source/modules/water/files/FileOutputStream.h

   1 /*
   2   ==============================================================================
   3
   4    This file is part of the Water library.
   5    Copyright (c) 2016 ROLI Ltd.
   6    Copyright (C) 2017-2022 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_FILEOUTPUTSTREAM_H_INCLUDED
  27 #define WATER_FILEOUTPUTSTREAM_H_INCLUDED
  28
  29 #include "../files/File.h"
  30 #include "../memory/HeapBlock.h"
  31 #include "../streams/OutputStream.h"
  32
  33 namespace water {
  34
  35 //==============================================================================
  36 /**
  37     An output stream that writes into a local file.
  38
  39     @see OutputStream, FileInputStream, File::createOutputStream
  40 */
  41 class FileOutputStream  : public OutputStream
  42 {
  43 public:
  44     //==============================================================================
  45     /** Creates a FileOutputStream.
  46
  47         If the file doesn't exist, it will first be created. If the file can't be
  48         created or opened (for example, because the parent directory of the file
  49         does not exist), the failedToOpen() method will return true.
  50
  51         If the file already exists when opened, the stream's write-position will
  52         be set to the end of the file. To overwrite an existing file,
  53         use File::deleteFile() before opening the stream, or use setPosition(0)
  54         after it's opened (although this won't truncate the file).
  55
  56         Destroying a FileOutputStream object does not force the operating system
  57         to write the buffered data to disk immediately. If this is required you
  58         should call flush() before triggering the destructor.
  59
  60         @see TemporaryFile
  61     */
  62     FileOutputStream (const File& fileToWriteTo,
  63                       size_t bufferSizeToUse = 16384);
  64
  65     /** Destructor. */
  66     ~FileOutputStream();
  67
  68     //==============================================================================
  69     /** Returns the file that this stream is writing to.
  70     */
  71     const File& getFile() const                         { return file; }
  72
  73     /** Returns the status of the file stream.
  74         The result will be ok if the file opened successfully. If an error occurs while
  75         opening or writing to the file, this will contain an error message.
  76     */
  77     const Result& getStatus() const noexcept            { return status; }
  78
  79     /** Returns true if the stream couldn't be opened for some reason.
  80         @see getResult()
  81     */
  82     bool failedToOpen() const noexcept                  { return status.failed(); }
  83
  84     /** Returns true if the stream opened without problems.
  85         @see getResult()
  86     */
  87     bool openedOk() const noexcept                      { return status.wasOk(); }
  88
  89     /** Attempts to truncate the file to the current write position.
  90         To truncate a file to a specific size, first use setPosition() to seek to the
  91         appropriate location, and then call this method.
  92     */
  93     Result truncate();
  94
  95     //==============================================================================
  96     void flush() override;
  97     int64 getPosition() override;
  98     bool setPosition (int64) override;
  99     bool write (const void*, size_t) override;
 100     bool writeRepeatedByte (uint8 byte, size_t numTimesToRepeat) override;
 101
 102
 103 private:
 104     //==============================================================================
 105     File file;
 106     void* fileHandle;
 107     Result status;
 108     int64 currentPosition;
 109     size_t bufferSize, bytesInBuffer;
 110     HeapBlock<char> buffer;
 111
 112     void openHandle();
 113     void closeHandle();
 114     void flushInternal();
 115     bool flushBuffer();
 116     int64 setPositionInternal (int64);
 117     ssize_t writeInternal (const void*, size_t);
 118
 119     CARLA_DECLARE_NON_COPYABLE (FileOutputStream)
 120 };
 121
 122 }
 123
 124 #endif // WATER_FILEOUTPUTSTREAM_H_INCLUDED