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[PATCH v2 04/21] Make git_path() aware of file relocation in $GIT_DIR

From
Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Date
Dec 14, 2013, 10:54 UTC
Message-ID
<1387018507-21999-5-git-send-email-pclouds@gmail.com>
In-Reply-To
<1387018507-21999-1-git-send-email-pclouds@gmail.com>

We allow the user to relocate certain paths out of $GIT_DIR via environment variables, e.g. GIT_OBJECT_DIRECTORY, GIT_INDEX_FILE and GIT_GRAFT_FILE. All callers are not supposed to use git_path() or git_pathdup() to get those paths. Instead they must use get_object_directory(), get_index_file() and get_graft_file() respectively. This is inconvenient and could be missed in review (there's git_path("objects/info/alternates") somewhere in sha1_file.c).

This patch makes git_path() and git_pathdup() understand those environment variables. So if you set GIT_OBJECT_DIRECTORY to /foo/bar, git_path("objects/abc") should return /tmp/bar/abc. The same is done for the two remaining env variables.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
---
 cache.h               |  1 +
 environment.c         |  9 ++++++--
 path.c                | 57 ++++++++++++++++++++++++++++++++++++++++++++++++---
 t/t0060-path-utils.sh | 54 ++++++++++++++++++++++++++++++++++++++++++++++++
 test-path-utils.c     |  7 +++++++
 5 files changed, 123 insertions(+), 5 deletions(-)
diff --git a/cache.h b/cache.h
index ce377e1..cdafbd7 100644
--- a/cache.h
+++ b/cache.h
@@ -584,6 +584,7 @@ extern int fsync_object_files;
 extern int core_preload_index;
 extern int core_apply_sparse_checkout;
 extern int precomposed_unicode;
+extern int git_db_env, git_index_env, git_graft_env;
 
 /*
  * The character that begins a commented line in user-editable file
diff --git a/environment.c b/environment.c
index 0a15349..1d74dde 100644
--- a/environment.c
+++ b/environment.c
@@ -81,6 +81,7 @@ static size_t namespace_len;
 
 static const char *git_dir;
 static char *git_object_dir, *git_index_file, *git_graft_file;
+int git_db_env, git_index_env, git_graft_env;
 
 /*
  * Repository-local GIT_* environment variables; see cache.h for details.
@@ -134,15 +135,19 @@ static void setup_git_env(void)
 	if (!git_object_dir) {
 		git_object_dir = xmalloc(strlen(git_dir) + 9);
 		sprintf(git_object_dir, "%s/objects", git_dir);
-	}
+	} else
+		git_db_env = 1;
 	git_index_file = getenv(INDEX_ENVIRONMENT);
 	if (!git_index_file) {
 		git_index_file = xmalloc(strlen(git_dir) + 7);
 		sprintf(git_index_file, "%s/index", git_dir);
-	}
+	} else
+		git_index_env = 1;
 	git_graft_file = getenv(GRAFT_ENVIRONMENT);
 	if (!git_graft_file)
 		git_graft_file = git_pathdup("info/grafts");
+	else
+		git_graft_env = 1;
 	if (getenv(NO_REPLACE_OBJECTS_ENVIRONMENT))
 		read_replace_refs = 0;
 	namespace = expand_namespace(getenv(GIT_NAMESPACE_ENVIRONMENT));
diff --git a/path.c b/path.c
index 08aa213..93e3ecc 100644
--- a/path.c
+++ b/path.c
@@ -50,10 +50,60 @@ char *mksnpath(char *buf, size_t n, const char *fmt, ...)
 	return cleanup_path(buf);
 }
 
+static void copy_path(char *dst, size_t n, const char *src)
+{
+	if (strlen(src) < n)
+		strcpy(dst, src);
+	else
+		strlcpy(dst, bad_path, n);
+}
+
+static int dir_prefix(const char *buf, const char *dir)
+{
+	int len = strlen(dir);
+	return !strncmp(buf, dir, len) &&
+		(is_dir_sep(buf[len]) || buf[len] == '\0');
+}
+
+/* $buf =~ m|$dir/+$file| but without regex */
+static int is_dir_file(const char *buf, const char *dir, const char *file)
+{
+	int len = strlen(dir);
+	if (strncmp(buf, dir, len) || !is_dir_sep(buf[len]))
+		return 0;
+	while (is_dir_sep(buf[len]))
+		len++;
+	return !strcmp(buf + len, file);
+}
+
+static void replace_dir(char *buf, size_t n, int len, const char *newdir)
+{
+	int newlen = strlen(newdir);
+	int buflen = strlen(buf);
+	if (buflen - len + newlen >= n) {
+		strlcpy(buf, bad_path, n);
+		return;
+	}
+	memmove(buf + newlen + 1, buf + len, buflen - len + 1);
+	memcpy(buf, newdir, newlen);
+	buf[newlen] = '/';
+}
+
+static void adjust_git_path(char *buf, size_t n, int git_dir_len)
+{
+	char *base = buf + git_dir_len;
+	if (git_graft_env && is_dir_file(base, "info", "grafts"))
+		copy_path(buf, n, get_graft_file());
+	else if (git_index_env && !strcmp(base, "index"))
+		copy_path(buf, n, get_index_file());
+	else if (git_db_env && dir_prefix(base, "objects"))
+		replace_dir(buf, n, git_dir_len + 7, get_object_directory());
+}
+
 static char *git_vsnpath(char *buf, size_t n, const char *fmt, va_list args)
 {
 	const char *git_dir = get_git_dir();
-	size_t len;
+	size_t len, total_len;
 
