** Open an incremental checkpoint handle.
*/
int sqlite3_ckpt_open(
  sqlite3 *db, 
  unsigned char *a, int n, 
  sqlite3_ckpt **ppCkpt
){
  Pager *pPager;
  Btree *pBt;
  int rc;

  *ppCkpt = 0;
  sqlite3_mutex_enter(db->mutex);
  pBt = db->aDb[0].pBt;




  pPager = sqlite3BtreePager(pBt);


  rc = sqlite3PagerWalCheckpointStart(db, pPager, a, n, ppCkpt);
  sqlite3_mutex_leave(db->mutex);
  return rc;
}


/*

** Open an incremental checkpoint handle.
*/
int sqlite3_ckpt_open(
  sqlite3 *db, 
  unsigned char *a, int n, 
  sqlite3_ckpt **ppCkpt
){
  Pager *pPager = 0;

  int rc;

  *ppCkpt = 0;
  sqlite3_mutex_enter(db->mutex);


  /* Find the Pager object. */
  rc = sqlite3_file_control(db,"main",SQLITE_FCNTL_ZIPVFS_PAGER,(void*)&pPager);
  if( rc!=SQLITE_OK ){
    pPager = sqlite3BtreePager(db->aDb[0].pBt);
  }

  rc = sqlite3PagerWalCheckpointStart(db, pPager, a, n, ppCkpt);
  sqlite3_mutex_leave(db->mutex);
  return rc;
}


/*

**
** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]]
** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging.  This
** opcode causes the xFileControl method to swap the file handle with the one
** pointed to by the pArg argument.  This capability is used during testing
** and only needs to be supported when SQLITE_TEST is defined.
**




** </ul>
*/
#define SQLITE_FCNTL_LOCKSTATE               1
#define SQLITE_GET_LOCKPROXYFILE             2
#define SQLITE_SET_LOCKPROXYFILE             3
#define SQLITE_LAST_ERRNO                    4
#define SQLITE_FCNTL_SIZE_HINT               5
................................................................................
#define SQLITE_FCNTL_TEMPFILENAME           16
#define SQLITE_FCNTL_MMAP_SIZE              18
#define SQLITE_FCNTL_TRACE                  19
#define SQLITE_FCNTL_HAS_MOVED              20
#define SQLITE_FCNTL_SYNC                   21
#define SQLITE_FCNTL_COMMIT_PHASETWO        22
#define SQLITE_FCNTL_WIN32_SET_HANDLE       23


/*
** CAPI3REF: Mutex Handle
**
** The mutex module within SQLite defines [sqlite3_mutex] to be an
** abstract type for a mutex object.  The SQLite core never looks
** at the internal representation of an [sqlite3_mutex].  It only

**
** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]]
** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging.  This
** opcode causes the xFileControl method to swap the file handle with the one
** pointed to by the pArg argument.  This capability is used during testing
** and only needs to be supported when SQLITE_TEST is defined.
**
** <li>[[SQLITE_FCNTL_ZIPVFS_PAGER]]
** The [SQLITE_FCNTL_ZIPVFS_PAGER] opcode is used by the OTA extension when
** updating a zipvfs database.
**
** </ul>
*/
#define SQLITE_FCNTL_LOCKSTATE               1
#define SQLITE_GET_LOCKPROXYFILE             2
#define SQLITE_SET_LOCKPROXYFILE             3
#define SQLITE_LAST_ERRNO                    4
#define SQLITE_FCNTL_SIZE_HINT               5
................................................................................
#define SQLITE_FCNTL_TEMPFILENAME           16
#define SQLITE_FCNTL_MMAP_SIZE              18
#define SQLITE_FCNTL_TRACE                  19
#define SQLITE_FCNTL_HAS_MOVED              20
#define SQLITE_FCNTL_SYNC                   21
#define SQLITE_FCNTL_COMMIT_PHASETWO        22
#define SQLITE_FCNTL_WIN32_SET_HANDLE       23
#define SQLITE_FCNTL_ZIPVFS_PAGER           24

/*
** CAPI3REF: Mutex Handle
**
** The mutex module within SQLite defines [sqlite3_mutex] to be an
** abstract type for a mutex object.  The SQLite core never looks
** at the internal representation of an [sqlite3_mutex].  It only