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[git] / diffcore-order.c
1 /*
2  * Copyright (C) 2005 Junio C Hamano
3  */
4 #include "cache.h"
5 #include "diff.h"
6 #include "diffcore.h"
7
8 static char **order;
9 static int order_cnt;
10
11 static void prepare_order(const char *orderfile)
12 {
13         int fd, cnt, pass;
14         void *map;
15         char *cp, *endp;
16         struct stat st;
17         size_t sz;
18
19         if (order)
20                 return;
21
22         fd = open(orderfile, O_RDONLY);
23         if (fd < 0)
24                 return;
25         if (fstat(fd, &st)) {
26                 close(fd);
27                 return;
28         }
29         sz = xsize_t(st.st_size);
30         map = mmap(NULL, sz, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
31         close(fd);
32         if (map == MAP_FAILED)
33                 return;
34         endp = (char *) map + sz;
35         for (pass = 0; pass < 2; pass++) {
36                 cnt = 0;
37                 cp = map;
38                 while (cp < endp) {
39                         char *ep;
40                         for (ep = cp; ep < endp && *ep != '\n'; ep++)
41                                 ;
42                         /* cp to ep has one line */
43                         if (*cp == '\n' || *cp == '#')
44                                 ; /* comment */
45                         else if (pass == 0)
46                                 cnt++;
47                         else {
48                                 if (*ep == '\n') {
49                                         *ep = 0;
50                                         order[cnt] = cp;
51                                 } else {
52                                         order[cnt] = xmemdupz(cp, ep - cp);
53                                 }
54                                 cnt++;
55                         }
56                         if (ep < endp)
57                                 ep++;
58                         cp = ep;
59                 }
60                 if (pass == 0) {
61                         order_cnt = cnt;
62                         order = xmalloc(sizeof(*order) * cnt);
63                 }
64         }
65 }
66
67 struct pair_order {
68         struct diff_filepair *pair;
69         int orig_order;
70         int order;
71 };
72
73 static int match_order(const char *path)
74 {
75         int i;
76         char p[PATH_MAX];
77
78         for (i = 0; i < order_cnt; i++) {
79                 strcpy(p, path);
80                 while (p[0]) {
81                         char *cp;
82                         if (!fnmatch(order[i], p, 0))
83                                 return i;
84                         cp = strrchr(p, '/');
85                         if (!cp)
86                                 break;
87                         *cp = 0;
88                 }
89         }
90         return order_cnt;
91 }
92
93 static int compare_pair_order(const void *a_, const void *b_)
94 {
95         struct pair_order const *a, *b;
96         a = (struct pair_order const *)a_;
97         b = (struct pair_order const *)b_;
98         if (a->order != b->order)
99                 return a->order - b->order;
100         return a->orig_order - b->orig_order;
101 }
102
103 void diffcore_order(const char *orderfile)
104 {
105         struct diff_queue_struct *q = &diff_queued_diff;
106         struct pair_order *o;
107         int i;
108
109         if (!q->nr)
110                 return;
111
112         o = xmalloc(sizeof(*o) * q->nr);
113         prepare_order(orderfile);
114         for (i = 0; i < q->nr; i++) {
115                 o[i].pair = q->queue[i];
116                 o[i].orig_order = i;
117                 o[i].order = match_order(o[i].pair->two->path);
118         }
119         qsort(o, q->nr, sizeof(*o), compare_pair_order);
120         for (i = 0; i < q->nr; i++)
121                 q->queue[i] = o[i].pair;
122         free(o);
123         return;
124 }