Merge branch 'jc/ll-merge-expose-path'
[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 /* Remember to update object flag allocation in object.h */
64 #define COMPLETE        (1U << 0)
65 #define SEEN            (1U << 1)
66 #define TO_SCAN         (1U << 2)
67
68 static struct commit_list *complete = NULL;
69
70 static int process_commit(struct walker *walker, struct commit *commit)
71 {
72         if (parse_commit(commit))
73                 return -1;
74
75         while (complete && complete->item->date >= commit->date) {
76                 pop_most_recent_commit(&complete, COMPLETE);
77         }
78
79         if (commit->object.flags & COMPLETE)
80                 return 0;
81
82         hashcpy(current_commit_sha1, commit->object.sha1);
83
84         walker_say(walker, "walk %s\n", sha1_to_hex(commit->object.sha1));
85
86         if (walker->get_tree) {
87                 if (process(walker, &commit->tree->object))
88                         return -1;
89                 if (!walker->get_all)
90                         walker->get_tree = 0;
91         }
92         if (walker->get_history) {
93                 struct commit_list *parents = commit->parents;
94                 for (; parents; parents = parents->next) {
95                         if (process(walker, &parents->item->object))
96                                 return -1;
97                 }
98         }
99         return 0;
100 }
101
102 static int process_tag(struct walker *walker, struct tag *tag)
103 {
104         if (parse_tag(tag))
105                 return -1;
106         return process(walker, tag->tagged);
107 }
108
109 static struct object_list *process_queue = NULL;
110 static struct object_list **process_queue_end = &process_queue;
111
112 static int process_object(struct walker *walker, struct object *obj)
113 {
114         if (obj->type == OBJ_COMMIT) {
115                 if (process_commit(walker, (struct commit *)obj))
116                         return -1;
117                 return 0;
118         }
119         if (obj->type == OBJ_TREE) {
120                 if (process_tree(walker, (struct tree *)obj))
121                         return -1;
122                 return 0;
123         }
124         if (obj->type == OBJ_BLOB) {
125                 return 0;
126         }
127         if (obj->type == OBJ_TAG) {
128                 if (process_tag(walker, (struct tag *)obj))
129                         return -1;
130                 return 0;
131         }
132         return error("Unable to determine requirements "
133                      "of type %s for %s",
134                      typename(obj->type), sha1_to_hex(obj->sha1));
135 }
136
137 static int process(struct walker *walker, struct object *obj)
138 {
139         if (obj->flags & SEEN)
140                 return 0;
141         obj->flags |= SEEN;
142
143         if (has_sha1_file(obj->sha1)) {
144                 /* We already have it, so we should scan it now. */
145                 obj->flags |= TO_SCAN;
146         }
147         else {
148                 if (obj->flags & COMPLETE)
149                         return 0;
150                 walker->prefetch(walker, obj->sha1);
151         }
152
153         object_list_insert(obj, process_queue_end);
154         process_queue_end = &(*process_queue_end)->next;
155         return 0;
156 }
157
158 static int loop(struct walker *walker)
159 {
160         struct object_list *elem;
161
162         while (process_queue) {
163                 struct object *obj = process_queue->item;
164                 elem = process_queue;
165                 process_queue = elem->next;
166                 free(elem);
167                 if (!process_queue)
168                         process_queue_end = &process_queue;
169
170                 /* If we are not scanning this object, we placed it in
171                  * the queue because we needed to fetch it first.
