root / snf-pithos-backend / pithos / backends / util.py @ 1f3f907f
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# Copyright 2011-2012 GRNET S.A. All rights reserved.
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#
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# Redistribution and use in source and binary forms, with or
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# without modification, are permitted provided that the following
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# conditions are met:
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#
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# 1. Redistributions of source code must retain the above
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# copyright notice, this list of conditions and the following
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# disclaimer.
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#
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# 2. Redistributions in binary form must reproduce the above
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# copyright notice, this list of conditions and the following
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# disclaimer in the documentation and/or other materials
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# provided with the distribution.
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#
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# THIS SOFTWARE IS PROVIDED BY GRNET S.A. ``AS IS'' AND ANY EXPRESS
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# OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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# PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL GRNET S.A OR
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# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
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# USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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# AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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# POSSIBILITY OF SUCH DAMAGE.
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#
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# The views and conclusions contained in the software and
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# documentation are those of the authors and should not be
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# interpreted as representing official policies, either expressed
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# or implied, of GRNET S.A.
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from synnefo.lib.pool import ObjectPool |
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from new import instancemethod |
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from select import select |
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from traceback import print_exc |
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from pithos.backends import connect_backend |
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USAGE_LIMIT = 500
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class PithosBackendPool(ObjectPool): |
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def __init__(self, size=None, db_module=None, db_connection=None, |
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block_module=None, block_path=None, block_umask=None, |
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queue_module=None, queue_hosts=None, |
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queue_exchange=None, free_versioning=True, |
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quotaholder_enabled=True,
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quotaholder_url=None, quotaholder_token=None, |
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block_params=None):
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super(PithosBackendPool, self).__init__(size=size) |
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self.db_module = db_module
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self.db_connection = db_connection
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self.block_module = block_module
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self.block_path = block_path
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self.block_umask = block_umask
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self.queue_module = queue_module
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self.block_params = block_params
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self.queue_hosts = queue_hosts
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self.queue_exchange = queue_exchange
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self.quotaholder_enabled = quotaholder_enabled
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self.quotaholder_url = quotaholder_url
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self.quotaholder_token = quotaholder_token
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self.free_versioning = free_versioning
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def _pool_create(self): |
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backend = connect_backend(db_module=self.db_module,
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db_connection=self.db_connection,
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block_module=self.block_module,
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block_path=self.block_path,
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block_umask=self.block_umask,
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queue_module=self.queue_module,
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block_params=self.block_params,
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queue_hosts=self.queue_hosts,
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queue_exchange=self.queue_exchange,
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quotaholder_enabled=self.quotaholder_enabled,
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quotaholder_url=self.quotaholder_url,
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quotaholder_token=self.quotaholder_token,
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free_versioning=self.free_versioning)
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backend._real_close = backend.close |
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backend.close = instancemethod(_pooled_backend_close, backend, |
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type(backend))
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backend._pool = self
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backend._use_count = USAGE_LIMIT |
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backend.messages = [] |
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return backend
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def _pool_verify(self, backend): |
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wrapper = backend.wrapper |
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conn = wrapper.conn |
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if conn.closed:
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return False |
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if conn.in_transaction():
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conn.close() |
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return False |
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try:
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fd = conn.connection.connection.fileno() |
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r, w, x = select([fd], (), (), 0)
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if r:
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conn.close() |
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return False |
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except:
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print_exc() |
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return False |
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return True |
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def _pool_cleanup(self, backend): |
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c = backend._use_count - 1
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if c < 0: |
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backend._real_close() |
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return True |
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backend._use_count = c |
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wrapper = backend.wrapper |
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if wrapper.trans is not None: |
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conn = wrapper.conn |
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if conn.closed:
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wrapper.trans = None
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else:
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wrapper.rollback() |
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backend.messages = [] |
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return False |
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def _pooled_backend_close(backend): |
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backend._pool.pool_put(backend) |