fetch.c

   1 #include "fetch.h"
   2
   3 #include "cache.h"
   4 #include "commit.h"
   5 #include "tree.h"
   6 #include "tag.h"
   7 #include "blob.h"
   8 #include "refs.h"
   9
  10 const char *write_ref = NULL;
  11
  12 const unsigned char *current_ref = NULL;
  13
  14 int get_tree = 0;
  15 int get_history = 0;
  16 int get_all = 0;
  17 int get_verbosely = 0;
  18 static unsigned char current_commit_sha1[20];
  19
  20 void pull_say(const char *fmt, const char *hex)
  21 {
  22         if (get_verbosely)
  23                 fprintf(stderr, fmt, hex);
  24 }
  25
  26 static void report_missing(const char *what, const unsigned char *missing)
  27 {
  28         char missing_hex[41];
  29
  30         strcpy(missing_hex, sha1_to_hex(missing));;
  31         fprintf(stderr,
  32                 "Cannot obtain needed %s %s\nwhile processing commit %s.\n",
  33                 what, missing_hex, sha1_to_hex(current_commit_sha1));
  34 }
  35
  36 static int process(struct object *obj);
  37
  38 static int process_tree(struct tree *tree)
  39 {
  40         struct tree_entry_list *entry;
  41
  42         if (parse_tree(tree))
  43                 return -1;
  44
  45         entry = tree->entries;
  46         tree->entries = NULL;
  47         while (entry) {
  48                 struct tree_entry_list *next = entry->next;
  49                 if (process(entry->item.any))
  50                         return -1;
  51                 free(entry);
  52                 entry = next;
  53         }
  54         return 0;
  55 }
  56
  57 #define COMPLETE        1U
  58 #define TO_SCAN         4U
  59 #define SEEN            16U
  60
  61 static struct commit_list *complete = NULL;
  62
  63 static int process_commit(struct commit *commit)
  64 {
  65         if (parse_commit(commit))
  66                 return -1;
  67
  68         while (complete && complete->item->date >= commit->date) {
  69                 pop_most_recent_commit(&complete, COMPLETE);
  70         }
  71
  72         if (commit->object.flags & COMPLETE)
  73                 return 0;
  74
  75         memcpy(current_commit_sha1, commit->object.sha1, 20);
  76
  77         pull_say("walk %s\n", sha1_to_hex(commit->object.sha1));
  78
  79         if (get_tree) {
  80                 if (process(&commit->tree->object))
  81                         return -1;
  82                 if (!get_all)
  83                         get_tree = 0;
  84         }
  85         if (get_history) {
  86                 struct commit_list *parents = commit->parents;
  87                 for (; parents; parents = parents->next) {
  88                         if (process(&parents->item->object))
  89                                 return -1;
  90                 }
  91         }
  92         return 0;
  93 }
  94
  95 static int process_tag(struct tag *tag)
  96 {
  97         if (parse_tag(tag))
  98                 return -1;
  99         return process(tag->tagged);
 100 }
 101
 102 static struct object_list *process_queue = NULL;
 103 static struct object_list **process_queue_end = &process_queue;
 104
 105 static int process_object(struct object *obj)
 106 {
 107         if (obj->type == commit_type) {
 108                 if (process_commit((struct commit *)obj))
 109                         return -1;
 110                 return 0;
 111         }
 112         if (obj->type == tree_type) {
 113                 if (process_tree((struct tree *)obj))
 114                         return -1;
 115                 return 0;
 116         }
 117         if (obj->type == blob_type) {
 118                 return 0;
 119         }
 120         if (obj->type == tag_type) {
 121                 if (process_tag((struct tag *)obj))
 122                         return -1;
 123                 return 0;
 124         }
 125         return error("Unable to determine requirements "
 126                      "of type %s for %s",
 127                      obj->type, sha1_to_hex(obj->sha1));
 128 }
 129
 130 static int process(struct object *obj)
 131 {
 132         if (obj->flags & SEEN)
 133                 return 0;
 134         obj->flags |= SEEN;
 135
 136         if (has_sha1_file(obj->sha1)) {
 137                 parse_object(obj->sha1);
 138                 /* We already have it, so we should scan it now. */
 139                 if (obj->flags & TO_SCAN)
 140                         return 0;
 141                 obj->flags |= TO_SCAN;
 142         } else {
 143                 if (obj->flags & COMPLETE)
 144                         return 0;
 145                 prefetch(obj->sha1);
 146         }
 147
 148         object_list_insert(obj, process_queue_end);
 149         process_queue_end = &(*process_queue_end)->next;
 150         return 0;
 151 }
 152
 153 static int loop(void)
 154 {
 155         struct object_list *elem;
 156
 157         while (process_queue) {
 158                 struct object *obj = process_queue->item;
 159                 elem = process_queue;
 160                 process_queue = elem->next;
 161                 free(elem);
 162                 if (!process_queue)
 163                         process_queue_end = &process_queue;
 164
 165                 /* If we are not scanning this object, we placed it in
 166                  * the queue because we needed to fetch it first.
 167                  */
 168                 if (! (obj->flags & TO_SCAN)) {
 169                         if (!has_sha1_file(obj->sha1) && fetch(obj->sha1)) {
 170                                 report_missing(obj->type
 171                                                ? obj->type
 172                                                : "object", obj->sha1);
 173                                 return -1;
 174                         }
 175                 }
 176                 if (!obj->type)
 177                         parse_object(obj->sha1);
 178                 if (process_object(obj))
 179                         return -1;
 180         }
 181         return 0;
 182 }
 183
 184 static int interpret_target(char *target, unsigned char *sha1)
 185 {
 186         if (!get_sha1_hex(target, sha1))
 187                 return 0;
 188         if (!check_ref_format(target)) {
 189                 if (!fetch_ref(target, sha1)) {
 190                         return 0;
 191                 }
 192         }
 193         return -1;
 194 }
 195
 196 static int mark_complete(const char *path, const unsigned char *sha1)
 197 {
 198         struct commit *commit = lookup_commit_reference_gently(sha1, 1);
 199         if (commit) {
 200                 commit->object.flags |= COMPLETE;
 201                 insert_by_date(commit, &complete);
 202         }
 203         return 0;
 204 }
 205
 206 int pull(char *target)
 207 {
 208         unsigned char sha1[20];
 209         int fd = -1;
 210
 211         save_commit_buffer = 0;
 212         if (write_ref && current_ref) {
 213                 fd = lock_ref_sha1(write_ref, current_ref);
 214                 if (fd < 0)
 215                         return -1;
 216         }
 217
 218         for_each_ref(mark_complete);
 219
 220         if (interpret_target(target, sha1))
 221                 return error("Could not interpret %s as something to pull",
 222                              target);
 223         if (process(lookup_unknown_object(sha1)))
 224                 return -1;
 225         if (loop())
 226                 return -1;
 227
 228         if (write_ref) {
 229                 if (current_ref) {
 230                         write_ref_sha1(write_ref, fd, sha1);
 231                 } else {
 232                         write_ref_sha1_unlocked(write_ref, sha1);
 233                 }
 234         }
 235         return 0;
 236 }