Line data    Source code

       1             : /*
       2             :  * Copyright (C) 2007 Oracle.  All rights reserved.
       3             :  *
       4             :  * This program is free software; you can redistribute it and/or
       5             :  * modify it under the terms of the GNU General Public
       6             :  * License v2 as published by the Free Software Foundation.
       7             :  *
       8             :  * This program is distributed in the hope that it will be useful,
       9             :  * but WITHOUT ANY WARRANTY; without even the implied warranty of
      10             :  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      11             :  * General Public License for more details.
      12             :  *
      13             :  * You should have received a copy of the GNU General Public
      14             :  * License along with this program; if not, write to the
      15             :  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
      16             :  * Boston, MA 021110-1307, USA.
      17             :  */
      18             : 
      19             : #ifndef __HASH__
      20             : #define __HASH__
      21             : 
      22             : int __init btrfs_hash_init(void);
      23             : 
      24             : void btrfs_hash_exit(void);
      25             : 
      26             : u32 btrfs_crc32c(u32 crc, const void *address, unsigned int length);
      27             : 
      28             : static inline u64 btrfs_name_hash(const char *name, int len)
      29             : {
      30      191017 :         return btrfs_crc32c((u32)~1, name, len);
      31             : }
      32             : 
      33             : /*
      34             :  * Figure the key offset of an extended inode ref
      35             :  */
      36             : static inline u64 btrfs_extref_hash(u64 parent_objectid, const char *name,
      37             :                                     int len)
      38             : {
      39        3863 :         return (u64) btrfs_crc32c(parent_objectid, name, len);
      40             : }
      41             : 
      42             : #endif