| 1 | /* -*-c-*- |
| 2 | * |
| 3 | * $Id: crc32.c,v 1.2 2004/03/21 23:52:58 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 1.2 2004/03/21 23:52:58 mdw |
| 34 | * Ooops, how did that slip by? Fix return type of @ghcopy@. |
| 35 | * |
| 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 | |
| 91 | static ghash *ghcopy(ghash *h) |
| 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 -------------------------------------------------*/ |