worktree: refactor find_linked_symref function
[git/git.git] / worktree.c
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1#include "cache.h"
2#include "refs.h"
3#include "strbuf.h"
4#include "worktree.h"
5
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6/*
7 * read 'path_to_ref' into 'ref'. Also if is_detached is not NULL,
8 * set is_detached to 1 (0) if the ref is detatched (is not detached).
9 *
10 * $GIT_COMMON_DIR/$symref (e.g. HEAD) is practically outside $GIT_DIR so
11 * for linked worktrees, `resolve_ref_unsafe()` won't work (it uses
12 * git_path). Parse the ref ourselves.
13 *
14 * return -1 if the ref is not a proper ref, 0 otherwise (success)
15 */
16static int parse_ref(char *path_to_ref, struct strbuf *ref, int *is_detached)
17{
18 if (is_detached)
19 *is_detached = 0;
20 if (!strbuf_readlink(ref, path_to_ref, 0)) {
21 /* HEAD is symbolic link */
22 if (!starts_with(ref->buf, "refs/") ||
23 check_refname_format(ref->buf, 0))
24 return -1;
25 } else if (strbuf_read_file(ref, path_to_ref, 0) >= 0) {
26 /* textual symref or detached */
27 if (!starts_with(ref->buf, "ref:")) {
28 if (is_detached)
29 *is_detached = 1;
30 } else {
31 strbuf_remove(ref, 0, strlen("ref:"));
32 strbuf_trim(ref);
33 if (check_refname_format(ref->buf, 0))
34 return -1;
35 }
36 } else
37 return -1;
38 return 0;
39}
40
41static char *find_main_symref(const char *symref, const char *branch)
42{
43 struct strbuf sb = STRBUF_INIT;
44 struct strbuf path = STRBUF_INIT;
45 struct strbuf gitdir = STRBUF_INIT;
46 char *existing = NULL;
47
48 strbuf_addf(&path, "%s/%s", get_git_common_dir(), symref);
49 if (parse_ref(path.buf, &sb, NULL) < 0)
50 goto done;
51 if (strcmp(sb.buf, branch))
52 goto done;
53 strbuf_addstr(&gitdir, get_git_common_dir());
54 strbuf_strip_suffix(&gitdir, ".git");
55 existing = strbuf_detach(&gitdir, NULL);
56done:
57 strbuf_release(&path);
58 strbuf_release(&sb);
59 strbuf_release(&gitdir);
60
61 return existing;
62}
63
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64static char *find_linked_symref(const char *symref, const char *branch,
65 const char *id)
66{
67 struct strbuf sb = STRBUF_INIT;
68 struct strbuf path = STRBUF_INIT;
69 struct strbuf gitdir = STRBUF_INIT;
70 char *existing = NULL;
71
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72 if (!id)
73 die("Missing linked worktree name");
ac6c561b 74
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75 strbuf_addf(&path, "%s/worktrees/%s/%s", get_git_common_dir(), id, symref);
76
77 if (parse_ref(path.buf, &sb, NULL) < 0)
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78 goto done;
79 if (strcmp(sb.buf, branch))
80 goto done;
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81 strbuf_reset(&path);
82 strbuf_addf(&path, "%s/worktrees/%s/gitdir", get_git_common_dir(), id);
83 if (strbuf_read_file(&gitdir, path.buf, 0) <= 0)
84 goto done;
85 strbuf_rtrim(&gitdir);
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86 strbuf_strip_suffix(&gitdir, ".git");
87
88 existing = strbuf_detach(&gitdir, NULL);
89done:
90 strbuf_release(&path);
91 strbuf_release(&sb);
92 strbuf_release(&gitdir);
93
94 return existing;
95}
96
97char *find_shared_symref(const char *symref, const char *target)
98{
99 struct strbuf path = STRBUF_INIT;
100 DIR *dir;
101 struct dirent *d;
102 char *existing;
103
1ceb7f90 104 if ((existing = find_main_symref(symref, target)))
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105 return existing;
106
107 strbuf_addf(&path, "%s/worktrees", get_git_common_dir());
108 dir = opendir(path.buf);
109 strbuf_release(&path);
110 if (!dir)
111 return NULL;
112
113 while ((d = readdir(dir)) != NULL) {
114 if (!strcmp(d->d_name, ".") || !strcmp(d->d_name, ".."))
115 continue;
116 existing = find_linked_symref(symref, target, d->d_name);
117 if (existing)
118 goto done;
119 }
120done:
121 closedir(dir);
122
123 return existing;
124}