blob: bc898839f91a3668dfe5c3d6797e8c34da5e0ea3 [file] [log] [blame]
// Copyright 2017 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 <vector>
#include "base/macros.h"
#include "components/zucchini/buffer_view.h"
#include "components/zucchini/element_detection.h"
#include "components/zucchini/image_utils.h"
namespace zucchini {
// A base class for ensemble matching strategies, which identify Elements in a
// "new" and "old" archives, and match each "new" Element to an "old" Element.
// Matched pairs can then be passed to Disassembler for architecture-specific
// patching. Notes:
// - A matched Element pair must have the same ExecutableType.
// - Special case: Exact matches are ignored, since they can be patched directly
// without architecture-specific patching.
// - Multiple "new" Elements may match a common "old" Element.
// - A "new" Element may have no match. This can happen when no viable match
// exists, or when an exact match is skipped.
class EnsembleMatcher {
virtual ~EnsembleMatcher();
// Interface to main matching feature. Returns whether match was successful.
// This should be called at most once per instace.
virtual bool RunMatch(ConstBufferView old_image,
ConstBufferView new_image) = 0;
// Accessors to RunMatch() results.
const std::vector<ElementMatch>& matches() const { return matches_; }
size_t num_identical() const { return num_identical_; }
// Post-processes |matches_| to remove potentially unfavorable entries.
void Trim();
// Storage of matched elements: A list of matched pairs, where the list of
// "new" elements have increasing offsets and don't overlap. May be empty.
std::vector<ElementMatch> matches_;
// Number of identical matches found in match candidates. These should be
// excluded from |matches_|.
size_t num_identical_ = 0;
} // namespace zucchini