diff-lib.c: constness strengthening
[git] / walker.c
1 #include "cache.h"
2 #include "walker.h"
3 #include "commit.h"
4 #include "tree.h"
5 #include "tree-walk.h"
6 #include "tag.h"
7 #include "blob.h"
8 #include "refs.h"
9
10 static unsigned char current_commit_sha1[20];
11
12 void walker_say(struct walker *walker, const char *fmt, const char *hex)
13 {
14         if (walker->get_verbosely)
15                 fprintf(stderr, fmt, hex);
16 }
17
18 static void report_missing(const struct object *obj)
19 {
20         char missing_hex[41];
21         strcpy(missing_hex, sha1_to_hex(obj->sha1));;
22         fprintf(stderr, "Cannot obtain needed %s %s\n",
23                 obj->type ? typename(obj->type): "object", missing_hex);
24         if (!is_null_sha1(current_commit_sha1))
25                 fprintf(stderr, "while processing commit %s.\n",
26                         sha1_to_hex(current_commit_sha1));
27 }
28
29 static int process(struct walker *walker, struct object *obj);
30
31 static int process_tree(struct walker *walker, struct tree *tree)
32 {
33         struct tree_desc desc;
34         struct name_entry entry;
35
36         if (parse_tree(tree))
37                 return -1;
38
39         init_tree_desc(&desc, tree->buffer, tree->size);
40         while (tree_entry(&desc, &entry)) {
41                 struct object *obj = NULL;
42
43                 /* submodule commits are not stored in the superproject */
44                 if (S_ISGITLINK(entry.mode))
45                         continue;
46                 if (S_ISDIR(entry.mode)) {
47                         struct tree *tree = lookup_tree(entry.sha1);
48                         if (tree)
49                                 obj = &tree->object;
50                 }
51                 else {
52                         struct blob *blob = lookup_blob(entry.sha1);
53                         if (blob)
54                                 obj = &blob->object;
55                 }
56                 if (!obj || process(walker, obj))
57                         return -1;
58         }
59         free(tree->buffer);
60         tree->buffer = NULL;
61         tree->size = 0;
62         return 0;
63 }
64
65 #define COMPLETE        (1U << 0)
66 #define SEEN            (1U << 1)
67 #define TO_SCAN         (1U << 2)
68
69 static struct commit_list *complete = NULL;
70
71 static int process_commit(struct walker *walker, struct commit *commit)
72 {
73         if (parse_commit(commit))
74                 return -1;
75
76         while (complete && complete->item->date >= commit->date) {
77                 pop_most_recent_commit(&complete, COMPLETE);
78         }
79
80         if (commit->object.flags & COMPLETE)
81                 return 0;
82
83         hashcpy(current_commit_sha1, commit->object.sha1);
84
85         walker_say(walker, "walk %s\n", sha1_to_hex(commit->object.sha1));
86
87         if (walker->get_tree) {
88                 if (process(walker, &commit->tree->object))
89                         return -1;
90                 if (!walker->get_all)
91                         walker->get_tree = 0;
92         }
93         if (walker->get_history) {
94                 struct commit_list *parents = commit->parents;
95                 for (; parents; parents = parents->next) {
96                         if (process(walker, &parents->item->object))
97                                 return -1;
98                 }
99         }
100         return 0;
101 }
102
103 static int process_tag(struct walker *walker, struct tag *tag)
104 {
105         if (parse_tag(tag))
106                 return -1;
107         return process(walker, tag->tagged);
108 }
109
110 static struct object_list *process_queue = NULL;
111 static struct object_list **process_queue_end = &process_queue;
112
113 static int process_object(struct walker *walker, struct object *obj)
114 {
115         if (obj->type == OBJ_COMMIT) {
116                 if (process_commit(walker, (struct commit *)obj))
117                         return -1;
118                 return 0;
119         }
120         if (obj->type == OBJ_TREE) {
121                 if (process_tree(walker, (struct tree *)obj))
122                         return -1;
123                 return 0;
124         }
125         if (obj->type == OBJ_BLOB) {
126                 return 0;
127         }
128         if (obj->type == OBJ_TAG) {
129                 if (process_tag(walker, (struct tag *)obj))
130                         return -1;
131                 return 0;
132         }
133         return error("Unable to determine requirements "
134                      "of type %s for %s",
135                      typename(obj->type), sha1_to_hex(obj->sha1));
136 }
137
138 static int process(struct walker *walker, struct object *obj)
139 {
140         if (obj->flags & SEEN)
141                 return 0;
142         obj->flags |= SEEN;
143
144         if (has_sha1_file(obj->sha1)) {
145                 /* We already have it, so we should scan it now. */
146                 obj->flags |= TO_SCAN;
147         }
148         else {
149                 if (obj->flags & COMPLETE)
150                         return 0;
151                 walker->prefetch(walker, obj->sha1);
152         }
153
154         object_list_insert(obj, process_queue_end);
155         process_queue_end = &(*process_queue_end)->next;
156         return 0;
157 }
158
159 static int loop(struct walker *walker)
160 {
161         struct object_list *elem;
162
163         while (process_queue) {
164                 struct object *obj = process_queue->item;
165                 elem = process_queue;
166                 process_queue = elem->next;
167                 free(elem);
168                 if (!process_queue)
169                         process_queue_end = &process_queue;
170
171                 /* If we are not scanning this object, we placed it in
172                  * the queue because we needed to fetch it first.
