os_truncate.c

/*-
 * See the file LICENSE for redistribution information.
 *
 * Copyright (c) 2004-2005
 *      Sleepycat Software.  All rights reserved.
 *
 * $Id: os_truncate.c,v 12.2 2005/08/10 15:47:27 bostic Exp $
 */

#include "db_config.h"

#ifndef NO_SYSTEM_INCLUDES
#include <sys/types.h>

#include <string.h>
#endif

#include "db_int.h"

/*
 * __os_truncate --
 *      Truncate the file.
 *
 * PUBLIC: int __os_truncate __P((DB_ENV *, DB_FH *, db_pgno_t, u_int32_t));
 */
int
__os_truncate(dbenv, fhp, pgno, pgsize)
        DB_ENV *dbenv;
        DB_FH *fhp;
        db_pgno_t pgno;
        u_int32_t pgsize;
{
        off_t offset;
        int ret;

        /*
         * Truncate a file so that "pgno" is discarded from the end of the
         * file.
         */
        offset = (off_t)pgsize * pgno;

        if (DB_GLOBAL(j_ftruncate) != NULL)
                ret = DB_GLOBAL(j_ftruncate)(fhp->fd, offset);
        else {
#ifdef HAVE_FTRUNCATE
                RETRY_CHK((ftruncate(fhp->fd, offset)), ret);
#else
                ret = DB_OPNOTSUP;
#endif
        }

        if (ret != 0)
                __db_err(dbenv,
                    "ftruncate: %lu: %s", (u_long)offset, strerror(ret));

        return (ret);
}

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