name-rev: respect const qualifier
[git] / walker.c
1 #include "cache.h"
2 #include "walker.h"
3 #include "repository.h"
4 #include "object-store.h"
5 #include "commit.h"
6 #include "tree.h"
7 #include "tree-walk.h"
8 #include "tag.h"
9 #include "blob.h"
10 #include "refs.h"
11
12 static struct object_id current_commit_oid;
13
14 void walker_say(struct walker *walker, const char *fmt, ...)
15 {
16         if (walker->get_verbosely) {
17                 va_list ap;
18                 va_start(ap, fmt);
19                 vfprintf(stderr, fmt, ap);
20                 va_end(ap);
21         }
22 }
23
24 static void report_missing(const struct object *obj)
25 {
26         fprintf(stderr, "Cannot obtain needed %s %s\n",
27                 obj->type ? type_name(obj->type): "object",
28                 oid_to_hex(&obj->oid));
29         if (!is_null_oid(&current_commit_oid))
30                 fprintf(stderr, "while processing commit %s.\n",
31                         oid_to_hex(&current_commit_oid));
32 }
33
34 static int process(struct walker *walker, struct object *obj);
35
36 static int process_tree(struct walker *walker, struct tree *tree)
37 {
38         struct tree_desc desc;
39         struct name_entry entry;
40
41         if (parse_tree(tree))
42                 return -1;
43
44         init_tree_desc(&desc, tree->buffer, tree->size);
45         while (tree_entry(&desc, &entry)) {
46                 struct object *obj = NULL;
47
48                 /* submodule commits are not stored in the superproject */
49                 if (S_ISGITLINK(entry.mode))
50                         continue;
51                 if (S_ISDIR(entry.mode)) {
52                         struct tree *tree = lookup_tree(the_repository,
53                                                         &entry.oid);
54                         if (tree)
55                                 obj = &tree->object;
56                 }
57                 else {
58                         struct blob *blob = lookup_blob(the_repository,
59                                                         &entry.oid);
60                         if (blob)
61                                 obj = &blob->object;
62                 }
63                 if (!obj || process(walker, obj))
64                         return -1;
65         }
66         free_tree_buffer(tree);
67         return 0;
68 }
69
70 /* Remember to update object flag allocation in object.h */
71 #define COMPLETE        (1U << 0)
72 #define SEEN            (1U << 1)
73 #define TO_SCAN         (1U << 2)
74
75 static struct commit_list *complete = NULL;
76
77 static int process_commit(struct walker *walker, struct commit *commit)
78 {
79         struct commit_list *parents;
80
81         if (parse_commit(commit))
82                 return -1;
83
84         while (complete && complete->item->date >= commit->date) {
85                 pop_most_recent_commit(&complete, COMPLETE);
86         }
87
88         if (commit->object.flags & COMPLETE)
89                 return 0;
90
91         oidcpy(&current_commit_oid, &commit->object.oid);
92
93         walker_say(walker, "walk %s\n", oid_to_hex(&commit->object.oid));
94
95         if (process(walker, &get_commit_tree(commit)->object))
96                 return -1;
97
98         for (parents = commit->parents; parents; parents = parents->next) {
99                 if (process(walker, &parents->item->object))
100                         return -1;
101         }
102
103         return 0;
104 }
105
106 static int process_tag(struct walker *walker, struct tag *tag)
107 {
108         if (parse_tag(tag))
109                 return -1;
110         return process(walker, tag->tagged);
111 }
112
113 static struct object_list *process_queue = NULL;
114 static struct object_list **process_queue_end = &process_queue;
115
116 static int process_object(struct walker *walker, struct object *obj)
117 {
118         if (obj->type == OBJ_COMMIT) {
119                 if (process_commit(walker, (struct commit *)obj))
120                         return -1;
121                 return 0;
122         }
123         if (obj->type == OBJ_TREE) {
124                 if (process_tree(walker, (struct tree *)obj))
125                         return -1;
126                 return 0;
127         }
128         if (obj->type == OBJ_BLOB) {
129                 return 0;
130         }
131         if (obj->type == OBJ_TAG) {
132                 if (process_tag(walker, (struct tag *)obj))
133                         return -1;
134                 return 0;
135         }
136         return error("Unable to determine requirements "
137                      "of type %s for %s",
138                      type_name(obj->type), oid_to_hex(&obj->oid));
139 }
140
141 static int process(struct walker *walker, struct object *obj)
142 {
143         if (obj->flags & SEEN)
144                 return 0;
145         obj->flags |= SEEN;
146
147         if (has_object_file(&obj->oid)) {
148                 /* We already have it, so we should scan it now. */
149                 obj->flags |= TO_SCAN;
150         }
151         else {
152                 if (obj->flags & COMPLETE)
153                         return 0;
154                 walker->prefetch(walker, obj->oid.hash);
155         }
156
157         object_list_insert(obj, process_queue_end);
158         process_queue_end = &(*process_queue_end)->next;
159         return 0;
160 }
161
162 static int loop(struct walker *walker)
163 {
164         struct object_list *elem;
165
166         while (process_queue) {
167                 struct object *obj = process_queue->item;
168                 elem = process_queue;
169                 process_queue = elem->next;
170                 free(elem);
171                 if (!process_queue)
172                         process_queue_end = &process_queue;
173
174                 /* If we are not scanning this object, we placed it in
175                  * the queue because we needed to fetch it first.
