db_server_cxxutil.cpp

mysql数据库源代码

new_ct_ent(int *errp)
{
	time_t t;
	ct_entry *ctp, *octp;
	int ret;

	if ((ret = __os_malloc(NULL, sizeof(ct_entry), &ctp)) != 0) {
		*errp = ret;
		return (NULL);
	}
	memset(ctp, 0, sizeof(ct_entry));
	/*
	 * Get the time as ID.  We may service more than one request per
	 * second however.  If we are, then increment id value until we
	 * find an unused one.  We insert entries in LRU fashion at the
	 * head of the list.  So, if the first entry doesn't match, then
	 * we know for certain that we can use our entry.
	 */
	if ((t = time(NULL)) == -1) {
		*errp = __os_get_errno();
		__os_free(NULL, ctp);
		return (NULL);
	}
	octp = LIST_FIRST(&__dbsrv_head);
	if (octp != NULL && octp->ct_id >= t)
		t = octp->ct_id + 1;
	ctp->ct_id = t;
	ctp->ct_idle = __dbsrv_idleto;
	ctp->ct_activep = &ctp->ct_active;
	ctp->ct_origp = NULL;
	ctp->ct_refcount = 1;

	LIST_INSERT_HEAD(&__dbsrv_head, ctp, entries);
	return (ctp);
}

extern "C" ct_entry *
get_tableent(long id)
{
	ct_entry *ctp;

	for (ctp = LIST_FIRST(&__dbsrv_head); ctp != NULL;
	    ctp = LIST_NEXT(ctp, entries))
		if (ctp->ct_id == id)
			return (ctp);
	return (NULL);
}

extern "C" ct_entry *
__dbsrv_sharedb(ct_entry *db_ctp, const char *name, const char *subdb, DBTYPE type, u_int32_t flags)
{
	ct_entry *ctp;

	/*
	 * Check if we can share a db handle.  Criteria for sharing are:
	 * If any of the non-sharable flags are set, we cannot share.
	 * Must be a db ctp, obviously.
	 * Must share the same env parent.
	 * Must be the same type, or current one DB_UNKNOWN.
	 * Must be same byteorder, or current one must not care.
	 * All flags must match.
	 * Must be same name, but don't share in-memory databases.
	 * Must be same subdb name.
	 */
	if (flags & DB_SERVER_DBNOSHARE)
		return (NULL);
	for (ctp = LIST_FIRST(&__dbsrv_head); ctp != NULL;
	    ctp = LIST_NEXT(ctp, entries)) {
		/*
		 * Skip ourselves.
		 */
		if (ctp == db_ctp)
			continue;
		if (ctp->ct_type != CT_DB)
			continue;
		if (ctp->ct_envparent != db_ctp->ct_envparent)
			continue;
		if (type != DB_UNKNOWN && ctp->ct_dbdp.type != type)
			continue;
		if (ctp->ct_dbdp.dbflags != LF_ISSET(DB_SERVER_DBFLAGS))
			continue;
		if (db_ctp->ct_dbdp.setflags != 0 &&
		    ctp->ct_dbdp.setflags != db_ctp->ct_dbdp.setflags)
			continue;
		if (name == NULL || ctp->ct_dbdp.db == NULL ||
		    strcmp(name, ctp->ct_dbdp.db) != 0)
			continue;
		if (subdb != ctp->ct_dbdp.subdb &&
		    (subdb == NULL || ctp->ct_dbdp.subdb == NULL ||
		    strcmp(subdb, ctp->ct_dbdp.subdb) != 0))
			continue;
		/*
		 * If we get here, then we match.
		 */
		ctp->ct_refcount++;
		return (ctp);
	}

	return (NULL);
}

extern "C" ct_entry *
__dbsrv_shareenv(ct_entry *env_ctp, home_entry *home, u_int32_t flags)
{
	ct_entry *ctp;

