Carla/source/modules/water/streams/MemoryInputStream.h

/*
  ==============================================================================

   This file is part of the Water library.
   Copyright (c) 2016 - ROLI Ltd.
   Copyright (C) 2021 Filipe Coelho <falktx@falktx.com>

   Permission is granted to use this software under the terms of the ISC license
   http://www.isc.org/downloads/software-support-policy/isc-license/

   Permission to use, copy, modify, and/or distribute this software for any
   purpose with or without fee is hereby granted, provided that the above
   copyright notice and this permission notice appear in all copies.

   THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH REGARD
   TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
   FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT,
   OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
   USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
   TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
   OF THIS SOFTWARE.

  ==============================================================================
*/

#ifndef WATER_MEMORYINPUTSTREAM_H_INCLUDED
#define WATER_MEMORYINPUTSTREAM_H_INCLUDED

#include "InputStream.h"
#include "../memory/MemoryBlock.h"
#include "../memory/HeapBlock.h"

namespace water {

//==============================================================================
/**
    Allows a block of data to be accessed as a stream.

    This can either be used to refer to a shared block of memory, or can make its
    own internal copy of the data when the MemoryInputStream is created.
*/
class MemoryInputStream  : public InputStream
{
public:
    //==============================================================================
    /** Creates a MemoryInputStream.

        @param sourceData               the block of data to use as the stream's source
        @param sourceDataSize           the number of bytes in the source data block
        @param keepInternalCopyOfData   if false, the stream will just keep a pointer to
                                        the source data, so this data shouldn't be changed
                                        for the lifetime of the stream; if this parameter is
                                        true, the stream will make its own copy of the
                                        data and use that.
    */
    MemoryInputStream (const void* sourceData,
                       size_t sourceDataSize,
                       bool keepInternalCopyOfData);

    /** Creates a MemoryInputStream.

        @param data                     a block of data to use as the stream's source
        @param keepInternalCopyOfData   if false, the stream will just keep a reference to
                                        the source data, so this data shouldn't be changed
                                        for the lifetime of the stream; if this parameter is
                                        true, the stream will make its own copy of the
                                        data and use that.
    */
    MemoryInputStream (const MemoryBlock& data,
                       bool keepInternalCopyOfData);

    /** Destructor. */
    ~MemoryInputStream();

    /** Returns a pointer to the source data block from which this stream is reading. */
    const void* getData() const noexcept        { return data; }

    /** Returns the number of bytes of source data in the block from which this stream is reading. */
    size_t getDataSize() const noexcept         { return dataSize; }

    //==============================================================================
    int64 getPosition() override;
    bool setPosition (int64 pos) override;
    int64 getTotalLength() override;
    bool isExhausted() override;
    int read (void* destBuffer, int maxBytesToRead) override;

private:
    //==============================================================================
    const void* data;
    size_t dataSize, position;
    HeapBlock<char> internalCopy;

    void createInternalCopy();

    CARLA_DECLARE_NON_COPY_CLASS (MemoryInputStream)
};

}

#endif   // WATER_MEMORYINPUTSTREAM_H_INCLUDED