Line data    Source code

       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             :  * This file incorporates work covered by the following license notice:
      10             :  *
      11             :  *   Licensed to the Apache Software Foundation (ASF) under one or more
      12             :  *   contributor license agreements. See the NOTICE file distributed
      13             :  *   with this work for additional information regarding copyright
      14             :  *   ownership. The ASF licenses this file to you under the Apache
      15             :  *   License, Version 2.0 (the "License"); you may not use this file
      16             :  *   except in compliance with the License. You may obtain a copy of
      17             :  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
      18             :  */
      19             : 
      20             : #include "file_image.h"
      21             : 
      22             : #include <unistd.h>
      23             : 
      24             : #include <errno.h>
      25             : #include <fcntl.h>
      26             : 
      27             : #include <sys/mman.h>
      28             : #include <sys/stat.h>
      29             : 
      30             : #include <string.h>
      31             : 
      32             : /*
      33             :  * file_image_open
      34             :  */
      35        4992 : int file_image_open (file_image * image, const char * filename)
      36             : {
      37        4992 :     int         result = 0;
      38             :     int         fd;
      39             :     struct stat st;
      40             :     void *      p;
      41             : 
      42        4992 :     if (image == 0)
      43           0 :         return (EINVAL);
      44             : 
      45        4992 :     image->m_base = MAP_FAILED, image->m_size = 0;
      46             : 
      47        4992 :     if ((fd = open (filename, O_RDONLY)) == -1)
      48         192 :         return (errno);
      49             : 
      50        4800 :     if (fstat (fd, &st) == -1)
      51             :     {
      52           0 :         result = errno;
      53           0 :         goto cleanup_and_leave;
      54             :     }
      55             : 
      56        4800 :     p = mmap (0, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
      57        4800 :     if (p == MAP_FAILED)
      58             :     {
      59           0 :         result = errno;
      60           0 :         goto cleanup_and_leave;
      61             :     }
      62             : 
      63        4800 :     image->m_base = p, image->m_size = st.st_size;
      64             : 
      65             : cleanup_and_leave:
      66        4800 :     close (fd);
      67        4800 :     return (result);
      68             : }
      69             : 
      70             : /*
      71             :  * file_image_pagein.
      72             :  */
      73        4800 : int file_image_pagein (file_image * image)
      74             : {
      75             :     file_image    w;
      76             :     long          s;
      77             :     size_t        k;
      78             :     // force touching of each page despite the optimizer
      79        4800 :     volatile char c = 0;
      80             : 
      81        4800 :     if (image == 0)
      82           0 :         return (EINVAL);
      83             : 
      84        4800 :     if ((w.m_base = image->m_base) == 0)
      85           0 :         return (EINVAL);
      86        4800 :     if ((w.m_size = image->m_size) == 0)
      87           0 :         return (0);
      88             : 
      89        4800 :     if (madvise (w.m_base, w.m_size, MADV_WILLNEED) == -1)
      90           0 :         return (errno);
      91             : 
      92        4800 :     if ((s = sysconf (_SC_PAGESIZE)) == -1)
      93           0 :         s = 0x1000;
      94             : 
      95        4800 :     k = (size_t)(s);
      96     9191136 :     while (w.m_size > k)
      97             :     {
      98     9181536 :         c ^= ((char*)(w.m_base))[0];
      99     9181536 :         w.m_base  = (char*)(w.m_base) + k;
     100     9181536 :         w.m_size -= k;
     101             :     }
     102        4800 :     if (w.m_size > 0)
     103             :     {
     104        4800 :         c ^= ((char*)(w.m_base))[0];
     105             :     }
     106             : 
     107        4800 :     return (0);
     108             : }
     109             : 
     110             : /*
     111             :  * file_image_close
     112             :  */
     113        4800 : int file_image_close (file_image * image)
     114             : {
     115        4800 :     if (image == 0)
     116           0 :         return (EINVAL);
     117             : 
     118        4800 :     if (munmap (image->m_base, image->m_size) == -1)
     119           0 :         return (errno);
     120             : 
     121        4800 :     image->m_base = 0, image->m_size = 0;
     122        4800 :     return (0);
     123             : }
     124             : 
     125             : /* vim:set shiftwidth=4 softtabstop=4 expandtab: */