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