avl_tree: Optimize swapping node for removal

[wimlib] / src / paths.c

diff --git a/src/paths.c b/src/paths.c
index 9becb2128185d6dddc06c5251332c9ca4bf53bca..68942f20265862c40923ffe64ba64fc184ef3d32 100644 (file)
--- a/src/paths.c
+++ b/src/paths.c
@@ -33,93 +33,92 @@
 
 /* Like the basename() function, but does not modify @path; it just returns a
  * pointer to it.  This assumes the path separator is the
- * OS_PREFERRED_PATH_SEPARATOR. */
+ * OS_PREFERRED_PATH_SEPARATOR.  */
 const tchar *
 path_basename(const tchar *path)
 {
        return path_basename_with_len(path, tstrlen(path));
 }
 
-/* Like path_basename(), but take an explicit string length. */
+/* Like path_basename(), but take an explicit string length.  */
 const tchar *
 path_basename_with_len(const tchar *path, size_t len)
 {
-       const tchar *p = &path[len] - 1;
-
-       /* Trailing slashes. */
-       while (1) {
-               if (p == path - 1)
-                       return T("");
-               if (*p != OS_PREFERRED_PATH_SEPARATOR)
-                       break;
-               p--;
-       }
+       const tchar *p = &path[len];
+
+       do {
+               if (p == path)
+                       return &path[len];
+       } while (*--p == OS_PREFERRED_PATH_SEPARATOR);
 
-       while ((p != path - 1) && *p != OS_PREFERRED_PATH_SEPARATOR)
-               p--;
+       do {
+               if (p == path)
+                       return &path[0];
+       } while (*--p != OS_PREFERRED_PATH_SEPARATOR);
 
-       return p + 1;
+       return ++p;
 }
 
 
-/*
- * Returns a pointer to the part of @path following the first colon in the last
- * path component, or NULL if the last path component does not contain a colon.
- */
+/* Returns a pointer to the part of @path following the first colon in the last
+ * path component, or NULL if the last path component does not contain a colon
+ * or has no characters following the first colon.  */
 const tchar *
 path_stream_name(const tchar *path)
 {
        const tchar *base = path_basename(path);
        const tchar *stream_name = tstrchr(base, T(':'));
-       if (!stream_name)
+       if (stream_name == NULL || *(stream_name + 1) == T('\0'))
                return NULL;
        else
                return stream_name + 1;
 }
 
-
-/* Duplicate a path; return empty string for NULL input. */
+/* Duplicate a path; return empty string for NULL input.  */
 tchar *
 canonicalize_fs_path(const tchar *fs_path)
 {
-       if (!fs_path)
+       if (fs_path == NULL)
                fs_path = T("");
        return TSTRDUP(fs_path);
 }
 
-/* 
- * canonicalize_wim_path - Given a user-provided path to a file within a WIM
+/*
+ * canonicalize_wim_path() - Given a user-provided path to a file within a WIM
  * image, translate it into a "canonical" path.
  *
- * To do this, we translate all supported path separators
- * (is_any_path_separator()) into the WIM_PATH_SEPARATOR, and strip any leading
- * and trailing slashes.  The returned string is allocated.  Note that there
- * still may be consecutive path separators within the string.  Furthermore, the
- * string may be empty, which indicates the root dentry of the WIM image.
+ * To do this, translate all supported path separators (is_any_path_separator())
+ * into the WIM_PATH_SEPARATOR, and strip any leading and trailing slashes.  The
+ * returned string is allocated.  Note that there still may be consecutive path
+ * separators within the string.  Furthermore, the string may be empty, which
+ * indicates the root dentry of the WIM image.
  */
 tchar *
 canonicalize_wim_path(const tchar *wim_path)
 {
-       tchar *p;
        tchar *canonical_path;
+       tchar *p;
 
        if (wim_path == NULL) {
                wim_path = T("");
        } else {
+               /* Strip leading path separators.  */
                while (is_any_path_separator(*wim_path))
                        wim_path++;
        }
+
        canonical_path = TSTRDUP(wim_path);
-       if (canonical_path) {
-               for (p = canonical_path; *p; p++)
-                       if (is_any_path_separator(*p))
-                               *p = WIM_PATH_SEPARATOR;
-               for (p = tstrchr(canonical_path, T('\0')) - 1;
-                    p >= canonical_path && *p == WIM_PATH_SEPARATOR;
-                    p--)
-               {
-                       *p = T('\0');
-               }
-       }
+       if (canonical_path == NULL)
+               return NULL;
+
+       /* Translate all path separators to WIM_PATH_SEPARATOR.  */
+       for (p = canonical_path; *p; p++)
+               if (is_any_path_separator(*p))
+                       *p = WIM_PATH_SEPARATOR;
+
+       /* Strip trailing path separators.  */
+       while (p > canonical_path && *--p == WIM_PATH_SEPARATOR)
+               *p = T('\0');
+
        return canonical_path;
 }