1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
|
/* ScummVM Tools
* Copyright (C) 2007 The ScummVM project
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* $URL$
* $Id$
*
*/
#include "stdafx.h"
#include "KmpSearch.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifdef _MSC_VER
__declspec(naked) void __fastcall KmpSearch::init(const char *subStr) {
__asm {
// kmp initialization, make jump table for mismatches
push esi
push edi
push ebp
push ebx
push ecx
mov esi, edx // edx: subStr argument
lea edi, [ecx + KmpSearch::_subStr] // this + 0x100
lea ebx, [ecx + KmpSearch::_retarget] // this
lea ebp, [ecx + 1]
mov byte ptr [ebx], -1
xor eax, eax
loopStart:
shr ecx, 8
test al, 3
jnz short dontLoad
mov ecx, dword ptr [esi + eax] // load next 4 bytes of subStr
mov dword ptr [edi], ecx // and copy them to this._subStr while we're at it
lea edi, [edi + 4]
dontLoad:
or cl, cl // end of subStr?
jz short endOfString
mov edx, eax // save counter (i) in edx
xlat // al = retarget[i]
inc al
mov byte ptr [ebp + edx], al // retarget[i + 1] = retarget[i] + 1
jz short decLoopEnd
decrementLoop:
dec al
mov ah, byte ptr [esi + eax] // ah = sub[retarget[i + 1] - 1]
cmp ah, cl // if (ah == sub[i])
jz short decLoopEnd // goto decLoopEnd
xlat // al = retarget[retarget[i + 1] - 1]
xor ah, ah
inc al // al = retarget[retarget[i + 1] - 1] + 1
mov byte ptr [ebp + edx], al // retarget[i + 1] = al
jnz short decrementLoop
decLoopEnd:
lea eax, [edx + 1] // i = i + 1
jmp short loopStart
endOfString:
pop ecx // this
mov [ecx + KmpSearch::_strLen], eax // length of substring (without '\0')
pop ebx
pop ebp
pop edi
pop esi
ret
}
}
__declspec(naked) char * __fastcall KmpSearch::search(const char *str) {
__asm {
push esi
push edi
push ebx
mov esi, edx // edx: str argument
lea edi, [ecx + KmpSearch::_subStr]
lea ebx, [ecx + KmpSearch::_retarget]
mov ch, byte ptr [ecx + KmpSearch::_strLen]
or ch, ch // if (_strLen == 0)
jz short endOfString // goto endOfString
xor edx, edx // index
mov cl, 3
searchLoop:
shr eax, 8
inc cl
test cl, 4
jz short skipRead
lodsd
xor cl, cl
skipRead:
test al, al
jz short endOfString
newIndexLoop:
cmp al, byte ptr [edi + edx] // while (c != sub[index]) {
jz short gotNewIndex
or edx, edx // if (index == 0)
jz short searchLoop // goto searchLoop
movzx edx, byte ptr [ebx + edx] // index = retarget[index]
jmp short newIndexLoop // }
gotNewIndex:
inc edx
cmp dl, ch // if (index != _strLen)
jne short searchLoop // goto searchLoop
movzx ebx, cl // bytes of eax used
movzx ecx, ch // length of subStr
lea eax, [esi + ebx - 3]
sub eax, ecx
pop ebx
pop edi
pop esi
ret
endOfString:
xor eax, eax // return NULL
pop ebx
pop edi
pop esi
ret
}
}
#else
void __fastcall KmpSearch::init(const char *subStr) {
strcpy(_subStr, subStr);
}
char * __fastcall KmpSearch::search(const char *str) {
return strstr(str, _subStr);
}
#endif
|
