blob: 2980b8306315230c50c37b58de8a5f00415f2e68 [file] [log] [blame]
// Copyright 2024 The Pigweed Authors
// 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
// 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 <cstddef>
#include "pw_multibuf/multibuf.h"
#include "pw_stream/stream.h"
namespace pw::multibuf {
/// A readable, writable, and seekable ``Stream`` implementation backed by a
/// ``MultiBuf``.
class Stream : public stream::SeekableReaderWriter {
Stream(MultiBuf& multibuf)
: multibuf_(multibuf),
multibuf_offset_(0) {}
/// Returns the ``MultiBuf`` backing this stream.
constexpr const MultiBuf& multibuf() const { return multibuf_; }
Status DoWrite(ConstByteSpan data) override;
StatusWithSize DoRead(ByteSpan destination) override;
/// Seeks the writer's cursor position within the multibuf. Only forward
/// seeking is permitted; attempting to seek backwards will result in an
/// `OUT_OF_RANGE`. This operation is `O(multibuf().Chunks().size())`.
Status DoSeek(ptrdiff_t offset, Whence origin) override;
size_t DoTell() override { return multibuf_offset_; }
size_t ConservativeLimit(LimitType) const override {
return multibuf_.size() - multibuf_offset_;
MultiBuf& multibuf_;
MultiBuf::iterator iterator_;
size_t multibuf_offset_;
} // namespace pw::multibuf