hgext/inotify/linux/__init__.py
author Matt Mackall <mpm@selenic.com>
Mon, 12 May 2008 11:37:08 -0500
changeset 6599 cd4db3999ef9
parent 6239 39cfcef4f463
child 7875 553aa0cbeab6
permissions -rw-r--r--
status: use match helpers for various users
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
6239
39cfcef4f463 Add inotify extension
Bryan O'Sullivan <bos@serpentine.com>
parents:
diff changeset
     1
# __init__.py - low-level interfaces to the Linux inotify subsystem
39cfcef4f463 Add inotify extension
Bryan O'Sullivan <bos@serpentine.com>
parents:
diff changeset
     2
39cfcef4f463 Add inotify extension
Bryan O'Sullivan <bos@serpentine.com>
parents:
diff changeset
     3
# Copyright 2006 Bryan O'Sullivan <bos@serpentine.com>
39cfcef4f463 Add inotify extension
Bryan O'Sullivan <bos@serpentine.com>
parents:
diff changeset
     4
39cfcef4f463 Add inotify extension
Bryan O'Sullivan <bos@serpentine.com>
parents:
diff changeset
     5
# This library is free software; you can redistribute it and/or modify
39cfcef4f463 Add inotify extension
Bryan O'Sullivan <bos@serpentine.com>
parents:
diff changeset
     6
# it under the terms of version 2.1 of the GNU Lesser General Public
39cfcef4f463 Add inotify extension
Bryan O'Sullivan <bos@serpentine.com>
parents:
diff changeset
     7
# License, incorporated herein by reference.
39cfcef4f463 Add inotify extension
Bryan O'Sullivan <bos@serpentine.com>
parents:
diff changeset
     8
39cfcef4f463 Add inotify extension
Bryan O'Sullivan <bos@serpentine.com>
parents:
diff changeset
     9
'''Low-level interface to the Linux inotify subsystem.
39cfcef4f463 Add inotify extension
Bryan O'Sullivan <bos@serpentine.com>
parents:
diff changeset
    10
39cfcef4f463 Add inotify extension
Bryan O'Sullivan <bos@serpentine.com>
parents:
diff changeset
    11
The inotify subsystem provides an efficient mechanism for file status
39cfcef4f463 Add inotify extension
Bryan O'Sullivan <bos@serpentine.com>
parents:
diff changeset
    12
monitoring and change notification.
39cfcef4f463 Add inotify extension
Bryan O'Sullivan <bos@serpentine.com>
parents:
diff changeset
    13
39cfcef4f463 Add inotify extension
Bryan O'Sullivan <bos@serpentine.com>
parents:
diff changeset
    14
This package provides the low-level inotify system call interface and
39cfcef4f463 Add inotify extension
Bryan O'Sullivan <bos@serpentine.com>
parents:
diff changeset
    15
associated constants and helper functions.
39cfcef4f463 Add inotify extension
Bryan O'Sullivan <bos@serpentine.com>
parents:
diff changeset
    16
39cfcef4f463 Add inotify extension
Bryan O'Sullivan <bos@serpentine.com>
parents:
diff changeset
    17
For a higher-level interface that remains highly efficient, use the
39cfcef4f463 Add inotify extension
Bryan O'Sullivan <bos@serpentine.com>
parents:
diff changeset
    18
inotify.watcher package.'''
39cfcef4f463 Add inotify extension
Bryan O'Sullivan <bos@serpentine.com>
parents:
diff changeset
    19
39cfcef4f463 Add inotify extension
Bryan O'Sullivan <bos@serpentine.com>
parents:
diff changeset
    20
__author__ = "Bryan O'Sullivan <bos@serpentine.com>"
39cfcef4f463 Add inotify extension
Bryan O'Sullivan <bos@serpentine.com>
parents:
diff changeset
    21
39cfcef4f463 Add inotify extension
Bryan O'Sullivan <bos@serpentine.com>
parents:
diff changeset
    22
from _inotify import *
39cfcef4f463 Add inotify extension
Bryan O'Sullivan <bos@serpentine.com>
parents:
diff changeset
    23
39cfcef4f463 Add inotify extension
Bryan O'Sullivan <bos@serpentine.com>
parents:
diff changeset
    24
procfs_path = '/proc/sys/fs/inotify'
39cfcef4f463 Add inotify extension
Bryan O'Sullivan <bos@serpentine.com>
parents:
diff changeset
    25
39cfcef4f463 Add inotify extension
Bryan O'Sullivan <bos@serpentine.com>
parents:
diff changeset
    26
def _read_procfs_value(name):
39cfcef4f463 Add inotify extension
Bryan O'Sullivan <bos@serpentine.com>
parents:
diff changeset
    27
    def read_value():
39cfcef4f463 Add inotify extension
Bryan O'Sullivan <bos@serpentine.com>
parents:
diff changeset
    28
        try:
39cfcef4f463 Add inotify extension
Bryan O'Sullivan <bos@serpentine.com>
parents:
diff changeset
    29
            return int(open(procfs_path + '/' + name).read())
39cfcef4f463 Add inotify extension
Bryan O'Sullivan <bos@serpentine.com>
parents:
diff changeset
    30
        except OSError, err:
39cfcef4f463 Add inotify extension
Bryan O'Sullivan <bos@serpentine.com>
parents:
diff changeset
    31
            return None
39cfcef4f463 Add inotify extension
Bryan O'Sullivan <bos@serpentine.com>
parents:
diff changeset
    32
39cfcef4f463 Add inotify extension
Bryan O'Sullivan <bos@serpentine.com>
parents:
diff changeset
    33
    read_value.__doc__ = '''Return the value of the %s setting from /proc.
39cfcef4f463 Add inotify extension
Bryan O'Sullivan <bos@serpentine.com>
parents:
diff changeset
    34
39cfcef4f463 Add inotify extension
Bryan O'Sullivan <bos@serpentine.com>
parents:
diff changeset
    35
    If inotify is not enabled on this system, return None.''' % name
39cfcef4f463 Add inotify extension
Bryan O'Sullivan <bos@serpentine.com>
parents:
diff changeset
    36
39cfcef4f463 Add inotify extension
Bryan O'Sullivan <bos@serpentine.com>
parents:
diff changeset
    37
    return read_value
39cfcef4f463 Add inotify extension
Bryan O'Sullivan <bos@serpentine.com>
parents:
diff changeset
    38
39cfcef4f463 Add inotify extension
Bryan O'Sullivan <bos@serpentine.com>
parents:
diff changeset
    39
max_queued_events = _read_procfs_value('max_queued_events')
39cfcef4f463 Add inotify extension
Bryan O'Sullivan <bos@serpentine.com>
parents:
diff changeset
    40
max_user_instances = _read_procfs_value('max_user_instances')
39cfcef4f463 Add inotify extension
Bryan O'Sullivan <bos@serpentine.com>
parents:
diff changeset
    41
max_user_watches = _read_procfs_value('max_user_watches')