Add --keep option to keep downloaded packs to git-fetch.
[git/git.git] / describe.c
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908e5310
LT
1#include "cache.h"
2#include "commit.h"
635d4134 3#include "tag.h"
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4#include "refs.h"
5
6#define SEEN (1u << 0)
7
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8static const char describe_usage[] =
9"git-describe [--all] [--tags] [--abbrev=<n>] <committish>*";
908e5310 10
635d4134 11static int all = 0; /* Default to annotated tags only */
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12static int tags = 0; /* But allow any tags if --tags is specified */
13
14#define DEFAULT_ABBREV 8 /* maybe too many */
15static int abbrev = DEFAULT_ABBREV;
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16
17static int names = 0, allocs = 0;
18static struct commit_name {
19 const struct commit *commit;
64deb858 20 int prio; /* annotated tag = 2, tag = 1, head = 0 */
5a2282de 21 char path[FLEX_ARRAY]; /* more */
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22} **name_array = NULL;
23
24static struct commit_name *match(struct commit *cmit)
25{
26 int i = names;
27 struct commit_name **p = name_array;
28
29 while (i-- > 0) {
30 struct commit_name *n = *p++;
31 if (n->commit == cmit)
32 return n;
33 }
34 return NULL;
35}
36
64deb858
JH
37static void add_to_known_names(const char *path,
38 const struct commit *commit,
39 int prio)
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40{
41 int idx;
42 int len = strlen(path)+1;
43 struct commit_name *name = xmalloc(sizeof(struct commit_name) + len);
44
45 name->commit = commit;
64deb858 46 name->prio = prio;
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47 memcpy(name->path, path, len);
48 idx = names;
49 if (idx >= allocs) {
50 allocs = (idx + 50) * 3 / 2;
51 name_array = xrealloc(name_array, allocs*sizeof(*name_array));
52 }
53 name_array[idx] = name;
54 names = ++idx;
55}
56
57static int get_name(const char *path, const unsigned char *sha1)
58{
59 struct commit *commit = lookup_commit_reference_gently(sha1, 1);
64deb858
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60 struct object *object;
61 int prio;
62
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63 if (!commit)
64 return 0;
64deb858 65 object = parse_object(sha1);
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66 /* If --all, then any refs are used.
67 * If --tags, then any tags are used.
68 * Otherwise only annotated tags are used.
69 */
64deb858
JH
70 if (!strncmp(path, "refs/tags/", 10)) {
71 if (object->type == tag_type)
72 prio = 2;
73 else
74 prio = 1;
75 }
76 else
77 prio = 0;
78
635d4134 79 if (!all) {
64deb858
JH
80 if (!prio)
81 return 0;
82 if (!tags && prio < 2)
635d4134 83 return 0;
635d4134 84 }
64deb858 85 add_to_known_names(all ? path + 5 : path + 10, commit, prio);
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86 return 0;
87}
88
89static int compare_names(const void *_a, const void *_b)
90{
91 struct commit_name *a = *(struct commit_name **)_a;
92 struct commit_name *b = *(struct commit_name **)_b;
93 unsigned long a_date = a->commit->date;
94 unsigned long b_date = b->commit->date;
64deb858
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95
96 if (a->prio != b->prio)
97 return b->prio - a->prio;
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98 return (a_date > b_date) ? -1 : (a_date == b_date) ? 0 : 1;
99}
100
101static void describe(struct commit *cmit)
102{
103 struct commit_list *list;
104 static int initialized = 0;
105 struct commit_name *n;
106
107 if (!initialized) {
108 initialized = 1;
109 for_each_ref(get_name);
110 qsort(name_array, names, sizeof(*name_array), compare_names);
111 }
112
113 n = match(cmit);
114 if (n) {
115 printf("%s\n", n->path);
116 return;
117 }
118
119 list = NULL;
120 commit_list_insert(cmit, &list);
121 while (list) {
122 struct commit *c = pop_most_recent_commit(&list, SEEN);
123 n = match(c);
124 if (n) {
4cdf78bf 125 printf("%s-g%s\n", n->path,
2d9e7c9f 126 find_unique_abbrev(cmit->object.sha1, abbrev));
f8f9c73c 127 break;
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128 }
129 }
f8f9c73c 130 clear_commit_marks(cmit, SEEN);
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131}
132
133int main(int argc, char **argv)
134{
135 int i;
136
137 for (i = 1; i < argc; i++) {
138 const char *arg = argv[i];
139 unsigned char sha1[20];
140 struct commit *cmit;
141
142 if (!strcmp(arg, "--all")) {
143 all = 1;
144 continue;
145 }
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146 if (!strcmp(arg, "--tags")) {
147 tags = 1;
148 continue;
149 }
150 if (!strncmp(arg, "--abbrev=", 9)) {
151 abbrev = strtoul(arg + 9, NULL, 10);
152 if (abbrev < 4 || 40 <= abbrev)
153 abbrev = DEFAULT_ABBREV;
154 continue;
155 }
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156 if (get_sha1(arg, sha1) < 0)
157 usage(describe_usage);
158 cmit = lookup_commit_reference(sha1);
159 if (!cmit)
160 usage(describe_usage);
161 describe(cmit);
162 }
163 return 0;
164}