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 << 0)
  58 #define SEEN            (1U << 1)
  59 #define TO_SCAN         (1U << 2)
  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                 /* We already have it, so we should scan it now. */
 138                 obj->flags |= TO_SCAN;
 139         } else {
 140                 if (obj->flags & COMPLETE)
 141                         return 0;
 142                 prefetch(obj->sha1);
 143         }
 144
 145         object_list_insert(obj, process_queue_end);
 146         process_queue_end = &(*process_queue_end)->next;
 147         return 0;
 148 }
 149
 150 static int loop(void)
 151 {
 152         struct object_list *elem;
 153
 154         while (process_queue) {
 155                 struct object *obj = process_queue->item;
 156                 elem = process_queue;
 157                 process_queue = elem->next;
 158                 free(elem);
 159                 if (!process_queue)
 160                         process_queue_end = &process_queue;
 161
 162                 /* If we are not scanning this object, we placed it in
 163                  * the queue because we needed to fetch it first.
 164                  */
 165                 if (! (obj->flags & TO_SCAN)) {
 166                         if (!has_sha1_file(obj->sha1) && fetch(obj->sha1)) {
 167                                 report_missing(obj->type
 168                                                ? obj->type
 169                                                : "object", obj->sha1);
 170                                 return -1;
 171                         }
 172                 }
 173                 if (!obj->type)
 174                         parse_object(obj->sha1);
 175                 if (process_object(obj))
 176                         return -1;
 177         }
 178         return 0;
 179 }
 180
 181 static int interpret_target(char *target, unsigned char *sha1)
 182 {
 183         if (!get_sha1_hex(target, sha1))
 184                 return 0;
 185         if (!check_ref_format(target)) {
 186                 if (!fetch_ref(target, sha1)) {
 187                         return 0;
 188                 }
 189         }
 190         return -1;
 191 }
 192
 193 static int mark_complete(const char *path, const unsigned char *sha1)
 194 {
 195         struct commit *commit = lookup_commit_reference_gently(sha1, 1);
 196         if (commit) {
 197                 commit->object.flags |= COMPLETE;
 198                 insert_by_date(commit, &complete);
 199         }
 200         return 0;
 201 }
 202
 203 int pull(char *target)
 204 {
 205         unsigned char sha1[20];
 206         int fd = -1;
 207
 208         save_commit_buffer = 0;
 209         if (write_ref && current_ref) {
 210                 fd = lock_ref_sha1(write_ref, current_ref);
 211                 if (fd < 0)
 212                         return -1;
 213         }
 214
 215         for_each_ref(mark_complete);
 216
 217         if (interpret_target(target, sha1))
 218                 return error("Could not interpret %s as something to pull",
 219                              target);
 220         if (process(lookup_unknown_object(sha1)))
 221                 return -1;
 222         if (loop())
 223                 return -1;
 224
 225         if (write_ref) {
 226                 if (current_ref) {
 227                         write_ref_sha1(write_ref, fd, sha1);
 228                 } else {
 229                         write_ref_sha1_unlocked(write_ref, sha1);
 230                 }
 231         }
 232         return 0;
 233 }