shallow.c

   1 #include "cache.h"
   2 #include "commit.h"
   3 #include "tag.h"
   4 #include "pkt-line.h"
   5
   6 static int is_shallow = -1;
   7 static struct stat shallow_stat;
   8 static char *alternate_shallow_file;
   9
  10 void set_alternate_shallow_file(const char *path)
  11 {
  12         if (is_shallow != -1)
  13                 die("BUG: is_repository_shallow must not be called before set_alternate_shallow_file");
  14         free(alternate_shallow_file);
  15         alternate_shallow_file = path ? xstrdup(path) : NULL;
  16 }
  17
  18 int register_shallow(const unsigned char *sha1)
  19 {
  20         struct commit_graft *graft =
  21                 xmalloc(sizeof(struct commit_graft));
  22         struct commit *commit = lookup_commit(sha1);
  23
  24         hashcpy(graft->sha1, sha1);
  25         graft->nr_parent = -1;
  26         if (commit && commit->object.parsed)
  27                 commit->parents = NULL;
  28         return register_commit_graft(graft, 0);
  29 }
  30
  31 int is_repository_shallow(void)
  32 {
  33         FILE *fp;
  34         char buf[1024];
  35         const char *path = alternate_shallow_file;
  36
  37         if (is_shallow >= 0)
  38                 return is_shallow;
  39
  40         if (!path)
  41                 path = git_path("shallow");
  42         /*
  43          * fetch-pack sets '--shallow-file ""' as an indicator that no
  44          * shallow file should be used. We could just open it and it
  45          * will likely fail. But let's do an explicit check instead.
  46          */
  47         if (!*path ||
  48             stat(path, &shallow_stat) ||
  49             (fp = fopen(path, "r")) == NULL) {
  50                 is_shallow = 0;
  51                 return is_shallow;
  52         }
  53         is_shallow = 1;
  54
  55         while (fgets(buf, sizeof(buf), fp)) {
  56                 unsigned char sha1[20];
  57                 if (get_sha1_hex(buf, sha1))
  58                         die("bad shallow line: %s", buf);
  59                 register_shallow(sha1);
  60         }
  61         fclose(fp);
  62         return is_shallow;
  63 }
  64
  65 struct commit_list *get_shallow_commits(struct object_array *heads, int depth,
  66                 int shallow_flag, int not_shallow_flag)
  67 {
  68         int i = 0, cur_depth = 0;
  69         struct commit_list *result = NULL;
  70         struct object_array stack = OBJECT_ARRAY_INIT;
  71         struct commit *commit = NULL;
  72
  73         while (commit || i < heads->nr || stack.nr) {
  74                 struct commit_list *p;
  75                 if (!commit) {
  76                         if (i < heads->nr) {
  77                                 commit = (struct commit *)
  78                                         deref_tag(heads->objects[i++].item, NULL, 0);
  79                                 if (!commit || commit->object.type != OBJ_COMMIT) {
  80                                         commit = NULL;
  81                                         continue;
  82                                 }
  83                                 if (!commit->util)
  84                                         commit->util = xmalloc(sizeof(int));
  85                                 *(int *)commit->util = 0;
  86                                 cur_depth = 0;
  87                         } else {
  88                                 commit = (struct commit *)
  89                                         stack.objects[--stack.nr].item;
  90                                 cur_depth = *(int *)commit->util;
  91                         }
  92                 }
  93                 if (parse_commit(commit))
  94                         die("invalid commit");
  95                 cur_depth++;
  96                 if (cur_depth >= depth) {
  97                         commit_list_insert(commit, &result);
  98                         commit->object.flags |= shallow_flag;
  99                         commit = NULL;
 100                         continue;
 101                 }
 102                 commit->object.flags |= not_shallow_flag;
 103                 for (p = commit->parents, commit = NULL; p; p = p->next) {
 104                         if (!p->item->util) {
 105                                 int *pointer = xmalloc(sizeof(int));
 106                                 p->item->util = pointer;
 107                                 *pointer =  cur_depth;
 108                         } else {
 109                                 int *pointer = p->item->util;
 110                                 if (cur_depth >= *pointer)
 111                                         continue;
 112                                 *pointer = cur_depth;
 113                         }
 114                         if (p->next)
 115                                 add_object_array(&p->item->object,
 116                                                 NULL, &stack);
 117                         else {
 118                                 commit = p->item;
 119                                 cur_depth = *(int *)commit->util;
 120                         }
 121                 }
 122         }
 123
 124         return result;
 125 }
 126
 127 void check_shallow_file_for_update(void)
 128 {
 129         struct stat st;
 130
 131         if (!is_shallow)
 132                 return;
 133         else if (is_shallow == -1)
 134                 die("BUG: shallow must be initialized by now");
 135
 136         if (stat(git_path("shallow"), &st))
 137                 die("shallow file was removed during fetch");
 138         else if (st.st_mtime != shallow_stat.st_mtime
 139 #ifdef USE_NSEC
 140                  || ST_MTIME_NSEC(st) != ST_MTIME_NSEC(shallow_stat)
 141 #endif
 142                    )
 143                 die("shallow file was changed during fetch");
 144 }
 145
 146 struct write_shallow_data {
 147         struct strbuf *out;
 148         int use_pack_protocol;
 149         int count;
 150 };
 151
 152 static int write_one_shallow(const struct commit_graft *graft, void *cb_data)
 153 {
 154         struct write_shallow_data *data = cb_data;
 155         const char *hex = sha1_to_hex(graft->sha1);
 156         if (graft->nr_parent != -1)
 157                 return 0;
 158         data->count++;
 159         if (data->use_pack_protocol)
 160                 packet_buf_write(data->out, "shallow %s", hex);
 161         else {
 162                 strbuf_addstr(data->out, hex);
 163                 strbuf_addch(data->out, '\n');
 164         }
 165         return 0;
 166 }
 167
 168 int write_shallow_commits(struct strbuf *out, int use_pack_protocol)
 169 {
 170         struct write_shallow_data data;
 171         data.out = out;
 172         data.use_pack_protocol = use_pack_protocol;
 173         data.count = 0;
 174         for_each_commit_graft(write_one_shallow, &data);
 175         return data.count;
 176 }
 177
 178 void setup_alternate_shallow(struct lock_file *shallow_lock,
 179                              const char **alternate_shallow_file)
 180 {
 181         struct strbuf sb = STRBUF_INIT;
 182         int fd;
 183
 184         check_shallow_file_for_update();
 185         fd = hold_lock_file_for_update(shallow_lock, git_path("shallow"),
 186                                        LOCK_DIE_ON_ERROR);
 187         if (write_shallow_commits(&sb, 0)) {
 188                 if (write_in_full(fd, sb.buf, sb.len) != sb.len)
 189                         die_errno("failed to write to %s",
 190                                   shallow_lock->filename);
 191                 *alternate_shallow_file = shallow_lock->filename;
 192         } else
 193                 /*
 194                  * is_repository_shallow() sees empty string as "no
 195                  * shallow file".
 196                  */
 197                 *alternate_shallow_file = "";
 198         strbuf_release(&sb);
 199 }