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Diffstat (limited to 'ensemble_matcher.h')
-rw-r--r-- | ensemble_matcher.h | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/ensemble_matcher.h b/ensemble_matcher.h new file mode 100644 index 0000000..bc89883 --- /dev/null +++ b/ensemble_matcher.h @@ -0,0 +1,62 @@ +// 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. + +#ifndef COMPONENTS_ZUCCHINI_ENSEMBLE_MATCHER_H_ +#define COMPONENTS_ZUCCHINI_ENSEMBLE_MATCHER_H_ + +#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 { + public: + 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_; } + + protected: + // 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; + + private: + DISALLOW_COPY_AND_ASSIGN(EnsembleMatcher); +}; + +} // namespace zucchini + +#endif // COMPONENTS_ZUCCHINI_ENSEMBLE_MATCHER_H_ |