samples/parselib/src/main/cpp/stream/MemInputStream.h

/*
 * Copyright 2019 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#ifndef _IO_STREAM_MEMINPUTSTREAM_H_
#define _IO_STREAM_MEMINPUTSTREAM_H_

#include "InputStream.h"

namespace parselib {

/**
 * A concrete implementation of InputStream for a memory buffer data source
 */
class MemInputStream : public InputStream {
public:
    /** constructor. Caller is presumed to have allocated and filled the memory buffer */
    MemInputStream(unsigned char *buff, int32_t len) : mBuffer(buff), mBufferLen(len), mPos(0) {}
    virtual ~MemInputStream() {}

    virtual int32_t read(void *buff, int32_t numBytes);

    virtual int32_t peek(void *buff, int32_t numBytes);

    virtual void advance(int32_t numBytes);

    virtual int32_t getPos();

    virtual void setPos(int32_t pos);

private:
    /** Points to the data buffer to stream from. */
    unsigned char *mBuffer;

    /** Total number of bytes in the memory buffer */
    int32_t mBufferLen;

    /** The index of the next byte to read */
    int32_t mPos;
};

} // namespace parselib

#endif // _IO_STREAM_MEMINPUTSTREAM_H_