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);
  60         tree->buffer = NULL;
  61         tree->size = 0;
  62         tree->object.parsed = 0;
  63         return 0;
  64 }
  65
  66 #define COMPLETE        (1U << 0)
  67 #define SEEN            (1U << 1)
  68 #define TO_SCAN         (1U << 2)
  69
  70 static struct commit_list *complete = NULL;
  71
  72 static int process_commit(struct walker *walker, struct commit *commit)
  73 {
  74         if (parse_commit(commit))
  75                 return -1;
  76
  77         while (complete && complete->item->date >= commit->date) {
  78                 pop_most_recent_commit(&complete, COMPLETE);
  79         }
  80
  81         if (commit->object.flags & COMPLETE)
  82                 return 0;
  83
  84         hashcpy(current_commit_sha1, commit->object.sha1);
  85
  86         walker_say(walker, "walk %s\n", sha1_to_hex(commit->object.sha1));
  87
  88         if (walker->get_tree) {
  89                 if (process(walker, &commit->tree->object))
  90                         return -1;
  91                 if (!walker->get_all)
  92                         walker->get_tree = 0;
  93         }
  94         if (walker->get_history) {
  95                 struct commit_list *parents = commit->parents;
  96                 for (; parents; parents = parents->next) {
  97                         if (process(walker, &parents->item->object))
  98                                 return -1;
  99                 }
 100         }
 101         return 0;
 102 }
 103
 104 static int process_tag(struct walker *walker, struct tag *tag)
 105 {
 106         if (parse_tag(tag))
 107                 return -1;
 108         return process(walker, tag->tagged);
 109 }
 110
 111 static struct object_list *process_queue = NULL;
 112 static struct object_list **process_queue_end = &process_queue;
 113
 114 static int process_object(struct walker *walker, struct object *obj)
 115 {
 116         if (obj->type == OBJ_COMMIT) {
 117                 if (process_commit(walker, (struct commit *)obj))
 118                         return -1;
 119                 return 0;
 120         }
 121         if (obj->type == OBJ_TREE) {
 122                 if (process_tree(walker, (struct tree *)obj))
 123                         return -1;
 124                 return 0;
 125         }
 126         if (obj->type == OBJ_BLOB) {
 127                 return 0;
 128         }
 129         if (obj->type == OBJ_TAG) {
 130                 if (process_tag(walker, (struct tag *)obj))
 131                         return -1;
 132                 return 0;
 133         }
 134         return error("Unable to determine requirements "
 135                      "of type %s for %s",
 136                      typename(obj->type), sha1_to_hex(obj->sha1));
 137 }
 138
 139 static int process(struct walker *walker, struct object *obj)
 140 {
 141         if (obj->flags & SEEN)
 142                 return 0;
 143         obj->flags |= SEEN;
 144
 145         if (has_sha1_file(obj->sha1)) {
 146                 /* We already have it, so we should scan it now. */
 147                 obj->flags |= TO_SCAN;
 148         }
 149         else {
 150                 if (obj->flags & COMPLETE)
 151                         return 0;
 152                 walker->prefetch(walker, obj->sha1);
 153         }
 154
 155         object_list_insert(obj, process_queue_end);
 156         process_queue_end = &(*process_queue_end)->next;
 157         return 0;
 158 }
 159
 160 static int loop(struct walker *walker)
 161 {
 162         struct object_list *elem;
 163
 164         while (process_queue) {
 165                 struct object *obj = process_queue->item;
 166                 elem = process_queue;
 167                 process_queue = elem->next;
 168                 free(elem);
 169                 if (!process_queue)
 170                         process_queue_end = &process_queue;
 171
 172                 /* If we are not scanning this object, we placed it in
 173                  * the queue because we needed to fetch it first.
 174                  */
 175                 if (! (obj->flags & TO_SCAN)) {
 176                         if (walker->fetch(walker, obj->sha1)) {
 177                                 report_missing(obj);
 178                                 return -1;
 179                         }
 180                 }
 181                 if (!obj->type)
 182                         parse_object(obj->sha1);
 183                 if (process_object(walker, obj))
 184                         return -1;
 185         }
 186         return 0;
 187 }
 188
 189 static int interpret_target(struct walker *walker, char *target, unsigned char *sha1)
 190 {
 191         if (!get_sha1_hex(target, sha1))
 192                 return 0;
 193         if (!check_refname_format(target, 0)) {
 194                 struct ref *ref = alloc_ref(target);
 195                 if (!walker->fetch_ref(walker, ref)) {
 196                         hashcpy(sha1, ref->old_sha1);
 197                         free(ref);
 198                         return 0;
 199                 }
 200                 free(ref);
 201         }
 202         return -1;
 203 }
 204
 205 static int mark_complete(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 206 {
 207         struct commit *commit = lookup_commit_reference_gently(sha1, 1);
 208         if (commit) {
 209                 commit->object.flags |= COMPLETE;
 210                 commit_list_insert_by_date(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                         *target = xrealloc(*target, targets_alloc * sizeof(**target));
 234                         *write_ref = xrealloc(*write_ref, targets_alloc * sizeof(**write_ref));
 235                 }
 236                 (*target)[targets] = xstrdup(tg_one);
 237                 (*write_ref)[targets] = rf_one ? xstrdup(rf_one) : NULL;
 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 ref_lock **lock = xcalloc(targets, sizeof(struct ref_lock *));
 257         unsigned char *sha1 = xmalloc(targets * 20);
 258         char *msg;
 259         int ret;
 260         int i;
 261
 262         save_commit_buffer = 0;
 263
 264         for (i = 0; i < targets; i++) {
 265                 if (!write_ref || !write_ref[i])
 266                         continue;
 267
 268                 lock[i] = lock_ref_sha1(write_ref[i], NULL);
 269                 if (!lock[i]) {
 270                         error("Can't lock ref %s", write_ref[i]);
 271                         goto unlock_and_fail;
 272                 }
 273         }
 274
 275         if (!walker->get_recover)
 276                 for_each_ref(mark_complete, NULL);
 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 unlock_and_fail;
 282                 }
 283                 if (process(walker, lookup_unknown_object(&sha1[20 * i])))
 284                         goto unlock_and_fail;
 285         }
 286
 287         if (loop(walker))
 288                 goto unlock_and_fail;
 289
 290         if (write_ref_log_details) {
 291                 msg = xmalloc(strlen(write_ref_log_details) + 12);
 292                 sprintf(msg, "fetch from %s", write_ref_log_details);
 293         } else {
 294                 msg = NULL;
 295         }
 296         for (i = 0; i < targets; i++) {
 297                 if (!write_ref || !write_ref[i])
 298                         continue;
 299                 ret = write_ref_sha1(lock[i], &sha1[20 * i], msg ? msg : "fetch (unknown)");
 300                 lock[i] = NULL;
 301                 if (ret)
 302                         goto unlock_and_fail;
 303         }
 304         free(msg);
 305
 306         return 0;
 307
 308 unlock_and_fail:
 309         for (i = 0; i < targets; i++)
 310                 if (lock[i])
 311                         unlock_ref(lock[i]);
 312
 313         return -1;
 314 }
 315
 316 void walker_free(struct walker *walker)
 317 {
 318         walker->cleanup(walker);
 319         free(walker);
 320 }