walker.c

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