Remove the deprecated statcache module.

1 files changed, 82 insertions, 0 deletions

diff --git a/Lib/lib-old/statcache.py b/Lib/lib-old/statcache.py
new file mode 100644
index 0000000..d478393
--- /dev/null
+++ b/Lib/lib-old/statcache.py
@@ -0,0 +1,82 @@
+"""Maintain a cache of stat() information on files.
+
+There are functions to reset the cache or to selectively remove items.
+"""
+
+import warnings
+warnings.warn("The statcache module is obsolete.  Use os.stat() instead.",
+              DeprecationWarning)
+del warnings
+
+import os as _os
+from stat import *
+
+__all__ = ["stat","reset","forget","forget_prefix","forget_dir",
+           "forget_except_prefix","isdir"]
+
+# The cache.  Keys are pathnames, values are os.stat outcomes.
+# Remember that multiple threads may be calling this!  So, e.g., that
+# path in cache returns 1 doesn't mean the cache will still contain
+# path on the next line.  Code defensively.
+
+cache = {}
+
+def stat(path):
+    """Stat a file, possibly out of the cache."""
+    ret = cache.get(path, None)
+    if ret is None:
+        cache[path] = ret = _os.stat(path)
+    return ret
+
+def reset():
+    """Clear the cache."""
+    cache.clear()
+
+# For thread saftey, always use forget() internally too.
+def forget(path):
+    """Remove a given item from the cache, if it exists."""
+    try:
+        del cache[path]
+    except KeyError:
+        pass
+
+def forget_prefix(prefix):
+    """Remove all pathnames with a given prefix."""
+    for path in cache.keys():
+        if path.startswith(prefix):
+            forget(path)
+
+def forget_dir(prefix):
+    """Forget a directory and all entries except for entries in subdirs."""
+
+    # Remove trailing separator, if any.  This is tricky to do in a
+    # x-platform way.  For example, Windows accepts both / and \ as
+    # separators, and if there's nothing *but* a separator we want to
+    # preserve that this is the root.  Only os.path has the platform
+    # knowledge we need.
+    from os.path import split, join
+    prefix = split(join(prefix, "xxx"))[0]
+    forget(prefix)
+    for path in cache.keys():
+        # First check that the path at least starts with the prefix, so
+        # that when it doesn't we can avoid paying for split().
+        if path.startswith(prefix) and split(path)[0] == prefix:
+            forget(path)
+
+def forget_except_prefix(prefix):
+    """Remove all pathnames except with a given prefix.
+
+    Normally used with prefix = '/' after a chdir().
+    """
+
+    for path in cache.keys():
+        if not path.startswith(prefix):
+            forget(path)
+
+def isdir(path):
+    """Return True if directory, else False."""
+    try:
+        st = stat(path)
+    except _os.error:
+        return False
+    return S_ISDIR(st.st_mode)