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// Copyright 2015 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 COURGETTE_LABEL_MANAGER_H_
#define COURGETTE_LABEL_MANAGER_H_
#include <vector>
#include "base/macros.h"
#include "courgette/image_utils.h"
namespace courgette {
// A container to store and manage Label instances. A key consideration is peak
// memory usage reduction. To this end we preallocate Label instances in bulk,
// and carefully control transient memory usage when initializing Labels.
class LabelManager {
public:
// An adaptor to sequentially traverse multiple RVAs. This is useful for RVA
// translation without extra storage. For example, we might have a stored list
// of RVA locations, but we want to traverse the matching RVA targets.
class RvaVisitor {
public:
virtual ~RvaVisitor();
// Returns the number of remaining RVAs to visit.
virtual size_t Remaining() const = 0;
// Returns the current RVA.
virtual RVA Get() const = 0;
// Advances to the next RVA.
virtual void Next() = 0;
};
LabelManager();
virtual ~LabelManager();
// Initializes |labels_| using RVAs from |rva_visitor|. Each distinct RVA from
// |rva_visitor| yields a Label with |rva_| assigned as the RVA, and |count_|
// assigned as the repeat.
void Read(RvaVisitor* rva_visitor);
// Removes |labels_| elements whose |count_| is less than |count_threshold|.
void RemoveUnderusedLabels(int32 count_threshold);
// Efficiently searches for a Label that targets |rva|. Returns the pointer to
// the stored Label instance if found, or null otherwise.
Label* Find(RVA rva);
// TODO(huangs): Move AssignRemainingIndexes() here.
protected:
// The main list of Label instances, sorted by the |rva_| member.
std::vector<Label> labels_;
private:
DISALLOW_COPY_AND_ASSIGN(LabelManager);
};
} // namespace courgette
#endif // COURGETTE_LABEL_MANAGER_H_
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