86 lines
2.6 KiB
Python
86 lines
2.6 KiB
Python
# Copyright (c) 2013 Hewlett-Packard Development Company, L.P.
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
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# implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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"""Metadata cache.
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Files within the cache as passed to hook commands invoked by
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os-collect-command.
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The cache also stores the last version of a file in order to detect changes
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that occur - hook commands are only automatically invoked when one or more
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metadata sources have changed things.
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The last version of a file is available under $FILENAME.last.
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"""
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import json
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import os
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import shutil
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import tempfile
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from oslo_config import cfg
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def get_path(name):
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return os.path.join(cfg.CONF.cachedir, '%s.json' % name)
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def store(name, content):
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if not os.path.exists(cfg.CONF.cachedir):
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os.mkdir(cfg.CONF.cachedir)
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changed = False
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dest_path = get_path(name)
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orig_path = '%s.orig' % dest_path
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last_path = '%s.last' % dest_path
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with tempfile.NamedTemporaryFile(
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dir=cfg.CONF.cachedir,
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delete=False) as new:
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new.write(json.dumps(content, indent=1).encode('utf-8'))
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new.flush()
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if not os.path.exists(orig_path):
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shutil.copy(new.name, orig_path)
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changed = True
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os.rename(new.name, dest_path)
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if not changed:
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if os.path.exists(last_path):
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with open(last_path) as then:
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then_value = json.load(then)
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if then_value != content:
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changed = True
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else:
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changed = True
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return (changed, dest_path)
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def commit(name):
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dest_path = get_path(name)
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if os.path.exists(dest_path):
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shutil.copy(dest_path, '%s.last' % dest_path)
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def store_meta_list(name, data_keys):
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'''Store a json list of the files that should be present after store.'''
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final_list = [get_path(k) for k in data_keys]
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dest = get_path(name)
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with tempfile.NamedTemporaryFile(prefix='tmp_meta_list.',
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dir=os.path.dirname(dest),
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delete=False) as out:
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out.write(json.dumps(final_list).encode('utf-8'))
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os.rename(out.name, dest)
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return dest
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