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/*
* Copyright (C) 2018 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.
*/
#include "bit_memory_region.h"
#include "gtest/gtest.h"
namespace art {
static void CheckBits(uint8_t* data,
size_t size,
uint32_t init,
size_t offset,
size_t length,
uint32_t value) {
for (size_t i = 0; i < size * kBitsPerByte; i++) {
uint8_t expected = (offset <= i && i < offset + length) ? value >> (i - offset) : init;
uint8_t actual = data[i / kBitsPerByte] >> (i % kBitsPerByte);
EXPECT_EQ(expected & 1, actual & 1);
}
}
TEST(BitMemoryRegion, TestVarint) {
for (size_t start_bit_offset = 0; start_bit_offset <= 32; start_bit_offset++) {
uint32_t values[] = { 0, 1, 11, 12, 15, 16, 255, 256, 1u << 16, 1u << 24, ~1u, ~0u };
for (uint32_t value : values) {
std::vector<uint8_t> buffer;
BitMemoryWriter<std::vector<uint8_t>> writer(&buffer, start_bit_offset);
writer.WriteVarint(value);
BitMemoryReader reader(buffer.data(), start_bit_offset);
uint32_t result = reader.ReadVarint();
uint32_t upper_bound = RoundUp(MinimumBitsToStore(value), kBitsPerByte) + kVarintBits;
EXPECT_EQ(writer.NumberOfWrittenBits(), reader.NumberOfReadBits());
EXPECT_EQ(value, result);
EXPECT_GE(upper_bound, writer.NumberOfWrittenBits());
}
}
}
TEST(BitMemoryRegion, TestBit) {
uint8_t data[sizeof(uint32_t) * 2];
for (size_t bit_offset = 0; bit_offset < 2 * sizeof(uint32_t) * kBitsPerByte; ++bit_offset) {
for (uint32_t initial_value = 0; initial_value <= 1; initial_value++) {
for (uint32_t value = 0; value <= 1; value++) {
// Check Store and Load with bit_offset set on the region.
std::fill_n(data, sizeof(data), initial_value * 0xFF);
BitMemoryRegion bmr1(MemoryRegion(&data, sizeof(data)), bit_offset, 1);
bmr1.StoreBit(0, value);
EXPECT_EQ(bmr1.LoadBit(0), value);
CheckBits(data, sizeof(data), initial_value, bit_offset, 1, value);
// Check Store and Load with bit_offset set on the methods.
std::fill_n(data, sizeof(data), initial_value * 0xFF);
BitMemoryRegion bmr2(MemoryRegion(&data, sizeof(data)));
bmr2.StoreBit(bit_offset, value);
EXPECT_EQ(bmr2.LoadBit(bit_offset), value);
CheckBits(data, sizeof(data), initial_value, bit_offset, 1, value);
}
}
}
}
TEST(BitMemoryRegion, TestBits) {
uint8_t data[sizeof(uint32_t) * 4];
for (size_t bit_offset = 0; bit_offset < 3 * sizeof(uint32_t) * kBitsPerByte; ++bit_offset) {
uint32_t mask = 0;
for (size_t bit_length = 0; bit_length < sizeof(uint32_t) * kBitsPerByte; ++bit_length) {
const uint32_t value = 0xDEADBEEF & mask;
for (uint32_t initial_value = 0; initial_value <= 1; initial_value++) {
// Check Store and Load with bit_offset set on the region.
std::fill_n(data, sizeof(data), initial_value * 0xFF);
BitMemoryRegion bmr1(MemoryRegion(&data, sizeof(data)), bit_offset, bit_length);
bmr1.StoreBits(0, value, bit_length);
EXPECT_EQ(bmr1.LoadBits(0, bit_length), value);
CheckBits(data, sizeof(data), initial_value, bit_offset, bit_length, value);
// Check Store and Load with bit_offset set on the methods.
std::fill_n(data, sizeof(data), initial_value * 0xFF);
BitMemoryRegion bmr2(MemoryRegion(&data, sizeof(data)));
bmr2.StoreBits(bit_offset, value, bit_length);
EXPECT_EQ(bmr2.LoadBits(bit_offset, bit_length), value);
CheckBits(data, sizeof(data), initial_value, bit_offset, bit_length, value);
}
mask = (mask << 1) | 1;
}
}
}
} // namespace art