ladybird/Tests/AK/TestBitStream.cpp
Martin Janiczek d52ffcd830 LibTest: Add more numeric generators
Rename unsigned_int generator to number_u32.
Add generators:
- number_u64
- number_f64
- percentage
2024-01-12 16:42:51 -07:00

288 lines
9.8 KiB
C++

/*
* Copyright (c) 2023, Tim Schumacher <timschumi@gmx.de>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/BitStream.h>
#include <AK/MemoryStream.h>
#include <LibTest/TestCase.h>
using namespace Test::Randomized;
// Note: This does not do any checks on the internal representation, it just ensures that the behavior of the input and output streams match.
TEST_CASE(little_endian_bit_stream_input_output_match)
{
auto memory_stream = make<AllocatingMemoryStream>();
// Note: The bit stream only ever reads from/writes to the underlying stream in one byte chunks,
// so testing with sizes that will not trigger a write will yield unexpected results.
LittleEndianOutputBitStream bit_write_stream { MaybeOwned<Stream>(*memory_stream) };
LittleEndianInputBitStream bit_read_stream { MaybeOwned<Stream>(*memory_stream) };
// Test two mirrored chunks of a fully mirrored pattern to check that we are not dropping bits.
{
MUST(bit_write_stream.write_bits(0b1111u, 4));
MUST(bit_write_stream.write_bits(0b1111u, 4));
MUST(bit_write_stream.flush_buffer_to_stream());
auto result = MUST(bit_read_stream.read_bits(4));
EXPECT_EQ(0b1111u, result);
result = MUST(bit_read_stream.read_bits(4));
EXPECT_EQ(0b1111u, result);
}
{
MUST(bit_write_stream.write_bits(0b0000u, 4));
MUST(bit_write_stream.write_bits(0b0000u, 4));
MUST(bit_write_stream.flush_buffer_to_stream());
auto result = MUST(bit_read_stream.read_bits(4));
EXPECT_EQ(0b0000u, result);
result = MUST(bit_read_stream.read_bits(4));
EXPECT_EQ(0b0000u, result);
}
// Test two mirrored chunks of a non-mirrored pattern to check that we are writing bits within a pattern in the correct order.
{
MUST(bit_write_stream.write_bits(0b1000u, 4));
MUST(bit_write_stream.write_bits(0b1000u, 4));
MUST(bit_write_stream.flush_buffer_to_stream());
auto result = MUST(bit_read_stream.read_bits(4));
EXPECT_EQ(0b1000u, result);
result = MUST(bit_read_stream.read_bits(4));
EXPECT_EQ(0b1000u, result);
}
// Test two different chunks to check that we are not confusing their order.
{
MUST(bit_write_stream.write_bits(0b1000u, 4));
MUST(bit_write_stream.write_bits(0b0100u, 4));
MUST(bit_write_stream.flush_buffer_to_stream());
auto result = MUST(bit_read_stream.read_bits(4));
EXPECT_EQ(0b1000u, result);
result = MUST(bit_read_stream.read_bits(4));
EXPECT_EQ(0b0100u, result);
}
// Test a pattern that spans multiple bytes.
{
MUST(bit_write_stream.write_bits(0b1101001000100001u, 16));
MUST(bit_write_stream.flush_buffer_to_stream());
auto result = MUST(bit_read_stream.read_bits(16));
EXPECT_EQ(0b1101001000100001u, result);
}
}
// Note: This does not do any checks on the internal representation, it just ensures that the behavior of the input and output streams match.
TEST_CASE(big_endian_bit_stream_input_output_match)
{
auto memory_stream = make<AllocatingMemoryStream>();
// Note: The bit stream only ever reads from/writes to the underlying stream in one byte chunks,
// so testing with sizes that will not trigger a write will yield unexpected results.
BigEndianOutputBitStream bit_write_stream { MaybeOwned<Stream>(*memory_stream) };
BigEndianInputBitStream bit_read_stream { MaybeOwned<Stream>(*memory_stream) };
// Test two mirrored chunks of a fully mirrored pattern to check that we are not dropping bits.
{
MUST(bit_write_stream.write_bits(0b1111u, 4));
MUST(bit_write_stream.write_bits(0b1111u, 4));
auto result = MUST(bit_read_stream.read_bits(4));
EXPECT_EQ(0b1111u, result);
result = MUST(bit_read_stream.read_bits(4));
EXPECT_EQ(0b1111u, result);
}
{
MUST(bit_write_stream.write_bits(0b0000u, 4));
MUST(bit_write_stream.write_bits(0b0000u, 4));
auto result = MUST(bit_read_stream.read_bits(4));
EXPECT_EQ(0b0000u, result);
result = MUST(bit_read_stream.read_bits(4));
EXPECT_EQ(0b0000u, result);
}
// Test two mirrored chunks of a non-mirrored pattern to check that we are writing bits within a pattern in the correct order.
{
MUST(bit_write_stream.write_bits(0b1000u, 4));
MUST(bit_write_stream.write_bits(0b1000u, 4));
auto result = MUST(bit_read_stream.read_bits(4));
EXPECT_EQ(0b1000u, result);
result = MUST(bit_read_stream.read_bits(4));
EXPECT_EQ(0b1000u, result);
}
// Test two different chunks to check that we are not confusing their order.
{
MUST(bit_write_stream.write_bits(0b1000u, 4));
MUST(bit_write_stream.write_bits(0b0100u, 4));
auto result = MUST(bit_read_stream.read_bits(4));
EXPECT_EQ(0b1000u, result);
result = MUST(bit_read_stream.read_bits(4));
EXPECT_EQ(0b0100u, result);
}
// Test a pattern that spans multiple bytes.
