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, ...)
  13 {
  14         if (walker->get_verbosely) {
  15                 va_list ap;
  16                 va_start(ap, fmt);
  17                 vfprintf(stderr, fmt, ap);
  18                 va_end(ap);
  19         }
  20 }
  21
  22 static void report_missing(const struct object *obj)
  23 {
  24         fprintf(stderr, "Cannot obtain needed %s %s\n",
  25                 obj->type ? typename(obj->type): "object",
  26                 oid_to_hex(&obj->oid));
  27         if (!is_null_sha1(current_commit_sha1))
  28                 fprintf(stderr, "while processing commit %s.\n",
  29                         sha1_to_hex(current_commit_sha1));
  30 }
  31
  32 static int process(struct walker *walker, struct object *obj);
  33
  34 static int process_tree(struct walker *walker, struct tree *tree)
  35 {
  36         struct tree_desc desc;
  37         struct name_entry entry;
  38
  39         if (parse_tree(tree))
  40                 return -1;
  41
  42         init_tree_desc(&desc, tree->buffer, tree->size);
  43         while (tree_entry(&desc, &entry)) {
  44                 struct object *obj = NULL;
  45
  46                 /* submodule commits are not stored in the superproject */
  47                 if (S_ISGITLINK(entry.mode))
  48                         continue;
  49                 if (S_ISDIR(entry.mode)) {
  50                         struct tree *tree = lookup_tree(entry.oid->hash);
  51                         if (tree)
  52                                 obj = &tree->object;
  53                 }
  54                 else {
  55                         struct blob *blob = lookup_blob(entry.oid);
  56                         if (blob)
  57                                 obj = &blob->object;
  58                 }
  59                 if (!obj || process(walker, obj))
  60                         return -1;
  61         }
  62         free_tree_buffer(tree);
  63         return 0;
  64 }
  65
  66 /* Remember to update object flag allocation in object.h */
  67 #define COMPLETE        (1U << 0)
  68 #define SEEN            (1U << 1)
  69 #define TO_SCAN         (1U << 2)
  70
  71 static struct commit_list *complete = NULL;
  72
  73 static int process_commit(struct walker *walker, struct commit *commit)
  74 {
  75         if (parse_commit(commit))
  76                 return -1;
  77
  78         while (complete && complete->item->date >= commit->date) {
  79                 pop_most_recent_commit(&complete, COMPLETE);
  80         }
  81
  82         if (commit->object.flags & COMPLETE)
  83                 return 0;
  84
  85         hashcpy(current_commit_sha1, commit->object.oid.hash);
  86
  87         walker_say(walker, "walk %s\n", oid_to_hex(&commit->object.oid));
  88
  89         if (walker->get_tree) {
  90                 if (process(walker, &commit->tree->object))
  91                         return -1;
  92                 if (!walker->get_all)
  93                         walker->get_tree = 0;
  94         }
  95         if (walker->get_history) {
  96                 struct commit_list *parents = commit->parents;
  97                 for (; parents; parents = parents->next) {
  98                         if (process(walker, &parents->item->object))
  99                                 return -1;
 100                 }
 101         }
 102         return 0;
 103 }
 104
 105 static int process_tag(struct walker *walker, struct tag *tag)
 106 {
 107         if (parse_tag(tag))
 108                 return -1;
 109         return process(walker, tag->tagged);
 110 }
 111
 112 static struct object_list *process_queue = NULL;
 113 static struct object_list **process_queue_end = &process_queue;
 114
 115 static int process_object(struct walker *walker, struct object *obj)
 116 {
 117         if (obj->type == OBJ_COMMIT) {
 118                 if (process_commit(walker, (struct commit *)obj))
 119                         return -1;
 120                 return 0;
 121         }
 122         if (obj->type == OBJ_TREE) {
 123                 if (process_tree(walker, (struct tree *)obj))
 124                         return -1;
 125                 return 0;
 126         }
 127         if (obj->type == OBJ_BLOB) {
 128                 return 0;
 129         }
 130         if (obj->type == OBJ_TAG) {
 131                 if (process_tag(walker, (struct tag *)obj))
 132                         return -1;
 133                 return 0;
 134         }
 135         return error("Unable to determine requirements "
 136                      "of type %s for %s",
 137                      typename(obj->type), oid_to_hex(&obj->oid));
 138 }
 139
 140 static int process(struct walker *walker, struct object *obj)
 141 {
 142         if (obj->flags & SEEN)
 143                 return 0;
 144         obj->flags |= SEEN;
 145
 146         if (has_object_file(&obj->oid)) {
 147                 /* We already have it, so we should scan it now. */
 148                 obj->flags |= TO_SCAN;
 149         }
 150         else {
 151                 if (obj->flags & COMPLETE)
 152                         return 0;
 153                 walker->prefetch(walker, obj->oid.hash);
 154         }
 155
 156         object_list_insert(obj, process_queue_end);
 157         process_queue_end = &(*process_queue_end)->next;
 158         return 0;
 159 }
 160
 161 static int loop(struct walker *walker)
 162 {
 163         struct object_list *elem;
 164
 165         while (process_queue) {
 166                 struct object *obj = process_queue->item;
 167                 elem = process_queue;
 168                 process_queue = elem->next;
 169                 free(elem);
 170                 if (!process_queue)
 171                         process_queue_end = &process_queue;
 172
 173                 /* If we are not scanning this object, we placed it in
 174                  * the queue because we needed to fetch it first.
