Use simpler relative_path when set_git_dir

Using a relative_path as git_dir first appears in v1.5.6-1-g044bbbc.
It will make git_dir shorter only if git_dir is inside work_tree,
and this will increase performance. But my last refactor effort on
relative_path function (commit v1.8.3-rc2-12-ge02ca72) changed that.
Always use relative_path as git_dir may bring troubles like
$gmane/234434.

Because new relative_path is a combination of original relative_path
from path.c and original path_relative from quote.c, so in order to
restore the origin implementation, save the original relative_path
as remove_leading_path, and call it in setup.c.

Suggested-by: Karsten Blees <karsten.blees@gmail.com>
Signed-off-by: Jiang Xin <worldhello.net@gmail.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>

diff --git a/cache.h b/cache.h
index 8e42256942bdb3b1170938094963970a8e4fad66..94475bd9eeda2edf86d005837d84d405e6836fe6 100644 (file)
--- a/cache.h
+++ b/cache.h
@@ -737,6 +737,7 @@ int is_directory(const char *);
 const char *real_path(const char *path);
 const char *real_path_if_valid(const char *path);
 const char *absolute_path(const char *path);
+const char *remove_leading_path(const char *in, const char *prefix);
 const char *relative_path(const char *in, const char *prefix, struct strbuf *sb);
 int normalize_path_copy(char *dst, const char *src);
 int longest_ancestor_length(const char *path, struct string_list *prefixes);

diff --git a/path.c b/path.c
index 0c16dc5fdb2153ba984d05cb5bfb23fd16a8f82d..fa62da58ed9ad21ef47a679f8522add5a548e4e0 100644 (file)
--- a/path.c
+++ b/path.c
@@ -557,6 +557,51 @@ const char *relative_path(const char *in, const char *prefix,
        return sb->buf;
 }
 
+/*
+ * A simpler implementation of relative_path
+ *
+ * Get relative path by removing "prefix" from "in". This function
+ * first appears in v1.5.6-1-g044bbbc, and makes git_dir shorter
+ * to increase performance when traversing the path to work_tree.
+ */
+const char *remove_leading_path(const char *in, const char *prefix)
+{
+       static char buf[PATH_MAX + 1];
+       int i = 0, j = 0;
+
+       if (!prefix || !prefix[0])
+               return in;
+       while (prefix[i]) {
+               if (is_dir_sep(prefix[i])) {
+                       if (!is_dir_sep(in[j]))
+                               return in;
+                       while (is_dir_sep(prefix[i]))
+                               i++;
+                       while (is_dir_sep(in[j]))
+                               j++;
+                       continue;
+               } else if (in[j] != prefix[i]) {
+                       return in;
+               }
+               i++;
+               j++;
+       }
+       if (
+           /* "/foo" is a prefix of "/foo" */
+           in[j] &&
+           /* "/foo" is not a prefix of "/foobar" */
+           !is_dir_sep(prefix[i-1]) && !is_dir_sep(in[j])
+          )
+               return in;
+       while (is_dir_sep(in[j]))
+               j++;
+       if (!in[j])
+               strcpy(buf, ".");
+       else
+               strcpy(buf, in + j);
+       return buf;
+}
+
 /*
  * It is okay if dst == src, but they should not overlap otherwise.
  *

diff --git a/setup.c b/setup.c
index 0d9ea6239f2512760b4104440362d2e3758b3f09..dad39c1abaac9a749f899623927722f648259133 100644 (file)
--- a/setup.c
+++ b/setup.c
@@ -360,7 +360,6 @@ int is_inside_work_tree(void)
 
 void setup_work_tree(void)
 {
-       struct strbuf sb = STRBUF_INIT;
        const char *work_tree, *git_dir;
        static int initialized = 0;
 
@@ -380,10 +379,8 @@ void setup_work_tree(void)
        if (getenv(GIT_WORK_TREE_ENVIRONMENT))
                setenv(GIT_WORK_TREE_ENVIRONMENT, ".", 1);
 
-       set_git_dir(relative_path(git_dir, work_tree, &sb));
+       set_git_dir(remove_leading_path(git_dir, work_tree));
        initialized = 1;
-
-       strbuf_release(&sb);
 }
 
 static int check_repository_format_gently(const char *gitdir, int *nongit_ok)