173                  */
174                 if (! (obj->flags & TO_SCAN)) {
175                         if (walker->fetch(walker, obj->sha1)) {
176                                 report_missing(obj);
177                                 return -1;
178                         }
179                 }
180                 if (!obj->type)
181                         parse_object(obj->sha1);
182                 if (process_object(walker, obj))
183                         return -1;
184         }
185         return 0;
186 }
187
188 static int interpret_target(struct walker *walker, char *target, unsigned char *sha1)
189 {
190         if (!get_sha1_hex(target, sha1))
191                 return 0;
192         if (!check_ref_format(target)) {
193                 if (!walker->fetch_ref(walker, target, sha1)) {
194                         return 0;
195                 }
196         }
197         return -1;
198 }
199
200 static int mark_complete(const char *path, const unsigned char *sha1, int flag, void *cb_data)
201 {
202         struct commit *commit = lookup_commit_reference_gently(sha1, 1);
203         if (commit) {
204                 commit->object.flags |= COMPLETE;
205                 insert_by_date(commit, &complete);
206         }
207         return 0;
208 }
209
210 int walker_targets_stdin(char ***target, const char ***write_ref)
211 {
212         int targets = 0, targets_alloc = 0;
213         struct strbuf buf;
214         *target = NULL; *write_ref = NULL;
215         strbuf_init(&buf, 0);
216         while (1) {
217                 char *rf_one = NULL;
218                 char *tg_one;
219
220                 if (strbuf_getline(&buf, stdin, '\n') == EOF)
221                         break;
222                 tg_one = buf.buf;
223                 rf_one = strchr(tg_one, '\t');
224                 if (rf_one)
225                         *rf_one++ = 0;
226
227                 if (targets >= targets_alloc) {
228                         targets_alloc = targets_alloc ? targets_alloc * 2 : 64;
229                         *target = xrealloc(*target, targets_alloc * sizeof(**target));
230                         *write_ref = xrealloc(*write_ref, targets_alloc * sizeof(**write_ref));
231                 }
232                 (*target)[targets] = xstrdup(tg_one);
233                 (*write_ref)[targets] = rf_one ? xstrdup(rf_one) : NULL;
234                 targets++;
235         }
236         strbuf_release(&buf);
237         return targets;
238 }
239
240 void walker_targets_free(int targets, char **target, const char **write_ref)
241 {
242         while (targets--) {
243                 free(target[targets]);
244                 if (write_ref && write_ref[targets])
245                         free((char *) write_ref[targets]);
246         }
247 }
248
249 int walker_fetch(struct walker *walker, int targets, char **target,
250                  const char **write_ref, const char *write_ref_log_details)
251 {
252         struct ref_lock **lock = xcalloc(targets, sizeof(struct ref_lock *));
253         unsigned char *sha1 = xmalloc(targets * 20);
254         char *msg;
255         int ret;
256         int i;
257
258         save_commit_buffer = 0;
259         track_object_refs = 0;
260
261         for (i = 0; i < targets; i++) {
262                 if (!write_ref || !write_ref[i])
263                         continue;
264
265                 lock[i] = lock_ref_sha1(write_ref[i], NULL);
266                 if (!lock[i]) {
267                         error("Can't lock ref %s", write_ref[i]);
268                         goto unlock_and_fail;
269                 }
270         }
271
272         if (!walker->get_recover)
273                 for_each_ref(mark_complete, NULL);
274
275         for (i = 0; i < targets; i++) {
276                 if (interpret_target(walker, target[i], &sha1[20 * i])) {
277                         error("Could not interpret response from server '%s' as something to pull", target[i]);
278                         goto unlock_and_fail;
279                 }
280                 if (process(walker, lookup_unknown_object(&sha1[20 * i])))
281                         goto unlock_and_fail;
282         }
283
284         if (loop(walker))
285                 goto unlock_and_fail;
286
287         if (write_ref_log_details) {
288                 msg = xmalloc(strlen(write_ref_log_details) + 12);
289                 sprintf(msg, "fetch from %s", write_ref_log_details);
290         } else {
291                 msg = NULL;
292         }
293         for (i = 0; i < targets; i++) {
294                 if (!write_ref || !write_ref[i])
295                         continue;
296                 ret = write_ref_sha1(lock[i], &sha1[20 * i], msg ? msg : "fetch (unknown)");
297                 lock[i] = NULL;
298                 if (ret)
299                         goto unlock_and_fail;
300         }
301         free(msg);
302
303         return 0;
304
305 unlock_and_fail:
306         for (i = 0; i < targets; i++)
307                 if (lock[i])
308                         unlock_ref(lock[i]);
309
310         return -1;
311 }
312
313 void walker_free(struct walker *walker)
314 {
315         walker->cleanup(walker);
316         free(walker);
317 }