git.oblomov.eu Git - git/blob - shallow.c

   1 #include "cache.h"
   2 #include "commit.h"
   3 #include "tag.h"
   4 #include "pkt-line.h"
   5 #include "remote.h"
   6 #include "refs.h"
   7 #include "sha1-array.h"
   8 #include "diff.h"
   9 #include "revision.h"
  10 #include "commit-slab.h"
  11
  12 static int is_shallow = -1;
  13 static struct stat shallow_stat;
  14 static char *alternate_shallow_file;
  15
  16 void set_alternate_shallow_file(const char *path)
  17 {
  18         if (is_shallow != -1)
  19                 die("BUG: is_repository_shallow must not be called before set_alternate_shallow_file");
  20         free(alternate_shallow_file);
  21         alternate_shallow_file = path ? xstrdup(path) : NULL;
  22 }
  23
  24 int register_shallow(const unsigned char *sha1)
  25 {
  26         struct commit_graft *graft =
  27                 xmalloc(sizeof(struct commit_graft));
  28         struct commit *commit = lookup_commit(sha1);
  29
  30         hashcpy(graft->sha1, sha1);
  31         graft->nr_parent = -1;
  32         if (commit && commit->object.parsed)
  33                 commit->parents = NULL;
  34         return register_commit_graft(graft, 0);
  35 }
  36
  37 int is_repository_shallow(void)
  38 {
  39         FILE *fp;
  40         char buf[1024];
  41         const char *path = alternate_shallow_file;
  42
  43         if (is_shallow >= 0)
  44                 return is_shallow;
  45
  46         if (!path)
  47                 path = git_path("shallow");
  48         /*
  49          * fetch-pack sets '--shallow-file ""' as an indicator that no
  50          * shallow file should be used. We could just open it and it
  51          * will likely fail. But let's do an explicit check instead.
  52          */
  53         if (!*path ||
  54             stat(path, &shallow_stat) ||
  55             (fp = fopen(path, "r")) == NULL) {
  56                 is_shallow = 0;
  57                 return is_shallow;
  58         }
  59         is_shallow = 1;
  60
  61         while (fgets(buf, sizeof(buf), fp)) {
  62                 unsigned char sha1[20];
  63                 if (get_sha1_hex(buf, sha1))
  64                         die("bad shallow line: %s", buf);
  65                 register_shallow(sha1);
  66         }
  67         fclose(fp);
  68         return is_shallow;
  69 }
  70
  71 struct commit_list *get_shallow_commits(struct object_array *heads, int depth,
  72                 int shallow_flag, int not_shallow_flag)
  73 {
  74         int i = 0, cur_depth = 0;
  75         struct commit_list *result = NULL;
  76         struct object_array stack = OBJECT_ARRAY_INIT;
  77         struct commit *commit = NULL;
  78
  79         while (commit || i < heads->nr || stack.nr) {
  80                 struct commit_list *p;
  81                 if (!commit) {
  82                         if (i < heads->nr) {
  83                                 commit = (struct commit *)
  84                                         deref_tag(heads->objects[i++].item, NULL, 0);
  85                                 if (!commit || commit->object.type != OBJ_COMMIT) {
  86                                         commit = NULL;
  87                                         continue;
  88                                 }
  89                                 if (!commit->util)
  90                                         commit->util = xmalloc(sizeof(int));
  91                                 *(int *)commit->util = 0;
  92                                 cur_depth = 0;
  93                         } else {
  94                                 commit = (struct commit *)
  95                                         stack.objects[--stack.nr].item;
  96                                 cur_depth = *(int *)commit->util;
  97                         }
  98                 }
  99                 if (parse_commit(commit))
 100                         die("invalid commit");
 101                 cur_depth++;
 102                 if (cur_depth >= depth) {
 103                         commit_list_insert(commit, &result);
 104                         commit->object.flags |= shallow_flag;
