sal/osl/unx/readwrite_helper.c

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * Version: MPL 1.1 / GPLv3+ / LGPLv3+
   4  *
   5  * The contents of this file are subject to the Mozilla Public License Version
   6  * 1.1 (the "License"); you may not use this file except in compliance with
   7  * the License or as specified alternatively below. You may obtain a copy of
   8  * the License at http://www.mozilla.org/MPL/
   9  *
  10  * Software distributed under the License is distributed on an "AS IS" basis,
  11  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  12  * for the specific language governing rights and limitations under the
  13  * License.
  14  *
  15  * The Initial Developer of the Original Code is
  16  *       Julien Chaffraix <julien.chaffraix@gmail.com>
  17  * Portions created by the Initial Developer are Copyright (C) 2011 the
  18  * Initial Developer. All Rights Reserved.
  19  *
  20  * Major Contributor(s):
  21  *
  22  * For minor contributions see the git repository.
  23  *
  24  * Alternatively, the contents of this file may be used under the terms of
  25  * either the GNU General Public License Version 3 or later (the "GPLv3+"), or
  26  * the GNU Lesser General Public License Version 3 or later (the "LGPLv3+"),
  27  * in which case the provisions of the GPLv3+ or the LGPLv3+ are applicable
  28  * instead of those above.
  29  */
  30
  31 #include "readwrite_helper.h"
  32
  33 #include <osl/diagnose.h>
  34 #include <system.h>
  35
  36 sal_Bool safeWrite(int fd, void* data, sal_uInt32 dataSize)
  37 {
  38     sal_Int32 nToWrite = dataSize;
  39     unsigned char* dataToWrite = data;
  40
  41     // Check for overflow as we convert a signed to an unsigned.
  42     OSL_ASSERT(dataSize == (sal_uInt32)nToWrite);
  43     while ( nToWrite ) {
  44         sal_Int32 nWritten = write(fd, dataToWrite, nToWrite);
  45         if ( nWritten < 0 ) {
  46             if ( errno == EINTR )
  47                 continue;
  48
  49             return sal_False;
  50
  51         }
  52
  53         OSL_ASSERT(nWritten > 0);
  54         nToWrite -= nWritten;
  55         dataToWrite += nWritten;
  56     }
  57
  58     return sal_True;
  59 }
  60
  61 sal_Bool safeRead( int fd, void* buffer, sal_uInt32 count )
  62 {
  63     sal_Int32 nToRead = count;
  64     unsigned char* bufferForReading = buffer;
  65
  66     // Check for overflow as we convert a signed to an unsigned.
  67     OSL_ASSERT(count == (sal_uInt32)nToRead);
  68     while ( nToRead ) {
  69         sal_Int32 nRead = read(fd, bufferForReading, nToRead);
  70         if ( nRead < 0 ) {
  71             // We were interrupted before reading, retry.
  72             if (errno == EINTR)
  73                 continue;
  74
  75             return sal_False;
  76         }
  77
  78         // If we reach the EOF, we consider this a partial transfer and thus
  79         // an error.
  80         if ( nRead == 0 )
  81             return sal_False;
  82
  83         nToRead -= nRead;
  84         bufferForReading += nRead;
  85     }
  86
  87     return sal_True;
  88 }
  89
  90 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */