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