path-list documentation: document all functions and data structures
[gitweb.git] / symlinks.c
index be9ace6c04ce1fe7d53d85f30adab2218ec1ec65..5a5e781a15d7d9cb60797958433eca896b31ec85 100644 (file)
@@ -1,48 +1,64 @@
 #include "cache.h"
 
-int has_symlink_leading_path(const char *name, char *last_symlink)
-{
+struct pathname {
+       int len;
        char path[PATH_MAX];
-       const char *sp, *ep;
-       char *dp;
-
-       sp = name;
-       dp = path;
-
-       if (last_symlink && *last_symlink) {
-               size_t last_len = strlen(last_symlink);
-               size_t len = strlen(name);
-               if (last_len < len &&
-                   !strncmp(name, last_symlink, last_len) &&
-                   name[last_len] == '/')
-                       return 1;
-               *last_symlink = '\0';
+};
+
+/* Return matching pathname prefix length, or zero if not matching */
+static inline int match_pathname(int len, const char *name, struct pathname *match)
+{
+       int match_len = match->len;
+       return (len > match_len &&
+               name[match_len] == '/' &&
+               !memcmp(name, match->path, match_len)) ? match_len : 0;
+}
+
+static inline void set_pathname(int len, const char *name, struct pathname *match)
+{
+       if (len < PATH_MAX) {
+               match->len = len;
+               memcpy(match->path, name, len);
+               match->path[len] = 0;
        }
+}
+
+int has_symlink_leading_path(int len, const char *name)
+{
+       static struct pathname link, nonlink;
+       char path[PATH_MAX];
+       struct stat st;
+       char *sp;
+       int known_dir;
 
-       while (1) {
-               size_t len;
-               struct stat st;
+       /*
+        * See if the last known symlink cache matches.
+        */
+       if (match_pathname(len, name, &link))
+               return 1;
 
-               ep = strchr(sp, '/');
-               if (!ep)
-                       break;
-               len = ep - sp;
-               if (PATH_MAX <= dp + len - path + 2)
-                       return 0; /* new name is longer than that??? */
-               memcpy(dp, sp, len);
-               dp[len] = 0;
+       /*
+        * Get rid of the last known directory part
+        */
+       known_dir = match_pathname(len, name, &nonlink);
+
+       while ((sp = strchr(name + known_dir + 1, '/')) != NULL) {
+               int thislen = sp - name ;
+               memcpy(path, name, thislen);
+               path[thislen] = 0;
 
                if (lstat(path, &st))
                        return 0;
+               if (S_ISDIR(st.st_mode)) {
+                       set_pathname(thislen, path, &nonlink);
+                       known_dir = thislen;
+                       continue;
+               }
                if (S_ISLNK(st.st_mode)) {
-                       if (last_symlink)
-                               strcpy(last_symlink, path);
+                       set_pathname(thislen, path, &link);
                        return 1;
                }
-
-               dp[len++] = '/';
-               dp = dp + len;
-               sp = ep + 1;
+               break;
        }
        return 0;
 }