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# Copyright (C) 2007 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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"""A collection of file names which is persisted on a transport."""
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from bzrlib.lazy_import import lazy_import
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lazy_import(globals(), """
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class FileNames(object):
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"""A collection of file names.
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The file names are persisted to a file on a transport, and cand be
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added, removed and initialised.
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The set of names are stored in a flat file, one name per line.
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New names are allocated sequentially.
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Initialisation creates an empty file.
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This is intended to support management of modest numbers of files in
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write-locked environments which may be read from unlistable transports.
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The save method must be called to cause the state to be saved to the
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Finally, load is used to obtain a previously saved set.
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def __init__(self, transport, index_name):
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"""Create a collection on transport called index_name."""
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self._transport = transport
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self._index_name = index_name
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for number in xrange(self._cap):
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if str(number) not in self._names:
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self._names.add(str(number))
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raise errors.BzrError('too many files')
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"""Initialise the collection."""
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"""Load the names from the transport."""
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self._names = set(self._transport.get_bytes(
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self._index_name).split('\n'))
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self._names.discard('')
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"""What are the names in this collection?"""
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return frozenset(self._names)
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def remove(self, name):
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"""Remove name from the collection."""
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self._names.remove(name)
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"""Save the set of names."""
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self._transport.put_bytes(self._index_name, '\n'.join(self._names))
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bzrlib/file_names.py
