1 (******************************************************************************)
2 (* ALLFIX sample procedures *)
3 (* Copyright (C) 1992,96 Harms Software Engineering, all rights reserved *)
4 (* *)
5 (* All information in this documentation is *)
6 (* subject to change without prior notice *)
7 (******************************************************************************)
8
9 Unit Crc;
10
11 INTERFACE
12
GetCRCnull13 Function GetCRC(Const Name: string): LongInt;
CalcCRCnull14 Function CalcCRC(Const s: String): Longint;
CRCstring2Numnull15 Function CRCstring2Num(Const f: string): Longint;
16
17 IMPLEMENTATION
18
19 {$IfNDef FPC}
20 Uses Crt;
21 {$Else}
22 Uses GeneralP;
23 {$EndIf}
24
25 CONST crc_32_tab: ARRAY[0..255] OF LONGINT = (
26 $00000000, $77073096, $ee0e612c, $990951ba, $076dc419, $706af48f,
27 $e963a535,$9e6495a3,
28 $0edb8832, $79dcb8a4, $e0d5e91e, $97d2d988, $09b64c2b, $7eb17cbd,
29 $e7b82d07,$90bf1d91,
30 $1db71064, $6ab020f2, $f3b97148, $84be41de, $1adad47d, $6ddde4eb,
31 $f4d4b551,$83d385c7,
32 $136c9856, $646ba8c0, $fd62f97a, $8a65c9ec, $14015c4f, $63066cd9,
33 $fa0f3d63,$8d080df5,
34 $3b6e20c8, $4c69105e, $d56041e4, $a2677172, $3c03e4d1, $4b04d447,
35 $d20d85fd,$a50ab56b,
36 $35b5a8fa, $42b2986c, $dbbbc9d6, $acbcf940, $32d86ce3, $45df5c75,
37 $dcd60dcf,$abd13d59,
38 $26d930ac, $51de003a, $c8d75180, $bfd06116, $21b4f4b5, $56b3c423,
39 $cfba9599,$b8bda50f,
40 $2802b89e, $5f058808, $c60cd9b2, $b10be924, $2f6f7c87, $58684c11,
41 $c1611dab,$b6662d3d,
42 $76dc4190, $01db7106, $98d220bc, $efd5102a, $71b18589, $06b6b51f,
43 $9fbfe4a5,$e8b8d433,
44 $7807c9a2, $0f00f934, $9609a88e, $e10e9818, $7f6a0dbb, $086d3d2d,
45 $91646c97,$e6635c01,
46 $6b6b51f4, $1c6c6162, $856530d8, $f262004e, $6c0695ed, $1b01a57b,
47 $8208f4c1,$f50fc457,
48 $65b0d9c6, $12b7e950, $8bbeb8ea, $fcb9887c, $62dd1ddf, $15da2d49,
49 $8cd37cf3,$fbd44c65,
50 $4db26158, $3ab551ce, $a3bc0074, $d4bb30e2, $4adfa541, $3dd895d7,
51 $a4d1c46d,$d3d6f4fb,
52 $4369e96a, $346ed9fc, $ad678846, $da60b8d0, $44042d73, $33031de5,
53 $aa0a4c5f,$dd0d7cc9,
54 $5005713c, $270241aa, $be0b1010, $c90c2086, $5768b525, $206f85b3,
55 $b966d409,$ce61e49f,
56 $5edef90e, $29d9c998, $b0d09822, $c7d7a8b4, $59b33d17, $2eb40d81,
57 $b7bd5c3b,$c0ba6cad,
58 $edb88320, $9abfb3b6, $03b6e20c, $74b1d29a, $ead54739, $9dd277af,
59 $04db2615,$73dc1683,
60 $e3630b12, $94643b84, $0d6d6a3e, $7a6a5aa8, $e40ecf0b, $9309ff9d,
61 $0a00ae27,$7d079eb1,
62 $f00f9344, $8708a3d2, $1e01f268, $6906c2fe, $f762575d, $806567cb,
63 $196c3671,$6e6b06e7,
64 $fed41b76, $89d32be0, $10da7a5a, $67dd4acc, $f9b9df6f, $8ebeeff9,
65 $17b7be43,$60b08ed5,
66 $d6d6a3e8, $a1d1937e, $38d8c2c4, $4fdff252, $d1bb67f1, $a6bc5767,
67 $3fb506dd,$48b2364b,
68 $d80d2bda, $af0a1b4c, $36034af6, $41047a60, $df60efc3, $a867df55,
69 $316e8eef,$4669be79,
70 $cb61b38c, $bc66831a, $256fd2a0, $5268e236, $cc0c7795, $bb0b4703,
71 $220216b9,$5505262f,
72 $c5ba3bbe, $b2bd0b28, $2bb45a92, $5cb36a04, $c2d7ffa7, $b5d0cf31,
73 $2cd99e8b,$5bdeae1d,
74 $9b64c2b0, $ec63f226, $756aa39c, $026d930a, $9c0906a9, $eb0e363f,
