SQLite

/*
** 2004 April 6
**
** 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.
**
*************************************************************************
** $Id: btree.c,v 1.653 2009/07/06 18:56:13 danielk1977 Exp $
**
** This file implements a external (disk-based) database using BTrees.
** See the header comment on "btreeInt.h" for additional information.
** Including a description of file format and an overview of operation.
*/
#include "btreeInt.h"

** to page number pOvfl was obtained, then *ppPage is set to point to that
** reference. It is the responsibility of the caller to call releasePage()
** on *ppPage to free the reference. In no reference was obtained (because
** the pointer-map was used to obtain the value for *pPgnoNext), then
** *ppPage is set to zero.
*/
static int getOverflowPage(
  BtShared *pBt, 
  Pgno ovfl,                   /* Overflow page */
  MemPage **ppPage,            /* OUT: MemPage handle (may be NULL) */
  Pgno *pPgnoNext              /* OUT: Next overflow page number */
){
  Pgno next = 0;
  MemPage *pPage = 0;
  int rc = SQLITE_OK;

**
*************************************************************************
** This file contains code used for creating, destroying, and populating
** a VDBE (or an "sqlite3_stmt" as it is known to the outside world.)  Prior
** to version 2.8.7, all this code was combined into the vdbe.c source file.
** But that file was getting too big so this subroutines were split out.
**
** $Id: vdbeaux.c,v 1.468 2009/07/06 00:44:09 drh Exp $
*/
#include "sqliteInt.h"
#include "vdbeInt.h"



/*

**
** If an IO error occurs, an SQLITE_IOERR_XXX error code is returned. 
** Otherwise SQLITE_OK.
*/
int sqlite3VdbeCloseStatement(Vdbe *p, int eOp){
  sqlite3 *const db = p->db;
  int rc = SQLITE_OK;
  if( p->iStatement && db->nStatement ){
    int i;
    const int iSavepoint = p->iStatement-1;

    assert( eOp==SAVEPOINT_ROLLBACK || eOp==SAVEPOINT_RELEASE);
    assert( db->nStatement>0 );
    assert( p->iStatement==(db->nStatement+db->nSavepoint) );

    int isSpecialError;            /* Set to true if a 'special' error */

    /* Lock all btrees used by the statement */
    sqlite3VdbeMutexArrayEnter(p);

    /* Check for one of the special errors */
    mrc = p->rc & 0xff;

    isSpecialError = mrc==SQLITE_NOMEM || mrc==SQLITE_IOERR
                     || mrc==SQLITE_INTERRUPT || mrc==SQLITE_FULL;
    if( isSpecialError ){
      /* If the query was read-only, we need do no rollback at all. Otherwise,
      ** proceed with the special handling.
      */
      if( !p->readOnly || mrc!=SQLITE_INTERRUPT ){
        if( p->rc==SQLITE_IOERR_BLOCKED && p->usesStmtJournal ){
          eStatementOp = SAVEPOINT_ROLLBACK;
          p->rc = SQLITE_BUSY;
        }else if( (mrc==SQLITE_NOMEM || mrc==SQLITE_FULL)
                   && p->usesStmtJournal ){
          eStatementOp = SAVEPOINT_ROLLBACK;
        }else{
          /* We are forced to roll back the active transaction. Before doing
          ** so, abort any other statements this handle currently has active.
          */
          invalidateCursorsOnModifiedBtrees(db);
          sqlite3RollbackAll(db);

** the result code.  Write any error message text into *pzErrMsg.
*/
int sqlite3VdbeFinalize(Vdbe *p){
  int rc = SQLITE_OK;
  if( p->magic==VDBE_MAGIC_RUN || p->magic==VDBE_MAGIC_HALT ){
    rc = sqlite3VdbeReset(p);
    assert( (rc & p->db->errMask)==rc );
  }else if( p->magic!=VDBE_MAGIC_INIT ){
    return SQLITE_MISUSE;
  }
  sqlite3VdbeDelete(p);
  return rc;
}

/*
** Call the destructor for each auxdata entry in pVdbeFunc for which

/*
** Delete an entire VDBE.
*/
void sqlite3VdbeDelete(Vdbe *p){
  int i;
  sqlite3 *db;

  if( p==0 ) return;
  db = p->db;
  if( p->pPrev ){
    p->pPrev->pNext = p->pNext;
  }else{
    assert( db->pVdbe==p );
    db->pVdbe = p->pNext;
  }