sal/osl/unx/readwrite_helper.c

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  */
   9
  10 #include "readwrite_helper.h"
  11
  12 #include <osl/diagnose.h>
  13 #include <system.h>
  14
  15 sal_Bool safeWrite(int fd, void* data, sal_uInt32 dataSize)
  16 {
  17     sal_Int32 nToWrite = dataSize;
  18     unsigned char* dataToWrite = data;
  19
  20     // Check for overflow as we convert a signed to an unsigned.
  21     OSL_ASSERT(dataSize == (sal_uInt32)nToWrite);
  22     while ( nToWrite ) {
  23         sal_Int32 nWritten = write(fd, dataToWrite, nToWrite);
  24         if ( nWritten < 0 ) {
  25             if ( errno == EINTR )
  26                 continue;
  27
  28             return sal_False;
  29
  30         }
  31
  32         OSL_ASSERT(nWritten > 0);
  33         nToWrite -= nWritten;
  34         dataToWrite += nWritten;
  35     }
  36
  37     return sal_True;
  38 }
  39
  40 sal_Bool safeRead( int fd, void* buffer, sal_uInt32 count )
  41 {
  42     sal_Int32 nToRead = count;
  43     unsigned char* bufferForReading = buffer;
  44
  45     // Check for overflow as we convert a signed to an unsigned.
  46     OSL_ASSERT(count == (sal_uInt32)nToRead);
  47     while ( nToRead ) {
  48         sal_Int32 nRead = read(fd, bufferForReading, nToRead);
  49         if ( nRead < 0 ) {
  50             // We were interrupted before reading, retry.
  51             if (errno == EINTR)
  52                 continue;
  53
  54             return sal_False;
  55         }
  56
  57         // If we reach the EOF, we consider this a partial transfer and thus
  58         // an error.
  59         if ( nRead == 0 )
  60             return sal_False;
  61
  62         nToRead -= nRead;
  63         bufferForReading += nRead;
  64     }
  65
  66     return sal_True;
  67 }
  68
  69 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */