** 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.
**
*************************************************************************
** $Id: btree.c,v 1.280 2006/01/06 01:42:58 drh Exp $
**
** This file implements a external (disk-based) database using BTrees.
** For a detailed discussion of BTrees, refer to
**
**     Donald E. Knuth, THE ART OF COMPUTER PROGRAMMING, Volume 3:
**     "Sorting And Searching", pages 473-480. Addison-Wesley
**     Publishing Company, Reading, Massachusetts.
................................................................................

  /* Close the pager and free the shared-btree structure */
  assert( !pBt->pCursor );
  sqlite3pager_close(pBt->pPager);
  if( pBt->xFreeSchema && pBt->pSchema ){
    pBt->xFreeSchema(pBt->pSchema);
  }

  sqliteFree(pBt);
  return SQLITE_OK;
}

/*
** Change the busy handler callback function.
*/

** 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.
**
*************************************************************************
** $Id: btree.c,v 1.281 2006/01/06 06:33:12 danielk1977 Exp $
**
** This file implements a external (disk-based) database using BTrees.
** For a detailed discussion of BTrees, refer to
**
**     Donald E. Knuth, THE ART OF COMPUTER PROGRAMMING, Volume 3:
**     "Sorting And Searching", pages 473-480. Addison-Wesley
**     Publishing Company, Reading, Massachusetts.
................................................................................

  /* Close the pager and free the shared-btree structure */
  assert( !pBt->pCursor );
  sqlite3pager_close(pBt->pPager);
  if( pBt->xFreeSchema && pBt->pSchema ){
    pBt->xFreeSchema(pBt->pSchema);
  }
  sqliteFree(pBt->pSchema);
  sqliteFree(pBt);
  return SQLITE_OK;
}

/*
** Change the busy handler callback function.
*/

**     CREATE INDEX
**     DROP INDEX
**     creating ID lists
**     BEGIN TRANSACTION
**     COMMIT
**     ROLLBACK
**
** $Id: build.c,v 1.367 2006/01/05 11:34:34 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** This routine is called when a new SQL statement is beginning to
** be parsed.  Initialize the pParse structure as needed.
................................................................................
** it is not unlinked from the Table that it indexes.
** Unlinking from the Table must be done by the calling function.
*/
static void sqliteDeleteIndex(sqlite3 *db, Index *p){
  Index *pOld;
  const char *zName = p->zName;

  assert( db!=0 && zName!=0 );
  pOld = sqlite3HashInsert(&p->pSchema->idxHash, zName, strlen( zName)+1, 0);
  assert( pOld==0 || pOld==p );
  freeIndex(p);
}

/*
** For the index called zIdxName which is found in the database iDb,
................................................................................
** schema-cookie mismatch occurs.
**
** If iDb<=0 then reset the internal schema tables for all database
** files.  If iDb>=2 then reset the internal schema for only the
** single file indicated.
*/
void sqlite3ResetInternalSchema(sqlite3 *db, int iDb){
  HashElem *pElem;
  Hash temp1;
  Hash temp2;
  int i, j;

  assert( iDb>=0 && iDb<db->nDb );
  db->flags &= ~SQLITE_Initialized;
  for(i=iDb; i<db->nDb; i++){
    Db *pDb = &db->aDb[i];
    if( pDb->pSchema ){
      temp1 = pDb->pSchema->tblHash;
      temp2 = pDb->pSchema->trigHash;
      sqlite3HashInit(&pDb->pSchema->trigHash, SQLITE_HASH_STRING, 0);
      sqlite3HashClear(&pDb->pSchema->aFKey);
      sqlite3HashClear(&pDb->pSchema->idxHash);
      for(pElem=sqliteHashFirst(&temp2); pElem; pElem=sqliteHashNext(pElem)){
        sqlite3DeleteTrigger((Trigger*)sqliteHashData(pElem));
      }
      sqlite3HashClear(&temp2);
      sqlite3HashInit(&pDb->pSchema->tblHash, SQLITE_HASH_STRING, 0);
      for(pElem=sqliteHashFirst(&temp1); pElem; pElem=sqliteHashNext(pElem)){
        Table *pTab = sqliteHashData(pElem);
        sqlite3DeleteTable(db, pTab);
      }
      sqlite3HashClear(&temp1);
      pDb->pSchema->pSeqTab = 0;
      DbClearProperty(db, i, DB_SchemaLoaded);
    }
    if( iDb>0 ) return;
  }
  assert( iDb==0 );
  db->flags &= ~SQLITE_InternChanges;

