Merge branch 'jc/cache-tree'
[git] / diffcore-pickaxe.c
1 /*
2  * Copyright (C) 2005 Junio C Hamano
3  */
4 #include "cache.h"
5 #include "diff.h"
6 #include "diffcore.h"
7
8 #include <regex.h>
9
10 static unsigned int contains(struct diff_filespec *one,
11                              const char *needle, unsigned long len,
12                              regex_t *regexp)
13 {
14         unsigned int cnt;
15         unsigned long offset, sz;
16         const char *data;
17         if (diff_populate_filespec(one, 0))
18                 return 0;
19
20         sz = one->size;
21         data = one->data;
22         cnt = 0;
23
24         if (regexp) {
25                 regmatch_t regmatch;
26                 int flags = 0;
27
28                 while (*data && !regexec(regexp, data, 1, &regmatch, flags)) {
29                         flags |= REG_NOTBOL;
30                         data += regmatch.rm_so;
31                         if (*data) data++;
32                         cnt++;
33                 }
34
35         } else { /* Classic exact string match */
36                 /* Yes, I've heard of strstr(), but the thing is *data may
37                  * not be NUL terminated.  Sue me.
38                  */
39                 for (offset = 0; offset + len <= sz; offset++) {
40                         /* we count non-overlapping occurrences of needle */
41                         if (!memcmp(needle, data + offset, len)) {
42                                 offset += len - 1;
43                                 cnt++;
44                         }
45                 }
46         }
47         return cnt;
48 }
49
50 void diffcore_pickaxe(const char *needle, int opts)
51 {
52         struct diff_queue_struct *q = &diff_queued_diff;
53         unsigned long len = strlen(needle);
54         int i, has_changes;
55         regex_t regex, *regexp = NULL;
56         struct diff_queue_struct outq;
57         outq.queue = NULL;
58         outq.nr = outq.alloc = 0;
59
60         if (opts & DIFF_PICKAXE_REGEX) {
61                 int err;
62                 err = regcomp(&regex, needle, REG_EXTENDED | REG_NEWLINE);
63                 if (err) {
64                         /* The POSIX.2 people are surely sick */
65                         char errbuf[1024];
66                         regerror(err, &regex, errbuf, 1024);
67                         regfree(&regex);
68                         die("invalid pickaxe regex: %s", errbuf);
69                 }
70                 regexp = &regex;
71         }
72
73         if (opts & DIFF_PICKAXE_ALL) {
74                 /* Showing the whole changeset if needle exists */
75                 for (i = has_changes = 0; !has_changes && i < q->nr; i++) {
76                         struct diff_filepair *p = q->queue[i];
77                         if (!DIFF_FILE_VALID(p->one)) {
78                                 if (!DIFF_FILE_VALID(p->two))
79                                         continue; /* ignore unmerged */
80                                 /* created */
81                                 if (contains(p->two, needle, len, regexp))
82                                         has_changes++;
83                         }
84                         else if (!DIFF_FILE_VALID(p->two)) {
85                                 if (contains(p->one, needle, len, regexp))
86                                         has_changes++;
87                         }
88                         else if (!diff_unmodified_pair(p) &&
89                                  contains(p->one, needle, len, regexp) !=
90                                  contains(p->two, needle, len, regexp))
91                                 has_changes++;
92                 }
93                 if (has_changes)
94                         return; /* not munge the queue */
95
96                 /* otherwise we will clear the whole queue
97                  * by copying the empty outq at the end of this
98                  * function, but first clear the current entries
99                  * in the queue.
100                  */
101                 for (i = 0; i < q->nr; i++)
102                         diff_free_filepair(q->queue[i]);
103         }
104         else 
105                 /* Showing only the filepairs that has the needle */
106                 for (i = 0; i < q->nr; i++) {
107                         struct diff_filepair *p = q->queue[i];
108                         has_changes = 0;
109                         if (!DIFF_FILE_VALID(p->one)) {
110                                 if (!DIFF_FILE_VALID(p->two))
111                                         ; /* ignore unmerged */
112                                 /* created */
113                                 else if (contains(p->two, needle, len, regexp))
114                                         has_changes = 1;
115                         }
116                         else if (!DIFF_FILE_VALID(p->two)) {
117                                 if (contains(p->one, needle, len, regexp))
118                                         has_changes = 1;
119                         }
120                         else if (!diff_unmodified_pair(p) &&
121                                  contains(p->one, needle, len, regexp) !=
122                                  contains(p->two, needle, len, regexp))
123                                 has_changes = 1;
124
125                         if (has_changes)
126                                 diff_q(&outq, p);
127                         else
128                                 diff_free_filepair(p);
129                 }
130
131         if (opts & DIFF_PICKAXE_REGEX) {
132                 regfree(&regex);
133         }
134
135         free(q->queue);
136         *q = outq;
137         return;
138 }