juce/source/src/io/files/juce_FileInputStream.cpp

   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 #include "../../core/juce_StandardHeader.h"
  27
  28 BEGIN_JUCE_NAMESPACE
  29
  30 #include "juce_FileInputStream.h"
  31
  32
  33 //==============================================================================
  34 int64 juce_fileSetPosition (void* handle, int64 pos);
  35
  36
  37 //==============================================================================
  38 FileInputStream::FileInputStream (const File& f)
  39     : file (f),
  40       fileHandle (nullptr),
  41       currentPosition (0),
  42       totalSize (0),
  43       status (Result::ok()),
  44       needToSeek (true)
  45 {
  46     openHandle();
  47 }
  48
  49 FileInputStream::~FileInputStream()
  50 {
  51     closeHandle();
  52 }
  53
  54 //==============================================================================
  55 int64 FileInputStream::getTotalLength()
  56 {
  57     return totalSize;
  58 }
  59
  60 int FileInputStream::read (void* buffer, int bytesToRead)
  61 {
  62     if (needToSeek)
  63     {
  64         if (juce_fileSetPosition (fileHandle, currentPosition) < 0)
  65             return 0;
  66
  67         needToSeek = false;
  68     }
  69
  70     const size_t num = readInternal (buffer, bytesToRead);
  71     currentPosition += num;
  72
  73     return (int) num;
  74 }
  75
  76 bool FileInputStream::isExhausted()
  77 {
  78     return currentPosition >= totalSize;
  79 }
  80
  81 int64 FileInputStream::getPosition()
  82 {
  83     return currentPosition;
  84 }
  85
  86 bool FileInputStream::setPosition (int64 pos)
  87 {
  88     pos = jlimit ((int64) 0, totalSize, pos);
  89
  90     needToSeek |= (currentPosition != pos);
  91     currentPosition = pos;
  92
  93     return true;
  94 }
  95
  96 END_JUCE_NAMESPACE