worktree.c

   1 #include "cache.h"
   2 #include "refs.h"
   3 #include "strbuf.h"
   4 #include "worktree.h"
   5
   6 void free_worktrees(struct worktree **worktrees)
   7 {
   8         int i = 0;
   9
  10         for (i = 0; worktrees[i]; i++) {
  11                 free(worktrees[i]->path);
  12                 free(worktrees[i]->git_dir);
  13                 free(worktrees[i]->head_ref);
  14                 free(worktrees[i]);
  15         }
  16         free (worktrees);
  17 }
  18
  19 /*
  20  * read 'path_to_ref' into 'ref'.  Also if is_detached is not NULL,
  21  * set is_detached to 1 (0) if the ref is detached (is not detached).
  22  *
  23  * $GIT_COMMON_DIR/$symref (e.g. HEAD) is practically outside $GIT_DIR so
  24  * for linked worktrees, `resolve_ref_unsafe()` won't work (it uses
  25  * git_path). Parse the ref ourselves.
  26  *
  27  * return -1 if the ref is not a proper ref, 0 otherwise (success)
  28  */
  29 static int parse_ref(char *path_to_ref, struct strbuf *ref, int *is_detached)
  30 {
  31         if (is_detached)
  32                 *is_detached = 0;
  33         if (!strbuf_readlink(ref, path_to_ref, 0)) {
  34                 /* HEAD is symbolic link */
  35                 if (!starts_with(ref->buf, "refs/") ||
  36                                 check_refname_format(ref->buf, 0))
  37                         return -1;
  38         } else if (strbuf_read_file(ref, path_to_ref, 0) >= 0) {
  39                 /* textual symref or detached */
  40                 if (!starts_with(ref->buf, "ref:")) {
  41                         if (is_detached)
  42                                 *is_detached = 1;
  43                 } else {
  44                         strbuf_remove(ref, 0, strlen("ref:"));
  45                         strbuf_trim(ref);
  46                         if (check_refname_format(ref->buf, 0))
  47                                 return -1;
  48                 }
  49         } else
  50                 return -1;
  51         return 0;
  52 }
  53
  54 /**
  55  * Add the head_sha1 and head_ref (if not detached) to the given worktree
  56  */
  57 static void add_head_info(struct strbuf *head_ref, struct worktree *worktree)
  58 {
  59         if (head_ref->len) {
  60                 if (worktree->is_detached) {
  61                         get_sha1_hex(head_ref->buf, worktree->head_sha1);
  62                 } else {
  63                         resolve_ref_unsafe(head_ref->buf, 0, worktree->head_sha1, NULL);
  64                         worktree->head_ref = strbuf_detach(head_ref, NULL);
  65                 }
  66         }
  67 }
  68
  69 /**
  70  * get the main worktree
  71  */
  72 static struct worktree *get_main_worktree(void)
  73 {
  74         struct worktree *worktree = NULL;
  75         struct strbuf path = STRBUF_INIT;
  76         struct strbuf worktree_path = STRBUF_INIT;
  77         struct strbuf gitdir = STRBUF_INIT;
  78         struct strbuf head_ref = STRBUF_INIT;
  79         int is_bare = 0;
  80         int is_detached = 0;
  81
  82         strbuf_addf(&gitdir, "%s", absolute_path(get_git_common_dir()));
  83         strbuf_addbuf(&worktree_path, &gitdir);
  84         is_bare = !strbuf_strip_suffix(&worktree_path, "/.git");
  85         if (is_bare)
  86                 strbuf_strip_suffix(&worktree_path, "/.");
  87
  88         strbuf_addf(&path, "%s/HEAD", get_git_common_dir());
  89
  90         if (parse_ref(path.buf, &head_ref, &is_detached) < 0)
  91                 goto done;
  92
  93         worktree = xmalloc(sizeof(struct worktree));
  94         worktree->path = strbuf_detach(&worktree_path, NULL);
  95         worktree->git_dir = strbuf_detach(&gitdir, NULL);
  96         worktree->is_bare = is_bare;
  97         worktree->head_ref = NULL;
  98         worktree->is_detached = is_detached;
  99         add_head_info(&head_ref, worktree);
 100
 101 done:
 102         strbuf_release(&path);
 103         strbuf_release(&gitdir);
 104         strbuf_release(&worktree_path);
 105         strbuf_release(&head_ref);
 106         return worktree;
 107 }
 108