 105                         commit = NULL;
 106                         continue;
 107                 }
 108                 commit->object.flags |= not_shallow_flag;
 109                 for (p = commit->parents, commit = NULL; p; p = p->next) {
 110                         if (!p->item->util) {
 111                                 int *pointer = xmalloc(sizeof(int));
 112                                 p->item->util = pointer;
 113                                 *pointer =  cur_depth;
 114                         } else {
 115                                 int *pointer = p->item->util;
 116                                 if (cur_depth >= *pointer)
 117                                         continue;
 118                                 *pointer = cur_depth;
 119                         }
 120                         if (p->next)
 121                                 add_object_array(&p->item->object,
 122                                                 NULL, &stack);
 123                         else {
 124                                 commit = p->item;
 125                                 cur_depth = *(int *)commit->util;
 126                         }
 127                 }
 128         }
 129
 130         return result;
 131 }
 132
 133 void check_shallow_file_for_update(void)
 134 {
 135         struct stat st;
 136
 137         if (!is_shallow)
 138                 return;
 139         else if (is_shallow == -1)
 140                 die("BUG: shallow must be initialized by now");
 141
 142         if (stat(git_path("shallow"), &st))
 143                 die("shallow file was removed during fetch");
 144         else if (st.st_mtime != shallow_stat.st_mtime
 145 #ifdef USE_NSEC
 146                  || ST_MTIME_NSEC(st) != ST_MTIME_NSEC(shallow_stat)
 147 #endif
 148                    )
 149                 die("shallow file was changed during fetch");
 150 }
 151
 152 struct write_shallow_data {
 153         struct strbuf *out;
 154         int use_pack_protocol;
 155         int count;
 156 };
 157
 158 static int write_one_shallow(const struct commit_graft *graft, void *cb_data)
 159 {
 160         struct write_shallow_data *data = cb_data;
 161         const char *hex = sha1_to_hex(graft->sha1);
 162         if (graft->nr_parent != -1)
 163                 return 0;
 164         data->count++;
 165         if (data->use_pack_protocol)
 166                 packet_buf_write(data->out, "shallow %s", hex);
 167         else {
 168                 strbuf_addstr(data->out, hex);
 169                 strbuf_addch(data->out, '\n');
 170         }
 171         return 0;
 172 }
 173
 174 int write_shallow_commits(struct strbuf *out, int use_pack_protocol,
 175                           const struct sha1_array *extra)
 176 {
 177         struct write_shallow_data data;
 178         int i;
 179         data.out = out;
 180         data.use_pack_protocol = use_pack_protocol;
 181         data.count = 0;
 182         for_each_commit_graft(write_one_shallow, &data);
 183         if (!extra)
 184                 return data.count;
 185         for (i = 0; i < extra->nr; i++) {
 186                 strbuf_addstr(out, sha1_to_hex(extra->sha1[i]));
 187                 strbuf_addch(out, '\n');
 188                 data.count++;
 189         }
 190         return data.count;
 191 }
 192
 193 char *setup_temporary_shallow(const struct sha1_array *extra)
 194 {
 195         struct strbuf sb = STRBUF_INIT;
 196         int fd;
 197
 198         if (write_shallow_commits(&sb, 0, extra)) {
 199                 struct strbuf path = STRBUF_INIT;
 200                 strbuf_addstr(&path, git_path("shallow_XXXXXX"));
 201                 fd = xmkstemp(path.buf);
 202                 if (write_in_full(fd, sb.buf, sb.len) != sb.len)
 203                         die_errno("failed to write to %s",
 204                                   path.buf);
 205                 close(fd);
 206                 strbuf_release(&sb);
 207                 return strbuf_detach(&path, NULL);
 208         }
 209         /*
 210          * is_repository_shallow() sees empty string as "no shallow
 211          * file".
