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
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
|
#include <u.h>
#include <libc.h>
#include <regexp.h>
#include "regimpl.h"
typedef struct RethreadQ RethreadQ;
struct RethreadQ
{
Rethread *head;
Rethread **tail;
};
int
rregexec(Reprog *prog, Rune *str, Resub *sem, int msize)
{
RethreadQ lists[2], *clist, *nlist, *tmp;
Rethread *t, *nextthr, **availthr;
Reinst *curinst;
Rune *rsp, *rep, endr, last;
int i, match, first, gen, pri, matchpri;
if(msize > NSUBEXPM)
msize = NSUBEXPM;
if(prog->startinst->gen != 0) {
for(curinst = prog->startinst; curinst < prog->startinst + prog->len; curinst++)
curinst->gen = 0;
}
clist = lists;
clist->head = nil;
clist->tail = &clist->head;
nlist = lists + 1;
nlist->head = nil;
nlist->tail = &nlist->head;
for(i = 0; i < prog->nthr; i++)
prog->thrpool[i] = prog->threads + i;
availthr = prog->thrpool + prog->nthr;
pri = matchpri = gen = match = 0;
rsp = str;
rep = nil;
endr = L'\0';
if(sem != nil && msize > 0) {
if(sem->rsp != nil)
rsp = sem->rsp;
if(sem->rep != nil && *sem->rep != L'\0') {
rep = sem->rep;
endr = *sem->rep;
*sem->rep = '\0';
}
}
last = 1;
for(; last != L'\0'; rsp++) {
gen++;
last = *rsp;
first = 1;
t = clist->head;
if(t == nil)
goto Start;
curinst = t->pc;
Again:
if(curinst->gen == gen)
goto Done;
curinst->gen = gen;
switch(curinst->op) {
case ORUNE:
if(*rsp != curinst->r)
goto Done;
case OANY: /* fallthrough */
Any:
nextthr = t->next;
t->pc = curinst + 1;
t->next = nil;
*nlist->tail = t;
nlist->tail = &t->next;
if(nextthr == nil)
break;
t = nextthr;
curinst = t->pc;
goto Again;
case OCLASS:
Class:
if(*rsp < curinst->r)
goto Done;
if(*rsp > curinst->r1) {
curinst++;
goto Class;
}
nextthr = t->next;
t->pc = curinst->a;
t->next = nil;
*nlist->tail = t;
nlist->tail = &t->next;
if(nextthr == nil)
break;
t = nextthr;
curinst = t->pc;
goto Again;
case ONOTNL:
if(*rsp != L'\n') {
curinst++;
goto Again;
}
goto Done;
case OBOL:
if(rsp == str || rsp[-1] == L'\n') {
curinst++;
goto Again;
}
goto Done;
case OEOL:
if(*rsp == L'\0' && rep == nil) {
curinst++;
goto Again;
}
if(*rsp == '\n')
goto Any;
goto Done;
case OJMP:
curinst = curinst->a;
goto Again;
case OSPLIT:
nextthr = *--availthr;
nextthr->pc = curinst->b;
if(msize > 0)
memcpy(nextthr->sem, t->sem, sizeof(Resub)*msize);
nextthr->pri = t->pri;
nextthr->next = t->next;
t->next = nextthr;
curinst = curinst->a;
goto Again;
case OSAVE:
if(curinst->sub < msize)
t->sem[curinst->sub].rsp = rsp;
curinst++;
goto Again;
case OUNSAVE:
if(curinst->sub == 0) {
/* "Highest" priority is the left-most longest. */
if (t->pri > matchpri)
goto Done;
match = 1;
matchpri = t->pri;
if(sem != nil && msize > 0) {
memcpy(sem, t->sem, sizeof(Resub)*msize);
sem->rep = rsp;
}
goto Done;
}
if(curinst->sub < msize)
t->sem[curinst->sub].rep = rsp;
curinst++;
goto Again;
Done:
*availthr++ = t;
t = t->next;
if(t == nil)
break;
curinst = t->pc;
goto Again;
}
Start:
/* Start again once if we haven't found anything. */
if(first == 1 && match == 0) {
first = 0;
t = *--availthr;
if(msize > 0)
memset(t->sem, 0, sizeof(Resub)*msize);
/* "Lower" priority thread */
t->pri = matchpri = pri++;
t->next = nil;
curinst = prog->startinst;
goto Again;
}
/* If we have a match and no extant threads, we are done. */
if(match == 1 && nlist->head == nil)
break;
tmp = clist;
clist = nlist;
nlist = tmp;
nlist->head = nil;
nlist->tail = &nlist->head;
}
if(rep != nil)
*rep = endr;
return match;
}
|
