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# Copyright (C) 2005 by Canonical Development 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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An implementation the primary storage type CompressedTextStore.
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This store keeps compressed versions of the full text. It does not
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do any sort of delta compression.
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from bzrlib.trace import mutter
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from bzrlib.errors import BzrError, FileExists
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from StringIO import StringIO
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class CompressedTextStore(bzrlib.store.TransportStore):
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"""Store that holds files indexed by unique names.
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Files can be added, but not modified once they are in. Typically
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the hash is used as the name, or something else known to be unique,
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Files are stored gzip compressed, with no delta compression.
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>>> st = ScratchCompressedTextStore()
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>>> st.add(StringIO('hello'), 'aa')
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You are not allowed to add an id that is already present.
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Entries can be retrieved as files, which may then be read.
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>>> st.add(StringIO('goodbye'), '123123')
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>>> st.get('123123').read()
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def _relpath(self, fileid, suffixes=[]):
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suffixes = suffixes + ['gz']
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return super(CompressedTextStore, self)._relpath(fileid, suffixes)
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def _add(self, fn, f):
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from cStringIO import StringIO
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from bzrlib.osutils import pumpfile
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if isinstance(f, basestring):
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gf = gzip.GzipFile(mode='wb', fileobj=sio)
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# if pumpfile handles files that don't fit in ram,
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# so will this function
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if isinstance(f, basestring):
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self._transport.put(fn, sio)
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def _copy_one(self, fileid, suffix, other, pb):
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if not (isinstance(other, CompressedTextStore)
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and other._prefixed == self._prefixed):
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return super(CompressedTextStore, self)._copy_one(fileid, suffix,
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if suffix is None or suffix == 'gz':
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path = self._relpath(fileid)
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path = self._relpath(fileid, [suffix])
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assert other._transport.copy_to([path], self._transport, pb=pb) == 1
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def __init__(self, transport, prefixed=False):
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super(CompressedTextStore, self).__init__(transport, prefixed)
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self.register_suffix('gz')
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def _get(self, filename):
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"""Returns a file reading from a particular entry."""
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f = self._transport.get(filename)
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# gzip.GzipFile.read() requires a tell() function
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# but some transports return objects that cannot seek
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# so buffer them in a StringIO instead
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if hasattr(f, 'tell'):
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return gzip.GzipFile(mode='rb', fileobj=f)
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from cStringIO import StringIO
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sio = StringIO(f.read())
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return gzip.GzipFile(mode='rb', fileobj=sio)
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def ScratchTextStore():
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return TextStore(ScratchTransport())
added
removed
bzrlib/store/compressed_text.py
