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                 parse_commit_or_die(commit);
  94                 cur_depth++;
  95                 if (cur_depth >= depth) {
  96                         commit_list_insert(commit, &result);
  97                         commit->object.flags |= shallow_flag;
  98                         commit = NULL;
  99                         continue;
 100                 }
 101                 commit->object.flags |= not_shallow_flag;
 102                 for (p = commit->parents, commit = NULL; p; p = p->next) {
 103                         if (!p->item->util) {
 104                                 int *pointer = xmalloc(sizeof(int));
 105                                 p->item->util = pointer;
 106                                 *pointer =  cur_depth;
 107                         } else {
 108                                 int *pointer = p->item->util;
 109                                 if (cur_depth >= *pointer)
 110                                         continue;
 111                                 *pointer = cur_depth;
 112                         }
 113                         if (p->next)
 114                                 add_object_array(&p->item->object,
 115                                                 NULL, &stack);
 116                         else {
 117                                 commit = p->item;
 118                                 cur_depth = *(int *)commit->util;
 119                         }
 120                 }
 121         }
 122
 123         return result;
 124 }
 125
 126 void check_shallow_file_for_update(void)
 127 {
 128         struct stat st;
 129
 130         if (!is_shallow)
 131                 return;
 132         else if (is_shallow == -1)
 133                 die("BUG: shallow must be initialized by now");
 134
 135         if (stat(git_path("shallow"), &st))
 136                 die("shallow file was removed during fetch");
 137         else if (st.st_mtime != shallow_stat.st_mtime
 138 #ifdef USE_NSEC
 139                  || ST_MTIME_NSEC(st) != ST_MTIME_NSEC(shallow_stat)
 140 #endif
 141                    )
 142                 die("shallow file was changed during fetch");
 143 }
 144
 145 struct write_shallow_data {
 146         struct strbuf *out;
 147         int use_pack_protocol;
 148         int count;
 149 };
 150
 151 static int write_one_shallow(const struct commit_graft *graft, void *cb_data)
 152 {
 153         struct write_shallow_data *data = cb_data;
 154         const char *hex = sha1_to_hex(graft->sha1);
 155         if (graft->nr_parent != -1)
 156                 return 0;
 157         data->count++;
 158         if (data->use_pack_protocol)
 159                 packet_buf_write(data->out, "shallow %s", hex);
 160         else {
 161                 strbuf_addstr(data->out, hex);
 162                 strbuf_addch(data->out, '\n');
 163         }
 164         return 0;
 165 }
 166
 167 int write_shallow_commits(struct strbuf *out, int use_pack_protocol)
 168 {
 169         struct write_shallow_data data;
 170         data.out = out;
 171         data.use_pack_protocol = use_pack_protocol;
 172         data.count = 0;
 173         for_each_commit_graft(write_one_shallow, &data);
 174         return data.count;
 175 }
 176
 177 char *setup_temporary_shallow(void)
 178 {
 179         struct strbuf sb = STRBUF_INIT;
 180         int fd;
 181
 182         if (write_shallow_commits(&sb, 0)) {
 183                 struct strbuf path = STRBUF_INIT;
 184                 strbuf_addstr(&path, git_path("shallow_XXXXXX"));
 185                 fd = xmkstemp(path.buf);
 186                 if (write_in_full(fd, sb.buf, sb.len) != sb.len)
 187                         die_errno("failed to write to %s",
 188                                   path.buf);
 189                 close(fd);
 190                 strbuf_release(&sb);
 191                 return strbuf_detach(&path, NULL);
 192         }
 193         /*
 194          * is_repository_shallow() sees empty string as "no shallow
 195          * file".
 196          */
 197         return xstrdup("");
 198 }
 199
 200 void setup_alternate_shallow(struct lock_file *shallow_lock,
 201                              const char **alternate_shallow_file)
 202 {
 203         struct strbuf sb = STRBUF_INIT;
 204         int fd;
 205
 206         check_shallow_file_for_update();
 207         fd = hold_lock_file_for_update(shallow_lock, git_path("shallow"),
 208                                        LOCK_DIE_ON_ERROR);
 209         if (write_shallow_commits(&sb, 0)) {
 210                 if (write_in_full(fd, sb.buf, sb.len) != sb.len)
 211                         die_errno("failed to write to %s",
 212                                   shallow_lock->filename);
 213                 *alternate_shallow_file = shallow_lock->filename;
 214         } else
 215                 /*
 216                  * is_repository_shallow() sees empty string as "no
 217                  * shallow file".
 218                  */
 219                 *alternate_shallow_file = "";
 220         strbuf_release(&sb);
 221 }