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
  58 #define TO_FETCH        2U
  59 #define TO_SCAN         4U
  60 #define SCANNED         8U
  61
  62 static struct commit_list *complete = NULL;
  63
  64 static int process_commit(struct commit *commit)
  65 {
  66         if (parse_commit(commit))
  67                 return -1;
  68
  69         while (complete && complete->item->date >= commit->date) {
  70                 pop_most_recent_commit(&complete, COMPLETE);
  71         }
  72
  73         if (commit->object.flags & COMPLETE)
  74                 return 0;
  75
  76         memcpy(current_commit_sha1, commit->object.sha1, 20);
  77
  78         pull_say("walk %s\n", sha1_to_hex(commit->object.sha1));
  79
  80         if (get_tree) {
  81                 if (process(&commit->tree->object))
  82                         return -1;
  83                 if (!get_all)
  84                         get_tree = 0;
  85         }
  86         if (get_history) {
  87                 struct commit_list *parents = commit->parents;
  88                 for (; parents; parents = parents->next) {
  89                         if (process(&parents->item->object))
  90                                 return -1;
  91                 }
  92         }
  93         return 0;
  94 }
  95
  96 static int process_tag(struct tag *tag)
  97 {
  98         if (parse_tag(tag))
  99                 return -1;
 100         return process(tag->tagged);
 101 }
 102
 103 static struct object_list *process_queue = NULL;
 104 static struct object_list **process_queue_end = &process_queue;
 105
 106 static int process_object(struct object *obj)
 107 {
 108         if (obj->flags & SCANNED)
 109                 return 0;
 110         obj->flags |= SCANNED;
 111
 112         if (obj->type == commit_type) {
 113                 if (process_commit((struct commit *)obj))
 114                         return -1;
 115                 return 0;
 116         }
 117         if (obj->type == tree_type) {
 118                 if (process_tree((struct tree *)obj))
 119                         return -1;
 120                 return 0;
 121         }
 122         if (obj->type == blob_type) {
 123                 return 0;
 124         }
 125         if (obj->type == tag_type) {
 126                 if (process_tag((struct tag *)obj))
 127                         return -1;
 128                 return 0;
 129         }
 130         return error("Unable to determine requirements "
 131                      "of type %s for %s",
 132                      obj->type, sha1_to_hex(obj->sha1));
 133 }
 134
 135 static int process(struct object *obj)
 136 {
 137         if (has_sha1_file(obj->sha1)) {
 138                 parse_object(obj->sha1);
 139                 /* We already have it, so we should scan it now. */
 140                 if (obj->flags & (SCANNED | TO_SCAN))
 141                         return 0;
 142                 object_list_insert(obj, process_queue_end);
 143                 process_queue_end = &(*process_queue_end)->next;
 144                 obj->flags |= TO_SCAN;
 145                 return 0;
 146         }
 147         if (obj->flags & (COMPLETE | TO_FETCH))
 148                 return 0;
 149         object_list_insert(obj, process_queue_end);
 150         process_queue_end = &(*process_queue_end)->next;
 151         obj->flags |= TO_FETCH;
 152
 153         prefetch(obj->sha1);
 154
 155         return 0;
 156 }
 157
 158 static int loop(void)
 159 {
 160         struct object_list *elem;
 161
 162         while (process_queue) {
 163                 struct object *obj = process_queue->item;
 164                 elem = process_queue;
 165                 process_queue = elem->next;
 166                 free(elem);
 167                 if (!process_queue)
 168                         process_queue_end = &process_queue;
 169
 170                 /* If we are not scanning this object, we placed it in
 171                  * the queue because we needed to fetch it first.
 172                  */
 173                 if (! (obj->flags & TO_SCAN)) {
 174                         if (!has_sha1_file(obj->sha1) && fetch(obj->sha1)) {
 175                                 report_missing(obj->type
 176                                                ? obj->type
 177                                                : "object", obj->sha1);
 178                                 return -1;
 179                         }
 180                 }
 181                 if (!obj->type)
 182                         parse_object(obj->sha1);
 183                 if (process_object(obj))
 184                         return -1;
 185         }
 186         return 0;
 187 }
 188
 189 static int interpret_target(char *target, unsigned char *sha1)
 190 {
 191         if (!get_sha1_hex(target, sha1))
 192                 return 0;
 193         if (!check_ref_format(target)) {
 194                 if (!fetch_ref(target, sha1)) {
 195                         return 0;
 196                 }
 197         }
 198         return -1;
 199 }
 200
 201 static int mark_complete(const char *path, const unsigned char *sha1)
 202 {
 203         struct commit *commit = lookup_commit_reference_gently(sha1, 1);
 204         if (commit) {
 205                 commit->object.flags |= COMPLETE;
 206                 insert_by_date(commit, &complete);
 207         }
 208         return 0;
 209 }
 210
 211 int pull(char *target)
 212 {
 213         unsigned char sha1[20];
 214         int fd = -1;
 215
 216         save_commit_buffer = 0;
 217         if (write_ref && current_ref) {
 218                 fd = lock_ref_sha1(write_ref, current_ref);
 219                 if (fd < 0)
 220                         return -1;
 221         }
 222
 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                 if (current_ref) {
 235                         write_ref_sha1(write_ref, fd, sha1);
 236                 } else {
 237                         write_ref_sha1_unlocked(write_ref, sha1);
 238                 }
 239         }
 240         return 0;
 241 }