**     CREATE INDEX
**     DROP INDEX
**     creating ID lists
**     BEGIN TRANSACTION
**     COMMIT
**     ROLLBACK
**
** $Id: build.c,v 1.483 2008/04/28 18:46:43 drh 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.
................................................................................
    ** (Bit 0 is for main, bit 1 is for temp, and so forth.)  Bits are
    ** set for each database that is used.  Generate code to start a
    ** transaction on each used database and to verify the schema cookie
    ** on each used database.
    */
    if( pParse->cookieGoto>0 ){
      u32 mask;
      int iDb, i;
      sqlite3VdbeJumpHere(v, pParse->cookieGoto-1);
      for(iDb=0, mask=1; iDb<db->nDb; mask<<=1, iDb++){
        if( (mask & pParse->cookieMask)==0 ) continue;
        sqlite3VdbeUsesBtree(v, iDb);
        sqlite3VdbeAddOp2(v,OP_Transaction, iDb, (mask & pParse->writeMask)!=0);
        sqlite3VdbeAddOp2(v,OP_VerifyCookie, iDb, pParse->cookieValue[iDb]);
      }
#ifndef SQLITE_OMIT_VIRTUALTABLE


      for(i=0; i<pParse->nVtabLock; i++){
        char *vtab = (char *)pParse->apVtabLock[i]->pVtab;
        sqlite3VdbeAddOp4(v, OP_VBegin, 0, 0, 0, vtab, P4_VTAB);
      }
      pParse->nVtabLock = 0;

#endif

      /* Once all the cookies have been verified and transactions opened, 
      ** obtain the required table-locks. This is a no-op unless the 
      ** shared-cache feature is enabled.
      */
      codeTableLocks(pParse);

**     CREATE INDEX
**     DROP INDEX
**     creating ID lists
**     BEGIN TRANSACTION
**     COMMIT
**     ROLLBACK
**
** $Id: build.c,v 1.484 2008/05/01 17:16:53 drh 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.
................................................................................
    ** (Bit 0 is for main, bit 1 is for temp, and so forth.)  Bits are
    ** set for each database that is used.  Generate code to start a
    ** transaction on each used database and to verify the schema cookie
    ** on each used database.
    */
    if( pParse->cookieGoto>0 ){
      u32 mask;
      int iDb;
      sqlite3VdbeJumpHere(v, pParse->cookieGoto-1);
      for(iDb=0, mask=1; iDb<db->nDb; mask<<=1, iDb++){
        if( (mask & pParse->cookieMask)==0 ) continue;
        sqlite3VdbeUsesBtree(v, iDb);
        sqlite3VdbeAddOp2(v,OP_Transaction, iDb, (mask & pParse->writeMask)!=0);
        sqlite3VdbeAddOp2(v,OP_VerifyCookie, iDb, pParse->cookieValue[iDb]);
      }
#ifndef SQLITE_OMIT_VIRTUALTABLE
      {
        int i;
        for(i=0; i<pParse->nVtabLock; i++){
          char *vtab = (char *)pParse->apVtabLock[i]->pVtab;
          sqlite3VdbeAddOp4(v, OP_VBegin, 0, 0, 0, vtab, P4_VTAB);
        }
        pParse->nVtabLock = 0;
      }
#endif

      /* Once all the cookies have been verified and transactions opened, 
      ** obtain the required table-locks. This is a no-op unless the 
      ** shared-cache feature is enabled.
      */
      codeTableLocks(pParse);

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains routines used for analyzing expressions and
** for generating VDBE code that evaluates expressions in SQLite.
**
** $Id: expr.c,v 1.370 2008/04/29 00:15:21 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** Return the 'affinity' of the expression pExpr if any.
**
................................................................................
  sqlite3 *db,            /* Handle for sqlite3DbMallocZero() (may be null) */
  int op,                 /* Expression opcode */
  Expr *pLeft,            /* Left operand */
  Expr *pRight,           /* Right operand */
  const Token *pToken     /* Argument token */
){
  Expr *pNew;
  static const Expr zeroExpr;
  pNew = sqlite3DbMallocRaw(db, sizeof(Expr));
  if( pNew==0 ){
    /* When malloc fails, delete pLeft and pRight. Expressions passed to 
    ** this function must always be allocated with sqlite3Expr() for this 
    ** reason. 
    */
    sqlite3ExprDelete(pLeft);
    sqlite3ExprDelete(pRight);
    return 0;
  }
  *pNew = zeroExpr;
  pNew->op = op;
  pNew->pLeft = pLeft;
  pNew->pRight = pRight;
  pNew->iAgg = -1;
  if( pToken ){
    assert( pToken->dyn==0 );
    pNew->span = pNew->token = *pToken;

