src/apps/mediaplayer/support/FileReadWrite.cpp

   1 /*
   2  * Copyright 2008, Haiku.
   3  * Distributed under the terms of the MIT License.
   4  *
   5  * Authors:
   6  *              Michael Pfeiffer        <laplace@users.sourceforge.net>
   7  *              Fredrik Modéen         <fredrik@modeen.se>
   8  */
   9 #include "FileReadWrite.h"
  10
  11 #include <UTF8.h>
  12 #include <Path.h>
  13
  14
  15 FileReadWrite::FileReadWrite(BFile* file, int32 sourceEncoding)
  16         : fFile(file),
  17           fSourceEncoding(sourceEncoding),
  18           fPositionInBuffer(0),
  19           fAmtRead(0)
  20 {}
  21
  22
  23 void
  24 FileReadWrite::SetEncoding(int32 sourceEncoding)
  25 {
  26         fSourceEncoding = sourceEncoding;
  27 }
  28
  29
  30 uint32
  31 FileReadWrite::GetEncoding() const
  32 {
  33         return fSourceEncoding;
  34 }
  35
  36
  37 status_t
  38 FileReadWrite::Write(const BString& contents) const
  39 {
  40         ssize_t written = fFile->Write(contents.String(), contents.Length());
  41         if (written != contents.Length())
  42                 return written < 0 ? (status_t)written : B_IO_ERROR;
  43
  44         return B_OK;
  45 }
  46
  47
  48 bool
  49 FileReadWrite::Next(BString& string)
  50 {
  51         // Fill up the buffer with the first chunk of data
  52         if (fPositionInBuffer == 0)
  53                 fAmtRead = fFile->Read(&fBuffer, sizeof(fBuffer));
  54         while (fAmtRead > 0) {
  55                 while (fPositionInBuffer < fAmtRead) {
  56                         // Return true if we hit a newline or the end of the file
  57                         // TODO: If the source file is expected to have different encoding,
  58                         // don't we need to check for the line endings in that encoding?!
  59                         if (fBuffer[fPositionInBuffer] == '\n') {
  60                                 fPositionInBuffer++;
  61                                 if (fSourceEncoding != -1) {
  62                                         int32 state = 0;
  63                                         int32 bufferLen = string.Length();
  64                                         int32 destBufferLen = bufferLen;
  65                                         char destination[destBufferLen];
  66                                         convert_to_utf8(fSourceEncoding, string.String(),
  67                                                 &bufferLen, destination, &destBufferLen, &state);
  68                                         string = destination;
  69                                 }
  70                                 return true;
  71                         }
  72                         // TODO: Adding one char at a time is very inefficient!
  73                         string += fBuffer[fPositionInBuffer];
  74                         fPositionInBuffer++;
  75                 }
  76
  77                 // Once the buffer runs out, grab some more and start again
  78                 fAmtRead = fFile->Read(&fBuffer, sizeof(fBuffer));
  79                 fPositionInBuffer = 0;
  80         }
  81         return false;
  82 }