blob: 6cf7fcdc0f9253911dc5a26fae34852c9f255595 [file] [log] [blame]
#!/usr/bin/env python
#
# Copyright 2007 Google Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
"""Common functionality for file watchers."""
import os
# A prefix for files and directories that we should not watch at all.
_IGNORED_PREFIX = '.'
# File suffixes that should be ignored.
_IGNORED_FILE_SUFFIXES = (
# Python temporaries
'.pyc',
'.pyo',
# Backups
'~',
# Emacs
'#',
# Vim
'.swp',
'.swo',
)
def ignore_file(filename):
"""Report whether a file should not be watched."""
filename = os.path.basename(filename)
return (
filename.startswith(_IGNORED_PREFIX) or
any(filename.endswith(suffix) for suffix in _IGNORED_FILE_SUFFIXES))
def _remove_pred(lst, pred):
"""Remove items from a list that match a predicate."""
# Walk the list in reverse because once an item is deleted,
# the indexes of any subsequent items change.
for idx in reversed(xrange(len(lst))):
if pred(lst[idx]):
del lst[idx]
def skip_ignored_dirs(dirs):
"""Skip directories that should not be watched."""
_remove_pred(dirs, lambda d: d.startswith(_IGNORED_PREFIX))
def skip_local_symlinks(roots, dirpath, directories):
"""Skip symlinks that link to another watched directory.
Our algorithm gets confused when the same directory is watched multiple times
due to symlinks.
Args:
roots: The realpath of the root of all directory trees being watched.
dirpath: The base directory that each of the directories are in (i.e.
the first element of a triplet obtained from os.walkpath).
directories: A list of directories in dirpath. This list is modified so
that any element which is a symlink to another directory is removed.
"""
def is_local_symlink(d):
d = os.path.join(dirpath, d)
if not os.path.islink(d):
return False
d = os.path.realpath(d)
return any(d.startswith(root) for root in roots)
_remove_pred(directories, is_local_symlink)