zTempPath[i] = 0;
  for(;;){
    sprintf(zBuf, "%s\\"TEMP_FILE_PREFIX, zTempPath);
    j = strlen(zBuf);
    sqliteRandomness(15, &zBuf[j]);
    for(i=0; i<15; i++, j++){
      zBuf[j] = (char)zChars[ ((unsigned char)zBuf[j])%(sizeof(zChars)-1) ];

    }
    zBuf[j] = 0;
    if( !sqliteOsFileExists(zBuf) ) break;
  }
#endif
#if OS_MAC
  static char zChars[] =

    } while( infoRec.dirInfo.ioDrDirID != fsRtDirID );
  }
  if( *zTempPath == 0 )
    getcwd(zTempPath, SQLITE_TEMPNAME_SIZE-24);
  for(;;){
    sprintf(zBuf, "%s"TEMP_FILE_PREFIX, zTempPath);
    j = strlen(zBuf);
    sqliteRandomness(15, &zBuf[j]);
    for(i=0; i<15; i++, j++){
      zBuf[j] = (char)zChars[ ((unsigned char)zBuf[j])%(sizeof(zChars)-1) ];

    }
    zBuf[j] = 0;
    if( !sqliteOsFileExists(zBuf) ) break;
  }
#endif
  return SQLITE_OK; 
}

  return rc;
#endif
#if OS_WIN
  int rc;
  if( id->locked>0 ){
    rc = SQLITE_OK;
  }else{
    int lk;
    int res;
    int cnt = 100;
    sqliteRandomness(sizeof(lk), &lk);
    lk = (lk & 0x7fffffff)%N_LOCKBYTE + 1;
    while( cnt-->0 && (res = LockFile(id->h, FIRST_LOCKBYTE, 0, 1, 0))==0 ){
      Sleep(1);
    }
    if( res ){
      UnlockFile(id->h, FIRST_LOCKBYTE+1, 0, N_LOCKBYTE, 0);
      if( isNT() ){
        OVERLAPPED ovlp;

  return rc;
#endif
#if OS_MAC
  int rc;
  if( id->locked>0 || id->refNumRF == -1 ){
    rc = SQLITE_OK;
  }else{
    int lk;
    OSErr res;
    int cnt = 5;
    ParamBlockRec params;
    sqliteRandomness(sizeof(lk), &lk);
    lk = (lk & 0x7fffffff)%N_LOCKBYTE + 1;
    memset(&params, 0, sizeof(params));
    params.ioParam.ioRefNum = id->refNumRF;
    params.ioParam.ioPosMode = fsFromStart;
    params.ioParam.ioPosOffset = FIRST_LOCKBYTE;
    params.ioParam.ioReqCount = 1;
    while( cnt-->0 && (res = PBLockRangeSync(&params))!=noErr ){
      UInt32 finalTicks;

** The pager is used to access a database disk file.  It implements
** atomic commit and rollback through the use of a journal file that
** is separate from the database file.  The pager also implements file
** locking to prevent two processes from writing the same database
** file simultaneously, or one process from reading the database while
** another is writing.
**
** @(#) $Id: pager.c,v 1.100 2004/02/11 09:46:32 drh Exp $
*/
#include "os.h"         /* Must be first to enable large file support */
#include "sqliteInt.h"
#include "pager.h"
#include <assert.h>
#include <string.h>

  pPager->origDbSize = pPager->dbSize;
  if( journal_format==JOURNAL_FORMAT_3 ){
    rc = sqliteOsWrite(&pPager->jfd, aJournalMagic3, sizeof(aJournalMagic3));
    if( rc==SQLITE_OK ){
      rc = write32bits(&pPager->jfd, pPager->noSync ? 0xffffffff : 0);
    }
    if( rc==SQLITE_OK ){
      sqliteRandomness(sizeof(pPager->cksumInit), &pPager->cksumInit);
      rc = write32bits(&pPager->jfd, pPager->cksumInit);
    }
  }else if( journal_format==JOURNAL_FORMAT_2 ){
    rc = sqliteOsWrite(&pPager->jfd, aJournalMagic2, sizeof(aJournalMagic2));
  }else{
    assert( journal_format==JOURNAL_FORMAT_1 );
    rc = sqliteOsWrite(&pPager->jfd, aJournalMagic1, sizeof(aJournalMagic1));

*************************************************************************
** This file contains code to implement a pseudo-random number
** generator (PRNG) for SQLite.
**
** Random numbers are used by some of the database backends in order
** to generate random integer keys for tables or random filenames.
**
** $Id: random.c,v 1.11 2004/02/11 09:46:33 drh Exp $
*/
#include "sqliteInt.h"
#include "os.h"


