add hg and python

sys/lib/python/dircache.py

@@ -0,0 +1,38 @@
+"""Read and cache directory listings.
+
+The listdir() routine returns a sorted list of the files in a directory,
+using a cache to avoid reading the directory more often than necessary.
+The annotate() routine appends slashes to directories."""
+
+import os
+
+__all__ = ["listdir", "opendir", "annotate", "reset"]
+
+cache = {}
+
+def reset():
+    """Reset the cache completely."""
+    global cache
+    cache = {}
+
+def listdir(path):
+    """List directory contents, using cache."""
+    try:
+        cached_mtime, list = cache[path]
+        del cache[path]
+    except KeyError:
+        cached_mtime, list = -1, []
+    mtime = os.stat(path).st_mtime
+    if mtime != cached_mtime:
+        list = os.listdir(path)
+        list.sort()
+    cache[path] = mtime, list
+    return list
+
+opendir = listdir # XXX backward compatibility
+
+def annotate(head, list):
+    """Add '/' suffixes to directories."""
+    for i in range(len(list)):
+        if os.path.isdir(os.path.join(head, list[i])):
+            list[i] = list[i] + '/'