SQLite

**
*************************************************************************
** Main file for the SQLite library.  The routines in this file
** implement the programmer interface to the library.  Routines in
** other files are for internal use by SQLite and should not be
** accessed by users of the library.
**
** $Id: main.c,v 1.330 2006/01/24 13:09:33 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>

/*
** The following constant value is used by the SQLITE_BIGENDIAN and

** current thread.
**
** This routine should only be called when there are no open
** database connections.
*/
int sqlite3_enable_shared_cache(int enable){
  ThreadData *pTd = sqlite3ThreadData();
  if( pTd ){



    /* It is only legal to call sqlite3_enable_shared_cache() when there
    ** are no currently open b-trees that were opened by the calling thread.
    ** This condition is only easy to detect if the shared-cache were 
    ** previously enabled (and is being disabled). 
    */
    if( pTd->pBtree && !enable ){
      assert( pTd->useSharedData );
      return SQLITE_MISUSE;
    }

    pTd->useSharedData = enable;
    sqlite3ReleaseThreadData();
  }
  return sqlite3ApiExit(0, SQLITE_OK);
}
#endif

/*
** This is a convenience routine that makes sure that all thread-specific
** data for this thread has been deallocated.
*/

** 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 1.256 2006/01/24 13:09:33 danielk1977 Exp $
*/
#ifndef SQLITE_OMIT_DISKIO
#include "sqliteInt.h"
#include "os.h"
#include "pager.h"
#include <assert.h>
#include <string.h>

** these cases sqlite3OsRead() will return an error, to which the correct 
** response is to zero the memory at pDest and continue.  A real IO error 
** will presumably recur and be picked up later (Todo: Think about this).
*/
void sqlite3pager_read_fileheader(Pager *pPager, int N, unsigned char *pDest){
  memset(pDest, 0, N);
  if( MEMDB==0 ){
    disable_simulated_io_errors();
    sqlite3OsSeek(pPager->fd, 0);
    sqlite3OsRead(pPager->fd, pDest, N);
    enable_simulated_io_errors();
  }
}

/*
** Return the total number of pages in the disk file associated with
** pPager. 
**

**
** 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 1.539 2006/01/24 13:09:33 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>
#include "vdbeInt.h"

/*

  assert( (pTos->flags & MEM_Dyn)==0 );
  pTos--;
  assert( i>=0 && i<=p->nCursor );
  pCx = p->apCsr[i];
  assert( pCx!=0 );
  pCrsr = pCx->pCursor;
  if( pCrsr!=0 ){
    int res;
    i64 v;         /* The record number on the P1 entry that matches K */
    char *zKey;    /* The value of K */
    int nKey;      /* Number of bytes in K */
    int len;       /* Number of bytes in K without the rowid at the end */
    int szRowid;   /* Size of the rowid column at the end of zKey */

    /* Make sure K is a string and make zKey point to K

# This file implements regression tests for SQLite library.  The
# focus of this file is testing for correct handling of I/O errors
# such as writes failing because the disk is full.
# 
# The tests in this file use special facilities that are only
# available in the SQLite test fixture.
#
# $Id: ioerr.test,v 1.25 2006/01/24 13:09:33 danielk1977 Exp $

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


# If SQLITE_DEFAULT_AUTOVACUUM is set to true, then a simulated IO error
# on the 8th IO operation in the SQL script below doesn't report an error.

  SELECT * FROM t1;
  BEGIN TRANSACTION;
  INSERT INTO t1 VALUES(1,2,3);
  INSERT INTO t1 VALUES(4,5,6);
  COMMIT;
  SELECT * FROM t1;
  DELETE FROM t1 WHERE a<100;
} -exclude [expr [string match [execsql {pragma auto_vacuum}] 1] ? 4 : 0]

# Test for IO errors during a VACUUM. 
#
# The first IO call is excluded from the test. This call attempts to read
# the file-header of the temporary database used by VACUUM. Since the
# database doesn't exist at that point, the IO error is not detected.
# 

    CREATE TABLE t2 AS SELECT * FROM t1;
    CREATE TABLE t3 AS SELECT * FROM t1;
    COMMIT;
    DROP TABLE t2;
  } -sqlbody {
    VACUUM;
  } -exclude [list \
      1 [expr [string match [execsql {pragma auto_vacuum}] 1]?9:-1]]
}

do_ioerr_test ioerr-3 -tclprep {
  execsql {
    PRAGMA cache_size = 10;
    BEGIN;
    CREATE TABLE abc(a);

# Test IO errors that may occur during a multi-file commit.
#
# Tests 8 and 17 are excluded when auto-vacuum is enabled for the same 
# reason as in test cases ioerr-1.XXX
set ex ""
if {[string match [execsql {pragma auto_vacuum}] 1]} {
  set ex [list 4 17]
}
do_ioerr_test ioerr-5 -sqlprep {
  ATTACH 'test2.db' AS test2;
} -sqlbody {
  BEGIN;
  CREATE TABLE t1(a,b,c);
  CREATE TABLE test2.t2(a,b,c);

# 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.
#
#***********************************************************************
# This file implements some common TCL routines used for regression
# testing the SQLite library
#
# $Id: tester.tcl,v 1.64 2006/01/24 13:09:33 danielk1977 Exp $

# Make sure tclsqlite3 was compiled correctly.  Abort now with an
# error message if not.
#
if {[sqlite3 -tcl-uses-utf]} {
  if {"\u1234"=="u1234"} {
    puts stderr "***** BUILD PROBLEM *****"

    # Execute the TCL Script created in the above block. If
    # there are at least N IO operations performed by SQLite as
    # a result of the script, the Nth will fail.
    do_test $testname.$n.3 {
      set r [catch $::ioerrorbody msg]
      set ::go [expr {$::sqlite_io_error_pending<=0}]
      set s [expr $::sqlite_io_error_hit==0]
      set ::sqlite_io_error_hit 0
      # puts "$::sqlite_io_error_pending $r $msg"
      # puts "r=$r s=$s go=$::go msg=\"$msg\""
      expr { ($s && !$r && !$::go) || (!$s && $r && $::go) }
      # expr {$::sqlite_io_error_pending>0 || $r!=0}
    } {1}

    # If an IO error occured, then the checksum of the database should
    # be the same as before the script that caused the IO error was run.
    if {$::go && $::ioerropts(-cksum)} {
      do_test $testname.$n.4 {