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);
  60         tree->buffer = NULL;
  61         tree->size = 0;
  62         return 0;
  63 }
  64
  65 #define COMPLETE        (1U << 0)
  66 #define SEEN            (1U << 1)
  67 #define TO_SCAN         (1U << 2)
  68
  69 static struct commit_list *complete = NULL;
  70
  71 static int process_commit(struct walker *walker, struct commit *commit)
  72 {
  73         if (parse_commit(commit))
  74                 return -1;
  75
  76         while (complete && complete->item->date >= commit->date) {
  77                 pop_most_recent_commit(&complete, COMPLETE);
  78         }
  79
  80         if (commit->object.flags & COMPLETE)
  81                 return 0;
  82
  83         hashcpy(current_commit_sha1, commit->object.sha1);
  84
  85         walker_say(walker, "walk %s\n", sha1_to_hex(commit->object.sha1));
  86
  87         if (walker->get_tree) {
  88                 if (process(walker, &commit->tree->object))
  89                         return -1;
  90                 if (!walker->get_all)
  91                         walker->get_tree = 0;
  92         }
  93         if (walker->get_history) {
  94                 struct commit_list *parents = commit->parents;
  95                 for (; 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                      typename(obj->type), sha1_to_hex(obj->sha1));
 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_sha1_file(obj->sha1)) {
 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->sha1);
 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->sha1)) {
 176                                 report_missing(obj);
 177                                 return -1;
 178                         }
 179                 }
 180                 if (!obj->type)
 181                         parse_object(obj->sha1);
 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, unsigned char *sha1)
 189 {
 190         if (!get_sha1_hex(target, sha1))
 191                 return 0;
 192         if (!check_ref_format(target)) {
 193                 if (!walker->fetch_ref(walker, target, sha1)) {
 194                         return 0;
 195                 }
 196         }
 197         return -1;
 198 }
 199
 200 static int mark_complete(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 201 {
 202         struct commit *commit = lookup_commit_reference_gently(sha1, 1);
 203         if (commit) {
 204                 commit->object.flags |= COMPLETE;
 205                 insert_by_date(commit, &complete);
 206         }
 207         return 0;
 208 }
 209
 210 int walker_targets_stdin(char ***target, const char ***write_ref)
 211 {
 212         int targets = 0, targets_alloc = 0;
 213         struct strbuf buf;
 214         *target = NULL; *write_ref = NULL;
 215         strbuf_init(&buf, 0);
 216         while (1) {
 217                 char *rf_one = NULL;
 218                 char *tg_one;
 219
 220                 if (strbuf_getline(&buf, stdin, '\n') == EOF)
 221                         break;
 222                 tg_one = buf.buf;
 223                 rf_one = strchr(tg_one, '\t');
 224                 if (rf_one)
 225                         *rf_one++ = 0;
 226
 227                 if (targets >= targets_alloc) {
 228                         targets_alloc = targets_alloc ? targets_alloc * 2 : 64;
 229                         *target = xrealloc(*target, targets_alloc * sizeof(**target));
 230                         *write_ref = xrealloc(*write_ref, targets_alloc * sizeof(**write_ref));
 231                 }
 232                 (*target)[targets] = xstrdup(tg_one);
 233                 (*write_ref)[targets] = rf_one ? xstrdup(rf_one) : NULL;
 234                 targets++;
 235         }
 236         strbuf_release(&buf);
 237         return targets;
 238 }
 239
 240 void walker_targets_free(int targets, char **target, const char **write_ref)
 241 {
 242         while (targets--) {
 243                 free(target[targets]);
 244                 if (write_ref && write_ref[targets])
 245                         free((char *) write_ref[targets]);
 246         }
 247 }
 248
 249 int walker_fetch(struct walker *walker, int targets, char **target,
 250                  const char **write_ref, const char *write_ref_log_details)
 251 {
 252         struct ref_lock **lock = xcalloc(targets, sizeof(struct ref_lock *));
 253         unsigned char *sha1 = xmalloc(targets * 20);
 254         char *msg;
 255         int ret;
 256         int i;
 257
 258         save_commit_buffer = 0;
 259         track_object_refs = 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 %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 }