From 68df54d6629ec019142eb149dd037774f2d11e7c Mon Sep 17 00:00:00 2001 From: Shubham Saini Date: Tue, 11 Dec 2018 15:31:23 +0530 Subject: First commit --- .../pip/_vendor/lockfile/__init__.py | 347 +++++++++++++++++++++ 1 file changed, 347 insertions(+) create mode 100644 venv/lib/python3.7/site-packages/pip-10.0.1-py3.7.egg/pip/_vendor/lockfile/__init__.py (limited to 'venv/lib/python3.7/site-packages/pip-10.0.1-py3.7.egg/pip/_vendor/lockfile/__init__.py') diff --git a/venv/lib/python3.7/site-packages/pip-10.0.1-py3.7.egg/pip/_vendor/lockfile/__init__.py b/venv/lib/python3.7/site-packages/pip-10.0.1-py3.7.egg/pip/_vendor/lockfile/__init__.py new file mode 100644 index 0000000..228e051 --- /dev/null +++ b/venv/lib/python3.7/site-packages/pip-10.0.1-py3.7.egg/pip/_vendor/lockfile/__init__.py @@ -0,0 +1,347 @@ +# -*- coding: utf-8 -*- + +""" +lockfile.py - Platform-independent advisory file locks. + +Requires Python 2.5 unless you apply 2.4.diff +Locking is done on a per-thread basis instead of a per-process basis. + +Usage: + +>>> lock = LockFile('somefile') +>>> try: +... lock.acquire() +... except AlreadyLocked: +... print 'somefile', 'is locked already.' +... except LockFailed: +... print 'somefile', 'can\\'t be locked.' +... else: +... print 'got lock' +got lock +>>> print lock.is_locked() +True +>>> lock.release() + +>>> lock = LockFile('somefile') +>>> print lock.is_locked() +False +>>> with lock: +... print lock.is_locked() +True +>>> print lock.is_locked() +False + +>>> lock = LockFile('somefile') +>>> # It is okay to lock twice from the same thread... +>>> with lock: +... lock.acquire() +... +>>> # Though no counter is kept, so you can't unlock multiple times... +>>> print lock.is_locked() +False + +Exceptions: + + Error - base class for other exceptions + LockError - base class for all locking exceptions + AlreadyLocked - Another thread or process already holds the lock + LockFailed - Lock failed for some other reason + UnlockError - base class for all unlocking exceptions + AlreadyUnlocked - File was not locked. + NotMyLock - File was locked but not by the current thread/process +""" + +from __future__ import absolute_import + +import functools +import os +import socket +import threading +import warnings + +# Work with PEP8 and non-PEP8 versions of threading module. +if not hasattr(threading, "current_thread"): + threading.current_thread = threading.currentThread +if not hasattr(threading.Thread, "get_name"): + threading.Thread.get_name = threading.Thread.getName + +__all__ = ['Error', 'LockError', 'LockTimeout', 'AlreadyLocked', + 'LockFailed', 'UnlockError', 'NotLocked', 'NotMyLock', + 'LinkFileLock', 'MkdirFileLock', 'SQLiteFileLock', + 'LockBase', 'locked'] + + +class Error(Exception): + """ + Base class for other exceptions. + + >>> try: + ... raise Error + ... except Exception: + ... pass + """ + pass + + +class LockError(Error): + """ + Base class for error arising from attempts to acquire the lock. + + >>> try: + ... raise LockError + ... except Error: + ... pass + """ + pass + + +class LockTimeout(LockError): + """Raised when lock creation fails within a user-defined period of time. + + >>> try: + ... raise LockTimeout + ... except LockError: + ... pass + """ + pass + + +class AlreadyLocked(LockError): + """Some other thread/process is locking the file. + + >>> try: + ... raise AlreadyLocked + ... except LockError: + ... pass + """ + pass + + +class LockFailed(LockError): + """Lock file creation failed for some other reason. + + >>> try: + ... raise LockFailed + ... except LockError: + ... pass + """ + pass + + +class UnlockError(Error): + """ + Base class for errors arising from attempts to release the lock. + + >>> try: + ... raise UnlockError + ... except Error: + ... pass + """ + pass + + +class NotLocked(UnlockError): + """Raised when an attempt is made to unlock an unlocked file. + + >>> try: + ... raise NotLocked + ... except UnlockError: + ... pass + """ + pass + + +class NotMyLock(UnlockError): + """Raised when an attempt is made to unlock a file someone else locked. + + >>> try: + ... raise NotMyLock + ... except UnlockError: + ... pass + """ + pass + + +class _SharedBase(object): + def __init__(self, path): + self.path = path + + def acquire(self, timeout=None): + """ + Acquire the lock. + + * If timeout is omitted (or None), wait forever trying to lock the + file. + + * If timeout > 0, try to acquire the lock for that many seconds. If + the lock period expires and the file is still locked, raise + LockTimeout. + + * If timeout <= 0, raise AlreadyLocked immediately if the file is + already locked. + """ + raise NotImplemented("implement in subclass") + + def release(self): + """ + Release the lock. + + If the file is not locked, raise NotLocked. + """ + raise NotImplemented("implement in subclass") + + def __enter__(self): + """ + Context manager support. + """ + self.acquire() + return self + + def __exit__(self, *_exc): + """ + Context manager support. + """ + self.release() + + def __repr__(self): + return "<%s: %r>" % (self.