75 $72076785,$05005713,
76 $95bf4a82, $e2b87a14, $7bb12bae, $0cb61b38, $92d28e9b, $e5d5be0d,
77 $7cdcefb7,$0bdbdf21,
78 $86d3d2d4, $f1d4e242, $68ddb3f8, $1fda836e, $81be16cd, $f6b9265b,
79 $6fb077e1,$18b74777,
80 $88085ae6, $ff0f6a70, $66063bca, $11010b5c, $8f659eff, $f862ae69,
81 $616bffd3,$166ccf45,
82 $a00ae278, $d70dd2ee, $4e048354, $3903b3c2, $a7672661, $d06016f7,
83 $4969474d,$3e6e77db,
84 $aed16a4a, $d9d65adc, $40df0b66, $37d83bf0, $a9bcae53, $debb9ec5,
85 $47b2cf7f,$30b5ffe9,
86 $bdbdf21c, $cabac28a, $53b39330, $24b4a3a6, $bad03605, $cdd70693,
87 $54de5729,$23d967bf,
88 $b3667a2e, $c4614ab8, $5d681b02, $2a6f2b94, $b40bbe37, $c30c8ea1,
89 $5a05df1b,$2d02ef8d);
90
GetCRCnull91 Function GetCRC(Const Name: string): LongInt;
92
93 (* This function returns the 32 bit CRC of a filename. It will return *)
94 (* a -1 if the file could not be found or opened. *)
95
96 Const Size = 4096;
97 Type Buffer = Array[1..Size] of Byte;
98
99 var f : file;
100 crc: longint;
101 Buf: ^Buffer;
102 {$IFDEF SPEED}
103 nr : longword;
104 {$ELSE}
105 {$IfDef VIRTUALPASCAL}
106 nr : LongInt;
107 {$ELSE}
108 nr : word;
109 {$ENDIF}
110 {$ENDIF}
111 Cnt: word;
112 IO : word;
113 i : Word;
114
115 begin
116 crc := $FFFFFFFF;
117 New(Buf);
118
119 assign(f,Name);
120 {$I-} reset(f,1); {$I+}
121 IO := IOresult;
122 If IO = 162 then
123 begin
124 cnt := 0;
125 While (Cnt < 10) and (IO = 162) do
126 begin
127 inc(Cnt);
128 delay(1000);
129 {$I-} Reset(f,1); {$I+}
130 IO := IOresult;
131 end;
132 end;
133 If IO = 0 then
134 begin
135 {$I-} Blockread(f,Buf^,Size,Nr); {$I+}
136 IO := IOResult;
137 while (nr > 0) do
138 begin
139 For cnt := 1 to nr do
140 Crc := crc_32_tab[byte(crc xor longint(Buf^[Cnt]))] xor ((crc shr 8) and $00FFFFFF);
141 {$I-} Blockread(f,Buf^,Size,Nr); {$I+}
142 IO := IOResult;
143 end;
144
145 {$I-} close(f); {$I+}
146 IO := IOResult;
147
148 Crc := not Crc;
149 end;
150
151 GetCRC := Crc;
152
153 Dispose(Buf);
154 end;
155
CalcCRCnull156 Function CalcCRC(Const s: string): Longint;
157
158 (* This function will return the 32 bit CRC of a string *)
159
160 var crc: longint;
161 Cnt: word;
162
163 begin
164 crc := $FFFFFFFF;
165
166 {$IfDef FPC}
167 For cnt := 1 to Length(s) do
168 Crc := crc_32_tab[byte(crc xor byte(s[Cnt]))] xor ((crc shr 8) and $00FFFFFF);
169 {$Else}
170 For cnt := 1 to Length(s) do
171 Crc := crc_32_tab[byte(crc xor longint(s[Cnt]))] xor ((crc shr 8) and $00FFFFFF);
172 {$EndIf}
173
174 CalcCRC := -(Crc+1);
175 end;
176
CRCstring2Numnull177 Function CRCstring2Num(Const f: string): Longint;
178
179 (* This function will convert a hexidecimal representation of a 32 bit *)
180 (* CRC to a numerical value *)
181
182 var CRC: Longint;
183 Cnt: Longint;
184 Weight: Longint;
185
186 begin
187 CRC := 0;
188
189 For cnt := 8 downto 1 do
190 begin
191 Weight := 1 shl ((8-cnt)*4);
192 If f[cnt] > #57 then
193 CRC := CRC + Weight*(Ord(f[cnt])-55) else
194 CRC := CRC + Weight*(Ord(f[cnt])-48);
195 end;
196 CRCstring2Num := Crc;
197 end;
198
199 end.
200
201