ladybird/Tests/AK/TestCircularBuffer.cpp
Lucas CHOLLET 3b824ec8c9 AK+Test: Fix a logic error in CircularBuffer::offset_of()
This error was introduced by 9a7accdd and had a significant impact on
`BufferedFile` behavior. Hence, we started seeing crash in test262.

By itself, the issue was a wrong calculation of the internal reading
spans when using the `read` and `until` parameters. Which can lead to
at worse crash in VERIFY and at least weird behaviors as missed needles
or detections out of bounds.

It was also accompanied by an erroneous test.

This patch fixes the bug, the test and also provides more tests.
2023-01-15 23:23:24 +00:00

351 lines
9.2 KiB
C++

/*
* Copyright (c) 2022, Lucas Chollet <lucas.chollet@free.fr>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <LibTest/TestCase.h>
#include <AK/CircularBuffer.h>
namespace {
CircularBuffer create_circular_buffer(size_t size)
{
auto buffer_or_error = CircularBuffer::create_empty(size);
EXPECT(!buffer_or_error.is_error());
return buffer_or_error.release_value();
}
void safe_write(CircularBuffer& buffer, u8 i)
{
Bytes b { &i, 1 };
auto written_bytes = buffer.write(b);
EXPECT_EQ(written_bytes, 1ul);
};
void safe_read(CircularBuffer& buffer, u8 supposed_result)
{
u8 read_value {};
Bytes b { &read_value, 1 };
b = buffer.read(b);
EXPECT_EQ(b.size(), 1ul);
EXPECT_EQ(*b.data(), supposed_result);
};
void safe_discard(CircularBuffer& buffer, size_t size)
{
auto result = buffer.discard(size);
EXPECT(!result.is_error());
};
}
TEST_CASE(simple_write_read)
{
auto buffer = create_circular_buffer(1);
safe_write(buffer, 42);
safe_read(buffer, 42);
}
TEST_CASE(writing_above_limits)
{
auto buffer = create_circular_buffer(1);
safe_write(buffer, 1);
u8 value = 42;
Bytes b { &value, 1 };
auto written_bytes = buffer.write(b);
EXPECT_EQ(written_bytes, 0ul);
}
TEST_CASE(usage_with_wrapping_around)
{
constexpr size_t capacity = 3;
auto buffer = create_circular_buffer(capacity);
for (unsigned i {}; i < capacity; ++i)
safe_write(buffer, i + 8);
EXPECT_EQ(buffer.used_space(), capacity);
EXPECT_EQ(buffer.empty_space(), 0ul);
safe_read(buffer, 0 + 8);
safe_read(buffer, 1 + 8);
EXPECT_EQ(buffer.used_space(), capacity - 2);
safe_write(buffer, 5);
safe_write(buffer, 6);
EXPECT_EQ(buffer.used_space(), capacity);
safe_read(buffer, 10);
safe_read(buffer, 5);
safe_read(buffer, 6);
EXPECT_EQ(buffer.used_space(), 0ul);
}
TEST_CASE(full_read_aligned)
{
constexpr size_t capacity = 3;
auto buffer = create_circular_buffer(capacity);
for (unsigned i {}; i < capacity; ++i)
safe_write(buffer, i);
EXPECT_EQ(buffer.used_space(), capacity);
EXPECT_EQ(buffer.empty_space(), 0ul);
u8 const source[] = { 0, 1, 2 };
u8 result[] = { 0, 0, 0 };
auto const bytes_or_error = buffer.read({ result, 3 });
EXPECT_EQ(bytes_or_error.size(), 3ul);
EXPECT_EQ(memcmp(source, result, 3), 0);
}
TEST_CASE(full_read_non_aligned)
{
constexpr size_t capacity = 3;
auto buffer = create_circular_buffer(capacity);
for (unsigned i {}; i < capacity; ++i)
safe_write(buffer, i + 5);
safe_read(buffer, 5);
safe_write(buffer, 42);
