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         fprintf(stderr, "Cannot obtain needed %s %s\n",
  21                 obj->type ? typename(obj->type): "object",
  22                 sha1_to_hex(obj->sha1));
  23         if (!is_null_sha1(current_commit_sha1))
  24                 fprintf(stderr, "while processing commit %s.\n",
  25                         sha1_to_hex(current_commit_sha1));
  26 }
  27
  28 static int process(struct walker *walker, struct object *obj);
  29
  30 static int process_tree(struct walker *walker, struct tree *tree)
  31 {
  32         struct tree_desc desc;
  33         struct name_entry entry;
  34
  35         if (parse_tree(tree))
  36                 return -1;
  37
  38         init_tree_desc(&desc, tree->buffer, tree->size);
  39         while (tree_entry(&desc, &entry)) {
  40                 struct object *obj = NULL;
  41
  42                 /* submodule commits are not stored in the superproject */
  43                 if (S_ISGITLINK(entry.mode))
  44                         continue;
  45                 if (S_ISDIR(entry.mode)) {
  46                         struct tree *tree = lookup_tree(entry.sha1);
  47                         if (tree)
  48                                 obj = &tree->object;
  49                 }
  50                 else {
  51                         struct blob *blob = lookup_blob(entry.sha1);
  52                         if (blob)
  53                                 obj = &blob->object;
  54                 }
  55                 if (!obj || process(walker, obj))
  56                         return -1;
  57         }
  58         free_tree_buffer(tree);
  59         return 0;
  60 }
  61
  62 /* Remember to update object flag allocation in object.h */
  63 #define COMPLETE        (1U << 0)
  64 #define SEEN            (1U << 1)
  65 #define TO_SCAN         (1U << 2)
  66
  67 static struct commit_list *complete = NULL;
  68
  69 static int process_commit(struct walker *walker, struct commit *commit)
  70 {
  71         if (parse_commit(commit))
  72                 return -1;
  73
  74         while (complete && complete->item->date >= commit->date) {
  75                 pop_most_recent_commit(&complete, COMPLETE);
  76         }
  77
  78         if (commit->object.flags & COMPLETE)
  79                 return 0;
  80
  81         hashcpy(current_commit_sha1, commit->object.sha1);
  82
  83         walker_say(walker, "walk %s\n", sha1_to_hex(commit->object.sha1));
  84
  85         if (walker->get_tree) {
  86                 if (process(walker, &commit->tree->object))
  87                         return -1;
  88                 if (!walker->get_all)
  89                         walker->get_tree = 0;
  90         }
  91         if (walker->get_history) {
  92                 struct commit_list *parents = commit->parents;
  93                 for (; parents; parents = parents->next) {
  94                         if (process(walker, &parents->item->object))
  95                                 return -1;
  96                 }
  97         }
  98         return 0;
  99 }
 100
 101 static int process_tag(struct walker *walker, struct tag *tag)
 102 {
 103         if (parse_tag(tag))
 104                 return -1;
 105         return process(walker, tag->tagged);
 106 }
 107
 108 static struct object_list *process_queue = NULL;
 109 static struct object_list **process_queue_end = &process_queue;
 110
 111 static int process_object(struct walker *walker, struct object *obj)
 112 {
 113         if (obj->type == OBJ_COMMIT) {
 114                 if (process_commit(walker, (struct commit *)obj))
 115                         return -1;
 116                 return 0;
 117         }
 118         if (obj->type == OBJ_TREE) {
 119                 if (process_tree(walker, (struct tree *)obj))
 120                         return -1;
 121                 return 0;
 122         }
 123         if (obj->type == OBJ_BLOB) {
 124                 return 0;
 125         }
 126         if (obj->type == OBJ_TAG) {
 127                 if (process_tag(walker, (struct tag *)obj))
 128                         return -1;
 129                 return 0;
 130         }
 131         return error("Unable to determine requirements "
 132                      "of type %s for %s",
 133                      typename(obj->type), sha1_to_hex(obj->sha1));
 134 }
 135
 136 static int process(struct walker *walker, struct object *obj)
 137 {
 138         if (obj->flags & SEEN)
 139                 return 0;
 140         obj->flags |= SEEN;
 141
 142         if (has_sha1_file(obj->sha1)) {
 143                 /* We already have it, so we should scan it now. */
 144                 obj->flags |= TO_SCAN;
 145         }
 146         else {
 147                 if (obj->flags & COMPLETE)
 148                         return 0;
 149                 walker->prefetch(walker, obj->sha1);
 150         }
 151
 152         object_list_insert(obj, process_queue_end);
 153         process_queue_end = &(*process_queue_end)->next;
 154         return 0;
 155 }
 156
 157 static int loop(struct walker *walker)
 158 {
 159         struct object_list *elem;
 160
 161         while (process_queue) {
 162                 struct object *obj = process_queue->item;
 163                 elem = process_queue;
 164                 process_queue = elem->next;
 165                 free(elem);
 166                 if (!process_queue)
 167                         process_queue_end = &process_queue;
 168
 169                 /* If we are not scanning this object, we placed it in
 170                  * the queue because we needed to fetch it first.
