Documentation/describe: improve one-line summary
[git.git] / walker.c
blobf149371e71ebdcdbd12336aace15b0fc20f74569
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"
10 static unsigned char current_commit_sha1[20];
12 void walker_say(struct walker *walker, const char *fmt, const char *hex)
14 if (walker->get_verbosely)
15 fprintf(stderr, fmt, hex);
18 static void report_missing(const struct object *obj)
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));
29 static int process(struct walker *walker, struct object *obj);
31 static int process_tree(struct walker *walker, struct tree *tree)
33 struct tree_desc desc;
34 struct name_entry entry;
36 if (parse_tree(tree))
37 return -1;
39 init_tree_desc(&desc, tree->buffer, tree->size);
40 while (tree_entry(&desc, &entry)) {
41 struct object *obj = NULL;
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;
51 else {
52 struct blob *blob = lookup_blob(entry.sha1);
53 if (blob)
54 obj = &blob->object;
56 if (!obj || process(walker, obj))
57 return -1;
59 free_tree_buffer(tree);
60 return 0;
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)
68 static struct commit_list *complete = NULL;
70 static int process_commit(struct walker *walker, struct commit *commit)
72 if (parse_commit(commit))
73 return -1;
75 while (complete && complete->item->date >= commit->date) {
76 pop_most_recent_commit(&complete, COMPLETE);
79 if (commit->object.flags & COMPLETE)
80 return 0;
82 hashcpy(current_commit_sha1, commit->object.sha1);
84 walker_say(walker, "walk %s\n", sha1_to_hex(commit->object.sha1));
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;
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;
99 return 0;
102 static int process_tag(struct walker *walker, struct tag *tag)
104 if (parse_tag(tag))
105 return -1;
106 return process(walker, tag->tagged);
109 static struct object_list *process_queue = NULL;
110 static struct object_list **process_queue_end = &process_queue;
112 static int process_object(struct walker *walker, struct object *obj)
114 if (obj->type == OBJ_COMMIT) {
115 if (process_commit(walker, (struct commit *)obj))
116 return -1;
117 return 0;
119 if (obj->type == OBJ_TREE) {
120 if (process_tree(walker, (struct tree *)obj))
121 return -1;
122 return 0;
124 if (obj->type == OBJ_BLOB) {
125 return 0;
127 if (obj->type == OBJ_TAG) {
128 if (process_tag(walker, (struct tag *)obj))
129 return -1;
130 return 0;
132 return error("Unable to determine requirements "
133 "of type %s for %s",
134 typename(obj->type), sha1_to_hex(obj->sha1));
137 static int process(struct walker *walker, struct object *obj)
139 if (obj->flags & SEEN)
140 return 0;
141 obj->flags |= SEEN;
143 if (has_sha1_file(obj->sha1)) {
144 /* We already have it, so we should scan it now. */
145 obj->flags |= TO_SCAN;
147 else {
148 if (obj->flags & COMPLETE)
149 return 0;
150 walker->prefetch(walker, obj->sha1);
153 object_list_insert(obj, process_queue_end);
154 process_queue_end = &(*process_queue_end)->next;
155 return 0;
158 static int loop(struct walker *walker)
160 struct object_list *elem;
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;
170 /* If we are not scanning this object, we placed it in
171 * the queue because we needed to fetch it first.
173 if (! (obj->flags & TO_SCAN)) {
174 if (walker->fetch(walker, obj->sha1)) {
175 report_missing(obj);
176 return -1;
179 if (!obj->type)
180 parse_object(obj->sha1);
181 if (process_object(walker, obj))
182 return -1;
184 return 0;
187 static int interpret_target(struct walker *walker, char *target, unsigned char *sha1)
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;
198 free(ref);
200 return -1;
203 static int mark_complete(const char *path, const unsigned char *sha1, int flag, void *cb_data)
205 struct commit *commit = lookup_commit_reference_gently(sha1, 1);
206 if (commit) {
207 commit->object.flags |= COMPLETE;
208 commit_list_insert(commit, &complete);
210 return 0;
213 int walker_targets_stdin(char ***target, const char ***write_ref)
215 int targets = 0, targets_alloc = 0;
216 struct strbuf buf = STRBUF_INIT;
217 *target = NULL; *write_ref = NULL;
218 while (1) {
219 char *rf_one = NULL;
220 char *tg_one;
222 if (strbuf_getline(&buf, stdin, '\n') == EOF)
223 break;
224 tg_one = buf.buf;
225 rf_one = strchr(tg_one, '\t');
226 if (rf_one)
227 *rf_one++ = 0;
229 if (targets >= targets_alloc) {
230 targets_alloc = targets_alloc ? targets_alloc * 2 : 64;
231 REALLOC_ARRAY(*target, targets_alloc);
232 REALLOC_ARRAY(*write_ref, targets_alloc);
234 (*target)[targets] = xstrdup(tg_one);
235 (*write_ref)[targets] = rf_one ? xstrdup(rf_one) : NULL;
236 targets++;
238 strbuf_release(&buf);
239 return targets;
242 void walker_targets_free(int targets, char **target, const char **write_ref)
244 while (targets--) {
245 free(target[targets]);
246 if (write_ref)
247 free((char *) write_ref[targets]);
251 int walker_fetch(struct walker *walker, int targets, char **target,
252 const char **write_ref, const char *write_ref_log_details)
254 struct strbuf refname = STRBUF_INIT;
255 struct strbuf err = STRBUF_INIT;
256 struct ref_transaction *transaction = NULL;
257 unsigned char *sha1 = xmalloc(targets * 20);
258 char *msg = NULL;
259 int i, ret = -1;
261 save_commit_buffer = 0;
263 if (write_ref) {
264 transaction = ref_transaction_begin(&err);
265 if (!transaction) {
266 error("%s", err.buf);
267 goto done;
271 if (!walker->get_recover) {
272 for_each_ref(mark_complete, NULL);
273 commit_list_sort_by_date(&complete);
276 for (i = 0; i < targets; i++) {
277 if (interpret_target(walker, target[i], &sha1[20 * i])) {
278 error("Could not interpret response from server '%s' as something to pull", target[i]);
279 goto done;
281 if (process(walker, lookup_unknown_object(&sha1[20 * i])))
282 goto done;
285 if (loop(walker))
286 goto done;
287 if (!write_ref) {
288 ret = 0;
289 goto done;
291 if (write_ref_log_details) {
292 msg = xstrfmt("fetch from %s", write_ref_log_details);
293 } else {
294 msg = NULL;
296 for (i = 0; i < targets; i++) {
297 if (!write_ref[i])
298 continue;
299 strbuf_reset(&refname);
300 strbuf_addf(&refname, "refs/%s", write_ref[i]);
301 if (ref_transaction_update(transaction, refname.buf,
302 &sha1[20 * i], NULL, 0, 0,
303 msg ? msg : "fetch (unknown)",
304 &err)) {
305 error("%s", err.buf);
306 goto done;
309 if (ref_transaction_commit(transaction, &err)) {
310 error("%s", err.buf);
311 goto done;
314 ret = 0;
316 done:
317 ref_transaction_free(transaction);
318 free(msg);
319 free(sha1);
320 strbuf_release(&err);
321 strbuf_release(&refname);
322 return ret;
325 void walker_free(struct walker *walker)
327 walker->cleanup(walker);
328 free(walker);