sparsecp.c

   1 /*
   2     Copyright (C) 2007-2009 Proxmox Server Solutions GmbH
   3
   4     Copyright: vzdump is under GNU GPL, the GNU General Public License.
   5
   6     This program is free software; you can redistribute it and/or modify
   7     it under the terms of the GNU General Public License as published by
   8     the Free Software Foundation; version 2 dated June, 1991.
   9
  10     This program 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
  13     GNU General Public License for more details.
  14
  15     You should have received a copy of the GNU General Public License
  16     along with this program; if not, write to the
  17     Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
  18     MA 02110-1301, USA.
  19
  20     Author: Dietmar Maurer <dietmar@proxmox.com>
  21
  22 */
  23
  24 #define _GNU_SOURCE
  25
  26 #include <sys/types.h>
  27 #include <sys/stat.h>
  28 #include <fcntl.h>
  29 #include <stdio.h>
  30 #include <stdlib.h>
  31 #include <unistd.h>
  32 #include <errno.h>
  33 #include <string.h>
  34 #include <time.h>
  35 #include <stdint.h>
  36 #include <getopt.h>
  37 #include <signal.h>
  38
  39 #include "utils.c"
  40
  41 #define BLOCKSIZE 512*8
  42
  43 static char *outname;
  44
  45 static void
  46 cleanup (void)
  47 {
  48   if (outname)
  49     unlink (outname);
  50 }
  51
  52 void term_handler()
  53 {
  54   fprintf (stderr, "received signal - terminate process\n");
  55   exit(-1);
  56 }
  57
  58 size_t
  59 sparse_cp (int infd, int outfd)
  60 {
  61   size_t total = 0;
  62   size_t count;
  63   char buffer[BLOCKSIZE];
  64   int last_write_made_hole = 0;
  65
  66   while ((count = safe_read (infd, buffer, sizeof (buffer))) > 0) {
  67     if (block_is_zero (buffer, count)) {
  68
  69       if (lseek (outfd, count, SEEK_CUR) < 0) {
  70         perror ("cannot lseek\n");
  71         exit (-1);
  72       }
  73       last_write_made_hole = 1;
  74     } else {
  75       full_write (outfd, buffer, count);
  76       last_write_made_hole = 0;
  77     }
  78     total += count;
  79   }
  80
  81   if (last_write_made_hole) {
  82     if (ftruncate (outfd, total) < 0) {
  83       perror ("cannot ftruncate\n");
  84       exit (-1);
  85     }
  86   }
  87
  88   return total;
  89 }
  90
  91 int
  92 main (int argc, char **argv)
  93 {
  94   struct sigaction sa;
  95
  96   if (argc != 2) {
  97     fprintf (stderr, "wrong number of arguments\n");
  98     exit (-1);
  99   }
 100
 101   time_t starttime = time(NULL);
 102
 103   outname = argv[1];
 104
 105   int outfd;
 106
 107   if ((outfd = open(outname, O_WRONLY|O_CREAT|O_TRUNC, 0644)) == -1) {
 108     fprintf (stderr, "unable to open file '%s' - %s\n",
 109              outname, strerror (errno));
 110     exit (-1);
 111   }
 112   atexit(cleanup);
 113
 114   setsig(&sa, SIGINT, term_handler, SA_RESTART);
 115   setsig(&sa, SIGQUIT, term_handler, SA_RESTART);
 116   setsig(&sa, SIGTERM, term_handler, SA_RESTART);
 117   setsig(&sa, SIGPIPE, term_handler, SA_RESTART);
 118
 119   size_t total = sparse_cp (0, outfd);
 120
 121   close (outfd);
 122
 123   time_t delay = time(NULL) - starttime;
 124   if (delay <= 0) delay = 1;
 125
 126   fprintf (stderr, "%zu bytes copied, %zd s, %.2f MiB/s\n", total, delay,
 127            (total/(1024*1024))/(float)delay);
 128
 129   outname = NULL;
 130
 131   exit (0);
 132 }