juce/source/src/io/streams/juce_BufferedInputStream.h

   1 /*
   2   ==============================================================================
   3
   4    This file is part of the JUCE library - "Jules' Utility Class Extensions"
   5    Copyright 2004-11 by Raw Material Software Ltd.
   6
   7   ------------------------------------------------------------------------------
   8
   9    JUCE can be redistributed and/or modified under the terms of the GNU General
  10    Public License (Version 2), as published by the Free Software Foundation.
  11    A copy of the license is included in the JUCE distribution, or can be found
  12    online at www.gnu.org/licenses.
  13
  14    JUCE is distributed in the hope that it will be useful, but WITHOUT ANY
  15    WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
  16    A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
  17
  18   ------------------------------------------------------------------------------
  19
  20    To release a closed-source product which uses JUCE, commercial licenses are
  21    available: visit www.rawmaterialsoftware.com/juce for more information.
  22
  23   ==============================================================================
  24 */
  25
  26 #ifndef __JUCE_BUFFEREDINPUTSTREAM_JUCEHEADER__
  27 #define __JUCE_BUFFEREDINPUTSTREAM_JUCEHEADER__
  28
  29 #include "juce_InputStream.h"
  30 #include "../../memory/juce_OptionalScopedPointer.h"
  31 #include "../../memory/juce_HeapBlock.h"
  32
  33
  34 //==============================================================================
  35 /** Wraps another input stream, and reads from it using an intermediate buffer
  36
  37     If you're using an input stream such as a file input stream, and making lots of
  38     small read accesses to it, it's probably sensible to wrap it in one of these,
  39     so that the source stream gets accessed in larger chunk sizes, meaning less
  40     work for the underlying stream.
  41 */
  42 class JUCE_API  BufferedInputStream  : public InputStream
  43 {
  44 public:
  45     //==============================================================================
  46     /** Creates a BufferedInputStream from an input source.
  47
  48         @param sourceStream                 the source stream to read from
  49         @param bufferSize                   the size of reservoir to use to buffer the source
  50         @param deleteSourceWhenDestroyed    whether the sourceStream that is passed in should be
  51                                             deleted by this object when it is itself deleted.
  52     */
  53     BufferedInputStream (InputStream* sourceStream,
  54                          int bufferSize,
  55                          bool deleteSourceWhenDestroyed);
  56
  57     /** Creates a BufferedInputStream from an input source.
  58
  59         @param sourceStream     the source stream to read from - the source stream  must not
  60                                 be deleted until this object has been destroyed.
  61         @param bufferSize       the size of reservoir to use to buffer the source
  62     */
  63     BufferedInputStream (InputStream& sourceStream, int bufferSize);
  64
  65     /** Destructor.
  66
  67         This may also delete the source stream, if that option was chosen when the
  68         buffered stream was created.
  69     */
  70     ~BufferedInputStream();
  71
  72
  73     //==============================================================================
  74     int64 getTotalLength();
  75     int64 getPosition();
  76     bool setPosition (int64 newPosition);
  77     int read (void* destBuffer, int maxBytesToRead);
  78     String readString();
  79     bool isExhausted();
  80
  81
  82 private:
  83     //==============================================================================
  84     OptionalScopedPointer<InputStream> source;
  85     int bufferSize;
  86     int64 position, lastReadPos, bufferStart, bufferOverlap;
  87     HeapBlock <char> buffer;
  88     void ensureBuffered();
  89
  90     JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (BufferedInputStream);
  91 };
  92
  93 #endif   // __JUCE_BUFFEREDINPUTSTREAM_JUCEHEADER__