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         struct name_entry entry;
  42
  43         if (parse_tree(tree))
  44                 return -1;
  45
  46         desc.buf = tree->buffer;
  47         desc.size = tree->size;
  48         while (tree_entry(&desc, &entry)) {
  49                 struct object *obj = NULL;
  50
  51                 if (S_ISDIR(entry.mode)) {
  52                         struct tree *tree = lookup_tree(entry.sha1);
  53                         if (tree)
  54                                 obj = &tree->object;
  55                 }
  56                 else {
  57                         struct blob *blob = lookup_blob(entry.sha1);
  58                         if (blob)
  59                                 obj = &blob->object;
  60                 }
  61                 if (!obj || process(obj))
  62                         return -1;
  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         unsigned char sha1[20];
 219
 220         save_commit_buffer = 0;
 221         track_object_refs = 0;
 222
 223         if (!get_recover)
 224                 for_each_ref(mark_complete);
 225
 226         if (interpret_target(target, sha1))
 227                 return error("Could not interpret %s as something to pull",
 228                              target);
 229         if (process(lookup_unknown_object(sha1)))
 230                 return -1;
 231         if (loop())
 232                 return -1;
 233
 234         if (write_ref)
 235                 write_ref_sha1_unlocked(write_ref, sha1);
 236         return 0;
 237 }