diff options
Diffstat (limited to 'Tests/AK/TestBitStream.cpp')
| -rw-r--r-- | Tests/AK/TestBitStream.cpp | 121 |
1 files changed, 121 insertions, 0 deletions
diff --git a/Tests/AK/TestBitStream.cpp b/Tests/AK/TestBitStream.cpp new file mode 100644 index 0000000000..0316ae863e --- /dev/null +++ b/Tests/AK/TestBitStream.cpp @@ -0,0 +1,121 @@ +/* + * Copyright (c) 2023, Tim Schumacher <timschumi@gmx.de> + * + * SPDX-License-Identifier: BSD-2-Clause + */ + +#include <AK/BitStream.h> +#include <LibCore/MemoryStream.h> +#include <LibTest/TestCase.h> + +// 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<Core::Stream::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. + auto bit_write_stream = MUST(LittleEndianOutputBitStream::construct(MaybeOwned<AK::Stream>(*memory_stream))); + auto bit_read_stream = MUST(LittleEndianInputBitStream::construct(MaybeOwned<AK::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); + } +} + +// 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<Core::Stream::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. + auto bit_write_stream = MUST(BigEndianOutputBitStream::construct(MaybeOwned<AK::Stream>(*memory_stream))); + auto bit_read_stream = MUST(BigEndianInputBitStream::construct(MaybeOwned<AK::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); + } +} |