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains routines used for analyzing expressions and
** for generating VDBE code that evaluates expressions in SQLite.
**
** $Id: expr.c,v 1.371 2008/05/01 17:16:53 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** Return the 'affinity' of the expression pExpr if any.
**
................................................................................
  sqlite3 *db,            /* Handle for sqlite3DbMallocZero() (may be null) */
  int op,                 /* Expression opcode */
  Expr *pLeft,            /* Left operand */
  Expr *pRight,           /* Right operand */
  const Token *pToken     /* Argument token */
){
  Expr *pNew;

  pNew = sqlite3DbMallocZero(db, sizeof(Expr));
  if( pNew==0 ){
    /* When malloc fails, delete pLeft and pRight. Expressions passed to 
    ** this function must always be allocated with sqlite3Expr() for this 
    ** reason. 
    */
    sqlite3ExprDelete(pLeft);
    sqlite3ExprDelete(pRight);
    return 0;
  }

  pNew->op = op;
  pNew->pLeft = pLeft;
  pNew->pRight = pRight;
  pNew->iAgg = -1;
  if( pToken ){
    assert( pToken->dyn==0 );
    pNew->span = pNew->token = *pToken;

** 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 1.437 2008/05/01 17:03:49 drh Exp $
*/
#ifndef SQLITE_OMIT_DISKIO
#include "sqliteInt.h"
#include <assert.h>
#include <string.h>

/*
................................................................................
** the btree layer handle that chore.
*/
#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
  static void pagerEnter(Pager *p){
    p->iInUseDB++;
    if( p->iInUseMM && p->iInUseDB==1 ){
      sqlite3_mutex *mutex;

      mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MEM2);

      p->iInUseDB = 0;
      sqlite3_mutex_enter(mutex);
      p->iInUseDB = 1;
      sqlite3_mutex_leave(mutex);
    }
    assert( p->iInUseMM==0 );
  }
................................................................................
  /* pPager->pBusyHandler = 0; */
  /* memset(pPager->aHash, 0, sizeof(pPager->aHash)); */
  *ppPager = pPager;
#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
  pPager->iInUseMM = 0;
  pPager->iInUseDB = 0;
  if( !memDb ){

    sqlite3_mutex *mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MEM2);

    sqlite3_mutex_enter(mutex);
    pPager->pNext = sqlite3PagerList;
    if( sqlite3PagerList ){
      assert( sqlite3PagerList->pPrev==0 );
      sqlite3PagerList->pPrev = pPager;
    }
    pPager->pPrev = 0;
................................................................................
** is made to roll it back. If an error occurs during the rollback 
** a hot journal may be left in the filesystem but no error is returned
** to the caller.
*/
int sqlite3PagerClose(Pager *pPager){
#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
  if( !MEMDB ){

    sqlite3_mutex *mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MEM2);

    sqlite3_mutex_enter(mutex);
    if( pPager->pPrev ){
      pPager->pPrev->pNext = pPager->pNext;
    }else{
      sqlite3PagerList = pPager->pNext;
    }
    if( pPager->pNext ){
................................................................................
  sqlite3_mutex *mutex;       /* The MEM2 mutex */
  Pager *pPager;              /* For looping over pagers */
  BusyHandler *savedBusy;     /* Saved copy of the busy handler */
  int rc = SQLITE_OK;

  /* Acquire the memory-management mutex
  */

  mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MEM2);

  sqlite3_mutex_enter(mutex);

  /* Signal all database connections that memory management wants
  ** to have access to the pagers.
  */
  for(pPager=sqlite3PagerList; pPager; pPager=pPager->pNext){
     pPager->iInUseMM = 1;

** 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 1.438 2008/05/01 17:16:53 drh Exp $
*/
#ifndef SQLITE_OMIT_DISKIO
#include "sqliteInt.h"
#include <assert.h>
#include <string.h>

