blob: 6bb1af900611b3ee64406120a0e5ffcb3a3f70b9 [file] [log] [blame]
// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include <stddef.h>
#include <memory>
#include "absl/strings/string_view.h"
#include "quiche/common/platform/api/quiche_export.h"
#include "quiche/common/platform/api/quiche_iovec.h"
namespace quiche {
// Abstract base class for classes which allocate and delete buffers.
class QUICHE_EXPORT_PRIVATE QuicheBufferAllocator {
virtual ~QuicheBufferAllocator() = default;
// Returns or allocates a new buffer of |size|. Never returns null.
virtual char* New(size_t size) = 0;
// Returns or allocates a new buffer of |size| if |flag_enable| is true.
// Otherwise, returns a buffer that is compatible with this class directly
// with operator new. Never returns null.
virtual char* New(size_t size, bool flag_enable) = 0;
// Releases a buffer.
virtual void Delete(char* buffer) = 0;
// Marks the allocator as being idle. Serves as a hint to notify the allocator
// that it should release any resources it's still holding on to.
virtual void MarkAllocatorIdle() {}
// A deleter that can be used to manage ownership of buffers allocated via
// QuicheBufferAllocator through std::unique_ptr.
class QUICHE_EXPORT_PRIVATE QuicheBufferDeleter {
explicit QuicheBufferDeleter(QuicheBufferAllocator* allocator)
: allocator_(allocator) {}
QuicheBufferAllocator* allocator() { return allocator_; }
void operator()(char* buffer) { allocator_->Delete(buffer); }
QuicheBufferAllocator* allocator_;
using QuicheUniqueBufferPtr = std::unique_ptr<char[], QuicheBufferDeleter>;
inline QuicheUniqueBufferPtr MakeUniqueBuffer(QuicheBufferAllocator* allocator,
size_t size) {
return QuicheUniqueBufferPtr(allocator->New(size),
// QuicheUniqueBufferPtr with a length attached to it. Similar to
// QuicheMemSlice, except unlike QuicheMemSlice, QuicheBuffer is mutable and is
// not platform-specific. Also unlike QuicheMemSlice, QuicheBuffer can be
// empty.
class QUICHE_EXPORT_PRIVATE QuicheBuffer {
QuicheBuffer() : buffer_(nullptr, QuicheBufferDeleter(nullptr)), size_(0) {}
QuicheBuffer(QuicheBufferAllocator* allocator, size_t size)
: buffer_(MakeUniqueBuffer(allocator, size)), size_(size) {}
QuicheBuffer(QuicheUniqueBufferPtr buffer, size_t size)
: buffer_(std::move(buffer)), size_(size) {}
// Make sure the move constructor zeroes out the size field.
QuicheBuffer(QuicheBuffer&& other)
: buffer_(std::move(other.buffer_)), size_(other.size_) {
other.buffer_ = nullptr;
other.size_ = 0;
QuicheBuffer& operator=(QuicheBuffer&& other) {
buffer_ = std::move(other.buffer_);
size_ = other.size_;
other.buffer_ = nullptr;
other.size_ = 0;
return *this;
// Factory method to create a QuicheBuffer that holds a copy of `data`.
static QuicheBuffer Copy(QuicheBufferAllocator* allocator,
absl::string_view data) {
QuicheBuffer buffer(allocator, data.size());
memcpy(,, data.size());
return buffer;
// Factory method to create a QuicheBuffer of length `buffer_length` that
// holds a copy of `buffer_length` bytes from `iov` starting at offset
// `iov_offset`. `iov` must be at least `iov_offset + buffer_length` total
// length.
static QuicheBuffer CopyFromIovec(QuicheBufferAllocator* allocator,
const struct iovec* iov, int iov_count,
size_t iov_offset, size_t buffer_length);
const char* data() const { return buffer_.get(); }
char* data() { return buffer_.get(); }
size_t size() const { return size_; }
bool empty() const { return size_ == 0; }
absl::string_view AsStringView() const {
return absl::string_view(data(), size());
// Releases the ownership of the underlying buffer.
QuicheUniqueBufferPtr Release() {
size_ = 0;
return std::move(buffer_);
QuicheUniqueBufferPtr buffer_;
size_t size_;
} // namespace quiche