view hgext/remotefilelog/connectionpool.py @ 41098:cfd95219102d

strip: move attributes shortcut assigned earlier

This series will add support for "soft" stripping using the archived phase in
addition to the usual heavy weight revlog stripping. First, we need to
refactor the strip function to extract logic common to the "soft-strip" case.

We are about to extract bits of the strip function into separate functions.
Those blocks of code contain variables for frequently accessed attributes. We
move those variables outside of the soon to be moved blocks.

# connectionpool.py - class for pooling peer connections for reuse
#
# Copyright 2017 Facebook, Inc.
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

from __future__ import absolute_import

from mercurial import (
    extensions,
    hg,
    sshpeer,
    util,
)

_sshv1peer = sshpeer.sshv1peer

class connectionpool(object):
    def __init__(self, repo):
        self._repo = repo
        self._pool = dict()

    def get(self, path):
        pathpool = self._pool.get(path)
        if pathpool is None:
            pathpool = list()
            self._pool[path] = pathpool

        conn = None
        if len(pathpool) > 0:
            try:
                conn = pathpool.pop()
                peer = conn.peer
                # If the connection has died, drop it
                if isinstance(peer, _sshv1peer):
                    if peer._subprocess.poll() is not None:
                        conn = None
            except IndexError:
                pass

        if conn is None:
            def _cleanup(orig):
                # close pipee first so peer.cleanup reading it won't deadlock,
                # if there are other processes with pipeo open (i.e. us).
                peer = orig.im_self
                if util.safehasattr(peer, 'pipee'):
                    peer.pipee.close()
                return orig()

            peer = hg.peer(self._repo.ui, {}, path)
            if util.safehasattr(peer, 'cleanup'):
                extensions.wrapfunction(peer, 'cleanup', _cleanup)

            conn = connection(pathpool, peer)

        return conn

    def close(self):
        for pathpool in self._pool.itervalues():
            for conn in pathpool:
                conn.close()
            del pathpool[:]

class connection(object):
    def __init__(self, pool, peer):
        self._pool = pool
        self.peer = peer

    def __enter__(self):
        return self

    def __exit__(self, type, value, traceback):
        # Only add the connection back to the pool if there was no exception,
        # since an exception could mean the connection is not in a reusable
        # state.
        if type is None:
            self._pool.append(self)
        else:
            self.close()

    def close(self):
        if util.safehasattr(self.peer, 'cleanup'):
            self.peer.cleanup()