/*
................................................................................
** the btree layer handle that chore.
*/
#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
  static void pagerEnter(Pager *p){
    p->iInUseDB++;
    if( p->iInUseMM && p->iInUseDB==1 ){
      sqlite3_mutex *mutex;
#ifndef SQLITE_MUTEX_NOOP
      mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MEM2);
#endif
      p->iInUseDB = 0;
      sqlite3_mutex_enter(mutex);
      p->iInUseDB = 1;
      sqlite3_mutex_leave(mutex);
    }
    assert( p->iInUseMM==0 );
  }
................................................................................
  /* pPager->pBusyHandler = 0; */
  /* memset(pPager->aHash, 0, sizeof(pPager->aHash)); */
  *ppPager = pPager;
#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
  pPager->iInUseMM = 0;
  pPager->iInUseDB = 0;
  if( !memDb ){
#ifndef SQLITE_MUTEX_NOOP
    sqlite3_mutex *mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MEM2);
#endif
    sqlite3_mutex_enter(mutex);
    pPager->pNext = sqlite3PagerList;
    if( sqlite3PagerList ){
      assert( sqlite3PagerList->pPrev==0 );
      sqlite3PagerList->pPrev = pPager;
    }
    pPager->pPrev = 0;
................................................................................
** is made to roll it back. If an error occurs during the rollback 
** a hot journal may be left in the filesystem but no error is returned
** to the caller.
*/
int sqlite3PagerClose(Pager *pPager){
#ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
  if( !MEMDB ){
#ifndef SQLITE_MUTEX_NOOP
    sqlite3_mutex *mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MEM2);
#endif
    sqlite3_mutex_enter(mutex);
    if( pPager->pPrev ){
      pPager->pPrev->pNext = pPager->pNext;
    }else{
      sqlite3PagerList = pPager->pNext;
    }
    if( pPager->pNext ){
................................................................................
  sqlite3_mutex *mutex;       /* The MEM2 mutex */
  Pager *pPager;              /* For looping over pagers */
  BusyHandler *savedBusy;     /* Saved copy of the busy handler */
  int rc = SQLITE_OK;

  /* Acquire the memory-management mutex
  */
#ifndef SQLITE_MUTEX_NOOP
  mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MEM2);
#endif
  sqlite3_mutex_enter(mutex);

  /* Signal all database connections that memory management wants
  ** to have access to the pagers.
  */
  for(pPager=sqlite3PagerList; pPager; pPager=pPager->pNext){
     pPager->iInUseMM = 1;

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** A TCL Interface to SQLite.  Append this file to sqlite3.c and
** compile the whole thing to build a TCL-enabled version of SQLite.
**
** $Id: tclsqlite.c,v 1.216 2008/04/16 00:28:14 drh Exp $
*/
#include "tcl.h"
#include <errno.h>

/*
** Some additional include files are needed if this file is not
** appended to the amalgamation.
................................................................................
  rc = Tcl_VarEval(pDb->interp, pDb->zBusy, " ", zVal, (char*)0);
  if( rc!=TCL_OK || atoi(Tcl_GetStringResult(pDb->interp)) ){
    return 0;
  }
  return 1;
}


/*
** This routine is invoked as the 'progress callback' for the database.
*/
static int DbProgressHandler(void *cd){
  SqliteDb *pDb = (SqliteDb*)cd;
  int rc;

................................................................................
  assert( pDb->zProgress );
  rc = Tcl_Eval(pDb->interp, pDb->zProgress);
  if( rc!=TCL_OK || atoi(Tcl_GetStringResult(pDb->interp)) ){
    return 1;
  }
  return 0;
}


#ifndef SQLITE_OMIT_TRACE
/*
** This routine is called by the SQLite trace handler whenever a new
** block of SQL is executed.  The TCL script in pDb->zTrace is executed.
*/
static void DbTraceHandler(void *cd, const char *zSql){

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** A TCL Interface to SQLite.  Append this file to sqlite3.c and
** compile the whole thing to build a TCL-enabled version of SQLite.
**
** $Id: tclsqlite.c,v 1.217 2008/05/01 17:16:53 drh Exp $
*/
#include "tcl.h"
#include <errno.h>

/*
** Some additional include files are needed if this file is not
** appended to the amalgamation.
................................................................................
  rc = Tcl_VarEval(pDb->interp, pDb->zBusy, " ", zVal, (char*)0);
  if( rc!=TCL_OK || atoi(Tcl_GetStringResult(pDb->interp)) ){
    return 0;
  }
  return 1;
}

#ifndef SQLITE_OMIT_PROGRESS_CALLBACK
/*
** This routine is invoked as the 'progress callback' for the database.
*/
static int DbProgressHandler(void *cd){
  SqliteDb *pDb = (SqliteDb*)cd;
  int rc;

................................................................................
  assert( pDb->zProgress );
  rc = Tcl_Eval(pDb->interp, pDb->zProgress);
  if( rc!=TCL_OK || atoi(Tcl_GetStringResult(pDb->interp)) ){
    return 1;
  }
  return 0;
}
#endif

#ifndef SQLITE_OMIT_TRACE
/*
** This routine is called by the SQLite trace handler whenever a new
** block of SQL is executed.  The TCL script in pDb->zTrace is executed.
*/
static void DbTraceHandler(void *cd, const char *zSql){

