| 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 | |