source/modules/water/files/FileInputStream.cpp

   1 /*
   2   ==============================================================================
   3
   4    This file is part of the Water library.
   5    Copyright (c) 2016 ROLI Ltd.
   6    Copyright (C) 2017 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 #include "FileInputStream.h"
  27
  28 namespace water {
  29
  30 static int64 water_fileSetPosition (void* handle, int64 pos);
  31
  32 //==============================================================================
  33 FileInputStream::FileInputStream (const File& f)
  34     : file (f),
  35       fileHandle (nullptr),
  36       currentPosition (0),
  37       status (Result::ok())
  38 {
  39     openHandle();
  40 }
  41
  42 int64 FileInputStream::getTotalLength()
  43 {
  44     // You should always check that a stream opened successfully before using it!
  45     wassert (openedOk());
  46
  47     return file.getSize();
  48 }
  49
  50 int FileInputStream::read (void* buffer, int bytesToRead)
  51 {
  52     // You should always check that a stream opened successfully before using it!
  53     wassert (openedOk());
  54
  55     // The buffer should never be null, and a negative size is probably a
  56     // sign that something is broken!
  57     wassert (buffer != nullptr && bytesToRead >= 0);
  58
  59     const size_t num = readInternal (buffer, (size_t) bytesToRead);
  60     currentPosition += (int64) num;
  61
  62     return (int) num;
  63 }
  64
  65 bool FileInputStream::isExhausted()
  66 {
  67     return currentPosition >= getTotalLength();
  68 }
  69
  70 int64 FileInputStream::getPosition()
  71 {
  72     return currentPosition;
  73 }
  74
  75 bool FileInputStream::setPosition (int64 pos)
  76 {
  77     // You should always check that a stream opened successfully before using it!
  78     wassert (openedOk());
  79
  80     if (pos != currentPosition)
  81         currentPosition = water_fileSetPosition (fileHandle, pos);
  82
  83     return currentPosition == pos;
  84 }
  85
  86 #ifdef CARLA_OS_WIN
  87 FileInputStream::~FileInputStream()
  88 {
  89     CloseHandle ((HANDLE) fileHandle);
  90 }
  91
  92 void FileInputStream::openHandle()
  93 {
  94     HANDLE h = CreateFileA (file.getFullPathName().toUTF8(), GENERIC_READ, FILE_SHARE_READ | FILE_SHARE_WRITE, 0,
  95                             OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL | FILE_FLAG_SEQUENTIAL_SCAN, 0);
  96
  97     if (h != INVALID_HANDLE_VALUE)
  98         fileHandle = (void*) h;
  99     else
 100         status = getResultForLastError();
 101 }
 102
 103 size_t FileInputStream::readInternal (void* buffer, size_t numBytes)
 104 {
 105     if (fileHandle != 0)
 106     {
 107         DWORD actualNum = 0;
 108         if (! ReadFile ((HANDLE) fileHandle, buffer, (DWORD) numBytes, &actualNum, 0))
 109         {
 110             status = getResultForLastError();
 111             actualNum = 0;
 112         }
 113
 114         return (size_t) actualNum;
 115     }
 116
 117     return 0;
 118 }
 119 #else
 120 FileInputStream::~FileInputStream()
 121 {
 122     if (fileHandle != 0)
 123         close (getFD (fileHandle));
 124 }
 125
 126 void FileInputStream::openHandle()
 127 {
 128     const int f = open (file.getFullPathName().toUTF8(), O_RDONLY, 00644);
 129
 130     if (f != -1)
 131         fileHandle = fdToVoidPointer (f);
 132     else
 133         status = getResultForErrno();
 134 }
 135
 136 size_t FileInputStream::readInternal (void* const buffer, const size_t numBytes)
 137 {
 138     ssize_t result = 0;
 139
 140     if (fileHandle != 0)
 141     {
 142         result = ::read (getFD (fileHandle), buffer, numBytes);
 143
 144         if (result < 0)
 145         {
 146             status = getResultForErrno();
 147             result = 0;
 148         }
 149     }
 150
 151     return (size_t) result;
 152 }
 153 #endif
 154
 155 }