# File: utils.py
# Library: DOPAL - DO Python Azureus Library
#
# 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; version 2 of the License.
#
# 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 ( see the COPYING file ).
#
# 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
'''
General utility functions.
'''
__pychecker__ = 'unusednames=metaclass_,attr_,no-unreachable'
# Converts a binary string character into a hexidecimal equivalent.
#
# >>> byte_to_hex_form('N')
# u'4E'
def byte_to_hex_form(byte):
# ord is used to convert the byte into it's numeric equivalent.
# hex will turn the number into a string like "0x5" or "0xa3"
# the slicing will chop off the "0x" prefix.
# zfill will change any single digit values to have a leading 0 character.
# upper will force all the A-F characters to be uppercase.
return unicode(hex(ord(byte))[2:].zfill(2).upper())
# Converts a binary string into a hexidecimal equivalent.
#
# >>> string_to_hex_form('xK3-')
# u'784B332D'
def string_to_hex_form(chars):
if not chars:
raise ValueError, "cannot convert empty string"
return ''.join([byte_to_hex_form(char) for char in chars])
# Converts a 2 character hexidecimal string into a binary character.
#
# >>> hex_form_to_byte(u'4E')
# 'L'
def hex_pair_to_byte(hex_pair):
return chr(int(hex_pair.encode('utf-8'), 16))
# Converts a hexidecimal string (a string containing only characters valid
# in use for displaying a hexidecimal number, i.e. 0123456789ABCDEF) into
# a binary string.
#
# >>> hex_string_to_binary(u'784B332D')
# 'xK3-'
def hex_string_to_binary(hex_string):
if len(hex_string) % 2:
raise ValueError, "string given has odd-number of characters, must be even"
if not hex_string:
raise ValueError, "cannot convert empty string"
return ''.join([hex_pair_to_byte(hex_string[i:i + 2]) for i in range(0, len(hex_string), 2)])
def make_short_object_id(object_id):
# Due to the way Azureus generates object ID's (it tends to be a
# long integer which is then incremented for each object it
# generates), we don't bother rendering the entire object ID
# as it would be too long (it can be as long as 20 characters).
#
# So instead, we only use the last 6 digits - turning the ID into
# hexidecimal. This gives us a range of 16**6 = 16.7 million. So
# Azureus would have to generate more than 16 million objects
# before it generates an ID which has the same short ID form as
# another object.
#
# We show the short ID as a way of easily seeing whether two
# objects represent the same remote object or not.
hex_id = hex(object_id)
if hex_id[-1] == 'L':
hex_short_id = hex_id[-7:-1]
else:
hex_short_id = hex_id[-6:]
return hex_short_id
def parse_azureus_version_string(ver_string):
ver_bits = ver_string.split('_', 2)
if len(ver_bits) == 1:
major_ver, minor_ver = ver_string, None
else:
major_ver, minor_ver = ver_bits
ver_segments = [int(bit) for bit in major_ver.split('.')]
if minor_ver:
if minor_ver[0].lower() == 'b':
ver_segments.append('b')
try:
beta_ver = int(minor_ver[1:])
except ValueError:
pass
else:
ver_segments.append(beta_ver)
return tuple(ver_segments)
#
# I love this code. :)
#
# I might turn it into something more generic, and use it elsewhere..
#
# Would be nicer if there was a better API for doing this, but given the amount
# of hackery that I'm doing right now, I won't complain. :)
#
# What a lot of effort just to act as if these methods were defined in the
# class itself.
import new
class MethodFactory(object):
def __init__(self, method_object):
_codeobj = method_object.func_code
code_arguments = [
_codeobj.co_argcount, _codeobj.co_nlocals, _codeobj.co_stacksize,
_codeobj.co_flags, _codeobj.co_code, _codeobj.co_consts,
_codeobj.co_names, _codeobj.co_varnames, _codeobj.co_filename,
_codeobj.co_name, _codeobj.co_firstlineno, _codeobj.co_lnotab,
]
self.code_arguments = code_arguments
def _build_function(self, name):
code_args = self.code_arguments[:]
code_args[9] = name
# code_args[8] = <modulename>
codeobj = new.code(*code_args)
return new.function(codeobj, {'__funcname__': name, '__builtins__': __builtins__}, name)
def make_instance_method(self, name, instanceobj):
method = self._build_function(name)
return new.instancemethod(method, instanceobj, type(instanceobj))
def make_class_method(self, name, classobj):
method = self._build_function(name)
return new.instancemethod(method, None, classobj)
def _not_implemented(self, *args, **kwargs):
class_name = self.__class__.__name__
funcname = __funcname__
raise NotImplementedError, "%(class_name)s.%(funcname)s" % locals()
not_implemented_factory = MethodFactory(_not_implemented)
make_not_implemented_class_method = not_implemented_factory.make_class_method
del _not_implemented, not_implemented_factory
def handle_kwargs(kwargs, *required, **optional):
result = {}
result.update(optional)
required_args = dict([(x, None) for x in required])
for kwarg_key, kwarg_value in kwargs.iteritems():
if optional.has_key(kwarg_key):
pass
else:
try:
required_args.pop(kwarg_key)
except KeyError:
raise TypeError, "unexpected keyword argument: %r" % kwarg_key
result[kwarg_key] = kwarg_value
if required_args:
missing_key = required_args.popitem()[0]
raise TypeError, "missing keyword argument: %r" % missing_key
return result
class Sentinel(object):
def __init__(self, value):
self.value = value
def __str__(self):
return str(self.value)
def __repr__(self):
return '<sentinel object (%r) at 0x%08X>' % (self.value, id(self))