 171                  */
 172                 if (! (obj->flags & TO_SCAN)) {
 173                         if (walker->fetch(walker, obj->sha1)) {
 174                                 report_missing(obj);
 175                                 return -1;
 176                         }
 177                 }
 178                 if (!obj->type)
 179                         parse_object(obj->sha1);
 180                 if (process_object(walker, obj))
 181                         return -1;
 182         }
 183         return 0;
 184 }
 185
 186 static int interpret_target(struct walker *walker, char *target, unsigned char *sha1)
 187 {
 188         if (!get_sha1_hex(target, sha1))
 189                 return 0;
 190         if (!check_refname_format(target, 0)) {
 191                 struct ref *ref = alloc_ref(target);
 192                 if (!walker->fetch_ref(walker, ref)) {
 193                         hashcpy(sha1, ref->old_sha1);
 194                         free(ref);
 195                         return 0;
 196                 }
 197                 free(ref);
 198         }
 199         return -1;
 200 }
 201
 202 static int mark_complete(const char *path, const struct object_id *oid,
 203                          int flag, void *cb_data)
 204 {
 205         struct commit *commit = lookup_commit_reference_gently(oid->hash, 1);
 206
 207         if (commit) {
 208                 commit->object.flags |= COMPLETE;
 209                 commit_list_insert(commit, &complete);
 210         }
 211         return 0;
 212 }
 213
 214 int walker_targets_stdin(char ***target, const char ***write_ref)
 215 {
 216         int targets = 0, targets_alloc = 0;
 217         struct strbuf buf = STRBUF_INIT;
 218         *target = NULL; *write_ref = NULL;
 219         while (1) {
 220                 char *rf_one = NULL;
 221                 char *tg_one;
 222
 223                 if (strbuf_getline(&buf, stdin, '\n') == EOF)
 224                         break;
 225                 tg_one = buf.buf;
 226                 rf_one = strchr(tg_one, '\t');
 227                 if (rf_one)
 228                         *rf_one++ = 0;
 229
 230                 if (targets >= targets_alloc) {
 231                         targets_alloc = targets_alloc ? targets_alloc * 2 : 64;
 232                         REALLOC_ARRAY(*target, targets_alloc);
 233                         REALLOC_ARRAY(*write_ref, targets_alloc);
 234                 }
 235                 (*target)[targets] = xstrdup(tg_one);
 236                 (*write_ref)[targets] = xstrdup_or_null(rf_one);
 237                 targets++;
 238         }
 239         strbuf_release(&buf);
 240         return targets;
 241 }
 242
 243 void walker_targets_free(int targets, char **target, const char **write_ref)
 244 {
 245         while (targets--) {
 246                 free(target[targets]);
 247                 if (write_ref)
 248                         free((char *) write_ref[targets]);
 249         }
 250 }
 251
 252 int walker_fetch(struct walker *walker, int targets, char **target,
 253                  const char **write_ref, const char *write_ref_log_details)
 254 {
 255         struct strbuf refname = STRBUF_INIT;
 256         struct strbuf err = STRBUF_INIT;
 257         struct ref_transaction *transaction = NULL;
 258         unsigned char *sha1 = xmalloc(targets * 20);
 259         char *msg = NULL;
 260         int i, ret = -1;
 261
 262         save_commit_buffer = 0;
 263
 264         if (write_ref) {
 265                 transaction = ref_transaction_begin(&err);
 266                 if (!transaction) {
 267                         error("%s", err.buf);
 268                         goto done;
 269                 }
 270         }
 271
 272         if (!walker->get_recover) {
 273                 for_each_ref(mark_complete, NULL);
 274                 commit_list_sort_by_date(&complete);
 275         }
 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 done;
 281                 }
 282                 if (process(walker, lookup_unknown_object(&sha1[20 * i])))
 283                         goto done;
 284         }
 285
 286         if (loop(walker))
 287                 goto done;
 288         if (!write_ref) {
 289                 ret = 0;
 290                 goto done;
 291         }
 292         if (write_ref_log_details) {
 293                 msg = xstrfmt("fetch from %s", write_ref_log_details);
 294         } else {
 295                 msg = NULL;
 296         }
 297         for (i = 0; i < targets; i++) {
 298                 if (!write_ref[i])
 299                         continue;
 300                 strbuf_reset(&refname);
 301                 strbuf_addf(&refname, "refs/%s", write_ref[i]);
 302                 if (ref_transaction_update(transaction, refname.buf,
 303                                            &sha1[20 * i], NULL, 0,
 304                                            msg ? msg : "fetch (unknown)",
 305                                            &err)) {
 306                         error("%s", err.buf);
 307                         goto done;
 308                 }
 309         }
 310         if (ref_transaction_commit(transaction, &err)) {
 311                 error("%s", err.buf);
 312                 goto done;
 313         }
 314
 315         ret = 0;
 316
 317 done:
 318         ref_transaction_free(transaction);
 319         free(msg);
 320         free(sha1);
 321         strbuf_release(&err);
 322         strbuf_release(&refname);
 323         return ret;
 324 }
 325
 326 void walker_free(struct walker *walker)
 327 {
 328         walker->cleanup(walker);
 329         free(walker);
 330 }