e7dc130f |
1 | /* -*-c-*- |
2 | * |
3 | * $Id: crc32.c,v 1.1 2001/04/19 18:26:32 mdw Exp $ |
4 | * |
5 | * Generic hash wrapper for CRC32 |
6 | * |
7 | * (c) 2001 Straylight/Edgeware |
8 | */ |
9 | |
10 | /*----- Licensing notice --------------------------------------------------* |
11 | * |
12 | * This file is part of Catacomb. |
13 | * |
14 | * Catacomb is free software; you can redistribute it and/or modify |
15 | * it under the terms of the GNU Library General Public License as |
16 | * published by the Free Software Foundation; either version 2 of the |
17 | * License, or (at your option) any later version. |
18 | * |
19 | * Catacomb is distributed in the hope that it will be useful, |
20 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
22 | * GNU Library General Public License for more details. |
23 | * |
24 | * You should have received a copy of the GNU Library General Public |
25 | * License along with Catacomb; if not, write to the Free |
26 | * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, |
27 | * MA 02111-1307, USA. |
28 | */ |
29 | |
30 | /*----- Revision history --------------------------------------------------* |
31 | * |
32 | * $Log: crc32.c,v $ |
33 | * Revision 1.1 2001/04/19 18:26:32 mdw |
34 | * Add CRC as another hash function. |
35 | * |
36 | */ |
37 | |
38 | /*----- Header files ------------------------------------------------------*/ |
39 | |
40 | #include <mLib/crc32.h> |
41 | #include <mLib/sub.h> |
42 | |
43 | #include "arena.h" |
44 | #include "crc32.h" |
45 | #include "ghash.h" |
46 | #include "paranoia.h" |
47 | |
48 | /*----- Main code ---------------------------------------------------------*/ |
49 | |
50 | typedef struct gctx { |
51 | ghash h; |
52 | uint32 c; |
53 | octet buf[4]; |
54 | } gctx; |
55 | |
56 | static const ghash_ops gops; |
57 | |
58 | static ghash *ghinit(void) |
59 | { |
60 | gctx *g = S_CREATE(gctx); |
61 | g->h.ops = &gops; |
62 | g->c = 0; |
63 | return (&g->h); |
64 | } |
65 | |
66 | static void ghhash(ghash *h, const void *p, size_t sz) |
67 | { |
68 | gctx *g = (gctx *)h; |
69 | CRC32(g->c, g->c, p, sz); |
70 | } |
71 | |
72 | static octet *ghdone(ghash *h, void *buf) |
73 | { |
74 | gctx *g = (gctx *)h; |
75 | if (!buf) |
76 | buf = g->buf; |
77 | STORE32(buf, g->c); |
78 | return (buf); |
79 | } |
80 | |
81 | static void ghdestroy(ghash *h) |
82 | { |
83 | gctx *g = (gctx *)h; |
84 | BURN(*g); |
85 | S_DESTROY(g); |
86 | } |
87 | |
88 | static void ghcopy(ghash *h) |
89 | { |
90 | gctx *g = (gctx *)h; |
91 | gctx *gg = S_CREATE(gctx); |
92 | memcpy(gg, g, sizeof(gctx)); |
93 | return (&gg->h); |
94 | } |
95 | |
96 | static const ghash_ops gops = { &gcrc32, ghhash, ghdone, ghdestroy, ghcopy }; |
97 | const gchash gcrc32 = { "crc32", 4, ghinit }; |
98 | |
99 | /*----- That's all, folks -------------------------------------------------*/ |