~bzr-pqm/bzr/bzr.dev

1911.2.3 by John Arbash Meinel
Moving everything into a new location so that we can cache more than just revision ids
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# Copyright (C) 2006 Canonical
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#
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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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#
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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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#
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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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# TODO: Some kind of command-line display of revision properties: 
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# perhaps show them in log -v and allow them as options to the commit command.
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"""Some functions to enable caching the conversion between unicode to utf8"""
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# Map revisions from and to utf8 encoding
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# Whenever we do an encode/decode operation, we save the result, so that
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# we don't have to do it again.
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_unicode_to_utf8_map = {}
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_utf8_to_unicode_map = {}
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def encode(unicode_str,
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           _uni_to_utf8=_unicode_to_utf8_map,
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           _utf8_to_uni=_utf8_to_unicode_map):
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    """Take this unicode revision id, and get a unicode version"""
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    try:
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        return _uni_to_utf8[unicode_str]
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    except KeyError:
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        _uni_to_utf8[unicode_str] = utf8_str = unicode_str.encode('utf-8')
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        _utf8_to_uni[utf8_str] = unicode_str
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        return utf8_str
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def decode(utf8_str,
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           _uni_to_utf8=_unicode_to_utf8_map,
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           _utf8_to_uni=_utf8_to_unicode_map):
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    """Take a utf8 revision id, and decode it, but cache the result"""
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    try:
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        return _utf8_to_uni[utf8_str]
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    except KeyError:
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        _utf8_to_uni[utf8_str] = unicode_str = utf8_str.decode('utf-8')
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        _uni_to_utf8[unicode_str] = utf8_str
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        return unicode_str
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1911.2.5 by John Arbash Meinel
Update cache tests, add a function to do something like intern() only for unicode objects
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def get_cached_unicode(unicode_str):
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    """Return a cached version of the unicode string.
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    This has a similar idea to that of intern() in that it tries
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    to return a singleton string. Only it works for unicode strings.
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    """
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    # This might return the same object, or it might return the cached one
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    # the decode() should just be a hash lookup, because the encode() side
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    # should add the entry to the maps
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    return decode(encode(unicode_str))
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1911.2.3 by John Arbash Meinel
Moving everything into a new location so that we can cache more than just revision ids
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def clear_encoding_cache():
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    """Clear the encoding and decoding caches"""
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    global _unicode_to_utf8_map, _utf8_to_unicode_map
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    _unicode_to_utf8_map.clear()
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    _utf8_to_unicode_map.clear()
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