EXPECT_EQ(buffer.used_space(), capacity);
EXPECT_EQ(buffer.empty_space(), 0ul);
u8 result[] = { 0, 0, 0 };
auto const bytes = buffer.read({ result, 3 });
EXPECT_EQ(bytes.size(), 3ul);
u8 const source[] = { 6, 7, 42 };
EXPECT_EQ(memcmp(source, result, 3), 0);
}
TEST_CASE(full_write_aligned)
{
constexpr size_t capacity = 3;
auto buffer = create_circular_buffer(capacity);
u8 const source[] = { 12, 13, 14 };
auto written_bytes = buffer.write({ source, 3 });
EXPECT_EQ(written_bytes, 3ul);
EXPECT_EQ(buffer.used_space(), capacity);
EXPECT_EQ(buffer.empty_space(), 0ul);
for (unsigned i {}; i < capacity; ++i)
safe_read(buffer, i + 12);
EXPECT_EQ(buffer.used_space(), 0ul);
}
TEST_CASE(full_write_non_aligned)
{
constexpr size_t capacity = 3;
auto buffer = create_circular_buffer(capacity);
safe_write(buffer, 10);
safe_read(buffer, 10);
u8 const source[] = { 12, 13, 14 };
auto written_bytes = buffer.write({ source, 3 });
EXPECT_EQ(written_bytes, 3ul);
EXPECT_EQ(buffer.used_space(), capacity);
EXPECT_EQ(buffer.empty_space(), 0ul);
for (unsigned i {}; i < capacity; ++i)
safe_read(buffer, i + 12);
EXPECT_EQ(buffer.used_space(), 0ul);
}
TEST_CASE(create_from_bytebuffer)
{
u8 const source[] = { 2, 4, 6 };
auto byte_buffer_or_error = ByteBuffer::copy(source, AK::array_size(source));
EXPECT(!byte_buffer_or_error.is_error());
auto byte_buffer = byte_buffer_or_error.release_value();
auto circular_buffer_or_error = CircularBuffer::create_initialized(move(byte_buffer));
EXPECT(!circular_buffer_or_error.is_error());
auto circular_buffer = circular_buffer_or_error.release_value();
EXPECT_EQ(circular_buffer.used_space(), circular_buffer.capacity());
EXPECT_EQ(circular_buffer.used_space(), 3ul);
safe_read(circular_buffer, 2);
safe_read(circular_buffer, 4);
safe_read(circular_buffer, 6);
}
TEST_CASE(discard)
{
constexpr size_t capacity = 3;
auto buffer = create_circular_buffer(capacity);
safe_write(buffer, 11);
safe_write(buffer, 12);
safe_discard(buffer, 1);
safe_read(buffer, 12);
EXPECT_EQ(buffer.used_space(), 0ul);
EXPECT_EQ(buffer.empty_space(), capacity);
}
TEST_CASE(discard_on_edge)
{
constexpr size_t capacity = 3;
auto buffer = create_circular_buffer(capacity);
safe_write(buffer, 11);
safe_write(buffer, 12);
safe_write(buffer, 13);
safe_discard(buffer, 2);
safe_write(buffer, 14);
safe_write(buffer, 15);
safe_discard(buffer, 2);
safe_read(buffer, 15);
EXPECT_EQ(buffer.used_space(), 0ul);
EXPECT_EQ(buffer.empty_space(), capacity);
}
TEST_CASE(discard_too_much)
{
constexpr size_t capacity = 3;
auto buffer = create_circular_buffer(capacity);
safe_write(buffer, 11);
safe_write(buffer, 12);
safe_discard(buffer, 2);
auto result = buffer.discard(2);
EXPECT(result.is_error());
}
TEST_CASE(offset_of)
{
auto const source = "Well Hello Friends!"sv;
auto byte_buffer_or_error = ByteBuffer::copy(source.bytes());
EXPECT(!byte_buffer_or_error.is_error());
auto byte_buffer = byte_buffer_or_error.release_value();
auto circular_buffer_or_error = CircularBuffer::create_initialized(byte_buffer);
EXPECT(!circular_buffer_or_error.is_error());
