source/modules/water/streams/MemoryInputStream.h

   1 /*
   2   ==============================================================================
   3
   4    This file is part of the Water library.
   5    Copyright (c) 2016 - ROLI Ltd.
   6    Copyright (C) 2021-2022 Filipe Coelho <falktx@falktx.com>
   7
   8    Permission is granted to use this software under the terms of the ISC license
   9    http://www.isc.org/downloads/software-support-policy/isc-license/
  10
  11    Permission to use, copy, modify, and/or distribute this software for any
  12    purpose with or without fee is hereby granted, provided that the above
  13    copyright notice and this permission notice appear in all copies.
  14
  15    THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH REGARD
  16    TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
  17    FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT,
  18    OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
  19    USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
  20    TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
  21    OF THIS SOFTWARE.
  22
  23   ==============================================================================
  24 */
  25
  26 #ifndef WATER_MEMORYINPUTSTREAM_H_INCLUDED
  27 #define WATER_MEMORYINPUTSTREAM_H_INCLUDED
  28
  29 #include "InputStream.h"
  30 #include "../memory/MemoryBlock.h"
  31 #include "../memory/HeapBlock.h"
  32
  33 namespace water {
  34
  35 //==============================================================================
  36 /**
  37     Allows a block of data to be accessed as a stream.
  38
  39     This can either be used to refer to a shared block of memory, or can make its
  40     own internal copy of the data when the MemoryInputStream is created.
  41 */
  42 class MemoryInputStream  : public InputStream
  43 {
  44 public:
  45     //==============================================================================
  46     /** Creates a MemoryInputStream.
  47
  48         @param sourceData               the block of data to use as the stream's source
  49         @param sourceDataSize           the number of bytes in the source data block
  50         @param keepInternalCopyOfData   if false, the stream will just keep a pointer to
  51                                         the source data, so this data shouldn't be changed
  52                                         for the lifetime of the stream; if this parameter is
  53                                         true, the stream will make its own copy of the
  54                                         data and use that.
  55     */
  56     MemoryInputStream (const void* sourceData,
  57                        size_t sourceDataSize,
  58                        bool keepInternalCopyOfData);
  59
  60     /** Creates a MemoryInputStream.
  61
  62         @param data                     a block of data to use as the stream's source
  63         @param keepInternalCopyOfData   if false, the stream will just keep a reference to
  64                                         the source data, so this data shouldn't be changed
  65                                         for the lifetime of the stream; if this parameter is
  66                                         true, the stream will make its own copy of the
  67                                         data and use that.
  68     */
  69     MemoryInputStream (const MemoryBlock& data,
  70                        bool keepInternalCopyOfData);
  71
  72     /** Destructor. */
  73     ~MemoryInputStream();
  74
  75     /** Returns a pointer to the source data block from which this stream is reading. */
  76     const void* getData() const noexcept        { return data; }
  77
  78     /** Returns the number of bytes of source data in the block from which this stream is reading. */
  79     size_t getDataSize() const noexcept         { return dataSize; }
  80
  81     //==============================================================================
  82     int64 getPosition() override;
  83     bool setPosition (int64 pos) override;
  84     int64 getTotalLength() override;
  85     bool isExhausted() override;
  86     int read (void* destBuffer, int maxBytesToRead) override;
  87
  88 private:
  89     //==============================================================================
  90     const void* data;
  91     size_t dataSize, position;
  92     HeapBlock<char> internalCopy;
  93
  94     void createInternalCopy();
  95
  96     CARLA_DECLARE_NON_COPYABLE (MemoryInputStream)
  97 };
  98
  99 }
 100
 101 #endif   // WATER_MEMORYINPUTSTREAM_H_INCLUDED