SQLite

** 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 1.114 2004/06/09 14:17:21 drh Exp $
*/
#include "os.h"         /* Must be first to enable large file support */
#include "sqliteInt.h"
#include "pager.h"
#include <assert.h>
#include <string.h>

      rc = sqlite3OsSync(&pPager->fd);
    }
  }

sync_exit:
  return rc;
}

#ifdef SQLITE_DEBUG
/*
** Return the current state of the file lock for the given pager.
** The return value is one of NO_LOCK, SHARED_LOCK, RESERVED_LOCK,
** PENDING_LOCK, or EXCLUSIVE_LOCK.
*/
int sqlite3pager_lockstate(Pager *pPager){
  return pPager->fd.locktype;
}
#endif

#ifdef SQLITE_TEST
/*
** Print a listing of all referenced pages and their ref count.
*/
void sqlite3pager_refdump(Pager *pPager){
  PgHdr *pPg;

**    May you share freely, never taking more than you give.
**
*************************************************************************
** This header file defines the interface that the sqlite page cache
** subsystem.  The page cache subsystem reads and writes a file a page
** at a time and provides a journal for rollback.
**
** @(#) $Id: pager.h,v 1.32 2004/06/09 14:17:21 drh Exp $
*/

/*
** The size of a page.
**
** You can change this value to another (reasonable) value you want.
** It need not be a power of two, though the interface to the disk

void sqlite3pager_dont_rollback(void*);
void sqlite3pager_dont_write(Pager*, Pgno);
int *sqlite3pager_stats(Pager*);
void sqlite3pager_set_safety_level(Pager*,int);
const char *sqlite3pager_filename(Pager*);
int sqlite3pager_rename(Pager*, const char *zNewName);
void sqlite3pager_set_codec(Pager*,void(*)(void*,void*,Pgno,int),void*);

#ifdef SQLITE_DEBUG
int sqlite3pager_lockstate(Pager*);
#endif

#ifdef SQLITE_TEST
void sqlite3pager_refdump(Pager*);
int pager3_refinfo_enable;
#endif

/*
** 2003 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.
**
*************************************************************************
** This file contains code used to implement the PRAGMA command.
**
** $Id: pragma.c,v 1.40 2004/06/09 14:17:21 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

#ifdef SQLITE_DEBUG
# include "pager.h"
# include "btree.h"
#endif

/*
** Interpret the given string as a boolean value.
*/
static int getBoolean(const char *z){
  static char *azTrue[] = { "yes", "on", "true" };
  int i;

        if( !pEnc->zName ){
          sqlite3Error(pParse->db, SQLITE_ERROR, 
              "Unsupported encoding: %s", zRight);
        }
      }
    }
  }else

#ifdef SQLITE_DEBUG
  /*
  ** Report the current state of file logs for all databases
  */
  if( sqlite3StrICmp(zLeft, "lock_status")==0 ){
    static char *azLockName[] = {
      "unlocked", "shared", "reserved", "pending", "exclusive"
    };
    int i;
    Vdbe *v = sqlite3GetVdbe(pParse);
    sqlite3VdbeSetNumCols(v, 2);
    sqlite3VdbeSetColName(v, 0, "database", P3_STATIC);
    sqlite3VdbeSetColName(v, 1, "status", P3_STATIC);
    for(i=0; i<db->nDb; i++){
      Btree *pBt;
      Pager *pPager;
      if( db->aDb[i].zName==0 ) continue;
      sqlite3VdbeOp3(v, OP_String, 0, 0, db->aDb[i].zName, P3_STATIC);
      pBt = db->aDb[i].pBt;
      if( pBt==0 || (pPager = sqlite3BtreePager(pBt))==0 ){
        sqlite3VdbeOp3(v, OP_String, 0, 0, "closed", P3_STATIC);
      }else{
        int j = sqlite3pager_lockstate(pPager);
        sqlite3VdbeOp3(v, OP_String, 0, 0, 
            (j>=0 && j<=4) ? azLockName[j] : "unknown", P3_STATIC);
      }
      sqlite3VdbeAddOp(v, OP_Callback, 2, 0);
    }
  }else
#endif

  {}
  sqliteFree(zLeft);
  sqliteFree(zRight);
}