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libsrc/blockio.cxx

Go to the documentation of this file.

/**********************************************************************
 * Copyright 2002 Jeff Rush <jrush@taupro.com>
 * Original Copyright 1979-2002 Udanax.com
 *
 * This file is part of the Udanax xanalogical storage system.
 *
 * Udanax is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * Udanax is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Udanax; if not, write to the Free Software Foundation,
 * Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 **********************************************************************/

/* Modification History:
 * $Log: blockio.cxx,v $
 * Revision 1.3  2004/09/11 13:59:21  jrush
 * Changed all fprintf's to stderr to use the Nana library L() macro.  Also
 * removed a 2-3 minor compiler warnings.
 *
 * Revision 1.2  2004/09/04 16:02:17  jrush
 * Added Doxygen headers before each and every function definition.
 *
 * Revision 1.1  2004/08/28 13:35:26  jrush
 * Catching up CVS to various incomplete versions on local disk.
 *
 *
 */

#include <stdio.h>
#include <memory.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <netinet/in.h>
#include <errno.h>

#include "udanax.h"

    FileBlockIO::OpenStatus
FileBlockIO::open(
    const char *filename)
{
    // Try to Open an Existing File
    blockfd = ::open(filename, O_RDWR, 0);
    if (blockfd >= 0)
        return OS_OPENED; // Existing Media was Found and Opened

    errno = 0;

    // Else Try to Create a New File
    blockfd = creat(filename, 0660);
    if (blockfd >= 0)
        return OS_CREATED; // No Media Found so a New One was Created

    // Error: Unable to Open or Create the File
    perror("FileBlockIO::open");
    return OS_FAILED;
}

    void
FileBlockIO::close()
{
    if (::close(blockfd) != 0) {
        perror("FileBlockIO::close");
        assert(0); // close failed
    }
}

    bool
FileBlockIO::get(
    void     *buf,
    int       buflen,
    BlockNum  blockno)
{
    L("FileBlockIO::get(buf=0x%08lX, buflen=%d, blockno=%d) blocksize=%d\n", buf, buflen, blockno, blocksize);
    assert(buf != NULL);
    assert(blockno != 0);
    assert( goodblock(blockno) );
//    assert(buflen <= blocksize);

//OBSOLETE    if (!enffileread) {
//OBSOLETE        if (close(enffiledes) != 0)
//OBSOLETE            perror("close failed in readloaf");
//OBSOLETE
//OBSOLETE        if ((enffiledes = open("enf.enf",  O_RDWR, 0)) == -1) {
//OBSOLETE            perror("open");
//OBSOLETE            assert(0); // open
//OBSOLETE        }
//OBSOLETE        enffileread = true;
//OBSOLETE    }

    if (lseek(blockfd, (long) blockno * blocksize, 0) < 0) {
        perror("FileBlockIO::get");
        return false;
    }

    int nbytes = read(blockfd, buf, buflen);
    assert(nbytes > 0); // Incorrect Usage of Assertion

    stats.blocks_read++;
    return true;
}

    bool
FileBlockIO::put(
    void     *buf,
    int       buflen,
    BlockNum  blockno)
{
    L("FileBlockIO::put(buf=0x%08lX, buflen=%d, blockno=%d) blocksize=%d\n", buf, buflen, blockno, blocksize);
    assert(buf != NULL);
    assert(blockno != 0);
    assert( goodblock(blockno) );
    assert(buflen <= blocksize);

    if (lseek(blockfd, (long) blockno * blocksize, 0) < 0) {
        perror("FileBlockIO::put");
        return false;
    }

    int nbytes = write(blockfd, buf, buflen);
    assert(nbytes >= 0); // Incorrect Usage of Assert

    stats.blocks_written++;
    return true;
}

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