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// Copyright 2018 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.
#ifndef COMPONENTS_ZUCCHINI_IMPOSED_ENSEMBLE_MATCHER_H_
#define COMPONENTS_ZUCCHINI_IMPOSED_ENSEMBLE_MATCHER_H_
#include <stddef.h>
#include <string>
#include <vector>
#include "components/zucchini/buffer_view.h"
#include "components/zucchini/element_detection.h"
#include "components/zucchini/ensemble_matcher.h"
namespace zucchini {
// A class to parse imposed match format, which is either an empty string (no
// imposed patch), or a string formatted as:
// "#+#=#+#,#+#=#+#,..." (e.g., "1+2=3+4", "1+2=3+4,5+6=7+8"),
// where "#+#=#+#" encodes a match as 4 unsigned integers:
// [offset in "old", size in "old", offset in "new", size in "new"].
class ImposedMatchParser {
public:
enum Status {
kSuccess,
kInvalidDelimiter,
kParseError,
kOutOfBound,
kOverlapInNew,
kTypeMismatch,
};
ImposedMatchParser();
ImposedMatchParser(const ImposedMatchParser&) = delete;
const ImposedMatchParser& operator=(const ImposedMatchParser&) = delete;
~ImposedMatchParser();
// Parses |imposed_matches| and writes the results to member variables.
// |old_image| and |new_image| are used for validation. Returns a Status value
// to signal success or various error modes. |detector| is used to validate
// Element types for matched pairs. This should only be called once for each
// instance.
Status Parse(std::string imposed_matches,
ConstBufferView old_image,
ConstBufferView new_image,
ElementDetector&& detector);
size_t num_identical() const { return num_identical_; }
std::vector<ElementMatch>* mutable_matches() { return &matches_; }
std::vector<ElementMatch>* mutable_bad_matches() { return &bad_matches_; }
private:
size_t num_identical_ = 0;
std::vector<ElementMatch> matches_;
// Stores "forgiven" bad matches, so the caller can impose matches for
// unsupported image types (which will simply be ignored). Note that imposing
// matches for known but incompatible image types would result in error.
std::vector<ElementMatch> bad_matches_;
};
// An ensemble matcher that parses a format string that describes matches.
class ImposedEnsembleMatcher : public EnsembleMatcher {
public:
// |imposed_matches| specifies imposed maches, using a format described below.
// Validation is performed in RunMatch().
explicit ImposedEnsembleMatcher(const std::string& imposed_matches);
ImposedEnsembleMatcher(const ImposedEnsembleMatcher&) = delete;
const ImposedEnsembleMatcher& operator=(const ImposedEnsembleMatcher&) =
delete;
~ImposedEnsembleMatcher() override;
// EnsembleMatcher:
bool RunMatch(ConstBufferView old_image, ConstBufferView new_image) override;
private:
const std::string imposed_matches_;
};
} // namespace zucchini
#endif // COMPONENTS_ZUCCHINI_IMPOSED_ENSEMBLE_MATCHER_H_