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 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_entry_list *entry;
  42
  43         if (parse_tree(tree))
  44                 return -1;
  45
  46         entry = tree->entries;
  47         tree->entries = NULL;
  48         while (entry) {
  49                 struct tree_entry_list *next = entry->next;
  50                 if (process(entry->item.any))
  51                         return -1;
  52                 free(entry->name);
  53                 free(entry);
  54                 entry = next;
  55         }
  56         return 0;
  57 }
  58
  59 #define COMPLETE        (1U << 0)
  60 #define SEEN            (1U << 1)
  61 #define TO_SCAN         (1U << 2)
  62
  63 static struct commit_list *complete = NULL;
  64
  65 static int process_commit(struct commit *commit)
  66 {
  67         if (parse_commit(commit))
  68                 return -1;
  69
  70         while (complete && complete->item->date >= commit->date) {
  71                 pop_most_recent_commit(&complete, COMPLETE);
  72         }
  73
  74         if (commit->object.flags & COMPLETE)
  75                 return 0;
  76
  77         memcpy(current_commit_sha1, commit->object.sha1, 20);
  78
  79         pull_say("walk %s\n", sha1_to_hex(commit->object.sha1));
  80
  81         if (get_tree) {
  82                 if (process(&commit->tree->object))
  83                         return -1;
  84                 if (!get_all)
  85                         get_tree = 0;
  86         }
  87         if (get_history) {
  88                 struct commit_list *parents = commit->parents;
  89                 for (; parents; parents = parents->next) {
  90                         if (process(&parents->item->object))
  91                                 return -1;
  92                 }
  93         }
  94         return 0;
  95 }
  96
  97 static int process_tag(struct tag *tag)
  98 {
  99         if (parse_tag(tag))
 100                 return -1;
 101         return process(tag->tagged);
 102 }
 103
 104 static struct object_list *process_queue = NULL;
 105 static struct object_list **process_queue_end = &process_queue;
 106
 107 static int process_object(struct object *obj)
 108 {
 109         if (obj->type == commit_type) {
 110                 if (process_commit((struct commit *)obj))
 111                         return -1;
 112                 return 0;
 113         }
 114         if (obj->type == tree_type) {
 115                 if (process_tree((struct tree *)obj))
 116                         return -1;
 117                 return 0;
 118         }
 119         if (obj->type == blob_type) {
 120                 return 0;
 121         }
 122         if (obj->type == tag_type) {
 123                 if (process_tag((struct tag *)obj))
 124                         return -1;
 125                 return 0;
 126         }
 127         return error("Unable to determine requirements "
 128                      "of type %s for %s",
 129                      obj->type, sha1_to_hex(obj->sha1));
 130 }
 131
 132 static int process(struct object *obj)
 133 {
 134         if (obj->flags & SEEN)
 135                 return 0;
 136         obj->flags |= SEEN;
 137
 138         if (has_sha1_file(obj->sha1)) {
 139                 /* We already have it, so we should scan it now. */
 140                 obj->flags |= TO_SCAN;
 141         } else {
 142                 if (obj->flags & COMPLETE)
 143                         return 0;
 144                 prefetch(obj->sha1);
 145         }
 146
 147         object_list_insert(obj, process_queue_end);
 148         process_queue_end = &(*process_queue_end)->next;
 149         return 0;
 150 }
 151
 152 static int loop(void)
 153 {
 154         struct object_list *elem;
 155
 156         while (process_queue) {
 157                 struct object *obj = process_queue->item;
 158                 elem = process_queue;
 159                 process_queue = elem->next;
 160                 free(elem);
 161                 if (!process_queue)
 162                         process_queue_end = &process_queue;
 163
 164                 /* If we are not scanning this object, we placed it in
 165                  * the queue because we needed to fetch it first.
 166                  */
 167                 if (! (obj->flags & TO_SCAN)) {
 168                         if (!has_sha1_file(obj->sha1) && fetch(obj->sha1)) {
 169                                 report_missing(obj->type
 170                                                ? obj->type
 171                                                : "object", obj->sha1);
 172                                 return -1;
 173                         }
 174                 }
 175                 if (!obj->type)
 176                         parse_object(obj->sha1);
 177                 if (process_object(obj))
 178                         return -1;
 179         }
 180         return 0;
 181 }
 182
 183 static int interpret_target(char *target, unsigned char *sha1)
 184 {
 185         if (!get_sha1_hex(target, sha1))
 186                 return 0;
 187         if (!check_ref_format(target)) {
 188                 if (!fetch_ref(target, sha1)) {
 189                         return 0;
 190                 }
 191         }
 192         return -1;
 193 }
 194
 195 static int mark_complete(const char *path, const unsigned char *sha1)
 196 {
 197         struct commit *commit = lookup_commit_reference_gently(sha1, 1);
 198         if (commit) {
 199                 commit->object.flags |= COMPLETE;
 200                 insert_by_date(commit, &complete);
 201         }
 202         return 0;
 203 }
 204
 205 int pull(char *target)
 206 {
 207         unsigned char sha1[20];
 208         int fd = -1;
 209
 210         save_commit_buffer = 0;
 211         track_object_refs = 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         if (!get_recover) {
 219                 for_each_ref(mark_complete);
 220         }
 221
 222         if (interpret_target(target, sha1))
 223                 return error("Could not interpret %s as something to pull",
 224                              target);
 225         if (process(lookup_unknown_object(sha1)))
 226                 return -1;
 227         if (loop())
 228                 return -1;
 229
 230         if (write_ref) {
 231                 if (current_ref) {
 232                         write_ref_sha1(write_ref, fd, sha1);
 233                 } else {
 234                         write_ref_sha1_unlocked(write_ref, sha1);
 235                 }
 236         }
 237         return 0;
 238 }