lib/libnisdb/db_vers.cc

	db_vers.cc revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 *  db_vers.cc
 *
 *  Copyright (c) 1988-2000 by Sun Microsystems, Inc.
 *  All Rights Reserved.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

#include <stdio.h>
#include <string.h>

#include "db_headers.h"
#include "db_vers.h"
#include "nisdb_mt.h"

const long unsigned MAXLOW = 32768*32768;

/* Constructor that makes copy of 'other'. */
vers::vers(vers* other)
{
    INITRW(vers);
    assign(other);
}

void
vers::assign(vers* other)
{
    WRITELOCKV(this, "w vers::assign");
    if (other == NULL) {
        syslog(LOG_ERR, "vers::vers: making copy of null vers?");
        vers_high = vers_low = time_sec = time_usec = 0;
    } else {
        time_sec = other->time_sec;
        time_usec = other->time_usec;
        vers_low = other->vers_low;
        vers_high = other->vers_high;
    }
    WRITEUNLOCKV(this, "wu vers::assign");
}

/*
 * Creates new 'vers' with next higher minor version.
 * If minor version exceeds MAXLOW, bump up major version instead.
 * Set timestamp to that of the current time.
 */
vers*
vers::nextminor()
{
    READLOCK(this, NULL, "r vers::nextminor");

    vers * newvers = new vers;

    if (newvers == NULL) {
        READUNLOCK(this, NULL, "ru vers::nextminor DB_MEMORY_LIMIT");
        FATAL3("vers::nextminor: cannot allocation space",
            DB_MEMORY_LIMIT, NULL);
    }

    struct timeval mt;
    gettimeofday(&mt, NULL);

    newvers->time_sec = (unsigned int) mt.tv_sec;
    newvers->time_usec = (unsigned int) mt.tv_usec;
    newvers->vers_low = (this->vers_low + 1);
    newvers->vers_high = (this->vers_high);

    if (newvers->vers_low >= MAXLOW){
        newvers->vers_high++;
        newvers->vers_low = 0;
    }

    READUNLOCK(this, newvers, "ru vers::nextminor");
    return (newvers);
}

/*
 * Creates new 'vers' with next higher major version.
 * Set timestamp to that of the current time.
 */
vers*
vers::nextmajor()
{
    READLOCK(this, NULL, "r vers::nextmajor");

    vers * newvers = new vers;

    if (newvers == NULL) {
        READUNLOCK(this, NULL, "ru vers::nextmajor DB_MEMORY_LIMIT");
        FATAL3("vers::nextminor: cannot allocation space",
            DB_MEMORY_LIMIT, NULL);
    }

    struct timeval mt;
    gettimeofday(&mt, NULL);

    newvers->time_sec = (unsigned int) mt.tv_sec;
    newvers->time_usec = (unsigned int) mt.tv_usec;
    newvers->vers_low = 0;
    newvers->vers_high = (this->vers_high+1);

    READUNLOCK(this, newvers, "ru vers::nextmajor");
    return (newvers);
}

/*
 * Predicate indicating whether this vers is earlier than 'other' in
 * terms of version numbers.
*/
bool_t
vers::earlier_than(vers *other)
{
    int ret, lret;

    if (other == NULL) {
        syslog(LOG_ERR,
            "vers::earlier_than: comparing against null vers");
        return (FALSE);
    }

    READLOCK(this, FALSE, "r vers::earlier_than");
    READLOCKNR(other, lret, "r other vers::earlier_than");
    if (lret != 0) {
        READUNLOCK(this, FALSE, "ru + r other vers::earlier_than");
        return (FALSE);
    }

    if (other->vers_high > vers_high) ret = TRUE;
    else if (other->vers_high < vers_high) ret = FALSE;
    else if (other->vers_low > vers_low) ret = TRUE;
    else ret = FALSE;

    READUNLOCKNR(other, lret, "ru other vers::earlier_than");
    READUNLOCK(this, ret, ((lret != 0) ?
                "ru + ru other vers::earlier_than" :
                "ru vers::earlier_than"));
    return (ret);
}

/* Print the value of this 'vers' to specified file. */
void
vers::print(FILE* file)
{
    char *thetime;
    thetime = ctime((long *) (&(time_sec)));
    thetime[strlen(thetime)-1] = 0;

    READLOCKV(this, "r vers::print");
    fprintf(file, "version=%u.%u %s:%u",
        vers_high,
        vers_low,
        /* time_sec, */
        thetime,
        time_usec);
    READUNLOCKV(this, "ru vers::print");
}

void
vers::zero() {
    WRITELOCKV(this, "r vers::zero");
    vers_high = vers_low = time_sec = time_usec = 0;
    WRITEUNLOCKV(this, "ru vers::zero");
}

bool_t
vers::equal( vers *other) {
    READLOCK(this, FALSE, "r vers::equal");
    bool_t ret = other != NULL &&
        vers_high == other->vers_high &&
        vers_low == other->vers_low &&
        time_sec == other->time_sec &&
        time_usec == other->time_usec;
    READUNLOCK(this, ret, "ru vers::equal");
    return (ret);
};