	/*
	 * Check if we can share an env.  Criteria for sharing are:
	 * Must be an env ctp, obviously.
	 * Must share the same home env.
	 * All flags must match.
	 */
	for (ctp = LIST_FIRST(&__dbsrv_head); ctp != NULL;
	    ctp = LIST_NEXT(ctp, entries)) {
		/*
		 * Skip ourselves.
		 */
		if (ctp == env_ctp)
			continue;
		if (ctp->ct_type != CT_ENV)
			continue;
		if (ctp->ct_envdp.home != home)
			continue;
		if (ctp->ct_envdp.envflags != flags)
			continue;
		if (ctp->ct_envdp.onflags != env_ctp->ct_envdp.onflags)
			continue;
		if (ctp->ct_envdp.offflags != env_ctp->ct_envdp.offflags)
			continue;
		/*
		 * If we get here, then we match.  The only thing left to
		 * check is the timeout.  Since the server timeout set by
		 * the client is a hint, for sharing we'll give them the
		 * benefit of the doubt and grant them the longer timeout.
		 */
		if (ctp->ct_timeout < env_ctp->ct_timeout)
			ctp->ct_timeout = env_ctp->ct_timeout;
		ctp->ct_refcount++;
		return (ctp);
	}

	return (NULL);
}

extern "C" void
__dbsrv_active(ct_entry *ctp)
{
	time_t t;
	ct_entry *envctp;

	if (ctp == NULL)
		return;
	if ((t = time(NULL)) == -1)
		return;
	*(ctp->ct_activep) = t;
	if ((envctp = ctp->ct_envparent) == NULL)
		return;
	*(envctp->ct_activep) = t;
	return;
}

extern "C" int
__db_close_int(long id, u_int32_t flags)
{
	Db *dbp;
	int ret;
	ct_entry *ctp;

	ret = 0;
	ctp = get_tableent(id);
	if (ctp == NULL)
		return (DB_NOSERVER_ID);
	DB_ASSERT(ctp->ct_type == CT_DB);
	if (__dbsrv_verbose && ctp->ct_refcount != 1)
		printf("Deref'ing dbp id %ld, refcount %d\n",
		    id, ctp->ct_refcount);
	if (--ctp->ct_refcount != 0)
		return (ret);
	dbp = ctp->ct_dbp;
	if (__dbsrv_verbose)
		printf("Closing dbp id %ld\n", id);

	ret = dbp->close(flags);
	__dbdel_ctp(ctp);
	return (ret);
}

extern "C" int
__dbc_close_int(ct_entry *dbc_ctp)
{
	Dbc *dbc;
	int ret;
	ct_entry *ctp;

	dbc = (Dbc *)dbc_ctp->ct_anyp;

	ret = dbc->close();
	/*
	 * If this cursor is a join cursor then we need to fix up the
	 * cursors that it was joined from so that they are independent again.
	 */
	if (dbc_ctp->ct_type & CT_JOINCUR)
		for (ctp = LIST_FIRST(&__dbsrv_head); ctp != NULL;
		    ctp = LIST_NEXT(ctp, entries)) {
			/*
			 * Test if it is a join cursor, and if it is part
			 * of this one.
			 */
			if ((ctp->ct_type & CT_JOIN) &&
			    ctp->ct_activep == &dbc_ctp->ct_active) {
				ctp->ct_type &= ~CT_JOIN;
				ctp->ct_activep = ctp->ct_origp;
				__dbsrv_active(ctp);
			}
		}
	__dbclear_ctp(dbc_ctp);
	return (ret);

}

extern "C" int
__dbenv_close_int(long id, u_int32_t flags, int force)
{
	DbEnv *dbenv;
	int ret;
	ct_entry *ctp;

	ret = 0;
	ctp = get_tableent(id);
	if (ctp == NULL)
		return (DB_NOSERVER_ID);
	DB_ASSERT(ctp->ct_type == CT_ENV);
	if (__dbsrv_verbose && ctp->ct_refcount != 1)
		printf("Deref'ing env id %ld, refcount %d\n",
		    id, ctp->ct_refcount);
	/*
	 * If we are timing out, we need to force the close, no matter
	 * what the refcount.
	 */
	if (--ctp->ct_refcount != 0 && !force)
		return (ret);
	dbenv = ctp->ct_envp;
	if (__dbsrv_verbose)
		printf("Closing env id %ld\n", id);