 175                  */
 176                 if (! (obj->flags & TO_SCAN)) {
 177                         if (walker->fetch(walker, obj->oid.hash)) {
 178                                 report_missing(obj);
 179                                 return -1;
 180                         }
 181                 }
 182                 if (!obj->type)
 183                         parse_object(obj->oid.hash);
 184                 if (process_object(walker, obj))
 185                         return -1;
 186         }
 187         return 0;
 188 }
 189
 190 static int interpret_target(struct walker *walker, char *target, unsigned char *sha1)
 191 {
 192         if (!get_sha1_hex(target, sha1))
 193                 return 0;
 194         if (!check_refname_format(target, 0)) {
 195                 struct ref *ref = alloc_ref(target);
 196                 if (!walker->fetch_ref(walker, ref)) {
 197                         hashcpy(sha1, ref->old_oid.hash);
 198                         free(ref);
 199                         return 0;
 200                 }
 201                 free(ref);
 202         }
 203         return -1;
 204 }
 205
 206 static int mark_complete(const char *path, const struct object_id *oid,
 207                          int flag, void *cb_data)
 208 {
 209         struct commit *commit = lookup_commit_reference_gently(oid, 1);
 210
 211         if (commit) {
 212                 commit->object.flags |= COMPLETE;
 213                 commit_list_insert(commit, &complete);
 214         }
 215         return 0;
 216 }
 217
 218 int walker_targets_stdin(char ***target, const char ***write_ref)
 219 {
 220         int targets = 0, targets_alloc = 0;
 221         struct strbuf buf = STRBUF_INIT;
 222         *target = NULL; *write_ref = NULL;
 223         while (1) {
 224                 char *rf_one = NULL;
 225                 char *tg_one;
 226
 227                 if (strbuf_getline_lf(&buf, stdin) == EOF)
 228                         break;
 229                 tg_one = buf.buf;
 230                 rf_one = strchr(tg_one, '\t');
 231                 if (rf_one)
 232                         *rf_one++ = 0;
 233
 234                 if (targets >= targets_alloc) {
 235                         targets_alloc = targets_alloc ? targets_alloc * 2 : 64;
 236                         REALLOC_ARRAY(*target, targets_alloc);
 237                         REALLOC_ARRAY(*write_ref, targets_alloc);
 238                 }
 239                 (*target)[targets] = xstrdup(tg_one);
 240                 (*write_ref)[targets] = xstrdup_or_null(rf_one);
 241                 targets++;
 242         }
 243         strbuf_release(&buf);
 244         return targets;
 245 }
 246
 247 void walker_targets_free(int targets, char **target, const char **write_ref)
 248 {
 249         while (targets--) {
 250                 free(target[targets]);
 251                 if (write_ref)
 252                         free((char *) write_ref[targets]);
 253         }
 254 }
 255
 256 int walker_fetch(struct walker *walker, int targets, char **target,
 257                  const char **write_ref, const char *write_ref_log_details)
 258 {
 259         struct strbuf refname = STRBUF_INIT;
 260         struct strbuf err = STRBUF_INIT;
 261         struct ref_transaction *transaction = NULL;
 262         unsigned char *sha1 = xmalloc(targets * 20);
 263         char *msg = NULL;
 264         int i, ret = -1;
 265
 266         save_commit_buffer = 0;
 267
 268         if (write_ref) {
 269                 transaction = ref_transaction_begin(&err);
 270                 if (!transaction) {
 271                         error("%s", err.buf);
 272                         goto done;
 273                 }
 274         }
 275
 276         if (!walker->get_recover) {
 277                 for_each_ref(mark_complete, NULL);
 278                 commit_list_sort_by_date(&complete);
 279         }
 280
 281         for (i = 0; i < targets; i++) {
 282                 if (interpret_target(walker, target[i], &sha1[20 * i])) {
 283                         error("Could not interpret response from server '%s' as something to pull", target[i]);
 284                         goto done;
 285                 }
 286                 if (process(walker, lookup_unknown_object(&sha1[20 * i])))
 287                         goto done;
 288         }
 289
 290         if (loop(walker))
 291                 goto done;
 292         if (!write_ref) {
 293                 ret = 0;
 294                 goto done;
 295         }
 296         if (write_ref_log_details) {
 297                 msg = xstrfmt("fetch from %s", write_ref_log_details);
 298         } else {
 299                 msg = NULL;
 300         }
 301         for (i = 0; i < targets; i++) {
 302                 if (!write_ref[i])
 303                         continue;
 304                 strbuf_reset(&refname);
 305                 strbuf_addf(&refname, "refs/%s", write_ref[i]);
 306                 if (ref_transaction_update(transaction, refname.buf,
 307                                            &sha1[20 * i], NULL, 0,
 308                                            msg ? msg : "fetch (unknown)",
 309                                            &err)) {
 310                         error("%s", err.buf);
 311                         goto done;
 312                 }
 313         }
 314         if (ref_transaction_commit(transaction, &err)) {
 315                 error("%s", err.buf);
 316                 goto done;
 317         }
 318
 319         ret = 0;
 320
 321 done:
 322         ref_transaction_free(transaction);
 323         free(msg);
 324         free(sha1);
 325         strbuf_release(&err);
 326         strbuf_release(&refname);
 327         return ret;
 328 }
 329
 330 void walker_free(struct walker *walker)
 331 {
 332         walker->cleanup(walker);
 333         free(walker);
 334 }