runtime/kioslave/thumbnail/djvucreator.cpp

   1 /*  This file is part of the KDE libraries
   2     Copyright (C) 2001 Malte Starostik <malte@kde.org>
   3     Copyright (C) 2001 Leon Bottou <leon@bottou.org>
   4
   5     This library is free software; you can redistribute it and/or
   6     modify it under the terms of the GNU Library General Public
   7     License as published by the Free Software Foundation; either
   8     version 2 of the License, or (at your option) any later version.
   9
  10     This library is distributed in the hope that it will be useful,
  11     but WITHOUT ANY WARRANTY; without even the implied warranty of
  12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13     Library General Public License for more details.
  14
  15     You should have received a copy of the GNU Library General Public License
  16     along with this library; see the file COPYING.LIB.  If not, write to
  17     the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  18     Boston, MA 02110-1301, USA.
  19 */
  20
  21
  22 #include "djvucreator.h"
  23
  24 #include <config-runtime.h>
  25
  26 #include <assert.h>
  27 #include <stdlib.h>
  28 #include <unistd.h>
  29 #include <signal.h>
  30 #ifdef HAVE_SYS_SELECT_H
  31 #include <sys/select.h>
  32 #endif
  33 #include <sys/time.h>
  34 #include <sys/wait.h>
  35 #include <fcntl.h>
  36 #include <errno.h>
  37
  38 #include <QFile>
  39 #include <QImage>
  40
  41 #include <kdemacros.h>
  42
  43
  44
  45 extern "C"
  46 {
  47     KDE_EXPORT ThumbCreator *new_creator()
  48     {
  49         return new DjVuCreator;
  50     }
  51 }
  52
  53 bool DjVuCreator::create(const QString &path, int width, int height, QImage &img)
  54 {
  55   int output[2];
  56   QByteArray data(1024, 'k');
  57   bool ok = false;
  58
  59   if (pipe(output) == -1)
  60     return false;
  61
  62   const char* argv[8];
  63   QByteArray sizearg, fnamearg;
  64   sizearg = QByteArray::number(width) + 'x' + QByteArray::number(height);
  65   fnamearg = QFile::encodeName( path );
  66   argv[0] = "ddjvu";
  67   argv[1] = "-page";
  68   argv[2] = "1";
  69   argv[3] = "-size";
  70   argv[4] = sizearg.data();
  71   argv[5] = fnamearg.data();
  72   argv[6] = 0;
  73
  74   pid_t pid = fork();
  75   if (pid == 0)
  76     {
  77       close(output[0]);
  78       dup2(output[1], STDOUT_FILENO);
  79       execvp(argv[0], const_cast<char *const *>(argv));
  80       exit(1);
  81     }
  82   else if (pid >= 0)
  83     {
  84       close(output[1]);
  85       int offset = 0;
  86       while (!ok) {
  87         fd_set fds;
  88         FD_ZERO(&fds);
  89         FD_SET(output[0], &fds);
  90         struct timeval tv;
  91         tv.tv_sec = 20;
  92         tv.tv_usec = 0;
  93         if (select(output[0] + 1, &fds, 0, 0, &tv) <= 0) {
  94           if (errno == EINTR || errno == EAGAIN)
  95             continue;
  96           break; // error or timeout
  97         }
  98         if (FD_ISSET(output[0], &fds)) {
  99           int count = read(output[0], data.data() + offset, 1024);
 100           if (count == -1)
 101             break;
 102           if (count) // prepare for next block
 103             {
 104               offset += count;
 105               data.resize(offset + 1024);
 106             }
 107           else // got all data
 108             {
 109               data.resize(offset);
 110               ok = true;
 111             }
 112         }
 113       }
 114       if (!ok)
 115         kill(pid, SIGTERM);
 116       int status = 0;
 117       if (waitpid(pid, &status, 0) != pid || (status != 0  && status != 256) )
 118         ok = false;
 119     }
 120   else
 121     {
 122       close(output[1]);
 123     }
 124
 125   close(output[0]);
 126   int l = img.loadFromData( data );
 127   return ok && l;
 128 }
 129
 130
 131 ThumbCreator::Flags DjVuCreator::flags() const
 132 {
 133   return static_cast<Flags>(DrawFrame);
 134 }
 135
 136