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 unsigned char *sha1, int flag, void *cb_data)
 204 {
 205         struct commit *commit = lookup_commit_reference_gently(sha1, 1);
 206         if (commit) {
 207                 commit->object.flags |= COMPLETE;
 208                 commit_list_insert_by_date(commit, &complete);
 209         }
 210         return 0;
 211 }
 212
 213 int walker_targets_stdin(char ***target, const char ***write_ref)
 214 {
 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;
 221
 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;
 228
 229                 if (targets >= targets_alloc) {
 230                         targets_alloc = targets_alloc ? targets_alloc * 2 : 64;
 231                         *target = xrealloc(*target, targets_alloc * sizeof(**target));
 232                         *write_ref = xrealloc(*write_ref, targets_alloc * sizeof(**write_ref));
 233                 }
 234                 (*target)[targets] = xstrdup(tg_one);
 235                 (*write_ref)[targets] = rf_one ? xstrdup(rf_one) : NULL;
 236                 targets++;
 237         }
 238         strbuf_release(&buf);
 239         return targets;
 240 }
 241
 242 void walker_targets_free(int targets, char **target, const char **write_ref)
 243 {
 244         while (targets--) {
 245                 free(target[targets]);
 246                 if (write_ref)
 247                         free((char *) write_ref[targets]);
 248         }
 249 }
 250
 251 int walker_fetch(struct walker *walker, int targets, char **target,
 252                  const char **write_ref, const char *write_ref_log_details)
 253 {
 254         struct ref_lock **lock = xcalloc(targets, sizeof(struct ref_lock *));
 255         unsigned char *sha1 = xmalloc(targets * 20);
 256         const char *msg;
 257         char *to_free = NULL;
 258         int ret;
 259         int i;
 260
 261         save_commit_buffer = 0;
 262
 263         for (i = 0; i < targets; i++) {
 264                 if (!write_ref || !write_ref[i])
 265                         continue;
 266
 267                 lock[i] = lock_ref_sha1(write_ref[i], NULL);
 268                 if (!lock[i]) {
 269                         error("Can't lock ref %s", write_ref[i]);
 270                         goto unlock_and_fail;
 271                 }
 272         }
 273
 274         if (!walker->get_recover)
 275                 for_each_ref(mark_complete, NULL);
 276
 277         for (i = 0; i < targets; i++) {
 278                 if (interpret_target(walker, target[i], &sha1[20 * i])) {
 279                         error("Could not interpret response from server '%s' as something to pull", target[i]);
 280                         goto unlock_and_fail;
 281                 }
 282                 if (process(walker, lookup_unknown_object(&sha1[20 * i])))
 283                         goto unlock_and_fail;
 284         }
 285
 286         if (loop(walker))
 287                 goto unlock_and_fail;
 288
 289         if (write_ref_log_details)
 290                 msg = to_free = xstrfmt("fetch from %s", write_ref_log_details);
 291         else
 292                 msg = "fetch (unknown)";
 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);
 297                 lock[i] = NULL;
 298                 if (ret)
 299                         goto unlock_and_fail;
 300         }
 301         free(to_free);
 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         free(to_free);
 310
 311         return -1;
 312 }
 313
 314 void walker_free(struct walker *walker)
 315 {
 316         walker->cleanup(walker);
 317         free(walker);
 318 }