auto circular_buffer = circular_buffer_or_error.release_value();
auto result = circular_buffer.offset_of("Well"sv);
EXPECT(result.has_value());
EXPECT_EQ(result.value(), 0ul);
result = circular_buffer.offset_of("Hello"sv);
EXPECT(result.has_value());
EXPECT_EQ(result.value(), 5ul);
safe_discard(circular_buffer, 5);
auto written_bytes = circular_buffer.write(byte_buffer.span().trim(5));
EXPECT_EQ(written_bytes, 5ul);
result = circular_buffer.offset_of("!Well"sv);
EXPECT(result.has_value());
EXPECT_EQ(result.value(), 13ul);
result = circular_buffer.offset_of("!Well"sv, {}, 12);
EXPECT(!result.has_value());
result = circular_buffer.offset_of("e"sv, 2);
EXPECT(result.has_value());
EXPECT_EQ(result.value(), 9ul);
}
TEST_CASE(offset_of_with_until_and_after)
{
auto const source = "Well Hello Friends!"sv;
auto byte_buffer_or_error = ByteBuffer::copy(source.bytes());
EXPECT(!byte_buffer_or_error.is_error());
auto byte_buffer = byte_buffer_or_error.release_value();
auto circular_buffer_or_error = CircularBuffer::create_initialized(byte_buffer);
EXPECT(!circular_buffer_or_error.is_error());
auto circular_buffer = circular_buffer_or_error.release_value();
auto result = circular_buffer.offset_of("Well Hello Friends!"sv, 0, 19);
EXPECT_EQ(result.value_or(42), 0ul);
result = circular_buffer.offset_of(" Hello"sv, 4, 10);
EXPECT_EQ(result.value_or(42), 4ul);
result = circular_buffer.offset_of("el"sv, 3, 10);
EXPECT_EQ(result.value_or(42), 6ul);
safe_discard(circular_buffer, 5);
auto written_bytes = circular_buffer.write(byte_buffer.span().trim(5));
EXPECT_EQ(written_bytes, 5ul);
result = circular_buffer.offset_of("Hello Friends!Well "sv, 0, 19);
EXPECT_EQ(result.value_or(42), 0ul);
result = circular_buffer.offset_of("o Frie"sv, 4, 10);
EXPECT_EQ(result.value_or(42), 4ul);
result = circular_buffer.offset_of("el"sv, 3, 17);
EXPECT_EQ(result.value_or(42), 15ul);
}
TEST_CASE(offset_of_with_until_and_after_wrapping_around)
{
auto const source = "Well Hello Friends!"sv;
auto byte_buffer_or_error = ByteBuffer::copy(source.bytes());
EXPECT(!byte_buffer_or_error.is_error());
auto byte_buffer = byte_buffer_or_error.release_value();
auto circular_buffer_or_error = CircularBuffer::create_empty(19);
EXPECT(!circular_buffer_or_error.is_error());
auto circular_buffer = circular_buffer_or_error.release_value();
auto written_bytes = circular_buffer.write(byte_buffer.span().trim(5));
EXPECT_EQ(written_bytes, 5ul);
auto result = circular_buffer.offset_of("Well "sv, 0, 5);
EXPECT_EQ(result.value_or(42), 0ul);
written_bytes = circular_buffer.write(byte_buffer.span().slice(5));
EXPECT_EQ(written_bytes, 14ul);
result = circular_buffer.offset_of("Hello Friends!"sv, 5, 19);
EXPECT_EQ(result.value_or(42), 5ul);
safe_discard(circular_buffer, 5);
result = circular_buffer.offset_of("Hello Friends!"sv, 0, 14);
EXPECT_EQ(result.value_or(42), 0ul);
written_bytes = circular_buffer.write(byte_buffer.span().trim(5));
EXPECT_EQ(written_bytes, 5ul);
result = circular_buffer.offset_of("Well "sv, 14, 19);
EXPECT_EQ(result.value_or(42), 14ul);
}