  /* If one or more of the auxiliary database files has been closed,
................................................................................
** data structure if db!=NULL.  If db==NULL, indices attached to
** the table are deleted, but it is assumed they have already been
** unlinked.
*/
void sqlite3DeleteTable(sqlite3 *db, Table *pTable){
  Index *pIndex, *pNext;
  FKey *pFKey, *pNextFKey;



  if( pTable==0 ) return;

  /* Do not delete the table until the reference count reaches zero. */
  pTable->nRef--;
  if( pTable->nRef>0 ){
    return;
................................................................................

#ifndef SQLITE_OMIT_FOREIGN_KEY
  /* Delete all foreign keys associated with this table.  The keys
  ** should have already been unlinked from the db->aFKey hash table 
  */
  for(pFKey=pTable->pFKey; pFKey; pFKey=pNextFKey){
    pNextFKey = pFKey->pNextFrom;
    assert( sqlite3SchemaToIndex(db, pTable->pSchema)<db->nDb );
    assert( sqlite3HashFind(&pTable->pSchema->aFKey,
                           pFKey->zTo, strlen(pFKey->zTo)+1)!=pFKey );
    sqliteFree(pFKey);
  }
#endif

  /* Delete the Table structure itself.

**     CREATE INDEX
**     DROP INDEX
**     creating ID lists
**     BEGIN TRANSACTION
**     COMMIT
**     ROLLBACK
**
** $Id: build.c,v 1.368 2006/01/06 06:33:13 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** This routine is called when a new SQL statement is beginning to
** be parsed.  Initialize the pParse structure as needed.
................................................................................
** it is not unlinked from the Table that it indexes.
** Unlinking from the Table must be done by the calling function.
*/
static void sqliteDeleteIndex(sqlite3 *db, Index *p){
  Index *pOld;
  const char *zName = p->zName;


  pOld = sqlite3HashInsert(&p->pSchema->idxHash, zName, strlen( zName)+1, 0);
  assert( pOld==0 || pOld==p );
  freeIndex(p);
}

/*
** For the index called zIdxName which is found in the database iDb,
................................................................................
** schema-cookie mismatch occurs.
**
** If iDb<=0 then reset the internal schema tables for all database
** files.  If iDb>=2 then reset the internal schema for only the
** single file indicated.
*/
void sqlite3ResetInternalSchema(sqlite3 *db, int iDb){



  int i, j;

  assert( iDb>=0 && iDb<db->nDb );
  db->flags &= ~SQLITE_Initialized;
  for(i=iDb; i<db->nDb; i++){
    Db *pDb = &db->aDb[i];
    if( pDb->pSchema ){















      sqlite3SchemaFree(pDb->pSchema);

    }
    if( iDb>0 ) return;
  }
  assert( iDb==0 );
  db->flags &= ~SQLITE_InternChanges;

  /* If one or more of the auxiliary database files has been closed,
................................................................................
** data structure if db!=NULL.  If db==NULL, indices attached to
** the table are deleted, but it is assumed they have already been
** unlinked.
*/
void sqlite3DeleteTable(sqlite3 *db, Table *pTable){
  Index *pIndex, *pNext;
  FKey *pFKey, *pNextFKey;

  db = 0;

  if( pTable==0 ) return;

  /* Do not delete the table until the reference count reaches zero. */
  pTable->nRef--;
  if( pTable->nRef>0 ){
    return;
................................................................................

#ifndef SQLITE_OMIT_FOREIGN_KEY
  /* Delete all foreign keys associated with this table.  The keys
  ** should have already been unlinked from the db->aFKey hash table 
  */
  for(pFKey=pTable->pFKey; pFKey; pFKey=pNextFKey){
    pNextFKey = pFKey->pNextFrom;

    assert( sqlite3HashFind(&pTable->pSchema->aFKey,
                           pFKey->zTo, strlen(pFKey->zTo)+1)!=pFKey );
    sqliteFree(pFKey);
  }
#endif

  /* Delete the Table structure itself.

