1# Copyright 2007 Matt Chaput. All rights reserved. 2# 3# Redistribution and use in source and binary forms, with or without 4# modification, are permitted provided that the following conditions are met: 5# 6# 1. Redistributions of source code must retain the above copyright notice, 7# this list of conditions and the following disclaimer. 8# 9# 2. Redistributions in binary form must reproduce the above copyright 10# notice, this list of conditions and the following disclaimer in the 11# documentation and/or other materials provided with the distribution. 12# 13# THIS SOFTWARE IS PROVIDED BY MATT CHAPUT ``AS IS'' AND ANY EXPRESS OR 14# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 15# MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO 16# EVENT SHALL MATT CHAPUT OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 17# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 18# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, 19# OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 20# LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 21# NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, 22# EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 23# 24# The views and conclusions contained in the software and documentation are 25# those of the authors and should not be interpreted as representing official 26# policies, either expressed or implied, of Matt Chaput. 27 28import sys 29from struct import Struct, calcsize 30 31 32IS_LITTLE = sys.byteorder == "little" 33 34_INT_SIZE = calcsize("!i") 35_SHORT_SIZE = calcsize("!H") 36_LONG_SIZE = calcsize("!Q") 37_FLOAT_SIZE = calcsize("!f") 38_DOUBLE_SIZE = calcsize("!d") 39 40_byte_struct = Struct("!B") 41_sbyte_struct = Struct("!b") 42_ushort_struct = Struct("!H") 43_int_struct = Struct("!i") 44_uint_struct = Struct("!I") 45_long_struct = Struct("!q") 46_ulong_struct = Struct("!Q") 47_float_struct = Struct("!f") 48_double_struct = Struct("!d") 49_ushort_le_struct = Struct("<H") 50_uint_le_struct = Struct("<I") 51 52pack_byte = _byte_struct.pack 53pack_sbyte = _sbyte_struct.pack 54pack_ushort = _ushort_struct.pack 55pack_int = _int_struct.pack 56pack_uint = _uint_struct.pack 57pack_long = _long_struct.pack 58pack_ulong = _ulong_struct.pack 59pack_float = _float_struct.pack 60pack_double = _double_struct.pack 61pack_ushort_le = _ushort_le_struct.pack 62pack_uint_le = _uint_le_struct.pack 63 64unpack_byte = _byte_struct.unpack # ord() might be faster 65unpack_sbyte = _sbyte_struct.unpack 66unpack_ushort = _ushort_struct.unpack 67unpack_int = _int_struct.unpack 68unpack_uint = _uint_struct.unpack 69unpack_long = _long_struct.unpack 70unpack_ulong = _ulong_struct.unpack 71unpack_float = _float_struct.unpack 72unpack_double = _double_struct.unpack 73unpack_ushort_le = _ushort_le_struct.unpack 74unpack_uint_le = _uint_le_struct.unpack 75 76if sys.version_info[0] < 3: 77 emptybytes = "" 78else: 79 emptybytes = "".encode("latin-1") 80