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 #include "strbuf.h"
  10
  11 static unsigned char current_commit_sha1[20];
  12
  13 void walker_say(struct walker *walker, const char *fmt, const char *hex)
  14 {
  15         if (walker->get_verbosely)
  16                 fprintf(stderr, fmt, hex);
  17 }
  18
  19 static void report_missing(const struct object *obj)
  20 {
  21         char missing_hex[41];
  22         strcpy(missing_hex, sha1_to_hex(obj->sha1));;
  23         fprintf(stderr, "Cannot obtain needed %s %s\n",
  24                 obj->type ? typename(obj->type): "object", missing_hex);
  25         if (!is_null_sha1(current_commit_sha1))
  26                 fprintf(stderr, "while processing commit %s.\n",
  27                         sha1_to_hex(current_commit_sha1));
  28 }
  29
  30 static int process(struct walker *walker, struct object *obj);
  31
  32 static int process_tree(struct walker *walker, struct tree *tree)
  33 {
  34         struct tree_desc desc;
  35         struct name_entry entry;
  36
  37         if (parse_tree(tree))
  38                 return -1;
  39
  40         init_tree_desc(&desc, tree->buffer, tree->size);
  41         while (tree_entry(&desc, &entry)) {
  42                 struct object *obj = NULL;
  43
  44                 /* submodule commits are not stored in the superproject */
  45                 if (S_ISGITLINK(entry.mode))
  46                         continue;
  47                 if (S_ISDIR(entry.mode)) {
  48                         struct tree *tree = lookup_tree(entry.sha1);
  49                         if (tree)
  50                                 obj = &tree->object;
  51                 }
  52                 else {
  53                         struct blob *blob = lookup_blob(entry.sha1);
  54                         if (blob)
  55                                 obj = &blob->object;
  56                 }
  57                 if (!obj || process(walker, obj))
  58                         return -1;
  59         }
  60         free(tree->buffer);
  61         tree->buffer = NULL;
  62         tree->size = 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_ref_format(target)) {
 194                 if (!walker->fetch_ref(walker, target, sha1)) {
 195                         return 0;
 196                 }
 197         }
 198         return -1;
 199 }
 200
 201 static int mark_complete(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 202 {
 203         struct commit *commit = lookup_commit_reference_gently(sha1, 1);
 204         if (commit) {
 205                 commit->object.flags |= COMPLETE;
 206                 insert_by_date(commit, &complete);
 207         }
 208         return 0;
 209 }
 210
 211 int walker_targets_stdin(char ***target, const char ***write_ref)
 212 {
 213         int targets = 0, targets_alloc = 0;
 214         struct strbuf buf;
 215         *target = NULL; *write_ref = NULL;
 216         strbuf_init(&buf);
 217         while (1) {
 218                 char *rf_one = NULL;
 219                 char *tg_one;
 220
 221                 read_line(&buf, stdin, '\n');
 222                 if (buf.eof)
 223                         break;
 224                 tg_one = buf.buf;
 225                 rf_one = strchr(tg_one, '\t');
 226                 if (rf_one)
 227                         *rf_one++ = 0;
 228
 229                 if (targets >= targets_alloc) {
 230                         targets_alloc = targets_alloc ? targets_alloc * 2 : 64;
 231                         *target = xrealloc(*target, targets_alloc * sizeof(**target));
 232                         *write_ref = xrealloc(*write_ref, targets_alloc * sizeof(**write_ref));
 233                 }
 234                 (*target)[targets] = xstrdup(tg_one);
 235                 (*write_ref)[targets] = rf_one ? xstrdup(rf_one) : NULL;
 236                 targets++;
 237         }
 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 && write_ref[targets])
 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         track_object_refs = 0;
 261
 262         for (i = 0; i < targets; i++) {
 263                 if (!write_ref || !write_ref[i])
 264                         continue;
 265
 266                 lock[i] = lock_ref_sha1(write_ref[i], NULL);
 267                 if (!lock[i]) {
 268                         error("Can't lock ref %s", write_ref[i]);
 269                         goto unlock_and_fail;
 270                 }
 271         }
 272
 273         if (!walker->get_recover)
 274                 for_each_ref(mark_complete, NULL);
 275
 276         for (i = 0; i < targets; i++) {
 277                 if (interpret_target(walker, target[i], &sha1[20 * i])) {
 278                         error("Could not interpret %s as something to pull", target[i]);
 279                         goto unlock_and_fail;
 280                 }
 281                 if (process(walker, lookup_unknown_object(&sha1[20 * i])))
 282                         goto unlock_and_fail;
 283         }
 284
 285         if (loop(walker))
 286                 goto unlock_and_fail;
 287
 288         if (write_ref_log_details) {
 289                 msg = xmalloc(strlen(write_ref_log_details) + 12);
 290                 sprintf(msg, "fetch from %s", write_ref_log_details);
 291         } else {
 292                 msg = NULL;
 293         }
 294         for (i = 0; i < targets; i++) {
 295                 if (!write_ref || !write_ref[i])
 296                         continue;
 297                 ret = write_ref_sha1(lock[i], &sha1[20 * i], msg ? msg : "fetch (unknown)");
 298                 lock[i] = NULL;
 299                 if (ret)
 300                         goto unlock_and_fail;
 301         }
 302         free(msg);
 303
 304         return 0;
 305
 306 unlock_and_fail:
 307         for (i = 0; i < targets; i++)
 308                 if (lock[i])
 309                         unlock_ref(lock[i]);
 310
 311         return -1;
 312 }
 313
 314 void walker_free(struct walker *walker)
 315 {
 316         walker->cleanup(walker);
 317         free(walker);
 318 }