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#include "cru/common/Buffer.h"
#include "cru/common/Exception.h"
#include <cstring>
namespace cru {
namespace {
void CheckSize(Index size) {
if (size < 0) {
throw Exception(u"Size of buffer can't be smaller than 0.");
}
}
} // namespace
Buffer::Buffer(Index size) {
CheckSize(size);
if (size == 0) {
ptr_ = nullptr;
size_ = used_begin_ = used_end_ = 0;
} else {
ptr_ = new std::byte[size];
size_ = size;
used_begin_ = used_end_ = 0;
}
}
Buffer::Buffer(const Buffer& other) { Copy_(other); }
Buffer::Buffer(Buffer&& other) noexcept { Move_(std::move(other)); }
Buffer& Buffer::operator=(const Buffer& other) {
if (this != &other) {
Delete_();
Copy_(other);
}
return *this;
}
Buffer& Buffer::operator=(Buffer&& other) noexcept {
if (this != &other) {
Delete_();
Move_(std::move(other));
}
return *this;
}
Buffer::~Buffer() { Delete_(); }
void Buffer::AssignBytes(Index dst_offset, std::byte* src, Index src_offset,
Index src_size, bool use_memmove) {
(use_memmove ? std::memmove : std::memcpy)(ptr_ + dst_offset,
src + src_offset, src_size);
}
void Buffer::ResizeBuffer(Index new_size, bool preserve_used) {
if (new_size == 0) {
Delete_();
ptr_ = nullptr;
size_ = used_begin_ = used_end_ = 0;
return;
}
auto old_ptr = ptr_;
ptr_ = new std::byte[new_size];
size_ = new_size;
used_begin_ = std::min(new_size, used_begin_);
used_end_ = std::min(new_size, used_end_);
if (old_ptr) {
if (preserve_used && used_begin_ < used_end_) {
std::memcpy(ptr_ + used_begin_, old_ptr + used_begin_,
used_end_ - used_begin_);
}
delete[] old_ptr;
}
}
Index Buffer::PushFront(std::byte* other, Index other_size, bool use_memmove) {
auto copy_size = std::min(used_begin_, other_size);
if (copy_size) {
used_begin_ -= copy_size;
(use_memmove ? std::memmove : std::memcpy)(ptr_ + used_begin_, other,
copy_size);
}
return copy_size;
}
Index Buffer::PushBack(std::byte* other, Index other_size, bool use_memmove) {
auto copy_size = std::min(size_ - used_end_, other_size);
if (copy_size) {
(use_memmove ? std::memmove : std::memcpy)(ptr_ + used_end_, other,
copy_size);
used_end_ += copy_size;
}
return copy_size;
}
Index Buffer::PopFront(Index size) {
auto move = std::min(used_begin_, size);
used_begin_ -= move;
return move;
}
Index Buffer::PopEnd(Index size) {
auto move = std::min(size_ - used_end_, size);
used_end_ += move;
return move;
}
void Buffer::Copy_(const Buffer& other) {
if (other.ptr_ == nullptr) {
ptr_ = nullptr;
size_ = used_begin_ = used_end_ = 0;
} else {
ptr_ = new std::byte[other.size_];
size_ = other.size_;
used_begin_ = other.used_begin_;
used_end_ = other.used_end_;
std::memcpy(ptr_ + used_begin_, other.ptr_ + used_begin_,
used_end_ - used_begin_);
}
}
void Buffer::Move_(Buffer&& other) noexcept {
ptr_ = other.ptr_;
size_ = other.size_;
used_begin_ = other.used_begin_;
used_end_ = other.used_end_;
other.ptr_ = nullptr;
other.size_ = other.used_begin_ = other.used_end_ = 0;
}
void Buffer::Delete_() noexcept {
if (ptr_) {
delete[] ptr_;
}
}
void swap(Buffer& left, Buffer& right) noexcept {
using std::swap;
swap(left.ptr_, right.ptr_);
swap(left.size_, right.size_);
swap(left.used_begin_, right.used_begin_);
swap(left.used_end_, right.used_end_);
}
} // namespace cru
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