{
MUST(bit_write_stream.write_bits(0b1101001000100001u, 16));
auto result = MUST(bit_read_stream.read_bits(16));
EXPECT_EQ(0b1101001000100001u, result);
}
}
TEST_CASE(bit_reads_beyond_stream_limits)
{
Array<u8, 1> const test_data { 0xFF };
{
auto memory_stream = make<FixedMemoryStream>(test_data);
auto bit_stream = make<LittleEndianInputBitStream>(move(memory_stream), LittleEndianInputBitStream::UnsatisfiableReadBehavior::Reject);
{
auto result = TRY_OR_FAIL(bit_stream->read_bits<u8>(6));
EXPECT_EQ(result, 0b111111);
}
{
auto result = bit_stream->read_bits<u8>(6);
EXPECT(result.is_error());
}
{
auto result = bit_stream->read_bits<u8>(6);
EXPECT(result.is_error());
}
}
{
// LittleEndianInputBitStream allows reading null bits beyond the original data
// for compatibility purposes if enabled.
auto memory_stream = make<FixedMemoryStream>(test_data);
auto bit_stream = make<LittleEndianInputBitStream>(move(memory_stream), LittleEndianInputBitStream::UnsatisfiableReadBehavior::FillWithZero);
{
auto result = TRY_OR_FAIL(bit_stream->read_bits<u8>(6));
EXPECT_EQ(result, 0b111111);
}
{
auto result = TRY_OR_FAIL(bit_stream->read_bits<u8>(6));
EXPECT_EQ(result, 0b000011);
}
{
auto result = TRY_OR_FAIL(bit_stream->read_bits<u8>(6));
EXPECT_EQ(result, 0b000000);
}
}
{
auto memory_stream = make<FixedMemoryStream>(test_data);
auto bit_stream = make<BigEndianInputBitStream>(move(memory_stream));
{
auto result = TRY_OR_FAIL(bit_stream->read_bits<u8>(6));
EXPECT_EQ(result, 0b111111);
}
{
auto result = bit_stream->read_bits<u8>(6);
EXPECT(result.is_error());
}
{
auto result = bit_stream->read_bits<u8>(6);
EXPECT(result.is_error());
}
}
}
RANDOMIZED_TEST_CASE(roundtrip_u8_little_endian)
{
GEN(n, Gen::number_u64(NumericLimits<u8>::max()));
auto memory_stream = make<AllocatingMemoryStream>();
LittleEndianOutputBitStream sut_write { MaybeOwned<Stream>(*memory_stream) };
LittleEndianInputBitStream sut_read { MaybeOwned<Stream>(*memory_stream) };
MUST(sut_write.write_bits(n, 8));
MUST(sut_write.flush_buffer_to_stream());
auto result = MUST(sut_read.read_bits<u64>(8));
EXPECT_EQ(result, n);
}
RANDOMIZED_TEST_CASE(roundtrip_u16_little_endian)
{
GEN(n, Gen::number_u64(NumericLimits<u16>::max()));
auto memory_stream = make<AllocatingMemoryStream>();
LittleEndianOutputBitStream sut_write { MaybeOwned<Stream>(*memory_stream) };
LittleEndianInputBitStream sut_read { MaybeOwned<Stream>(*memory_stream) };
MUST(sut_write.write_bits(n, 16));
MUST(sut_write.flush_buffer_to_stream());
auto result = MUST(sut_read.read_bits<u64>(16));
EXPECT_EQ(result, n);
}
RANDOMIZED_TEST_CASE(roundtrip_u32_little_endian)
{
GEN(n, Gen::number_u64(NumericLimits<u32>::max()));
auto memory_stream = make<AllocatingMemoryStream>();
LittleEndianOutputBitStream sut_write { MaybeOwned<Stream>(*memory_stream) };
LittleEndianInputBitStream sut_read { MaybeOwned<Stream>(*memory_stream) };
MUST(sut_write.write_bits(n, 32));
MUST(sut_write.flush_buffer_to_stream());
auto result = MUST(sut_read.read_bits<u64>(32));
EXPECT_EQ(result, n);
}
RANDOMIZED_TEST_CASE(roundtrip_u8_big_endian)
{
GEN(n, Gen::number_u64(NumericLimits<u8>::max()));
auto memory_stream = make<AllocatingMemoryStream>();
BigEndianOutputBitStream sut_write { MaybeOwned<Stream>(*memory_stream) };
BigEndianInputBitStream sut_read { MaybeOwned<Stream>(*memory_stream) };
MUST(sut_write.write_bits(n, 8));
auto result = MUST(sut_read.read_bits<u64>(8));
EXPECT_EQ(result, n);
}
RANDOMIZED_TEST_CASE(roundtrip_u16_big_endian)
{
GEN(n, Gen::number_u64(NumericLimits<u16>::max()));
auto memory_stream = make<AllocatingMemoryStream>();
BigEndianOutputBitStream sut_write { MaybeOwned<Stream>(*memory_stream) };
BigEndianInputBitStream sut_read { MaybeOwned<Stream>(*memory_stream) };
MUST(sut_write.write_bits(n, 16));
auto result = MUST(sut_read.read_bits<u64>(16));
EXPECT_EQ(result, n);
}
RANDOMIZED_TEST_CASE(roundtrip_u32_big_endian)
{
GEN(n, Gen::number_u64(NumericLimits<u32>::max()));
auto memory_stream = make<AllocatingMemoryStream>();
BigEndianOutputBitStream sut_write { MaybeOwned<Stream>(*memory_stream) };
BigEndianInputBitStream sut_read { MaybeOwned<Stream>(*memory_stream) };
MUST(sut_write.write_bits(n, 32));
auto result = MUST(sut_read.read_bits<u64>(32));
EXPECT_EQ(result, n);
}