 212          */
 213         return xstrdup("");
 214 }
 215
 216 void setup_alternate_shallow(struct lock_file *shallow_lock,
 217                              const char **alternate_shallow_file,
 218                              const struct sha1_array *extra)
 219 {
 220         struct strbuf sb = STRBUF_INIT;
 221         int fd;
 222
 223         check_shallow_file_for_update();
 224         fd = hold_lock_file_for_update(shallow_lock, git_path("shallow"),
 225                                        LOCK_DIE_ON_ERROR);
 226         if (write_shallow_commits(&sb, 0, extra)) {
 227                 if (write_in_full(fd, sb.buf, sb.len) != sb.len)
 228                         die_errno("failed to write to %s",
 229                                   shallow_lock->filename);
 230                 *alternate_shallow_file = shallow_lock->filename;
 231         } else
 232                 /*
 233                  * is_repository_shallow() sees empty string as "no
 234                  * shallow file".
 235                  */
 236                 *alternate_shallow_file = "";
 237         strbuf_release(&sb);
 238 }
 239
 240 static int advertise_shallow_grafts_cb(const struct commit_graft *graft, void *cb)
 241 {
 242         int fd = *(int *)cb;
 243         if (graft->nr_parent == -1)
 244                 packet_write(fd, "shallow %s\n", sha1_to_hex(graft->sha1));
 245         return 0;
 246 }
 247
 248 void advertise_shallow_grafts(int fd)
 249 {
 250         if (!is_repository_shallow())
 251                 return;
 252         for_each_commit_graft(advertise_shallow_grafts_cb, &fd);
 253 }
 254
 255 #define TRACE_KEY "GIT_TRACE_SHALLOW"
 256
 257 /*
 258  * Step 1, split sender shallow commits into "ours" and "theirs"
 259  * Step 2, clean "ours" based on .git/shallow
 260  */
 261 void prepare_shallow_info(struct shallow_info *info, struct sha1_array *sa)
 262 {
 263         int i;
 264         trace_printf_key(TRACE_KEY, "shallow: prepare_shallow_info\n");
 265         memset(info, 0, sizeof(*info));
 266         info->shallow = sa;
 267         if (!sa)
 268                 return;
 269         info->ours = xmalloc(sizeof(*info->ours) * sa->nr);
 270         info->theirs = xmalloc(sizeof(*info->theirs) * sa->nr);
 271         for (i = 0; i < sa->nr; i++) {
 272                 if (has_sha1_file(sa->sha1[i])) {
 273                         struct commit_graft *graft;
 274                         graft = lookup_commit_graft(sa->sha1[i]);
 275                         if (graft && graft->nr_parent < 0)
 276                                 continue;
 277                         info->ours[info->nr_ours++] = i;
 278                 } else
 279                         info->theirs[info->nr_theirs++] = i;
 280         }
 281 }
 282
 283 void clear_shallow_info(struct shallow_info *info)
 284 {
 285         free(info->ours);
 286         free(info->theirs);
 287 }
 288
 289 /* Step 4, remove non-existent ones in "theirs" after getting the pack */
 290
 291 void remove_nonexistent_theirs_shallow(struct shallow_info *info)
 292 {
 293         unsigned char (*sha1)[20] = info->shallow->sha1;
 294         int i, dst;
 295         trace_printf_key(TRACE_KEY, "shallow: remove_nonexistent_theirs_shallow\n");
 296         for (i = dst = 0; i < info->nr_theirs; i++) {
 297                 if (i != dst)
 298                         info->theirs[dst] = info->theirs[i];
 299                 if (has_sha1_file(sha1[info->theirs[i]]))
 300                         dst++;
 301         }
 302         info->nr_theirs = dst;
 303 }
 304
 305 /* Step 5, remove non-existent ones in "ours" in the pack */
 306 void remove_nonexistent_ours_in_pack(struct shallow_info *info,
 307                                      struct packed_git *p)
 308 {
 309         unsigned char (*sha1)[20] = info->shallow->sha1;
 310         int i, dst;
 311         trace_printf_key(TRACE_KEY, "shallow: remove_nonexistent_ours_in_pack\n");
 312         for (i = dst = 0; i < info->nr_ours; i++) {
 313                 if (i != dst)
 314                         info->ours[dst] = info->ours[i];
 315                 if (find_pack_entry_one(sha1[info->ours[i]], p))
 316                         dst++;
 317         }
 318         info->nr_ours = dst;
 319 }