SkRWBuffer.h

/*
 * Copyright 2015 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#ifndef SkRWBuffer_DEFINED
#define SkRWBuffer_DEFINED

#include "SkRefCnt.h"

struct SkBufferBlock;
struct SkBufferHead;
class SkRWBuffer;
class SkStreamAsset;

class SK_API SkROBuffer : public SkRefCnt {
public:
    size_t size() const { return fAvailable; }

    class SK_API Iter {
    public:
        Iter(const SkROBuffer*);

        void reset(const SkROBuffer*);

        const void* data() const;

        size_t size() const;

        bool next();
        
    private:
        const SkBufferBlock* fBlock;
        size_t               fRemaining;
        const SkROBuffer*    fBuffer;
    };

private:
    SkROBuffer(const SkBufferHead* head, size_t available, const SkBufferBlock* fTail);
    virtual ~SkROBuffer();

    const SkBufferHead*     fHead;
    const size_t            fAvailable;
    const SkBufferBlock*    fTail;

    friend class SkRWBuffer;
};

class SK_API SkRWBuffer {
public:
    SkRWBuffer(size_t initialCapacity = 0);
    ~SkRWBuffer();

    size_t size() const { return fTotalUsed; }
    void append(const void* buffer, size_t length);

    SkROBuffer* newRBufferSnapshot() const;
    SkStreamAsset* newStreamSnapshot() const;

#ifdef SK_DEBUG
    void validate() const;
#else
    void validate() const {}
#endif
    
private:
    SkBufferHead*   fHead;
    SkBufferBlock*  fTail;
    size_t          fTotalUsed;
};

#endif