Synnefo

# Copyright 2011-2012 GRNET S.A. All rights reserved.

#

# Redistribution and use in source and binary forms, with or

# without modification, are permitted provided that the following

# conditions are met:

#

#   1. Redistributions of source code must retain the above

#      copyright notice, this list of conditions and the following

#      disclaimer.

#

#   2. Redistributions in binary form must reproduce the above

#      copyright notice, this list of conditions and the following

#      disclaimer in the documentation and/or other materials

#      provided with the distribution.

#

# THIS SOFTWARE IS PROVIDED BY GRNET S.A. ``AS IS'' AND ANY EXPRESS

# OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED

# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

# PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL GRNET S.A OR

# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF

# USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED

# AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN

# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

# POSSIBILITY OF SUCH DAMAGE.

#

# The views and conclusions contained in the software and

# documentation are those of the authors and should not be

# interpreted as representing official policies, either expressed

# or implied, of GRNET S.A.

from objpool import ObjectPool

from synnefo.logic.rapi import GanetiRapiClient

from logging import getLogger

log = getLogger(__name__)

_pools = {}

_hashes = {}

pool_size = 8

class GanetiRapiClientPool(ObjectPool):

    """Pool of Ganeti RAPI Clients."""

    def __init__(self, host, port, user, passwd, size=None):

        log.debug("INIT: Initializing pool of size %d, host %s,"

                  " port %d, user %s", size, host, port, user)

        ObjectPool.__init__(self, size=size)

        self.host = host

        self.port = port

        self.user = user

        self.passwd = passwd

    def _pool_create(self):

        log.debug("CREATE: Creating new client from pool %r", self)

        client = GanetiRapiClient(self.host, self.port, self.user, self.passwd)

        client._pool = self

        return client

    def _pool_verify(self, client):

        return True

    def _pool_cleanup(self, conn):

        return False

def get_rapi_client(backend_id, backend_hash, host, port, user, passwd):

    """Get a ganeti RAPI client from pool."""

    log.debug("GET: Getting RAPI client")

    m = "%s cannot be None"

    if host is None:

        raise ValueError(m % "host")

    if port is None:

        raise ValueError(m % "port")

    # does the pool need to be created?

    if backend_hash not in _pools:

        log.debug("GET: No Pool. Creating new for host %s", host)

        pool = GanetiRapiClientPool(host, port, user, passwd, pool_size)

        _pools[backend_hash] = pool

        # Delete Pool for old backend_hash

        if backend_id in _hashes:

            del _pools[_hashes[backend_id]]

        _hashes[backend_id] = backend_hash

    obj = _pools[backend_hash].pool_get()

    log.debug("GET: Got object %r from pool", obj)

    return obj

def put_rapi_client(client):

    pool = client._pool

    log.debug("PUT: putting client %r back to pool %r", client, pool)

    if pool is None:

        log.debug("PUT: client %r does not have a pool", client)

        return

    pool.pool_put(client)