[PATCH] Rename/copy detection fix.
[git.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 #include "delta.h"
8
9 static int contains(struct diff_filespec *one,
10                     const char *needle, unsigned long len)
11 {
12         unsigned long offset, sz;
13         const char *data;
14         if (diff_populate_filespec(one))
15                 return 0;
16         sz = one->size;
17         data = one->data;
18         for (offset = 0; offset + len <= sz; offset++)
19                      if (!strncmp(needle, data + offset, len))
20                              return 1;
21         return 0;
22 }
23
24 void diffcore_pickaxe(const char *needle)
25 {
26         struct diff_queue_struct *q = &diff_queued_diff;
27         unsigned long len = strlen(needle);
28         int i;
29         struct diff_queue_struct outq;
30         outq.queue = NULL;
31         outq.nr = outq.alloc = 0;
32
33         for (i = 0; i < q->nr; i++) {
34                 struct diff_filepair *p = q->queue[i];
35                 int onum = outq.nr;
36                 if (!DIFF_FILE_VALID(p->one)) {
37                         if (!DIFF_FILE_VALID(p->two))
38                                 continue; /* ignore nonsense */
39                         /* created */
40                         if (contains(p->two, needle, len))
41                                 diff_q(&outq, p);
42                 }
43                 else if (!DIFF_FILE_VALID(p->two)) {
44                         if (contains(p->one, needle, len))
45                                 diff_q(&outq, p);
46                 }
47                 else if (contains(p->one, needle, len) !=
48                          contains(p->two, needle, len))
49                         diff_q(&outq, p);
50                 if (onum == outq.nr)
51                         free(p);
52         }
53         free(q->queue);
54         *q = outq;
55         return;
56 }