**    May you share freely, never taking more than you give.
**
*************************************************************************
** Code for testing the virtual table interfaces.  This code
** is not included in the SQLite library.  It is used for automated
** testing of the SQLite library.
**
** $Id: test_schema.c,v 1.13 2007/08/16 04:30:40 drh Exp $
*/

/* The code in this file defines a sqlite3 virtual-table module that
** provides a read-only view of the current database schema. There is one
** row in the schema table for each column in the database schema.
*/
#define SCHEMA \
................................................................................
  sqlite3_vtab_cursor base;
  sqlite3_stmt *pDbList;
  sqlite3_stmt *pTableList;
  sqlite3_stmt *pColumnList;
  int rowid;
};






/*
** Table destructor for the schema module.
*/
static int schemaDestroy(sqlite3_vtab *pVtab){
  sqlite3_free(pVtab);
  return 0;
}
................................................................................
  0,                           /* xSync */
  0,                           /* xCommit */
  0,                           /* xRollback */
  0,                           /* xFindMethod */
  0,                           /* xRename */
};



#ifdef SQLITE_TEST

/*
** Decode a pointer to an sqlite3 object.
*/
static int getDbPointer(Tcl_Interp *interp, const char *zA, sqlite3 **ppDb){

**    May you share freely, never taking more than you give.
**
*************************************************************************
** Code for testing the virtual table interfaces.  This code
** is not included in the SQLite library.  It is used for automated
** testing of the SQLite library.
**
** $Id: test_schema.c,v 1.14 2008/05/01 17:16:53 drh Exp $
*/

/* The code in this file defines a sqlite3 virtual-table module that
** provides a read-only view of the current database schema. There is one
** row in the schema table for each column in the database schema.
*/
#define SCHEMA \
................................................................................
  sqlite3_vtab_cursor base;
  sqlite3_stmt *pDbList;
  sqlite3_stmt *pTableList;
  sqlite3_stmt *pColumnList;
  int rowid;
};

/*
** None of this works unless we have virtual tables.
*/
#ifndef SQLITE_OMIT_VIRTUALTABLE

/*
** Table destructor for the schema module.
*/
static int schemaDestroy(sqlite3_vtab *pVtab){
  sqlite3_free(pVtab);
  return 0;
}
................................................................................
  0,                           /* xSync */
  0,                           /* xCommit */
  0,                           /* xRollback */
  0,                           /* xFindMethod */
  0,                           /* xRename */
};

#endif /* !defined(SQLITE_OMIT_VIRTUALTABLE) */

#ifdef SQLITE_TEST

/*
** Decode a pointer to an sqlite3 object.
*/
static int getDbPointer(Tcl_Interp *interp, const char *zA, sqlite3 **ppDb){

/*
** Check that the list looks to be internally consistent. This is used
** as part of an assert() statement as follows:
**
**   assert( stmtLruCheck() );
*/

static int stmtLruCheck(){
  Vdbe *p;
  for(p=sqlite3LruStatements.pFirst; p; p=p->pLruNext){
    assert(p->pLruNext || p==sqlite3LruStatements.pLast);
    assert(!p->pLruNext || p->pLruNext->pLruPrev==p);
    assert(p->pLruPrev || p==sqlite3LruStatements.pFirst);
    assert(!p->pLruPrev || p->pLruPrev->pLruNext==p);
  }
  return 1;
}


/*
** Add vdbe p to the end of the statement lru list. It is assumed that
** p is not already part of the list when this is called. The lru list
** is protected by the SQLITE_MUTEX_STATIC_LRU mutex.
*/
static void stmtLruAdd(Vdbe *p){

/*
** Check that the list looks to be internally consistent. This is used
** as part of an assert() statement as follows:
**
**   assert( stmtLruCheck() );
*/
#ifndef NDEBUG
static int stmtLruCheck(){
  Vdbe *p;
  for(p=sqlite3LruStatements.pFirst; p; p=p->pLruNext){
    assert(p->pLruNext || p==sqlite3LruStatements.pLast);
    assert(!p->pLruNext || p->pLruNext->pLruPrev==p);
    assert(p->pLruPrev || p==sqlite3LruStatements.pFirst);
    assert(!p->pLruPrev || p->pLruPrev->pLruNext==p);
  }
  return 1;
}
#endif

/*
** Add vdbe p to the end of the statement lru list. It is assumed that
** p is not already part of the list when this is called. The lru list
** is protected by the SQLITE_MUTEX_STATIC_LRU mutex.
*/
static void stmtLruAdd(Vdbe *p){