source/modules/juce_core/files/juce_FileInputStream.cpp

   1 /*
   2   ==============================================================================
   3
   4    This file is part of the JUCE library.
   5    Copyright (c) 2022 - Raw Material Software Limited
   6
   7    JUCE is an open source library subject to commercial or open-source
   8    licensing.
   9
  10    The code included in this file is provided under the terms of the ISC license
  11    http://www.isc.org/downloads/software-support-policy/isc-license. Permission
  12    To use, copy, modify, and/or distribute this software for any purpose with or
  13    without fee is hereby granted provided that the above copyright notice and
  14    this permission notice appear in all copies.
  15
  16    JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
  17    EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
  18    DISCLAIMED.
  19
  20   ==============================================================================
  21 */
  22
  23 namespace juce
  24 {
  25
  26 int64 juce_fileSetPosition (void* handle, int64 pos);
  27
  28
  29 //==============================================================================
  30 FileInputStream::FileInputStream (const File& f)  : file (f)
  31 {
  32     openHandle();
  33 }
  34
  35 int64 FileInputStream::getTotalLength()
  36 {
  37     // You should always check that a stream opened successfully before using it!
  38     jassert (openedOk());
  39
  40     return file.getSize();
  41 }
  42
  43 int FileInputStream::read (void* buffer, int bytesToRead)
  44 {
  45     // You should always check that a stream opened successfully before using it!
  46     jassert (openedOk());
  47
  48     // The buffer should never be null, and a negative size is probably a
  49     // sign that something is broken!
  50     jassert (buffer != nullptr && bytesToRead >= 0);
  51
  52     auto num = readInternal (buffer, (size_t) bytesToRead);
  53     currentPosition += (int64) num;
  54
  55     return (int) num;
  56 }
  57
  58 bool FileInputStream::isExhausted()
  59 {
  60     return currentPosition >= getTotalLength();
  61 }
  62
  63 int64 FileInputStream::getPosition()
  64 {
  65     return currentPosition;
  66 }
  67
  68 bool FileInputStream::setPosition (int64 pos)
  69 {
  70     // You should always check that a stream opened successfully before using it!
  71     jassert (openedOk());
  72
  73     if (pos != currentPosition)
  74         currentPosition = juce_fileSetPosition (fileHandle, pos);
  75
  76     return currentPosition == pos;
  77 }
  78
  79
  80 //==============================================================================
  81 //==============================================================================
  82 #if JUCE_UNIT_TESTS
  83
  84 struct FileInputStreamTests   : public UnitTest
  85 {
  86     FileInputStreamTests()
  87         : UnitTest ("FileInputStream", UnitTestCategories::streams)
  88     {}
  89
  90     void runTest() override
  91     {
  92         beginTest ("Open stream non-existent file");
  93         {
  94             auto tempFile = File::createTempFile (".txt");
  95             expect (! tempFile.exists());
  96
  97             FileInputStream stream (tempFile);
  98             expect (stream.failedToOpen());
  99         }
 100
 101         beginTest ("Open stream existing file");
 102         {
 103             auto tempFile = File::createTempFile (".txt");
 104             tempFile.create();
 105             expect (tempFile.exists());
 106
 107             FileInputStream stream (tempFile);
 108             expect (stream.openedOk());
 109         }
 110
 111         const MemoryBlock data ("abcdefghijklmnopqrstuvwxyz", 26);
 112         File f (File::createTempFile (".txt"));
 113         f.appendData (data.getData(), data.getSize());
 114         FileInputStream stream (f);
 115
 116         beginTest ("Read");
 117         {
 118             expectEquals (stream.getPosition(), (int64) 0);
 119             expectEquals (stream.getTotalLength(), (int64) data.getSize());
 120             expectEquals (stream.getNumBytesRemaining(), stream.getTotalLength());
 121             expect (! stream.isExhausted());
 122
 123             size_t numBytesRead = 0;
 124             MemoryBlock readBuffer (data.getSize());
 125
 126             while (numBytesRead < data.getSize())
 127             {
 128                 numBytesRead += (size_t) stream.read (&readBuffer[numBytesRead], 3);
 129
 130                 expectEquals (stream.getPosition(), (int64) numBytesRead);
 131                 expectEquals (stream.getNumBytesRemaining(), (int64) (data.getSize() - numBytesRead));
 132                 expect (stream.isExhausted() == (numBytesRead == data.getSize()));
 133             }
 134
 135             expectEquals (stream.getPosition(), (int64) data.getSize());
 136             expectEquals (stream.getNumBytesRemaining(), (int64) 0);
 137             expect (stream.isExhausted());
 138
 139             expect (readBuffer == data);
 140         }
 141
 142         beginTest ("Skip");
 143         {
 144             stream.setPosition (0);
 145             expectEquals (stream.getPosition(), (int64) 0);
 146             expectEquals (stream.getTotalLength(), (int64) data.getSize());
 147             expectEquals (stream.getNumBytesRemaining(), stream.getTotalLength());
 148             expect (! stream.isExhausted());
 149
 150             size_t numBytesRead = 0;
 151             const int numBytesToSkip = 5;
 152
 153             while (numBytesRead < data.getSize())
 154             {
 155                 stream.skipNextBytes (numBytesToSkip);
 156                 numBytesRead += numBytesToSkip;
 157                 numBytesRead = std::min (numBytesRead, data.getSize());
 158
 159                 expectEquals (stream.getPosition(), (int64) numBytesRead);
 160                 expectEquals (stream.getNumBytesRemaining(), (int64) (data.getSize() - numBytesRead));
 161                 expect (stream.isExhausted() == (numBytesRead == data.getSize()));
 162             }
 163
 164             expectEquals (stream.getPosition(), (int64) data.getSize());
 165             expectEquals (stream.getNumBytesRemaining(), (int64) 0);
 166             expect (stream.isExhausted());
 167
 168             f.deleteFile();
 169         }
 170     }
 171 };
 172
 173 static FileInputStreamTests fileInputStreamTests;
 174
 175 #endif
 176
 177 } // namespace juce