__class__.__name__, self.path) + + +class LockBase(_SharedBase): + """Base class for platform-specific lock classes.""" + def __init__(self, path, threaded=True, timeout=None): + """ + >>> lock = LockBase('somefile') + >>> lock = LockBase('somefile', threaded=False) + """ + super(LockBase, self).__init__(path) + self.lock_file = os.path.abspath(path) + ".lock" + self.hostname = socket.gethostname() + self.pid = os.getpid() + if threaded: + t = threading.current_thread() + # Thread objects in Python 2.4 and earlier do not have ident + # attrs. Worm around that. + ident = getattr(t, "ident", hash(t)) + self.tname = "-%x" % (ident & 0xffffffff) + else: + self.tname = "" + dirname = os.path.dirname(self.lock_file) + + # unique name is mostly about the current process, but must + # also contain the path -- otherwise, two adjacent locked + # files conflict (one file gets locked, creating lock-file and + # unique file, the other one gets locked, creating lock-file + # and overwriting the already existing lock-file, then one + # gets unlocked, deleting both lock-file and unique file, + # finally the last lock errors out upon releasing. + self.unique_name = os.path.join(dirname, + "%s%s.%s%s" % (self.hostname, + self.tname, + self.pid, + hash(self.path))) + self.timeout = timeout + + def is_locked(self): + """ + Tell whether or not the file is locked. + """ + raise NotImplemented("implement in subclass") + + def i_am_locking(self): + """ + Return True if this object is locking the file. + """ + raise NotImplemented("implement in subclass") + + def break_lock(self): + """ + Remove a lock. Useful if a locking thread failed to unlock. + """ + raise NotImplemented("implement in subclass") + + def __repr__(self): + return "<%s: %r -- %r>" % (self.__class__.__name__, self.unique_name, + self.path) + + +def _fl_helper(cls, mod, *args, **kwds): + warnings.warn("Import from %s module instead of lockfile package" % mod, + DeprecationWarning, stacklevel=2) + # This is a bit funky, but it's only for awhile. The way the unit tests + # are constructed this function winds up as an unbound method, so it + # actually takes three args, not two. We want to toss out self. + if not isinstance(args[0], str): + # We are testing, avoid the first arg + args = args[1:] + if len(args) == 1 and not kwds: + kwds["threaded"] = True + return cls(*args, **kwds) + + +def LinkFileLock(*args, **kwds): + """Factory function provided for backwards compatibility. + + Do not use in new code. Instead, import LinkLockFile from the + lockfile.linklockfile module. + """ + from . import linklockfile + return _fl_helper(linklockfile.LinkLockFile, "lockfile.linklockfile", + *args, **kwds) + + +def MkdirFileLock(*args, **kwds): + """Factory function provided for backwards compatibility. + + Do not use in new code. Instead, import MkdirLockFile from the + lockfile.mkdirlockfile module. + """ + from . import mkdirlockfile + return _fl_helper(mkdirlockfile.MkdirLockFile, "lockfile.mkdirlockfile", + *args, **kwds) + + +def SQLiteFileLock(*args, **kwds): + """Factory function provided for backwards compatibility. + + Do not use in new code. Instead, import SQLiteLockFile from the + lockfile.mkdirlockfile module. + """ + from . import sqlitelockfile + return _fl_helper(sqlitelockfile.SQLiteLockFile, "lockfile.sqlitelockfile", + *args, **kwds) + + +def locked(path, timeout=None): + """Decorator which enables locks for decorated function. + + Arguments: + - path: path for lockfile. + - timeout (optional): Timeout for acquiring lock. + + Usage: + @locked('/var/run/myname', timeout=0) + def myname(...): + ... + """ + def decor(func): + @functools.wraps(func) + def wrapper(*args, **kwargs): + lock = FileLock(path, timeout=timeout) + lock.acquire() + try: + return func(*args, **kwargs) + finally: + lock.release() + return wrapper + return decor + + +if hasattr(os, "link"): + from . import linklockfile as _llf + LockFile = _llf.LinkLockFile +else: + from . import mkdirlockfile as _mlf + LockFile = _mlf.MkdirLockFile + +FileLock = LockFile -- cgit v1.2.3