glossary: expand and clarify some definitions, prune cross-references
[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                                 }
52                                 else {
53                                         order[cnt] = xmalloc(ep-cp+1);
54                                         memcpy(order[cnt], cp, ep-cp);
55                                         order[cnt][ep-cp] = 0;
56                                 }
57                                 cnt++;
58                         }
59                         if (ep < endp)
60                                 ep++;
61                         cp = ep;
62                 }
63                 if (pass == 0) {
64                         order_cnt = cnt;
65                         order = xmalloc(sizeof(*order) * cnt);
66                 }
67         }
68 }
69
70 struct pair_order {
71         struct diff_filepair *pair;
72         int orig_order;
73         int order;
74 };
75
76 static int match_order(const char *path)
77 {
78         int i;
79         char p[PATH_MAX];
80
81         for (i = 0; i < order_cnt; i++) {
82                 strcpy(p, path);
83                 while (p[0]) {
84                         char *cp;
85                         if (!fnmatch(order[i], p, 0))
86                                 return i;
87                         cp = strrchr(p, '/');
88                         if (!cp)
89                                 break;
90                         *cp = 0;
91                 }
92         }
93         return order_cnt;
94 }
95
96 static int compare_pair_order(const void *a_, const void *b_)
97 {
98         struct pair_order const *a, *b;
99         a = (struct pair_order const *)a_;
100         b = (struct pair_order const *)b_;
101         if (a->order != b->order)
102                 return a->order - b->order;
103         return a->orig_order - b->orig_order;
104 }
105
106 void diffcore_order(const char *orderfile)
107 {
108         struct diff_queue_struct *q = &diff_queued_diff;
109         struct pair_order *o;
110         int i;
111
112         if (!q->nr)
113                 return;
114
115         o = xmalloc(sizeof(*o) * q->nr);
116         prepare_order(orderfile);
117         for (i = 0; i < q->nr; i++) {
118                 o[i].pair = q->queue[i];
119                 o[i].orig_order = i;
120                 o[i].order = match_order(o[i].pair->two->path);
121         }
122         qsort(o, q->nr, sizeof(*o), compare_pair_order);
123         for (i = 0; i < q->nr; i++)
124                 q->queue[i] = o[i].pair;
125         free(o);
126         return;
127 }