#!/usr/bin/python # # Copyright 2016 The Android Open Source Project # # 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 # # http://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. import unittest import cstruct # These aren't constants, they're classes. So, pylint: disable=invalid-name TestStructA = cstruct.Struct("TestStructA", "=BI", "byte1 int2") TestStructB = cstruct.Struct("TestStructB", "=BI", "byte1 int2") class CstructTest(unittest.TestCase): def CheckEquals(self, a, b): self.assertEqual(a, b) self.assertEqual(b, a) assert a == b assert b == a assert not (a != b) # pylint: disable=g-comparison-negation,superfluous-parens assert not (b != a) # pylint: disable=g-comparison-negation,superfluous-parens def CheckNotEquals(self, a, b): self.assertNotEqual(a, b) self.assertNotEqual(b, a) assert a != b assert b != a assert not (a == b) # pylint: disable=g-comparison-negation,superfluous-parens assert not (b == a) # pylint: disable=g-comparison-negation,superfluous-parens def testEqAndNe(self): a1 = TestStructA((1, 2)) a2 = TestStructA((2, 3)) a3 = TestStructA((1, 2)) b = TestStructB((1, 2)) self.CheckNotEquals(a1, b) self.CheckNotEquals(a2, b) self.CheckNotEquals(a1, a2) self.CheckNotEquals(a2, a3) for i in [a1, a2, a3, b]: self.CheckEquals(i, i) self.CheckEquals(a1, a3) def testNestedStructs(self): Nested = cstruct.Struct("Nested", "!HSSi", "word1 nest2 nest3 int4", [TestStructA, TestStructB]) DoubleNested = cstruct.Struct("DoubleNested", "SSB", "nest1 nest2 byte3", [TestStructA, Nested]) d = DoubleNested((TestStructA((1, 2)), Nested((5, TestStructA((3, 4)), TestStructB((7, 8)), 9)), 6)) expectedlen = (len(TestStructA) + 2 + len(TestStructA) + len(TestStructB) + 4 + 1) self.assertEqual(expectedlen, len(DoubleNested)) self.assertEqual(7, d.nest2.nest3.byte1) d.byte3 = 252 d.nest2.word1 = 33214 n = d.nest2 n.int4 = -55 t = n.nest3 t.int2 = 33627591 self.assertEqual(33627591, d.nest2.nest3.int2) expected = ( "DoubleNested(nest1=TestStructA(byte1=1, int2=2)," " nest2=Nested(word1=33214, nest2=TestStructA(byte1=3, int2=4)," " nest3=TestStructB(byte1=7, int2=33627591), int4=-55), byte3=252)") self.assertEqual(expected, str(d)) expected = ("01" "02000000" "81be" "03" "04000000" "07" "c71d0102" "ffffffc9" "fc").decode("hex") self.assertEqual(expected, d.Pack()) unpacked = DoubleNested(expected) self.CheckEquals(unpacked, d) def testNullTerminatedStrings(self): TestStruct = cstruct.Struct("TestStruct", "B16si16AH", "byte1 string2 int3 ascii4 word5") nullstr = "hello" + (16 - len("hello")) * "\x00" t = TestStruct((2, nullstr, 12345, nullstr, 33210)) expected = ("TestStruct(byte1=2, string2=68656c6c6f0000000000000000000000," " int3=12345, ascii4=hello, word5=33210)") self.assertEqual(expected, str(t)) embeddednull = "hello\x00visible123" t = TestStruct((2, embeddednull, 12345, embeddednull, 33210)) expected = ("TestStruct(byte1=2, string2=68656c6c6f0076697369626c65313233," " int3=12345, ascii4=hello\x00visible123, word5=33210)") self.assertEqual(expected, str(t)) def testZeroInitialization(self): TestStruct = cstruct.Struct("TestStruct", "B16si16AH", "byte1 string2 int3 ascii4 word5") t = TestStruct() self.assertEqual(0, t.byte1) self.assertEqual("\x00" * 16, t.string2) self.assertEqual(0, t.int3) self.assertEqual("\x00" * 16, t.ascii4) self.assertEqual(0, t.word5) self.assertEqual("\x00" * len(TestStruct), t.Pack()) def testKeywordInitialization(self): TestStruct = cstruct.Struct("TestStruct", "=B16sIH", "byte1 string2 int3 word4") text = "hello world! ^_^" text_bytes = text.encode("hex") # Populate all fields t1 = TestStruct(byte1=1, string2=text, int3=0xFEDCBA98, word4=0x1234) expected = ("01" + text_bytes + "98BADCFE" "3412").decode("hex") self.assertEqual(expected, t1.Pack()) # Partially populated t1 = TestStruct(string2=text, word4=0x1234) expected = ("00" + text_bytes + "00000000" "3412").decode("hex") self.assertEqual(expected, t1.Pack()) def testCstructOffset(self): TestStruct = cstruct.Struct("TestStruct", "B16si16AH", "byte1 string2 int3 ascii4 word5") nullstr = "hello" + (16 - len("hello")) * "\x00" t = TestStruct((2, nullstr, 12345, nullstr, 33210)) self.assertEqual(0, t.offset("byte1")) self.assertEqual(1, t.offset("string2")) # sizeof(byte) self.assertEqual(17, t.offset("int3")) # sizeof(byte) + 16*sizeof(char) # The integer is automatically padded by the struct module # to match native alignment. # offset = sizeof(byte) + 16*sizeof(char) + padding + sizeof(int) self.assertEqual(24, t.offset("ascii4")) self.assertEqual(40, t.offset("word5")) self.assertRaises(KeyError, t.offset, "random") # TODO: Add support for nested struct offset Nested = cstruct.Struct("Nested", "!HSSi", "word1 nest2 nest3 int4", [TestStructA, TestStructB]) DoubleNested = cstruct.Struct("DoubleNested", "SSB", "nest1 nest2 byte3", [TestStructA, Nested]) d = DoubleNested((TestStructA((1, 2)), Nested((5, TestStructA((3, 4)), TestStructB((7, 8)), 9)), 6)) self.assertEqual(0, d.offset("nest1")) self.assertEqual(len(TestStructA), d.offset("nest2")) self.assertEqual(len(TestStructA) + len(Nested), d.offset("byte3")) self.assertRaises(KeyError, t.offset, "word1") def testDefinitionFieldMismatch(self): cstruct.Struct("TestA", "=BI", "byte1 int2") cstruct.Struct("TestA", "=BxxxxxIx", "byte1 int2") with self.assertRaises(ValueError): cstruct.Struct("TestA", "=B", "byte1 int2") with self.assertRaises(ValueError): cstruct.Struct("TestA", "=BI", "byte1") Nested = cstruct.Struct("Nested", "!II", "int1 int2") cstruct.Struct("TestB", "=BSI", "byte1 nest2 int3", [Nested]) cstruct.Struct("TestB", "=BxSxIx", "byte1 nest2 int3", [Nested]) with self.assertRaises(ValueError): cstruct.Struct("TestB", "=BSI", "byte1 int3", [Nested]) with self.assertRaises(ValueError): cstruct.Struct("TestB", "=BSI", "byte1 nest2", [Nested]) cstruct.Struct("TestC", "=BSSI", "byte1 nest2 nest3 int4", [Nested, Nested]) with self.assertRaises(ValueError): cstruct.Struct("TestC", "=BSSI", "byte1 nest2 int4", [Nested, Nested]) if __name__ == "__main__": unittest.main()