Add google-endpoints to third_party/.

third_party/google-endpoints/rsa/_compat.py

+# -*- coding: utf-8 -*-
+#
+#  Copyright 2011 Sybren A. Stüvel <sybren@stuvel.eu>
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+
+"""Python compatibility wrappers."""
+
+from __future__ import absolute_import
+
+import sys
+from struct import pack
+
+try:
+    MAX_INT = sys.maxsize
+except AttributeError:
+    MAX_INT = sys.maxint
+
+MAX_INT64 = (1 << 63) - 1
+MAX_INT32 = (1 << 31) - 1
+MAX_INT16 = (1 << 15) - 1
+
+# Determine the word size of the processor.
+if MAX_INT == MAX_INT64:
+    # 64-bit processor.
+    MACHINE_WORD_SIZE = 64
+elif MAX_INT == MAX_INT32:
+    # 32-bit processor.
+    MACHINE_WORD_SIZE = 32
+else:
+    # Else we just assume 64-bit processor keeping up with modern times.
+    MACHINE_WORD_SIZE = 64
+
+try:
+    # < Python3
+    unicode_type = unicode
+except NameError:
+    # Python3.
+    unicode_type = str
+
+# Fake byte literals.
+if str is unicode_type:
+    def byte_literal(s):
+        return s.encode('latin1')
+else:
+    def byte_literal(s):
+        return s
+
+# ``long`` is no more. Do type detection using this instead.
+try:
+    integer_types = (int, long)
+except NameError:
+    integer_types = (int,)
+
+b = byte_literal
+
+# To avoid calling b() multiple times in tight loops.
+ZERO_BYTE = b('\x00')
+EMPTY_BYTE = b('')
+
+
+def is_bytes(obj):
+    """
+    Determines whether the given value is a byte string.
+
+    :param obj:
+        The value to test.
+    :returns:
+        ``True`` if ``value`` is a byte string; ``False`` otherwise.
+    """
+    return isinstance(obj, bytes)
+
+
+def is_integer(obj):
+    """
+    Determines whether the given value is an integer.
+
+    :param obj:
+        The value to test.
+    :returns:
+        ``True`` if ``value`` is an integer; ``False`` otherwise.
+    """
+    return isinstance(obj, integer_types)
+
+
+def byte(num):
+    """
+    Converts a number between 0 and 255 (both inclusive) to a base-256 (byte)
+    representation.
+
+    Use it as a replacement for ``chr`` where you are expecting a byte
+    because this will work on all current versions of Python::
+
+    :param num:
+        An unsigned integer between 0 and 255 (both inclusive).
+    :returns:
+        A single byte.
+    """
+    return pack("B", num)
+
+
+def get_word_alignment(num, force_arch=64,
+                       _machine_word_size=MACHINE_WORD_SIZE):
+    """
+    Returns alignment details for the given number based on the platform
+    Python is running on.
+
+    :param num:
+        Unsigned integral number.
+    :param force_arch:
+        If you don't want to use 64-bit unsigned chunks, set this to
+        anything other than 64. 32-bit chunks will be preferred then.
+        Default 64 will be used when on a 64-bit machine.
+    :param _machine_word_size:
+        (Internal) The machine word size used for alignment.
+    :returns:
+        4-tuple::
+
+            (word_bits, word_bytes,
+             max_uint, packing_format_type)
+    """
+    max_uint64 = 0xffffffffffffffff
+    max_uint32 = 0xffffffff
+    max_uint16 = 0xffff
+    max_uint8 = 0xff
+
+    if force_arch == 64 and _machine_word_size >= 64 and num > max_uint32:
+        # 64-bit unsigned integer.
+        return 64, 8, max_uint64, "Q"
+    elif num > max_uint16:
+        # 32-bit unsigned integer
+        return 32, 4, max_uint32, "L"
+    elif num > max_uint8:
+        # 16-bit unsigned integer.
+        return 16, 2, max_uint16, "H"
+    else:
+        # 8-bit unsigned integer.
+        return 8, 1, max_uint8, "B"