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 | |