patch_writer.h | Explore in Territory

// Copyright 2017 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef COMPONENTS_ZUCCHINI_PATCH_WRITER_H_
#define COMPONENTS_ZUCCHINI_PATCH_WRITER_H_

#include <stddef.h>
#include <stdint.h>

#include <map>
#include <optional>
#include <utility>
#include <vector>

#include "base/check.h"
#include "components/zucchini/buffer_sink.h"
#include "components/zucchini/buffer_view.h"
#include "components/zucchini/image_utils.h"
#include "components/zucchini/patch_utils.h"

namespace zucchini {

namespace patch {

// If sufficient space is available, serializes |element_match| into |sink| and
// returns true. Otherwise returns false, and |sink| will be in an undefined
// state.
bool SerializeElementMatch(const ElementMatch& element_match, BufferSink* sink);

// Returns the size in bytes required to serialize |element_match|.
size_t SerializedElementMatchSize(const ElementMatch& element_match);

// If sufficient space is available, serializes |buffer| into |sink| and returns
// true. Otherwise returns false, and |sink| will be in an undefined state.
bool SerializeBuffer(const std::vector<uint8_t>& buffer, BufferSink* sink);

// Returns the size in bytes required to serialize |buffer|.
size_t SerializedBufferSize(const std::vector<uint8_t>& buffer);

}  // namespace patch

// Each of *Sink classes below has an associated "main type", and performs the
// following:
// - Receives multiple "main type" elements (hence "Sink" in the name).
// - Encodes list of received data, and writes them to internal storage (e.g.,
//   applying delta encoding).
// - Writes encoded data to BufferSink.
//
// Common "core functions" implemented for *Sink classes are:
// - void PutNext(const MAIN_TYPE& inst): Encodes and writes an instance of
//   MAIN_TYPE to internal storage. Assumptions may be applied to successive
//   |inst| provided.
// - size_t SerializedSize() const: Returns the serialized size in bytes of
//   internal storage.
// - bool SerializeInto(BufferSink* sink) const: If |sink| has enough space,
//   serializes internal storage into |sink|, and returns true. Otherwise
//   returns false.
//
// Usage of *Sink instances don't mix, and PuttNext() have dissimilar
// interfaces. Therefore we do not use inheritance to relate *Sink classes,
// simply implement "core functions" with matching names.

// Sink for equivalences.
class EquivalenceSink { … };

// Sink for extra data.
class ExtraDataSink { … };

// Sink for raw delta.
class RawDeltaSink { … };

// Sink for reference delta.
class ReferenceDeltaSink { … };

// Sink for additional targets.
class TargetSink { … };

// Following are utility classes to write structured data forming a patch.

// Utility to write a patch element. A patch element contains all the
// information necessary to patch a single element. This class
// provides an interface to individually set different building blocks of data
// in the patch element.
class PatchElementWriter { … };

// Utility to write a Zucchini ensemble patch. An ensemble patch is the
// concatenation of a patch header with a vector of patch elements.
class EnsemblePatchWriter { … };

}  // namespace zucchini

#endif  // COMPONENTS_ZUCCHINI_PATCH_WRITER_H_
chromium/components/zucchini/patch_writer.h