 	len = strlen(git_dir);
 	if (n < len + 1)
@@ -61,9 +111,10 @@ static char *git_vsnpath(char *buf, size_t n, const char *fmt, va_list args)
 	memcpy(buf, git_dir, len);
 	if (len && !is_dir_sep(git_dir[len-1]))
 		buf[len++] = '/';
-	len += vsnprintf(buf + len, n - len, fmt, args);
-	if (len >= n)
+	total_len = len + vsnprintf(buf + len, n - len, fmt, args);
+	if (total_len >= n)
 		goto bad;
+	adjust_git_path(buf, n, len);
 	return cleanup_path(buf);
 bad:
 	strlcpy(buf, bad_path, n);
diff --git a/t/t0060-path-utils.sh b/t/t0060-path-utils.sh
index 07c10c8..bce16f5 100755
--- a/t/t0060-path-utils.sh
+++ b/t/t0060-path-utils.sh
@@ -223,4 +223,58 @@ relative_path "<null>"		"<empty>"	./
 relative_path "<null>"		"<null>"	./
 relative_path "<null>"		/foo/a/b	./
 
+test_expect_success 'git_path info/grafts without GIT_GRAFT_FILE' '
+	test-path-utils git_path info/grafts >actual1 &&
+	echo .git/info/grafts >expect1 &&
+	test_cmp expect1 actual1
+'
+
+test_expect_success 'git_path info/grafts with GIT_GRAFT_FILE' '
+	GIT_GRAFT_FILE=foo test-path-utils git_path info/grafts >actual2 &&
+	echo foo >expect2 &&
+	test_cmp expect2 actual2
+'
+
+test_expect_success 'git_path info/////grafts with GIT_GRAFT_FILE' '
+	GIT_GRAFT_FILE=foo test-path-utils git_path info/////grafts >actual2 &&
+	echo foo >expect2 &&
+	test_cmp expect2 actual2
+'
+
+test_expect_success 'git_path index' '
+	GIT_INDEX_FILE=foo test-path-utils git_path index >actual &&
+	echo foo >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'git_path index/foo' '
+	GIT_INDEX_FILE=foo test-path-utils git_path index/foo >actual &&
+	echo .git/index/foo >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'git_path index2' '
+	GIT_INDEX_FILE=foo test-path-utils git_path index2 >actual &&
+	echo .git/index2 >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'git_path objects' '
+	GIT_OBJECT_DIRECTORY=foo test-path-utils git_path objects >actual &&
+	echo foo/ >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'git_path objects/foo' '
+	GIT_OBJECT_DIRECTORY=foo test-path-utils git_path objects/foo >actual &&
+	echo foo//foo >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'git_path objects2' '
+	GIT_OBJECT_DIRECTORY=foo test-path-utils git_path objects2 >actual &&
+	echo .git/objects2 >expect &&
+	test_cmp expect actual
+'
+
 test_done
diff --git a/test-path-utils.c b/test-path-utils.c
index 3dd3744..55e4fe0 100644
--- a/test-path-utils.c
+++ b/test-path-utils.c
@@ -135,6 +135,13 @@ int main(int argc, char **argv)
 		return 0;
 	}
 
+	if (argc == 3 && !strcmp(argv[1], "git_path")) {
+		int nongit_ok = 0;
+		setup_git_directory_gently(&nongit_ok);
+		puts(git_path("%s", argv[2]));
+		return 0;
+	}
+
 	fprintf(stderr, "%s: unknown function name: %s\n", argv[0],
 		argv[1] ? argv[1] : "(there was none)");
 	return 1;

