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# Copyright (C) 2005 by Canonical Ltd
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# This program is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation; either version 2 of the License, or
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# (at your option) any later version.
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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# You should have received a copy of the GNU General Public License
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# along with this program; if not, write to the Free Software
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# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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from bzrlib.trace import mutter
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from bzrlib.store import Store
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from bzrlib.transport.local import LocalTransport
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class CachedStore(Store):
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"""A store that caches data locally, to avoid repeated downloads.
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The precacache method should be used to avoid server round-trips for
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def __init__(self, store, cache_dir):
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self.source_store = store
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self.cache_store = store.__class__(LocalTransport(cache_dir))
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def __getitem__(self, id):
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mutter("Cache add %s" % id)
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if id not in self.cache_store:
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self.cache_store.add(self.source_store[id], id)
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return self.cache_store[id]
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def __contains__(self, fileid):
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if fileid in self.cache_store:
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if fileid in self.source_store:
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# We could copy at this time
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def get(self, fileids, permit_failure=False, pb=None):
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fileids = list(fileids)
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hasids = self.cache_store.has(fileids)
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for has, fileid in zip(hasids, fileids):
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self.cache_store.copy_multi(self.source_store, needs,
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permit_failure=permit_failure)
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return self.cache_store.get(fileids,
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permit_failure=permit_failure, pb=pb)
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def prefetch(self, ids):
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"""Copy a series of ids into the cache, before they are used.
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For remote stores that support pipelining or async downloads, this can
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increase speed considerably.
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Failures while prefetching are ignored.
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mutter("Prefetch of ids %s" % ",".join(ids))
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self.cache_store.copy_multi(self.source_store, ids,
added
removed
bzrlib/meta_store.py
