/*
 * Copyright 2006 The Android Open Source Project
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */


#ifndef SkDeque_DEFINED
#define SkDeque_DEFINED

#include "SkTypes.h"

class SK_API SkDeque : SkNoncopyable {
public:
    explicit SkDeque(size_t elemSize);
    SkDeque(size_t elemSize, void* storage, size_t storageSize);
    ~SkDeque();

    bool    empty() const { return 0 == fCount; }
    int     count() const { return fCount; }
    size_t  elemSize() const { return fElemSize; }

    const void* front() const;
    const void* back() const;

    void* front() {
        return (void*)((const SkDeque*)this)->front();
    }

    void* back() {
        return (void*)((const SkDeque*)this)->back();
    }

    void* push_front();
    void* push_back();

    void pop_front();
    void pop_back();

private:
    struct Head;

public:
    class F2BIter {
    public:
        /**
         * Creates an uninitialized iterator. Must be reset()
         */
        F2BIter();

        F2BIter(const SkDeque& d);
        void* next();

        void reset(const SkDeque& d);

    private:
        SkDeque::Head*  fHead;
        char*           fPos;
        size_t          fElemSize;
    };

private:
    Head*   fFront;
    Head*   fBack;
    size_t  fElemSize;
    void*   fInitialStorage;
    int     fCount;

    friend class Iter;
};

#endif