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

   This file is part of the JUCE library.
   Copyright (c) 2017 - ROLI Ltd.

   JUCE is an open source library subject to commercial or open-source
   licensing.

   The code included in this file is provided 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.

   JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
   EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
   DISCLAIMED.

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

namespace juce
{

//==============================================================================
/**
    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.

    @tags{Core}
*/
class JUCE_API  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) override;
    int64 getTotalLength() override;
    bool isExhausted() override;
    int read (void* destBuffer, int maxBytesToRead) override;
    void skipNextBytes (int64 numBytesToSkip) override;

private:
    //==============================================================================
    const void* data;
    size_t dataSize, position = 0;
    HeapBlock<char> internalCopy;

    void createInternalCopy();

    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (MemoryInputStream)
};

} // namespace juce