**
*************************************************************************
** 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 1.315 2006/01/05 13:48:29 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>

/*
** The following constant value is used by the SQLITE_BIGENDIAN and
................................................................................
** Return the number of changes since the database handle was opened.
*/
int sqlite3_total_changes(sqlite3 *db){
  return db->nTotalChange;
}

/*
** Free a schema structure.



*/
void sqlite3SchemaFree(void *p){
  sqliteFree(p);






















}

DbSchema *sqlite3SchemaGet(Btree *pBt){
  DbSchema * p;
  if( pBt ){
    p = (DbSchema *)sqlite3BtreeSchema(pBt,sizeof(DbSchema),sqlite3SchemaFree);
  }else{
    p = (DbSchema *)sqliteMalloc(sizeof(DbSchema));
  }
  if( p ){
    sqlite3HashInit(&p->tblHash, SQLITE_HASH_STRING, 0);
    sqlite3HashInit(&p->idxHash, SQLITE_HASH_STRING, 0);
    sqlite3HashInit(&p->trigHash, SQLITE_HASH_STRING, 0);
    sqlite3HashInit(&p->aFKey, SQLITE_HASH_STRING, 1);
  }
  return p;
}

**
*************************************************************************
** 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 1.316 2006/01/06 06:33:13 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>

/*
** The following constant value is used by the SQLITE_BIGENDIAN and
................................................................................
** Return the number of changes since the database handle was opened.
*/
int sqlite3_total_changes(sqlite3 *db){
  return db->nTotalChange;
}

/*
** Free all resources held by the schema structure. The void* argument points
** at a DbSchema struct. This function does not call sqliteFree() on the 
** pointer itself, it just cleans up subsiduary resources (i.e. the contents
** of the schema hash tables).
*/
void sqlite3SchemaFree(void *p){

  Hash temp1;
  Hash temp2;
  HashElem *pElem;
  DbSchema *pSchema = (DbSchema *)p;

  temp1 = pSchema->tblHash;
  temp2 = pSchema->trigHash;
  sqlite3HashInit(&pSchema->trigHash, SQLITE_HASH_STRING, 0);
  sqlite3HashClear(&pSchema->aFKey);
  sqlite3HashClear(&pSchema->idxHash);
  for(pElem=sqliteHashFirst(&temp2); pElem; pElem=sqliteHashNext(pElem)){
    sqlite3DeleteTrigger((Trigger*)sqliteHashData(pElem));
  }
  sqlite3HashClear(&temp2);
  sqlite3HashInit(&pSchema->tblHash, SQLITE_HASH_STRING, 0);
  for(pElem=sqliteHashFirst(&temp1); pElem; pElem=sqliteHashNext(pElem)){
    Table *pTab = sqliteHashData(pElem);
    sqlite3DeleteTable(0, pTab);
  }
  sqlite3HashClear(&temp1);
  pSchema->pSeqTab = 0;
  pSchema->flags &= ~DB_SchemaLoaded;
}

DbSchema *sqlite3SchemaGet(Btree *pBt){
  DbSchema * p;
  if( pBt ){
    p = (DbSchema *)sqlite3BtreeSchema(pBt,sizeof(DbSchema),sqlite3SchemaFree);
  }else{
    p = (DbSchema *)sqliteMalloc(sizeof(DbSchema));
  }
  if( p && 0==p->file_format ){
    sqlite3HashInit(&p->tblHash, SQLITE_HASH_STRING, 0);
    sqlite3HashInit(&p->idxHash, SQLITE_HASH_STRING, 0);
    sqlite3HashInit(&p->trigHash, SQLITE_HASH_STRING, 0);
    sqlite3HashInit(&p->aFKey, SQLITE_HASH_STRING, 1);
  }
  return p;
}

**
*************************************************************************
** Utility functions used throughout sqlite.
**
** This file contains functions for allocating memory, comparing
** strings, and stuff like that.
**
** $Id: util.c,v 1.159 2005/12/29 01:11:37 drh Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <stdarg.h>
#include <ctype.h>

/*
................................................................................
  z = &zAlloc[TESTALLOC_OFFSET_STACK(p)];
  backtrace((void **)z, TESTALLOC_STACKFRAMES);

  /* Sanity check to make sure checkGuards() is working */
  checkGuards(p);
}





static void *getOsPointer(void *p)
{
  char *z = (char *)p;
  return (void *)(&z[-1 * TESTALLOC_OFFSET_DATA(p)]);
}

