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// Copyright 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.
#pragma once
#include "android/base/Compiler.h"
#include <algorithm>
#include <atomic>
#include <cinttypes>
#include <cstdlib>
#include <cstring>
#include <type_traits>
#include <vector>
#include <stdio.h>
#ifdef _WIN32
#include <malloc.h>
#endif
namespace android {
template <class T, size_t align>
class AlignedBuf {
public:
explicit AlignedBuf(size_t size) {
static_assert(align && ((align & (align - 1)) == 0),
"AlignedBuf only supports power-of-2 aligments.");
resizeImpl(size);
}
AlignedBuf(const AlignedBuf& other) : AlignedBuf(other.mSize) {
if (other.mBuffer) { // could have got moved out
std::copy(other.mBuffer, other.mBuffer + other.mSize, mBuffer);
}
}
AlignedBuf& operator=(const AlignedBuf& other) {
if (this != &other) {
AlignedBuf tmp(other);
*this = std::move(tmp);
}
return *this;
}
AlignedBuf(AlignedBuf&& other) { *this = std::move(other); }
AlignedBuf& operator=(AlignedBuf&& other) {
mBuffer = other.mBuffer;
mSize = other.mSize;
other.mBuffer = nullptr;
other.mSize = 0;
return *this;
}
~AlignedBuf() { if (mBuffer) freeImpl(mBuffer); } // account for getting moved out
void resize(size_t newSize) {
#if (defined(__GNUC__) && !defined(__clang__) && __GNUC__ <= 4) || \
defined(__OLD_STD_VERSION__)
// Older g++ doesn't support std::is_trivially_copyable.
constexpr bool triviallyCopyable =
std::has_trivial_copy_constructor<T>::value;
#else
constexpr bool triviallyCopyable = std::is_trivially_copyable<T>::value;
#endif
static_assert(triviallyCopyable,
"AlignedBuf can only resize trivially copyable values");
resizeImpl(newSize);
}
size_t size() const { return mSize; }
T* data() { return mBuffer; }
T& operator[](size_t index) { return mBuffer[index]; }
const T& operator[](size_t index) const { return mBuffer[index]; }
bool operator==(const AlignedBuf& other) const {
return 0 == std::memcmp(mBuffer, other.mBuffer, sizeof(T) * std::min(mSize, other.mSize));
}
private:
void resizeImpl(size_t newSize) {
if (newSize) {
size_t pad = std::max(align, sizeof(T));
size_t keepSize = std::min(newSize, mSize);
size_t newSizeBytes = ((align - 1 + newSize * sizeof(T) + pad) / align) * align;
std::vector<T> temp(mBuffer, mBuffer + keepSize);
mBuffer = static_cast<T*>(reallocImpl(mBuffer, newSizeBytes));
std::copy(temp.data(), temp.data() + keepSize, mBuffer);
} else {
if (mBuffer) freeImpl(mBuffer);
mBuffer = nullptr;
}
mSize = newSize;
}
void* reallocImpl(void* oldPtr, size_t sizeBytes) {
if (oldPtr) { freeImpl(oldPtr); }
// Platform aligned malloc might not behave right
// if we give it an alignemnt value smaller than sizeof(void*).
size_t actualAlign = std::max(align, sizeof(void*));
#ifdef _WIN32
return _aligned_malloc(sizeBytes, actualAlign);
#else
void* res;
if (posix_memalign(&res, actualAlign, sizeBytes)) {
fprintf(stderr, "%s: failed to alloc aligned memory\n", __func__);
abort();
}
return res;
#endif
}
void freeImpl(void* ptr) {
#ifdef _WIN32
_aligned_free(ptr);
#else
free(ptr);
#endif
}
T* mBuffer = nullptr;
size_t mSize = 0;
};
// Convenience function for aligned malloc across platforms
void* aligned_buf_alloc(size_t align, size_t size);
void aligned_buf_free(void* buf);
} // namespace android