SQLite

** 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 1.160 2007/06/07 19:08:33 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
/* #include <math.h> */
#include <stdlib.h>
#include <assert.h>
#include "vdbeInt.h"

** The zeroblob(N) function returns a zero-filled blob of size N bytes.
*/
static void zeroblobFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  i64 n;
  assert( argc==1 );
  n = sqlite3_value_int64(argv[0]);
  if( n>SQLITE_MAX_LENGTH ){
    sqlite3_result_error_toobig(context);
  }else{
  sqlite3_result_zeroblob(context, n);
}
}

/*
** The replace() function.  Three arguments are all strings: call
** them A, B, and C. The result is also a string which is derived
** from A by replacing every occurance of B with C.  The match
** must be exact.  Collating sequences are not used.
*/

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** 
** This file defines various limits of what SQLite can process.
**
** @(#) $Id: limits.h,v 1.8 2007/06/07 19:08:34 drh Exp $
*/

/*
** The maximum length of a TEXT or BLOB in bytes.   This also
** limits the size of a row in a table or index.
**
** The hard limit is the ability of a 32-bit signed integer

*/
#ifndef SQLITE_MAX_COMPOUND_SELECT
# define SQLITE_MAX_COMPOUND_SELECT 100
#endif

/*
** The maximum number of opcodes in a VDBE program.
** Not currently enforced.
*/
#ifndef SQLITE_MAX_VDBE_OP
# define SQLITE_MAX_VDBE_OP 25000
#endif

/*
** The maximum number of arguments to an SQL function.

**
** 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 1.624 2007/06/07 19:08:34 drh Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>
#include <math.h>
#include "vdbeInt.h"

  ** is encountered.
  */
too_big:
  sqlite3SetString(&p->zErrMsg, "string or blob too big", (char*)0);
  rc = SQLITE_TOOBIG;
  goto vdbe_halt;

  /* Jump to here if a malloc() fails.

  */
no_mem:
  sqlite3SetString(&p->zErrMsg, "out of memory", (char*)0);
  rc = SQLITE_NOMEM;
  goto vdbe_halt;

  /* Jump to here for an SQLITE_MISUSE error.

** If the given Mem* has a zero-filled tail, turn it into an ordinary
** blob stored in dynamically allocated space.
*/
#ifndef SQLITE_OMIT_INCRBLOB
int sqlite3VdbeMemExpandBlob(Mem *pMem){
  if( pMem->flags & MEM_Zero ){
    char *pNew;
    int nByte;
    assert( (pMem->flags & MEM_Blob)!=0 );
    nByte = pMem->n + pMem->u.i;
    if( nByte<=0 ) nByte = 1;
    pNew = sqliteMalloc(nByte);
    if( pNew==0 ){ 
      return SQLITE_NOMEM;
    }
    memcpy(pNew, pMem->z, pMem->n);
    memset(&pNew[pMem->n], 0, pMem->u.i);
    sqlite3VdbeMemRelease(pMem);
    pMem->z = pNew;

** n containing all zeros.
*/
void sqlite3VdbeMemSetZeroBlob(Mem *pMem, int n){
  sqlite3VdbeMemRelease(pMem);
  pMem->flags = MEM_Blob|MEM_Zero|MEM_Short;
  pMem->type = SQLITE_BLOB;
  pMem->n = 0;
  if( n<0 ) n = 0;
  pMem->u.i = n;
  pMem->z = pMem->zShort;
  pMem->enc = SQLITE_UTF8;
}

/*
** Delete any previous value and set the value stored in *pMem to val,

#    May you share freely, never taking more than you give.
#
#***********************************************************************
#
# This file contains tests to verify that the limits defined in
# sqlite source file limits.h are enforced.
#
# $Id: sqllimits1.test,v 1.10 2007/06/07 19:08:34 drh Exp $

set testdir [file dirname $argv0]
source $testdir/tester.tcl

# Test organization:
#
#     sqllimits-1.*:  SQLITE_MAX_LENGTH

#     sqllimits-6.*:   SQLITE_MAX_VDBE_OP               (sqlite todo)
#

#--------------------------------------------------------------------
# Test cases sqllimits-1.* test that the SQLITE_MAX_LENGTH limit
# is enforced.
#
do_test sqllimits-1.1.1 {
  catchsql { SELECT randomblob(2147483647) }
} {1 {string or blob too big}}
do_test sqllimits-1.1.2 {
  catchsql { SELECT zeroblob(2147483647) }
} {1 {string or blob too big}}

# Large, but allowable, blob-size.
#
set ::LARGESIZE [expr $SQLITE_MAX_LENGTH - 1] 

do_test sqllimits-1.2 {
  catchsql { SELECT LENGTH(randomblob($::LARGESIZE)) }
} "0 $::LARGESIZE"

do_test sqllimits-1.3 {
  catchsql { SELECT quote(randomblob($::LARGESIZE)) }
} {1 {string or blob too big}}

do_test sqllimits-1.4 {
  catchsql { SELECT LENGTH(zeroblob($::LARGESIZE)) }
} "0 $::LARGESIZE"

do_test sqllimits-1.5 {
  catchsql { SELECT quote(zeroblob($::LARGESIZE)) }
} {1 {string or blob too big}}

do_test sqllimits-1.6 {
  catchsql { SELECT zeroblob(-1) }
} {0 {}}

do_test sqllimits-1.9 {
  set ::str [string repeat A 65537]
  set ::rep [string repeat B 65537]
  catchsql { SELECT replace($::str, 'A', $::rep) }
} {1 {string or blob too big}}

#--------------------------------------------------------------------
# Test cases sqllimits-2.* test that the SQLITE_MAX_SQL_LENGTH limit

  set ::format "[string repeat A 60][string repeat "%J" $::N]"
  catchsql {
    SELECT strftime($::format, 1);
  }
} {1 {string or blob too big}}

finish_test

#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this file is testing of the zero-filled blob functionality
# including the sqlite3_bind_zeroblob(), sqlite3_result_zeroblob(),
# and the built-in zeroblob() SQL function.
#
# $Id: zeroblob.test,v 1.6 2007/06/07 19:08:34 drh Exp $

set testdir [file dirname $argv0]
source $testdir/tester.tcl

ifcapable !incrblob {
  finish_test
  return

} {{}}
do_test zeroblob-5.4 {
  execsql {
    SELECT CAST(zeroblob(100) AS BLOB);
  }
} [execsql {SELECT zeroblob(100)}]
  

# Check for malicious use of zeroblob.  Make sure nothing crashes.
#
do_test zeroblob-6.1.1 { 
  execsql {select zeroblob(-1)} 
} {{}} 
do_test zeroblob-6.1.2 { 
  execsql {select zeroblob(-10)} 
} {{}} 
do_test zeroblob-6.1.3 { 
  execsql {select zeroblob(-100)} 
} {{}} 
do_test zeroblob-6.2 { 
  execsql {select length(zeroblob(-1))} 
} {0} 
do_test zeroblob-6.3 { 
  execsql {select zeroblob(-1)|1} 
} {1} 
do_test zeroblob-6.4 { 
  catchsql {select length(zeroblob(2147483648))} 
} {1 {string or blob too big}} 
do_test zeroblob-6.5 { 
  catchsql {select zeroblob(2147483648)} 
} {1 {string or blob too big}} 

finish_test