mp_register.c

/*-
 * See the file LICENSE for redistribution information.
 *
 * Copyright (c) 1996-2005
 *      Sleepycat Software.  All rights reserved.
 *
 * $Id: mp_register.c,v 12.6 2005/10/07 20:21:33 ubell Exp $
 */

#include "db_config.h"

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

#include "db_int.h"
#include "dbinc/db_shash.h"
#include "dbinc/log.h"
#include "dbinc/mp.h"

/*
 * memp_register_pp --
 *      DB_ENV->memp_register pre/post processing.
 *
 * PUBLIC: int __memp_register_pp __P((DB_ENV *, int,
 * PUBLIC:     int (*)(DB_ENV *, db_pgno_t, void *, DBT *),
 * PUBLIC:     int (*)(DB_ENV *, db_pgno_t, void *, DBT *)));
 */
int
__memp_register_pp(dbenv, ftype, pgin, pgout)
        DB_ENV *dbenv;
        int ftype;
        int (*pgin) __P((DB_ENV *, db_pgno_t, void *, DBT *));
        int (*pgout) __P((DB_ENV *, db_pgno_t, void *, DBT *));
{
        DB_THREAD_INFO *ip;
        int ret;

        PANIC_CHECK(dbenv);
        ENV_REQUIRES_CONFIG(dbenv,
            dbenv->mp_handle, "DB_ENV->memp_register", DB_INIT_MPOOL);

        ENV_ENTER(dbenv, ip);
        REPLICATION_WRAP(dbenv,
            (__memp_register(dbenv, ftype, pgin, pgout)), ret);
        ENV_LEAVE(dbenv, ip);
        return (ret);
}

/*
 * memp_register --
 *      DB_ENV->memp_register.
 *
 * PUBLIC: int __memp_register __P((DB_ENV *, int,
 * PUBLIC:     int (*)(DB_ENV *, db_pgno_t, void *, DBT *),
 * PUBLIC:     int (*)(DB_ENV *, db_pgno_t, void *, DBT *)));
 */
int
__memp_register(dbenv, ftype, pgin, pgout)
        DB_ENV *dbenv;
        int ftype;
        int (*pgin) __P((DB_ENV *, db_pgno_t, void *, DBT *));
        int (*pgout) __P((DB_ENV *, db_pgno_t, void *, DBT *));
{
        DB_MPOOL *dbmp;
        DB_MPREG *mpreg;
        int ret;

        dbmp = dbenv->mp_handle;

        /*
         * We keep the DB pgin/pgout functions outside of the linked list
         * to avoid locking/unlocking the linked list on every page I/O.
         *
         * The Berkeley DB I/O conversion functions are registered when the
         * environment is first created, so there's no need for locking here.
         */
        if (ftype == DB_FTYPE_SET) {
                if (dbmp->pg_inout != NULL)
                        return (0);
                if ((ret =
                    __os_malloc(dbenv, sizeof(DB_MPREG), &dbmp->pg_inout)) != 0)
                        return (ret);
                dbmp->pg_inout->ftype = ftype;
                dbmp->pg_inout->pgin = pgin;
                dbmp->pg_inout->pgout = pgout;
                return (0);
        }

        /*
         * The item may already have been registered.  If already registered,
         * just update the entry, although it's probably unchanged.
         */
        MUTEX_LOCK(dbenv, dbmp->mutex);
        for (mpreg = LIST_FIRST(&dbmp->dbregq);
            mpreg != NULL; mpreg = LIST_NEXT(mpreg, q))
                if (mpreg->ftype == ftype) {
                        mpreg->pgin = pgin;
                        mpreg->pgout = pgout;
                        break;
                }

        if (mpreg == NULL) {                    /* New entry. */
                if ((ret = __os_malloc(dbenv, sizeof(DB_MPREG), &mpreg)) != 0)
                        return (ret);
                mpreg->ftype = ftype;
                mpreg->pgin = pgin;
                mpreg->pgout = pgout;

                LIST_INSERT_HEAD(&dbmp->dbregq, mpreg, q);
        }
        MUTEX_UNLOCK(dbenv, dbmp->mutex);

        return (0);
}

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