/usr/share/pyshared/xappy/fieldmappings.py is in python-xappy 0.5-5.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 | #!/usr/bin/env python
#
# Copyright (C) 2007 Lemur Consulting Ltd
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
r"""fieldmappings.py: Mappings from field names to term prefixes, etc.
"""
__docformat__ = "restructuredtext en"
import cPickle as _cPickle
class FieldMappings(object):
"""Mappings from field names to term prefixes, slot values, etc.
The following mappings are maintained:
- a mapping from field name to the string prefix to insert at the start of
terms.
- a mapping from field name to the slot numbers to store the field contents
in.
"""
__slots__ = '_prefixes', '_prefixcount', '_slots', '_slotcount',
def __init__(self, serialised=None):
"""Create a new field mapping object, or unserialise a saved one.
"""
if serialised is not None:
(self._prefixes, self._prefixcount,
self._slots, self._slotcount) = _cPickle.loads(serialised)
else:
self._prefixes = {}
self._prefixcount = 0
self._slots = {}
self._slotcount = 0
def _genPrefix(self):
"""Generate a previously unused prefix.
Prefixes are uppercase letters, and start with 'X' (this is a Xapian
convention, for compatibility with other Xapian tools: other starting
letters are reserved for special meanings):
>>> maps = FieldMappings()
>>> maps._genPrefix()
'XA'
>>> maps._genPrefix()
'XB'
>>> [maps._genPrefix() for i in xrange(60)]
['XC', 'XD', 'XE', 'XF', 'XG', 'XH', 'XI', 'XJ', 'XK', 'XL', 'XM', 'XN', 'XO', 'XP', 'XQ', 'XR', 'XS', 'XT', 'XU', 'XV', 'XW', 'XX', 'XY', 'XZ', 'XAA', 'XBA', 'XCA', 'XDA', 'XEA', 'XFA', 'XGA', 'XHA', 'XIA', 'XJA', 'XKA', 'XLA', 'XMA', 'XNA', 'XOA', 'XPA', 'XQA', 'XRA', 'XSA', 'XTA', 'XUA', 'XVA', 'XWA', 'XXA', 'XYA', 'XZA', 'XAB', 'XBB', 'XCB', 'XDB', 'XEB', 'XFB', 'XGB', 'XHB', 'XIB', 'XJB']
>>> maps = FieldMappings()
>>> [maps._genPrefix() for i in xrange(27*26 + 5)][-10:]
['XVZ', 'XWZ', 'XXZ', 'XYZ', 'XZZ', 'XAAA', 'XBAA', 'XCAA', 'XDAA', 'XEAA']
"""
res = []
self._prefixcount += 1
num = self._prefixcount
while num != 0:
ch = (num - 1) % 26
res.append(chr(ch + ord('A')))
num -= ch
num = num // 26
return 'X' + ''.join(res)
def get_fieldname_from_prefix(self, prefix):
"""Get a fieldname from a prefix.
If the prefix is not found, return None.
"""
for key, val in self._prefixes.iteritems():
if val == prefix:
return key
return None
def get_prefix(self, fieldname):
"""Get the prefix used for a given field name.
"""
return self._prefixes[fieldname]
def get_slot(self, fieldname, purpose):
"""Get the slot number used for a given field name and purpose.
"""
return self._slots[(fieldname, purpose)]
def add_prefix(self, fieldname):
"""Allocate a prefix for the given field.
If a prefix is already allocated for this field, this has no effect.
"""
if fieldname in self._prefixes:
return
self._prefixes[fieldname] = self._genPrefix()
def add_slot(self, fieldname, purpose, slotnum=None):
"""Allocate a slot number for the given field and purpose.
If a slot number is already allocated for this field and purpose, this
has no effect.
Returns the slot number allocated for the field and purpose (whether
newly allocated, or previously allocated).
If `slotnum` is supplied, the number contained in it is used to
allocate the new slot, instead of allocating a new number. No checks
will be made to ensure that the slot number doesn't collide with
existing (or later allocated) numbers: the main purpose of this
parameter is to share allocations - ie, to collide deliberately.
"""
try:
return self._slots[(fieldname, purpose)]
except KeyError:
pass
if slotnum is None:
self._slots[(fieldname, purpose)] = self._slotcount
self._slotcount += 1
return self._slotcount - 1
else:
self._slots[(fieldname, purpose)] = slotnum
return slotnum
def serialise(self):
"""Serialise the field mappings to a string.
This can be unserialised by passing the result of this method to the
constructor of a new FieldMappings object.
"""
return _cPickle.dumps((self._prefixes,
self._prefixcount,
self._slots,
self._slotcount,
), 2)
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