-- 
1.8.5.1.77.g42c48fa
Previous: Nguyễn Thái Ngọc DuyNext: Nguyễn Thái Ngọc Duy
Message 31 of 49 in “Support multiple worktrees”
  1. 0/7 Support multiple worktreesNguyễn Thái Ngọc Duy, Dec 11, 2013
  2. 1/7 Make git_path() beware of file relocation in $GIT_DIRNguyễn Thái Ngọc Duy, Dec 11, 2013
  3. Junio C HamanoDec 13, 2013
  4. 2/7 Add new environment variable $GIT_SUPER_DIRNguyễn Thái Ngọc Duy, Dec 11, 2013
  5. Junio C HamanoDec 13, 2013
  6. Duy NguyenDec 14, 2013
  7. Junio C HamanoDec 14, 2013
  8. 3/7 setup.c: add split-repo support to .git filesNguyễn Thái Ngọc Duy, Dec 11, 2013
  9. Junio C HamanoDec 13, 2013
  10. Jonathan NiederDec 13, 2013
  11. Duy NguyenDec 14, 2013
  12. Duy NguyenDec 23, 2013
  13. 4/7 setup.c: add split-repo support to is_git_directory()Nguyễn Thái Ngọc Duy, Dec 11, 2013
  14. 5/7 setup.c: reduce cleanup sites in setup_explicit_git_dir()Nguyễn Thái Ngọc Duy, Dec 11, 2013
  15. 6/7 setup.c: add split-repo support to setup_git_directory*Nguyễn Thái Ngọc Duy, Dec 11, 2013
  16. 7/7 init: add --split-repo with the same functionality as git-new-workdirNguyễn Thái Ngọc Duy, Dec 11, 2013
  17. 00/21 Support multiple worktreesNguyễn Thái Ngọc Duy, Dec 14, 2013
  18. 01/21 path.c: avoid PATH_MAX as buffer size from get_pathname()Nguyễn Thái Ngọc Duy, Dec 14, 2013
  19. Torsten BögershausenDec 15, 2013
  20. Duy NguyenDec 15, 2013
  21. Antoine PelisseDec 15, 2013
  22. 02/21 path.c: rename vsnpath() to git_vsnpath()Nguyễn Thái Ngọc Duy, Dec 14, 2013
  23. Ramsay JonesDec 14, 2013
  24. Duy NguyenDec 15, 2013
  25. Ramsay JonesDec 15, 2013
  26. Duy NguyenDec 16, 2013
  27. Jonathan NiederDec 16, 2013
  28. Junio C HamanoDec 16, 2013
  29. Ramsay JonesDec 16, 2013
  30. 03/21 path.c: move git_path() closer to similar functions git_pathdup()Nguyễn Thái Ngọc Duy, Dec 14, 2013
  31. 04/21 Make git_path() aware of file relocation in $GIT_DIRNguyễn Thái Ngọc Duy, Dec 14, 2013
  32. 05/21 reflog: use avoid constructing .lock path with git_pathNguyễn Thái Ngọc Duy, Dec 14, 2013
  33. 06/21 fast-import: use git_path() for accessing .git dir instead of get_git_dir()Nguyễn Thái Ngọc Duy, Dec 14, 2013
  34. 07/21 Add new environment variable $GIT_SUPER_DIRNguyễn Thái Ngọc Duy, Dec 14, 2013
  35. 08/21 setup.c: refactor path manipulation out of read_gitfile()Nguyễn Thái Ngọc Duy, Dec 14, 2013
  36. 09/21 setup.c: add split-repo support to .git filesNguyễn Thái Ngọc Duy, Dec 14, 2013
  37. 10/21 setup.c: add split-repo support to is_git_directory()Nguyễn Thái Ngọc Duy, Dec 14, 2013
  38. 11/21 setup.c: reduce cleanup sites in setup_explicit_git_dir()Nguyễn Thái Ngọc Duy, Dec 14, 2013
  39. 12/21 environment.c: support super .git file specified by $GIT_DIRNguyễn Thái Ngọc Duy, Dec 14, 2013
  40. 13/21 setup: support $GIT_SUPER_DIR as well as super .git filesNguyễn Thái Ngọc Duy, Dec 14, 2013
  41. 14/21 checkout: support checking out into a new working directoryNguyễn Thái Ngọc Duy, Dec 14, 2013
  42. 15/21 checkout: clean up half-prepared directories in --to modeNguyễn Thái Ngọc Duy, Dec 14, 2013
  43. 16/21 setup.c: keep track of the .git file location if readNguyễn Thái Ngọc Duy, Dec 14, 2013
  44. 17/21 prune: strategies for split repositoriesNguyễn Thái Ngọc Duy, Dec 14, 2013
  45. 18/21 refs: adjust reflog path for repos/<id>/HEADNguyễn Thái Ngọc Duy, Dec 14, 2013
  46. 19/21 refs: detach split repos' HEAD when the linked ref is updated/deletedNguyễn Thái Ngọc Duy, Dec 14, 2013
  47. 20/21 refs.c: refactor do_head_ref(... to do_one_head_ref("HEAD", ...Nguyễn Thái Ngọc Duy, Dec 14, 2013
  48. 21/21 revision: include repos/../HEAD in --allNguyễn Thái Ngọc Duy, Dec 14, 2013
  49. Duy NguyenDec 15, 2013

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