/*
** Get a single 8-bit random value from the RC4 PRNG.  The Mutex
** must be held while executing this routine.
**
** Why not just use a library random generator like lrand48() for this?
** Because the OP_NewRecno opcode in the VDBE depends on having a very
** good source of random numbers.  The lrand48() library function may
** well be good enough.  But maybe not.  Or maybe lrand48() has some
** subtle problems on some systems that could cause problems.  It is hard
** to know.  To minimize the risk of problems due to bad lrand48()
** implementations, SQLite uses this random number generator based
** on RC4, which we know works very well.
*/
static int randomByte(){
  unsigned char t;

  /* All threads share a single random number generator.
  ** This structure is the current state of the generator.
  */
  static struct {
    unsigned char isInit;          /* True if initialized */
    unsigned char i, j;            /* State variables */
    unsigned char s[256];          /* State variables */
  } prng;

  /* Initialize the state of the random number generator once,
  ** the first time this routine is called.  The seed value does
  ** not need to contain a lot of randomness since we are not
  ** trying to do secure encryption or anything like that...
  **

    prng.j = 0;
    prng.i = 0;
    sqliteOsRandomSeed(k);
    for(i=0; i<256; i++){
      prng.s[i] = i;
    }
    for(i=0; i<256; i++){

      prng.j += prng.s[i] + k[i];
      t = prng.s[prng.j];
      prng.s[prng.j] = prng.s[i];
      prng.s[i] = t;
    }
    prng.isInit = 1;
  }

  /* Generate and return single random byte
  */
  prng.i++;

  t = prng.s[prng.i];
  prng.j += t;
  prng.s[prng.i] = prng.s[prng.j];
  prng.s[prng.j] = t;
  t += prng.s[prng.i];
  return prng.s[t];
}

/*
** Return N random bytes.
*/
void sqliteRandomness(int N, void *pBuf){
  unsigned char *zBuf = pBuf;
  sqliteOsEnterMutex();




  while( N-- ){








    *(zBuf++) = randomByte();


  }
  sqliteOsLeaveMutex();

}

/*
** 2001 September 15
**
** 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.
**
*************************************************************************
** Internal interface definitions for SQLite.
**
** @(#) $Id: sqliteInt.h,v 1.210 2004/02/11 09:46:33 drh Exp $
*/
#include "config.h"
#include "sqlite.h"
#include "hash.h"
#include "vdbe.h"
#include "parse.h"
#include "btree.h"

int sqliteExprCheck(Parse*, Expr*, int, int*);
int sqliteExprType(Expr*);
int sqliteExprCompare(Expr*, Expr*);
int sqliteFuncId(Token*);
int sqliteExprResolveIds(Parse*, SrcList*, ExprList*, Expr*);
int sqliteExprAnalyzeAggregates(Parse*, Expr*);
Vdbe *sqliteGetVdbe(Parse*);
void sqliteRandomness(int, void*);

void sqliteRollbackAll(sqlite*);
void sqliteCodeVerifySchema(Parse*, int);
void sqliteBeginTransaction(Parse*, int);
void sqliteCommitTransaction(Parse*);
void sqliteRollbackTransaction(Parse*);
int sqliteExprIsConstant(Expr*);
int sqliteExprIsInteger(Expr*, int*);

**
*************************************************************************
** 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 1.10 2004/02/11 09:46:33 drh Exp $
*/
#include "sqliteInt.h"
#include "os.h"

/*
** A structure for holding a dynamic string - a string that can grow
** without bound. 

  rc = execsql(p->pzErrMsg, p->dbNew, zBuf);
  return rc;
}

/*
** Generate a random name of 20 character in length.
*/
static void randomName(unsigned char *zBuf){
  static const unsigned char zChars[] =
    "abcdefghijklmnopqrstuvwxyz"
    "0123456789";
  int i;
  sqliteRandomness(20, zBuf);
  for(i=0; i<20; i++){

    zBuf[i] = zChars[ zBuf[i]%(sizeof(zChars)-1) ];
  }
}
#endif

/*
** The non-standard VACUUM command is used to clean up the database,
** collapse free space, etc.  It is modelled after the VACUUM command

**
** Various scripts scan this source file in order to generate HTML
** documentation, headers files, or other derived files.  The formatting
** of the code in this file is, therefore, important.  See other comments
** in this file for details.  If in doubt, do not deviate from existing
** commenting and indentation practices when changing or adding code.
**
** $Id: vdbe.c,v 1.259 2004/02/11 09:46:33 drh Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>
#include "vdbeInt.h"

/*

      }
    }
    if( pC->useRandomRowid ){
      v = db->priorNewRowid;
      cnt = 0;
      do{
        if( v==0 || cnt>2 ){
          sqliteRandomness(sizeof(v), &v);
          if( cnt<5 ) v &= 0xffffff;
        }else{
          unsigned char r;
          sqliteRandomness(1, &r);
          v += r + 1;
        }
        if( v==0 ) continue;
        x = intToKey(v);
        rx = sqliteBtreeMoveto(pC->pCursor, &x, sizeof(int), &res);
        cnt++;
      }while( cnt<1000 && rx==SQLITE_OK && res==0 );
      db->priorNewRowid = v;