** 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 1.489 2008/09/11 10:29:16 danielk1977 Exp $
*/
#ifndef SQLITE_OMIT_DISKIO
#include "sqliteInt.h"

/*
** Macros for troubleshooting.  Normally turned off
*/
................................................................................

/*
** Set the page size to *pPageSize. If the suggest new page size is
** inappropriate, then an alternative page size is set to that
** value before returning.
*/
int sqlite3PagerSetPagesize(Pager *pPager, u16 *pPageSize){

  int rc = SQLITE_OK;
  u16 pageSize = *pPageSize;
  assert( pageSize==0 || (pageSize>=512 && pageSize<=SQLITE_MAX_PAGE_SIZE) );
  if( pageSize && pageSize!=pPager->pageSize 
   && (pPager->memDb==0 || pPager->dbSize==0)
   && sqlite3PcacheRefCount(pPager->pPCache)==0 
  ){
    char *pNew = (char *)sqlite3PageMalloc(pageSize);
    if( !pNew ){
      rc = SQLITE_NOMEM;
    }else{
      pager_reset(pPager);
      pPager->pageSize = pageSize;
      if( !pPager->memDb ) setSectorSize(pPager);
      sqlite3PageFree(pPager->pTmpSpace);
      pPager->pTmpSpace = pNew;
      sqlite3PcacheSetPageSize(pPager->pPCache, pageSize);
    }
  }
  *pPageSize = pPager->pageSize;

  return rc;
}

/*
** Return a pointer to the "temporary page" buffer held internally
** by the pager.  This is a buffer that is big enough to hold the
** entire content of a database page.  This buffer is used internally

** 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 1.490 2008/09/16 05:12:24 danielk1977 Exp $
*/
#ifndef SQLITE_OMIT_DISKIO
#include "sqliteInt.h"

/*
** Macros for troubleshooting.  Normally turned off
*/
................................................................................

/*
** Set the page size to *pPageSize. If the suggest new page size is
** inappropriate, then an alternative page size is set to that
** value before returning.
*/
int sqlite3PagerSetPagesize(Pager *pPager, u16 *pPageSize){
  int rc = pPager->errCode;
  if( rc==SQLITE_OK ){
    u16 pageSize = *pPageSize;
    assert( pageSize==0 || (pageSize>=512 && pageSize<=SQLITE_MAX_PAGE_SIZE) );
    if( pageSize && pageSize!=pPager->pageSize 
     && (pPager->memDb==0 || pPager->dbSize==0)
     && sqlite3PcacheRefCount(pPager->pPCache)==0 
    ){
      char *pNew = (char *)sqlite3PageMalloc(pageSize);
      if( !pNew ){
        rc = SQLITE_NOMEM;
      }else{
        pager_reset(pPager);
        pPager->pageSize = pageSize;
        if( !pPager->memDb ) setSectorSize(pPager);
        sqlite3PageFree(pPager->pTmpSpace);
        pPager->pTmpSpace = pNew;
        sqlite3PcacheSetPageSize(pPager->pPCache, pageSize);
      }
    }
    *pPageSize = pPager->pageSize;
  }
  return rc;
}

/*
** Return a pointer to the "temporary page" buffer held internally
** by the pager.  This is a buffer that is big enough to hold the
** entire content of a database page.  This buffer is used internally