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1 | /* -*-c-*- |
2 | * |
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3 | * $Id: crc32.c,v 1.2 2004/03/21 23:52:58 mdw Exp $ |
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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 $ |
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33 | * Revision 1.2 2004/03/21 23:52:58 mdw |
34 | * Ooops, how did that slip by? Fix return type of @ghcopy@. |
35 | * |
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36 | * Revision 1.1 2001/04/19 18:26:32 mdw |
37 | * Add CRC as another hash function. |
38 | * |
39 | */ |
40 | |
41 | /*----- Header files ------------------------------------------------------*/ |
42 | |
43 | #include <mLib/crc32.h> |
44 | #include <mLib/sub.h> |
45 | |
46 | #include "arena.h" |
47 | #include "crc32.h" |
48 | #include "ghash.h" |
49 | #include "paranoia.h" |
50 | |
51 | /*----- Main code ---------------------------------------------------------*/ |
52 | |
53 | typedef struct gctx { |
54 | ghash h; |
55 | uint32 c; |
56 | octet buf[4]; |
57 | } gctx; |
58 | |
59 | static const ghash_ops gops; |
60 | |
61 | static ghash *ghinit(void) |
62 | { |
63 | gctx *g = S_CREATE(gctx); |
64 | g->h.ops = &gops; |
65 | g->c = 0; |
66 | return (&g->h); |
67 | } |
68 | |
69 | static void ghhash(ghash *h, const void *p, size_t sz) |
70 | { |
71 | gctx *g = (gctx *)h; |
72 | CRC32(g->c, g->c, p, sz); |
73 | } |
74 | |
75 | static octet *ghdone(ghash *h, void *buf) |
76 | { |
77 | gctx *g = (gctx *)h; |
78 | if (!buf) |
79 | buf = g->buf; |
80 | STORE32(buf, g->c); |
81 | return (buf); |
82 | } |
83 | |
84 | static void ghdestroy(ghash *h) |
85 | { |
86 | gctx *g = (gctx *)h; |
87 | BURN(*g); |
88 | S_DESTROY(g); |
89 | } |
90 | |
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91 | static ghash *ghcopy(ghash *h) |
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92 | { |
93 | gctx *g = (gctx *)h; |
94 | gctx *gg = S_CREATE(gctx); |
95 | memcpy(gg, g, sizeof(gctx)); |
96 | return (&gg->h); |
97 | } |
98 | |
99 | static const ghash_ops gops = { &gcrc32, ghhash, ghdone, ghdestroy, ghcopy }; |
100 | const gchash gcrc32 = { "crc32", 4, ghinit }; |
101 | |
102 | /*----- That's all, folks -------------------------------------------------*/ |