 109 static struct worktree *get_linked_worktree(const char *id)
 110 {
 111         struct worktree *worktree = NULL;
 112         struct strbuf path = STRBUF_INIT;
 113         struct strbuf worktree_path = STRBUF_INIT;
 114         struct strbuf gitdir = STRBUF_INIT;
 115         struct strbuf head_ref = STRBUF_INIT;
 116         int is_detached = 0;
 117
 118         if (!id)
 119                 die("Missing linked worktree name");
 120
 121         strbuf_addf(&gitdir, "%s/worktrees/%s",
 122                         absolute_path(get_git_common_dir()), id);
 123         strbuf_addf(&path, "%s/gitdir", gitdir.buf);
 124         if (strbuf_read_file(&worktree_path, path.buf, 0) <= 0)
 125                 /* invalid gitdir file */
 126                 goto done;
 127
 128         strbuf_rtrim(&worktree_path);
 129         if (!strbuf_strip_suffix(&worktree_path, "/.git")) {
 130                 strbuf_reset(&worktree_path);
 131                 strbuf_addstr(&worktree_path, absolute_path("."));
 132                 strbuf_strip_suffix(&worktree_path, "/.");
 133         }
 134
 135         strbuf_reset(&path);
 136         strbuf_addf(&path, "%s/worktrees/%s/HEAD", get_git_common_dir(), id);
 137
 138         if (parse_ref(path.buf, &head_ref, &is_detached) < 0)
 139                 goto done;
 140
 141         worktree = xmalloc(sizeof(struct worktree));
 142         worktree->path = strbuf_detach(&worktree_path, NULL);
 143         worktree->git_dir = strbuf_detach(&gitdir, NULL);
 144         worktree->is_bare = 0;
 145         worktree->head_ref = NULL;
 146         worktree->is_detached = is_detached;
 147         add_head_info(&head_ref, worktree);
 148
 149 done:
 150         strbuf_release(&path);
 151         strbuf_release(&gitdir);
 152         strbuf_release(&worktree_path);
 153         strbuf_release(&head_ref);
 154         return worktree;
 155 }
 156
 157 struct worktree **get_worktrees(void)
 158 {
 159         struct worktree **list = NULL;
 160         struct strbuf path = STRBUF_INIT;
 161         DIR *dir;
 162         struct dirent *d;
 163         int counter = 0, alloc = 2;
 164
 165         list = xmalloc(alloc * sizeof(struct worktree *));
 166
 167         if ((list[counter] = get_main_worktree()))
 168                 counter++;
 169
 170         strbuf_addf(&path, "%s/worktrees", get_git_common_dir());
 171         dir = opendir(path.buf);
 172         strbuf_release(&path);
 173         if (dir) {
 174                 while ((d = readdir(dir)) != NULL) {
 175                         struct worktree *linked = NULL;
 176                         if (!strcmp(d->d_name, ".") || !strcmp(d->d_name, ".."))
 177                                 continue;
 178
 179                         if ((linked = get_linked_worktree(d->d_name))) {
 180                                 ALLOC_GROW(list, counter + 1, alloc);
 181                                 list[counter++] = linked;
 182                         }
 183                 }
 184                 closedir(dir);
 185         }
 186         ALLOC_GROW(list, counter + 1, alloc);
 187         list[counter] = NULL;
 188         return list;
 189 }
 190
 191 char *find_shared_symref(const char *symref, const char *target)
 192 {
 193         char *existing = NULL;
 194         struct strbuf path = STRBUF_INIT;
 195         struct strbuf sb = STRBUF_INIT;
 196         struct worktree **worktrees = get_worktrees();
 197         int i = 0;
 198
 199         for (i = 0; worktrees[i]; i++) {
 200                 strbuf_reset(&path);
 201                 strbuf_reset(&sb);
 202                 strbuf_addf(&path, "%s/%s", worktrees[i]->git_dir, symref);
 203
 204                 if (parse_ref(path.buf, &sb, NULL)) {
 205                         continue;
 206                 }
 207
 208                 if (!strcmp(sb.buf, target)) {
 209                         existing = xstrdup(worktrees[i]->path);
 210                         break;
 211                 }
 212         }
 213
 214         strbuf_release(&path);
 215         strbuf_release(&sb);
 216         free_worktrees(worktrees);
 217
 218         return existing;
 219 }