**
*************************************************************************
** Utility functions used throughout sqlite.
**
** This file contains functions for allocating memory, comparing
** strings, and stuff like that.
**
** $Id: util.c,v 1.160 2006/01/06 06:33:13 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <stdarg.h>
#include <ctype.h>

/*
................................................................................
  z = &zAlloc[TESTALLOC_OFFSET_STACK(p)];
  backtrace((void **)z, TESTALLOC_STACKFRAMES);

  /* Sanity check to make sure checkGuards() is working */
  checkGuards(p);
}

/*
** The argument is a malloc()ed pointer as returned by the test-wrapper.
** Return a pointer to the Os level allocation.
*/
static void *getOsPointer(void *p)
{
  char *z = (char *)p;
  return (void *)(&z[-1 * TESTALLOC_OFFSET_DATA(p)]);
}

#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this file is testing the SELECT statement.
#
# $Id: shared.test,v 1.2 2006/01/05 11:34:34 danielk1977 Exp $

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

ifcapable !shared_cache {
  finish_test
................................................................................
#
# shared-1.*: Simple test to verify basic sanity of table level locking when
#             two connections share a pager cache.
# shared-2.*: Test that a read transaction can co-exist with a 
#             write-transaction, including a simple test to ensure the 
#             external locking protocol is still working.
# shared-3.*: Simple test of read-uncommitted mode.


#

do_test shared-1.1 {
  # Open a second database on the file test.db. It should use the same pager
  # cache and schema as the original connection. Verify that only 1 file is 
  # opened.
  sqlite3 db2 test.db
................................................................................
    SELECT * FROM seq;
  }
} {}

catch {db close}
catch {db2 close}
catch {db3 close}





















































finish_test
sqlite3_enable_shared_cache $::enable_shared_cache

#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this file is testing the SELECT statement.
#
# $Id: shared.test,v 1.3 2006/01/06 06:33:13 danielk1977 Exp $

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

ifcapable !shared_cache {
  finish_test
................................................................................
#
# shared-1.*: Simple test to verify basic sanity of table level locking when
#             two connections share a pager cache.
# shared-2.*: Test that a read transaction can co-exist with a 
#             write-transaction, including a simple test to ensure the 
#             external locking protocol is still working.
# shared-3.*: Simple test of read-uncommitted mode.
#
# shared-4.*: Check that the schema is locked and unlocked correctly.
#

do_test shared-1.1 {
  # Open a second database on the file test.db. It should use the same pager
  # cache and schema as the original connection. Verify that only 1 file is 
  # opened.
  sqlite3 db2 test.db
................................................................................
    SELECT * FROM seq;
  }
} {}

catch {db close}
catch {db2 close}
catch {db3 close}

#--------------------------------------------------------------------------
# Tests shared-4.* test that the schema locking rules are applied 
# correctly. i.e.:
#
# 1. All transactions require a read-lock on the schemas of databases they
#    access.
# 2. Transactions that modify a database schema require a write-lock on that
#    schema.
# 3. It is not possible to compile a statement while another handle has a 
#    write-lock on the schema.
#

# Open two database handles db and db2. Each has a single attach database
# (as well as main):
#
#     db.main   ->   ./test.db
#     db.test2  ->   ./test2.db
#     db2.main  ->   ./test2.db
#     db2.test  ->   ./test.db
#
file delete -force test.db
file delete -force test2.db
file delete -force test2.db-journal
sqlite3 db  test.db
sqlite3 db2 test2.db
do_test shared-4.1.1 {
  set sqlite_open_file_count
} {2}
do_test shared-4.1.2 {
  execsql {ATTACH 'test2.db' AS test2}
  set sqlite_open_file_count
} {2}
do_test shared-4.1.3 {
  execsql {ATTACH 'test.db' AS test} db2
  set sqlite_open_file_count
} {2}

do_test shared-4.2.1 {
  execsql {
    CREATE TABLE abc(a, b, c);
    INSERT INTO abc VALUES('i', 'ii', 'iii');
  }
} {}
do_test shared-4.2.2 {
  execsql {
    SELECT * FROM test.abc;
  } db2
} {i ii iii}

catch {db2 close}
catch {db close}

finish_test
sqlite3_enable_shared_cache $::enable_shared_cache