1 // Copyright (C) 1999,2000 Bruce Guenter <bruceg@em.ca>

     2 //

     3 // This program is free software; you can redistribute it and/or modify

     4 // it under the terms of the GNU General Public License as published by

     5 // the Free Software Foundation; either version 2 of the License, or

     6 // (at your option) any later version.

     7 //

     8 // This program is distributed in the hope that it will be useful,

     9 // but WITHOUT ANY WARRANTY; without even the implied warranty of

    10 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

    11 // GNU General Public License for more details.

    12 //

    13 // You should have received a copy of the GNU General Public License

    14 // along with this program; if not, write to the Free Software

    15 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

    16 

    17 #include "fdbuf.h"

    18 #include <errno.h>

    19 #include <unistd.h>

    20 

    21 bool fdobuf::seek(unsigned o)

    22 {

    23   if(flags)

    24     return false;

    25 

    26   lock();

    27   unsigned buf_start = offset;

    28   unsigned buf_end = offset + buflength;

    29   if(o >= buf_start && o < buf_end) {

    30     bufpos = o - buf_start;

    31   }

    32   else {

    33     if(!nflush(false)) {

    34       unlock();

    35       return false;

    36     }

    37     if(lseek(fd, o, SEEK_SET) != (off_t)o) {

    38       errnum = errno;

    39       flags |= flag_error;

    40       unlock();

    41       return false;

    42     }

    43     offset = o;

    44   }

    45   count = 0;

    46   unlock();

    47   return true;

    48 }