1 /* $NetBSD: dirhash.h,v 1.6 2013/07/07 19:31:26 reinoud Exp $ */ 2 3 /* 4 * Copyright (c) 2008 Reinoud Zandijk 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 #ifndef _SYS_DIRHASH_H_ 29 #define _SYS_DIRHASH_H_ 30 31 #include <sys/queue.h> 32 #include <sys/dirent.h> 33 34 #ifndef DIRHASH_SIZE 35 #define DIRHASH_SIZE (1024*1024) 36 #endif 37 38 #define DIRHASH_HASHBITS 5 39 #define DIRHASH_HASHSIZE (1 << DIRHASH_HASHBITS) 40 #define DIRHASH_HASHMASK (DIRHASH_HASHSIZE - 1) 41 42 /* dirent's d_namlen is to avoid useless costly fid->dirent translations */ 43 struct dirhash_entry { 44 uint32_t hashvalue; 45 uint64_t offset; 46 uint32_t d_namlen; 47 uint32_t entry_size; 48 LIST_ENTRY(dirhash_entry) next; 49 }; 50 51 struct dirhash { 52 uint32_t flags; 53 uint32_t size; /* in bytes */ 54 uint32_t refcnt; 55 uint32_t num_files; 56 LIST_HEAD(, dirhash_entry) entries[DIRHASH_HASHSIZE]; 57 LIST_HEAD(, dirhash_entry) free_entries; 58 TAILQ_ENTRY(dirhash) next; 59 }; 60 61 #define DIRH_PURGED 0x0001 /* dirhash has been purged */ 62 #define DIRH_COMPLETE 0x0002 /* dirhash is complete */ 63 #define DIRH_BROKEN 0x0004 /* dirhash is broken on readin */ 64 #define DIRH_COMPACTABLE 0x0008 /* free space can be compacted */ 65 #define DIRH_FLAGBITS "\10\1PURGED\2COMPLETE\3BROKEN\4COMPACTABLE" 66 67 void dirhash_init(void); 68 /* void dirhash_finish(void); */ 69 70 void dirhash_purge(struct dirhash **); 71 void dirhash_purge_entries(struct dirhash *); 72 void dirhash_get(struct dirhash **); 73 void dirhash_put(struct dirhash *); 74 void dirhash_enter(struct dirhash *, struct dirent *, uint64_t, 75 uint32_t, int); 76 void dirhash_enter_freed(struct dirhash *, uint64_t, uint32_t); 77 void dirhash_remove(struct dirhash *, struct dirent *dirent, 78 uint64_t, uint32_t); 79 int dirhash_lookup(struct dirhash *, const char *, int, 80 struct dirhash_entry **); 81 int dirhash_lookup_freed(struct dirhash *, uint32_t, 82 struct dirhash_entry **); 83 bool dirhash_dir_isempty(struct dirhash *dirh); 84 85 #endif /* _SYS_DIRHASH_H_ */ 86