Merge branch 'jh/loose-object-dirs-creation-race'
[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(tree);
60         return 0;
61 }
62
63 #define COMPLETE        (1U << 0)
64 #define SEEN            (1U << 1)
65 #define TO_SCAN         (1U << 2)
66
67 static struct commit_list *complete = NULL;
68
69 static int process_commit(struct walker *walker, struct commit *commit)
70 {
71         if (parse_commit(commit))
72                 return -1;
73
74         while (complete && complete->item->date >= commit->date) {
75                 pop_most_recent_commit(&complete, COMPLETE);
76         }
77
78         if (commit->object.flags & COMPLETE)
79                 return 0;
80
81         hashcpy(current_commit_sha1, commit->object.sha1);
82
83         walker_say(walker, "walk %s\n", sha1_to_hex(commit->object.sha1));
84
85         if (walker->get_tree) {
86                 if (process(walker, &commit->tree->object))
87                         return -1;
88                 if (!walker->get_all)
89                         walker->get_tree = 0;
90         }
91         if (walker->get_history) {
92                 struct commit_list *parents = commit->parents;
93                 for (; parents; parents = parents->next) {
94                         if (process(walker, &parents->item->object))
95                                 return -1;
96                 }
97         }
98         return 0;
99 }
100
101 static int process_tag(struct walker *walker, struct tag *tag)
102 {
103         if (parse_tag(tag))
104                 return -1;
105         return process(walker, tag->tagged);
106 }
107
108 static struct object_list *process_queue = NULL;
109 static struct object_list **process_queue_end = &process_queue;
110
111 static int process_object(struct walker *walker, struct object *obj)
112 {
113         if (obj->type == OBJ_COMMIT) {
114                 if (process_commit(walker, (struct commit *)obj))
115                         return -1;
116                 return 0;
117         }
118         if (obj->type == OBJ_TREE) {
119                 if (process_tree(walker, (struct tree *)obj))
120                         return -1;
121                 return 0;
122         }
123         if (obj->type == OBJ_BLOB) {
124                 return 0;
125         }
126         if (obj->type == OBJ_TAG) {
127                 if (process_tag(walker, (struct tag *)obj))
128                         return -1;
129                 return 0;
130         }
131         return error("Unable to determine requirements "
132                      "of type %s for %s",
133                      typename(obj->type), sha1_to_hex(obj->sha1));
134 }
135
136 static int process(struct walker *walker, struct object *obj)
137 {
138         if (obj->flags & SEEN)
139                 return 0;
140         obj->flags |= SEEN;
141
142         if (has_sha1_file(obj->sha1)) {
143                 /* We already have it, so we should scan it now. */
144                 obj->flags |= TO_SCAN;
145         }
146         else {
147                 if (obj->flags & COMPLETE)
148                         return 0;
149                 walker->prefetch(walker, obj->sha1);
150         }
151
152         object_list_insert(obj, process_queue_end);
153         process_queue_end = &(*process_queue_end)->next;
154         return 0;
155 }
156
157 static int loop(struct walker *walker)
158 {
159         struct object_list *elem;
160
161         while (process_queue) {
162                 struct object *obj = process_queue->item;
163                 elem = process_queue;
164                 process_queue = elem->next;
165                 free(elem);
166                 if (!process_queue)
167                         process_queue_end = &process_queue;
168
169                 /* If we are not scanning this object, we placed it in
170                  * the queue because we needed to fetch it first.
171                  */
172                 if (! (obj->flags & TO_SCAN)) {
173                         if (walker->fetch(walker, obj->sha1)) {
174                                 report_missing(obj);
175                                 return -1;
176                         }
177                 }
178                 if (!obj->type)
179                         parse_object(obj->sha1);
180                 if (process_object(walker, obj))
181                         return -1;
182         }
183         return 0;
184 }
185
186 static int interpret_target(struct walker *walker, char *target, unsigned char *sha1)
187 {
188         if (!get_sha1_hex(target, sha1))
189                 return 0;
190         if (!check_refname_format(target, 0)) {
191                 struct ref *ref = alloc_ref(target);
192                 if (!walker->fetch_ref(walker, ref)) {
193                         hashcpy(sha1, ref->old_sha1);
194                         free(ref);
195                         return 0;
196                 }
197                 free(ref);
198         }
199         return -1;
200 }
201
202 static int mark_complete(const char *path, const unsigned char *sha1, int flag, void *cb_data)
203 {
204         struct commit *commit = lookup_commit_reference_gently(sha1, 1);
205         if (commit) {
206                 commit->object.flags |= COMPLETE;
207                 commit_list_insert_by_date(commit, &complete);
208         }
209         return 0;
210 }
211
212 int walker_targets_stdin(char ***target, const char ***write_ref)
213 {
214         int targets = 0, targets_alloc = 0;
215         struct strbuf buf = STRBUF_INIT;
216         *target = NULL; *write_ref = NULL;
217         while (1) {
218                 char *rf_one = NULL;
219                 char *tg_one;
220
221                 if (strbuf_getline(&buf, stdin, '\n') == EOF)
222                         break;
223                 tg_one = buf.buf;
224                 rf_one = strchr(tg_one, '\t');
225                 if (rf_one)
226                         *rf_one++ = 0;
227
228                 if (targets >= targets_alloc) {
229                         targets_alloc = targets_alloc ? targets_alloc * 2 : 64;
230                         *target = xrealloc(*target, targets_alloc * sizeof(**target));
231                         *write_ref = xrealloc(*write_ref, targets_alloc * sizeof(**write_ref));
232                 }
233                 (*target)[targets] = xstrdup(tg_one);
234                 (*write_ref)[targets] = rf_one ? xstrdup(rf_one) : NULL;
235                 targets++;
236         }
237         strbuf_release(&buf);
238         return targets;
239 }
240
241 void walker_targets_free(int targets, char **target, const char **write_ref)
242 {
243         while (targets--) {
244                 free(target[targets]);
245                 if (write_ref)
246                         free((char *) write_ref[targets]);
247         }
248 }
249
250 int walker_fetch(struct walker *walker, int targets, char **target,
251                  const char **write_ref, const char *write_ref_log_details)
252 {
253         struct ref_lock **lock = xcalloc(targets, sizeof(struct ref_lock *));
254         unsigned char *sha1 = xmalloc(targets * 20);
255         char *msg;
256         int ret;
257         int i;
258
259         save_commit_buffer = 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 }