172                  */
173                 if (! (obj->flags & TO_SCAN)) {
174                         if (walker->fetch(walker, obj->sha1)) {
175                                 report_missing(obj);
176                                 return -1;
177                         }
178                 }
179                 if (!obj->type)
180                         parse_object(obj->sha1);
181                 if (process_object(walker, obj))
182                         return -1;
183         }
184         return 0;
185 }
186
187 static int interpret_target(struct walker *walker, char *target, unsigned char *sha1)
188 {
189         if (!get_sha1_hex(target, sha1))
190                 return 0;
191         if (!check_refname_format(target, 0)) {
192                 struct ref *ref = alloc_ref(target);
193                 if (!walker->fetch_ref(walker, ref)) {
194                         hashcpy(sha1, ref->old_sha1);
195                         free(ref);
196                         return 0;
197                 }
198                 free(ref);
199         }
200         return -1;
201 }
202
203 static int mark_complete(const char *path, const struct object_id *oid,
204                          int flag, void *cb_data)
205 {
206         struct commit *commit = lookup_commit_reference_gently(oid->hash, 1);
207
208         if (commit) {
209                 commit->object.flags |= COMPLETE;
210                 commit_list_insert(commit, &complete);
211         }
212         return 0;
213 }
214
215 int walker_targets_stdin(char ***target, const char ***write_ref)
216 {
217         int targets = 0, targets_alloc = 0;
218         struct strbuf buf = STRBUF_INIT;
219         *target = NULL; *write_ref = NULL;
220         while (1) {
221                 char *rf_one = NULL;
222                 char *tg_one;
223
224                 if (strbuf_getline(&buf, stdin, '\n') == EOF)
225                         break;
226                 tg_one = buf.buf;
227                 rf_one = strchr(tg_one, '\t');
228                 if (rf_one)
229                         *rf_one++ = 0;
230
231                 if (targets >= targets_alloc) {
232                         targets_alloc = targets_alloc ? targets_alloc * 2 : 64;
233                         REALLOC_ARRAY(*target, targets_alloc);
234                         REALLOC_ARRAY(*write_ref, targets_alloc);
235                 }
236                 (*target)[targets] = xstrdup(tg_one);
237                 (*write_ref)[targets] = xstrdup_or_null(rf_one);
238                 targets++;
239         }
240         strbuf_release(&buf);
241         return targets;
242 }
243
244 void walker_targets_free(int targets, char **target, const char **write_ref)
245 {
246         while (targets--) {
247                 free(target[targets]);
248                 if (write_ref)
249                         free((char *) write_ref[targets]);
250         }
251 }
252
253 int walker_fetch(struct walker *walker, int targets, char **target,
254                  const char **write_ref, const char *write_ref_log_details)
255 {
256         struct strbuf refname = STRBUF_INIT;
257         struct strbuf err = STRBUF_INIT;
258         struct ref_transaction *transaction = NULL;
259         unsigned char *sha1 = xmalloc(targets * 20);
260         char *msg = NULL;
261         int i, ret = -1;
262
263         save_commit_buffer = 0;
264
265         if (write_ref) {
266                 transaction = ref_transaction_begin(&err);
267                 if (!transaction) {
268                         error("%s", err.buf);
269                         goto done;
270                 }
271         }
272
273         if (!walker->get_recover) {
274                 for_each_ref(mark_complete, NULL);
275                 commit_list_sort_by_date(&complete);
276         }
277
278         for (i = 0; i < targets; i++) {
279                 if (interpret_target(walker, target[i], &sha1[20 * i])) {
280                         error("Could not interpret response from server '%s' as something to pull", target[i]);
281                         goto done;
282                 }
283                 if (process(walker, lookup_unknown_object(&sha1[20 * i])))
284                         goto done;
285         }
286
287         if (loop(walker))
288                 goto done;
289         if (!write_ref) {
290                 ret = 0;
291                 goto done;
292         }
293         if (write_ref_log_details) {
294                 msg = xstrfmt("fetch from %s", write_ref_log_details);
295         } else {
296                 msg = NULL;
297         }
298         for (i = 0; i < targets; i++) {
299                 if (!write_ref[i])
300                         continue;
301                 strbuf_reset(&refname);
302                 strbuf_addf(&refname, "refs/%s", write_ref[i]);
303                 if (ref_transaction_update(transaction, refname.buf,
304                                            &sha1[20 * i], NULL, 0,
305                                            msg ? msg : "fetch (unknown)",
306                                            &err)) {
307                         error("%s", err.buf);
308                         goto done;
309                 }
310         }
311         if (ref_transaction_commit(transaction, &err)) {
312                 error("%s", err.buf);
313                 goto done;
314         }
315
316         ret = 0;
317
318 done:
319         ref_transaction_free(transaction);
320         free(msg);
321         free(sha1);
322         strbuf_release(&err);
323         strbuf_release(&refname);
324         return ret;
325 }
326
327 void walker_free(struct walker *walker)
328 {
329         walker->cleanup(walker);
330         free(walker);
331 }