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 #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 unsigned char *sha1, int flag, void *cb_data)
 203 {
 204         struct commit *commit = lookup_commit_reference_gently(sha1, 1);
 205         if (commit) {
 206                 commit->object.flags |= COMPLETE;
 207                 commit_list_insert_by_date(commit, &complete);
 208         }
 209         return 0;
 210 }
 211
 212 int walker_targets_stdin(char ***target, const char ***write_ref)
 213 {
 214         int targets = 0, targets_alloc = 0;
 215         struct strbuf buf = STRBUF_INIT;
 216         *target = NULL; *write_ref = NULL;
 217         while (1) {
 218                 char *rf_one = NULL;
 219                 char *tg_one;
 220
 221                 if (strbuf_getline(&buf, stdin, '\n') == EOF)
 222                         break;
 223                 tg_one = buf.buf;
 224                 rf_one = strchr(tg_one, '\t');
 225                 if (rf_one)
 226                         *rf_one++ = 0;
 227
 228                 if (targets >= targets_alloc) {
 229                         targets_alloc = targets_alloc ? targets_alloc * 2 : 64;
 230                         *target = xrealloc(*target, targets_alloc * sizeof(**target));
 231                         *write_ref = xrealloc(*write_ref, targets_alloc * sizeof(**write_ref));
 232                 }
 233                 (*target)[targets] = xstrdup(tg_one);
 234                 (*write_ref)[targets] = rf_one ? xstrdup(rf_one) : NULL;
 235                 targets++;
 236         }
 237         strbuf_release(&buf);
 238         return targets;
 239 }
 240
 241 void walker_targets_free(int targets, char **target, const char **write_ref)
 242 {
 243         while (targets--) {
 244                 free(target[targets]);
 245                 if (write_ref)
 246                         free((char *) write_ref[targets]);
 247         }
 248 }
 249
 250 int walker_fetch(struct walker *walker, int targets, char **target,
 251                  const char **write_ref, const char *write_ref_log_details)
 252 {
 253         struct ref_lock **lock = xcalloc(targets, sizeof(struct ref_lock *));
 254         unsigned char *sha1 = xmalloc(targets * 20);
 255         char *msg;
 256         int ret;
 257         int i;
 258
 259         save_commit_buffer = 0;
 260
 261         for (i = 0; i < targets; i++) {
 262                 if (!write_ref || !write_ref[i])
 263                         continue;
 264
 265                 lock[i] = lock_ref_sha1(write_ref[i], NULL);
 266                 if (!lock[i]) {
 267                         error("Can't lock ref %s", write_ref[i]);
 268                         goto unlock_and_fail;
 269                 }
 270         }
 271
 272         if (!walker->get_recover)
 273                 for_each_ref(mark_complete, NULL);
 274
 275         for (i = 0; i < targets; i++) {
 276                 if (interpret_target(walker, target[i], &sha1[20 * i])) {
 277                         error("Could not interpret response from server '%s' as something to pull", target[i]);
 278                         goto unlock_and_fail;
 279                 }
 280                 if (process(walker, lookup_unknown_object(&sha1[20 * i])))
 281                         goto unlock_and_fail;
 282         }
 283
 284         if (loop(walker))
 285                 goto unlock_and_fail;
 286
 287         if (write_ref_log_details) {
 288                 msg = xmalloc(strlen(write_ref_log_details) + 12);
 289                 sprintf(msg, "fetch from %s", write_ref_log_details);
 290         } else {
 291                 msg = NULL;
 292         }
 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 ? msg : "fetch (unknown)");
 297                 lock[i] = NULL;
 298                 if (ret)
 299                         goto unlock_and_fail;
 300         }
 301         free(msg);
 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
 310         return -1;
 311 }
 312
 313 void walker_free(struct walker *walker)
 314 {
 315         walker->cleanup(walker);
 316         free(walker);
 317 }