fetch.c

   1 #include "fetch.h"
   2
   3 #include "cache.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 const char *write_ref = NULL;
  12 const char *write_ref_log_details = NULL;
  13
  14 int get_tree = 0;
  15 int get_history = 0;
  16 int get_all = 0;
  17 int get_verbosely = 0;
  18 int get_recover = 0;
  19 static unsigned char current_commit_sha1[20];
  20
  21 void pull_say(const char *fmt, const char *hex)
  22 {
  23         if (get_verbosely)
  24                 fprintf(stderr, fmt, hex);
  25 }
  26
  27 static void report_missing(const char *what, const unsigned char *missing)
  28 {
  29         char missing_hex[41];
  30
  31         strcpy(missing_hex, sha1_to_hex(missing));;
  32         fprintf(stderr,
  33                 "Cannot obtain needed %s %s\nwhile processing commit %s.\n",
  34                 what, missing_hex, sha1_to_hex(current_commit_sha1));
  35 }
  36
  37 static int process(struct object *obj);
  38
  39 static int process_tree(struct tree *tree)
  40 {
  41         struct tree_desc desc;
  42
  43         if (parse_tree(tree))
  44                 return -1;
  45
  46         desc.buf = tree->buffer;
  47         desc.size = tree->size;
  48         while (desc.size) {
  49                 unsigned mode;
  50                 const char *name;
  51                 const unsigned char *sha1;
  52
  53                 sha1 = tree_entry_extract(&desc, &name, &mode);
  54                 update_tree_entry(&desc);
  55
  56                 if (S_ISDIR(mode)) {
  57                         struct tree *tree = lookup_tree(sha1);
  58                         process_tree(tree);
  59                 } else {
  60                         struct blob *blob = lookup_blob(sha1);
  61                         process(&blob->object);
  62                 }
  63         }
  64         free(tree->buffer);
  65         tree->buffer = NULL;
  66         tree->size = 0;
  67         return 0;
  68 }
  69
  70 #define COMPLETE        (1U << 0)
  71 #define SEEN            (1U << 1)
  72 #define TO_SCAN         (1U << 2)
  73
  74 static struct commit_list *complete = NULL;
  75
  76 static int process_commit(struct commit *commit)
  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         memcpy(current_commit_sha1, commit->object.sha1, 20);
  89
  90         pull_say("walk %s\n", sha1_to_hex(commit->object.sha1));
  91
  92         if (get_tree) {
  93                 if (process(&commit->tree->object))
  94                         return -1;
  95                 if (!get_all)
  96                         get_tree = 0;
  97         }
  98         if (get_history) {
  99                 struct commit_list *parents = commit->parents;
 100                 for (; parents; parents = parents->next) {
 101                         if (process(&parents->item->object))
 102                                 return -1;
 103                 }
 104         }
 105         return 0;
 106 }
 107
 108 static int process_tag(struct tag *tag)
 109 {
 110         if (parse_tag(tag))
 111                 return -1;
 112         return process(tag->tagged);
 113 }
 114
 115 static struct object_list *process_queue = NULL;
 116 static struct object_list **process_queue_end = &process_queue;
 117
 118 static int process_object(struct object *obj)
 119 {
 120         if (obj->type == commit_type) {
 121                 if (process_commit((struct commit *)obj))
 122                         return -1;
 123                 return 0;
 124         }
 125         if (obj->type == tree_type) {
 126                 if (process_tree((struct tree *)obj))
 127                         return -1;
 128                 return 0;
 129         }
 130         if (obj->type == blob_type) {
 131                 return 0;
 132         }
 133         if (obj->type == tag_type) {
 134                 if (process_tag((struct tag *)obj))
 135                         return -1;
 136                 return 0;
 137         }
 138         return error("Unable to determine requirements "
 139                      "of type %s for %s",
 140                      obj->type, sha1_to_hex(obj->sha1));
 141 }
 142
 143 static int process(struct object *obj)
 144 {
 145         if (obj->flags & SEEN)
 146                 return 0;
 147         obj->flags |= SEEN;
 148
 149         if (has_sha1_file(obj->sha1)) {
 150                 /* We already have it, so we should scan it now. */
 151                 obj->flags |= TO_SCAN;
 152         } else {
 153                 if (obj->flags & COMPLETE)
 154                         return 0;
 155                 prefetch(obj->sha1);
 156         }
 157
 158         object_list_insert(obj, process_queue_end);
 159         process_queue_end = &(*process_queue_end)->next;
 160         return 0;
 161 }
 162
 163 static int loop(void)
 164 {
 165         struct object_list *elem;
 166
 167         while (process_queue) {
 168                 struct object *obj = process_queue->item;
 169                 elem = process_queue;
 170                 process_queue = elem->next;
 171                 free(elem);
 172                 if (!process_queue)
 173                         process_queue_end = &process_queue;
 174
 175                 /* If we are not scanning this object, we placed it in
 176                  * the queue because we needed to fetch it first.
 177                  */
 178                 if (! (obj->flags & TO_SCAN)) {
 179                         if (fetch(obj->sha1)) {
 180                                 report_missing(obj->type
 181                                                ? obj->type
 182                                                : "object", obj->sha1);
 183                                 return -1;
 184                         }
 185                 }
 186                 if (!obj->type)
 187                         parse_object(obj->sha1);
 188                 if (process_object(obj))
 189                         return -1;
 190         }
 191         return 0;
 192 }
 193
 194 static int interpret_target(char *target, unsigned char *sha1)
 195 {
 196         if (!get_sha1_hex(target, sha1))
 197                 return 0;
 198         if (!check_ref_format(target)) {
 199                 if (!fetch_ref(target, sha1)) {
 200                         return 0;
 201                 }
 202         }
 203         return -1;
 204 }
 205
 206 static int mark_complete(const char *path, const unsigned char *sha1)
 207 {
 208         struct commit *commit = lookup_commit_reference_gently(sha1, 1);
 209         if (commit) {
 210                 commit->object.flags |= COMPLETE;
 211                 insert_by_date(commit, &complete);
 212         }
 213         return 0;
 214 }
 215
 216 int pull(char *target)
 217 {
 218         struct ref_lock *lock;
 219         unsigned char sha1[20];
 220         char *msg;
 221         int ret;
 222
 223         save_commit_buffer = 0;
 224         track_object_refs = 0;
 225         if (write_ref) {
 226                 lock = lock_ref_sha1(write_ref, NULL, 0);
 227                 if (!lock) {
 228                         error("Can't lock ref %s", write_ref);
 229                         return -1;
 230                 }
 231         }
 232
 233         if (!get_recover)
 234                 for_each_ref(mark_complete);
 235
 236         if (interpret_target(target, sha1)) {
 237                 error("Could not interpret %s as something to pull", target);
 238                 unlock_ref(lock);
 239                 return -1;
 240         }
 241         if (process(lookup_unknown_object(sha1))) {
 242                 unlock_ref(lock);
 243                 return -1;
 244         }
 245         if (loop()) {
 246                 unlock_ref(lock);
 247                 return -1;
 248         }
 249
 250         if (write_ref) {
 251                 if (write_ref_log_details) {
 252                         msg = xmalloc(strlen(write_ref_log_details) + 12);
 253                         sprintf(msg, "fetch from %s", write_ref_log_details);
 254                 } else
 255                         msg = NULL;
 256                 ret = write_ref_sha1(lock, sha1, msg ? msg : "fetch (unknown)");
 257                 if (msg)
 258                         free(msg);
 259                 return ret;
 260         }
 261         return 0;
 262 }