176                  */
177                 if (! (obj->flags & TO_SCAN)) {
178                         if (walker->fetch(walker, obj->oid.hash)) {
179                                 report_missing(obj);
180                                 return -1;
181                         }
182                 }
183                 if (!obj->type)
184                         parse_object(the_repository, &obj->oid);
185                 if (process_object(walker, obj))
186                         return -1;
187         }
188         return 0;
189 }
190
191 static int interpret_target(struct walker *walker, char *target, struct object_id *oid)
192 {
193         if (!get_oid_hex(target, oid))
194                 return 0;
195         if (!check_refname_format(target, 0)) {
196                 struct ref *ref = alloc_ref(target);
197                 if (!walker->fetch_ref(walker, ref)) {
198                         oidcpy(oid, &ref->old_oid);
199                         free(ref);
200                         return 0;
201                 }
202                 free(ref);
203         }
204         return -1;
205 }
206
207 static int mark_complete(const char *path, const struct object_id *oid,
208                          int flag, void *cb_data)
209 {
210         struct commit *commit = lookup_commit_reference_gently(the_repository,
211                                                                oid, 1);
212
213         if (commit) {
214                 commit->object.flags |= COMPLETE;
215                 commit_list_insert(commit, &complete);
216         }
217         return 0;
218 }
219
220 int walker_targets_stdin(char ***target, const char ***write_ref)
221 {
222         int targets = 0, targets_alloc = 0;
223         struct strbuf buf = STRBUF_INIT;
224         *target = NULL; *write_ref = NULL;
225         while (1) {
226                 char *rf_one = NULL;
227                 char *tg_one;
228
229                 if (strbuf_getline_lf(&buf, stdin) == EOF)
230                         break;
231                 tg_one = buf.buf;
232                 rf_one = strchr(tg_one, '\t');
233                 if (rf_one)
234                         *rf_one++ = 0;
235
236                 if (targets >= targets_alloc) {
237                         targets_alloc = targets_alloc ? targets_alloc * 2 : 64;
238                         REALLOC_ARRAY(*target, targets_alloc);
239                         REALLOC_ARRAY(*write_ref, targets_alloc);
240                 }
241                 (*target)[targets] = xstrdup(tg_one);
242                 (*write_ref)[targets] = xstrdup_or_null(rf_one);
243                 targets++;
244         }
245         strbuf_release(&buf);
246         return targets;
247 }
248
249 void walker_targets_free(int targets, char **target, const char **write_ref)
250 {
251         while (targets--) {
252                 free(target[targets]);
253                 if (write_ref)
254                         free((char *) write_ref[targets]);
255         }
256 }
257
258 int walker_fetch(struct walker *walker, int targets, char **target,
259                  const char **write_ref, const char *write_ref_log_details)
260 {
261         struct strbuf refname = STRBUF_INIT;
262         struct strbuf err = STRBUF_INIT;
263         struct ref_transaction *transaction = NULL;
264         struct object_id *oids = xmalloc(targets * sizeof(struct object_id));
265         char *msg = NULL;
266         int i, ret = -1;
267
268         save_commit_buffer = 0;
269
270         if (write_ref) {
271                 transaction = ref_transaction_begin(&err);
272                 if (!transaction) {
273                         error("%s", err.buf);
274                         goto done;
275                 }
276         }
277
278         if (!walker->get_recover) {
279                 for_each_ref(mark_complete, NULL);
280                 commit_list_sort_by_date(&complete);
281         }
282
283         for (i = 0; i < targets; i++) {
284                 if (interpret_target(walker, target[i], oids + i)) {
285                         error("Could not interpret response from server '%s' as something to pull", target[i]);
286                         goto done;
287                 }
288                 if (process(walker, lookup_unknown_object(&oids[i])))
289                         goto done;
290         }
291
292         if (loop(walker))
293                 goto done;
294         if (!write_ref) {
295                 ret = 0;
296                 goto done;
297         }
298         if (write_ref_log_details) {
299                 msg = xstrfmt("fetch from %s", write_ref_log_details);
300         } else {
301                 msg = NULL;
302         }
303         for (i = 0; i < targets; i++) {
304                 if (!write_ref[i])
305                         continue;
306                 strbuf_reset(&refname);
307                 strbuf_addf(&refname, "refs/%s", write_ref[i]);
308                 if (ref_transaction_update(transaction, refname.buf,
309                                            oids + i, NULL, 0,
310                                            msg ? msg : "fetch (unknown)",
311                                            &err)) {
312                         error("%s", err.buf);
313                         goto done;
314                 }
315         }
316         if (ref_transaction_commit(transaction, &err)) {
317                 error("%s", err.buf);
318                 goto done;
319         }
320
321         ret = 0;
322
323 done:
324         ref_transaction_free(transaction);
325         free(msg);
326         free(oids);
327         strbuf_release(&err);
328         strbuf_release(&refname);
329         return ret;
330 }
331
332 void walker_free(struct walker *walker)
333 {
334         walker->cleanup(walker);
335         free(walker);
336 }