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 #define SEEN            16U
  62
  63 static struct commit_list *complete = NULL;
  64
  65 static int process_commit(struct commit *commit)
  66 {
  67         if (parse_commit(commit))
  68                 return -1;
  69
  70         while (complete && complete->item->date >= commit->date) {
  71                 pop_most_recent_commit(&complete, COMPLETE);
  72         }
  73
  74         if (commit->object.flags & COMPLETE)
  75                 return 0;
  76
  77         memcpy(current_commit_sha1, commit->object.sha1, 20);
  78
  79         pull_say("walk %s\n", sha1_to_hex(commit->object.sha1));
  80
  81         if (get_tree) {
  82                 if (process(&commit->tree->object))
  83                         return -1;
  84                 if (!get_all)
  85                         get_tree = 0;
  86         }
  87         if (get_history) {
  88                 struct commit_list *parents = commit->parents;
  89                 for (; parents; parents = parents->next) {
  90                         if (process(&parents->item->object))
  91                                 return -1;
  92                 }
  93         }
  94         return 0;
  95 }
  96
  97 static int process_tag(struct tag *tag)
  98 {
  99         if (parse_tag(tag))
 100                 return -1;
 101         return process(tag->tagged);
 102 }
 103
 104 static struct object_list *process_queue = NULL;
 105 static struct object_list **process_queue_end = &process_queue;
 106
 107 static int process_object(struct object *obj)
 108 {
 109         if (obj->flags & SCANNED)
 110                 return 0;
 111         obj->flags |= SCANNED;
 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                 parse_object(obj->sha1);
 144                 /* We already have it, so we should scan it now. */
 145                 if (obj->flags & (SCANNED | TO_SCAN))
 146                         return 0;
 147                 object_list_insert(obj, process_queue_end);
 148                 process_queue_end = &(*process_queue_end)->next;
 149                 obj->flags |= TO_SCAN;
 150                 return 0;
 151         }
 152         if (obj->flags & (COMPLETE | TO_FETCH))
 153                 return 0;
 154         object_list_insert(obj, process_queue_end);
 155         process_queue_end = &(*process_queue_end)->next;
 156         obj->flags |= TO_FETCH;
 157
 158         prefetch(obj->sha1);
 159
 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 (!has_sha1_file(obj->sha1) && 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         int fd = -1;
 220
 221         save_commit_buffer = 0;
 222         if (write_ref && current_ref) {
 223                 fd = lock_ref_sha1(write_ref, current_ref);
 224                 if (fd < 0)
 225                         return -1;
 226         }
 227
 228         for_each_ref(mark_complete);
 229
 230         if (interpret_target(target, sha1))
 231                 return error("Could not interpret %s as something to pull",
 232                              target);
 233         if (process(lookup_unknown_object(sha1)))
 234                 return -1;
 235         if (loop())
 236                 return -1;
 237
 238         if (write_ref) {
 239                 if (current_ref) {
 240                         write_ref_sha1(write_ref, fd, sha1);
 241                 } else {
 242                         write_ref_sha1_unlocked(write_ref, sha1);
 243                 }
 244         }
 245         return 0;
 246 }