	ret = dbenv->close(flags);
	__dbdel_ctp(ctp);
	return (ret);
}

static int
add_home(char *home)
{
	home_entry *hp, *homep;
	int ret;

	if ((ret = __os_malloc(NULL, sizeof(home_entry), &hp)) != 0)
		return (ret);
	if ((ret = __os_malloc(NULL, strlen(home)+1, &hp->home)) != 0)
		return (ret);
	memcpy(hp->home, home, strlen(home)+1);
	hp->dir = home;
	hp->passwd = NULL;
	/*
	 * This loop is to remove any trailing path separators,
	 * to assure hp->name points to the last component.
	 */
	hp->name = __db_rpath(home);
	*(hp->name) = '\0';
	hp->name++;
	while (*(hp->name) == '\0') {
		hp->name = __db_rpath(home);
		*(hp->name) = '\0';
		hp->name++;
	}
	/*
	 * Now we have successfully added it.  Make sure there are no
	 * identical names.
	 */
	for (homep = LIST_FIRST(&__dbsrv_home); homep != NULL;
	    homep = LIST_NEXT(homep, entries))
		if (strcmp(homep->name, hp->name) == 0) {
			printf("Already added home name %s, at directory %s\n",
			    hp->name, homep->dir);
			return (-1);
		}
	LIST_INSERT_HEAD(&__dbsrv_home, hp, entries);
	if (__dbsrv_verbose)
		printf("Added home %s in dir %s\n", hp->name, hp->dir);
	return (0);
}

static int
add_passwd(char *passwd)
{
	home_entry *hp;

	/*
	 * We add the passwd to the last given home dir.  If there
	 * isn't a home dir, or the most recent one already has a
	 * passwd, then there is a user error.
	 */
	hp = LIST_FIRST(&__dbsrv_home);
	if (hp == NULL || hp->passwd != NULL)
		return (EINVAL);
	/*
	 * We've already strdup'ed the passwd above, so we don't need
	 * to malloc new space, just point to it.
	 */
	hp->passwd = passwd;
	return (0);
}

extern "C" home_entry *
get_home(char *name)
{
	home_entry *hp;

	for (hp = LIST_FIRST(&__dbsrv_home); hp != NULL;
	    hp = LIST_NEXT(hp, entries))
		if (strcmp(name, hp->name) == 0)
			return (hp);
	return (NULL);
}

static int
env_recover(char *progname)
{
	DbEnv *dbenv;
	home_entry *hp;
	u_int32_t flags;
	int exitval, ret;

	for (hp = LIST_FIRST(&__dbsrv_home); hp != NULL;
	    hp = LIST_NEXT(hp, entries)) {
		exitval = 0;
		dbenv = new DbEnv(DB_CXX_NO_EXCEPTIONS);
		if (__dbsrv_verbose == 1) {
			(void)dbenv->set_verbose(DB_VERB_RECOVERY, 1);
			(void)dbenv->set_verbose(DB_VERB_CHKPOINT, 1);
		}
		dbenv->set_errfile(stderr);
		dbenv->set_errpfx(progname);
		if (hp->passwd != NULL)
			(void)dbenv->set_encrypt(hp->passwd, DB_ENCRYPT_AES);

		/*
		 * Initialize the env with DB_RECOVER.  That is all we
		 * have to do to run recovery.
		 */
		if (__dbsrv_verbose)
			printf("Running recovery on %s\n", hp->home);
		flags = DB_CREATE | DB_INIT_LOCK | DB_INIT_LOG | DB_INIT_MPOOL |
		    DB_INIT_TXN | DB_USE_ENVIRON | DB_RECOVER;
		if ((ret = dbenv->open(hp->home, flags, 0)) != 0) {
			dbenv->err(ret, "DbEnv->open");
			goto error;
		}

		if (0) {
error:			exitval = 1;
		}
		if ((ret = dbenv->close(0)) != 0) {
			exitval = 1;
			fprintf(stderr, "%s: dbenv->close: %s\n",
			    progname, db_strerror(ret));
		}
		if (exitval)
			return (exitval);
	}
	return (0);
}