view hgext/remotefilelog/connectionpool.py @ 51711:832a1aeb576f

pytype: only try the hacky way of finding PYTHON if not provided

This allows us to work in more environments, like when using pyenv. This
syntax is compatible with all POSIX shells.

# 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 mercurial import (
    hg,
    sshpeer,
)

_sshv1peer = sshpeer.sshv1peer


class connectionpool:
    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:
            peer = hg.peer(self._repo.ui, {}, path)
            if hasattr(peer, '_cleanup'):

                class mypeer(peer.__class__):
                    def _cleanup(self, warn=None):
                        # close pipee first so peer.cleanup reading it won't
                        # deadlock, if there are other processes with pipeo
                        # open (i.e. us).
                        if hasattr(self, 'pipee'):
                            self.pipee.close()
                        return super(mypeer, self)._cleanup()

                peer.__class__ = mypeer

            conn = connection(pathpool, peer)

        return conn

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


class connection:
    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 hasattr(self.peer, 'cleanup'):
            self.peer.cleanup()