bt_open.c

这是linux下运行的mysql软件包,可用于linux 下安装 php + mysql + apach 的网络配置

	if ((ret =
	    __db_lget(dbc, 0, base_pgno, DB_LOCK_READ, 0, &metalock)) != 0)
		goto err;
	if ((ret = mpf->get(mpf, &base_pgno, 0, (PAGE **)&meta)) != 0)
		goto err;

	/*
	 * If the magic number is set, the tree has been created.  Correct
	 * any fields that may not be right.  Note, all of the local flags
	 * were set by DB->open.
	 *
	 * Otherwise, we'd better be in recovery or abort, in which case the
	 * metadata page will be created/initialized elsewhere.
	 */
	DB_ASSERT(meta->dbmeta.magic != 0 ||
	    IS_RECOVERING(dbp->dbenv) || F_ISSET(dbp, DB_AM_RECOVER));

	t->bt_maxkey = meta->maxkey;
	t->bt_minkey = meta->minkey;
	t->re_pad = meta->re_pad;
	t->re_len = meta->re_len;

	t->bt_meta = base_pgno;
	t->bt_root = meta->root;

	/*
	 * !!!
	 * If creating a subdatabase, we've already done an insert when
	 * we put the subdatabase's entry into the master database, so
	 * our last-page-inserted value is wrongly initialized for the
	 * master database, not the subdatabase we're creating.  I'm not
	 * sure where the *right* place to clear this value is, it's not
	 * intuitively obvious that it belongs here.
	 */
	t->bt_lpgno = PGNO_INVALID;

	/* We must initialize last_pgno, it could be stale. */
	if (!LF_ISSET(DB_RDONLY) && dbp->meta_pgno == PGNO_BASE_MD) {
		mpf->last_pgno(mpf, &meta->dbmeta.last_pgno);
		ret = mpf->put(mpf, meta, DB_MPOOL_DIRTY);
	} else
		ret = mpf->put(mpf, meta, 0);
	meta = NULL;

err:	/* Put the metadata page back. */
	if (meta != NULL && (t_ret = mpf->put(mpf, meta, 0)) != 0 && ret == 0)
		ret = t_ret;
	if ((t_ret = __LPUT(dbc, metalock)) != 0 && ret == 0)
		ret = t_ret;

	if ((t_ret = dbc->c_close(dbc)) != 0 && ret == 0)
		ret = t_ret;
	return (ret);
}

/*
 * __bam_init_meta --
 *
 * Initialize a btree meta-data page.  The following fields may need
 * to be updated later: last_pgno, root.
 */
static void
__bam_init_meta(dbp, meta, pgno, lsnp)
	DB *dbp;
	BTMETA *meta;
	db_pgno_t pgno;
	DB_LSN *lsnp;
{
	BTREE *t;

	memset(meta, 0, sizeof(BTMETA));
	meta->dbmeta.lsn = *lsnp;
	meta->dbmeta.pgno = pgno;
	meta->dbmeta.magic = DB_BTREEMAGIC;
	meta->dbmeta.version = DB_BTREEVERSION;
	meta->dbmeta.pagesize = dbp->pgsize;
	if (F_ISSET(dbp, DB_AM_CHKSUM))
		FLD_SET(meta->dbmeta.metaflags, DBMETA_CHKSUM);
	if (F_ISSET(dbp, DB_AM_ENCRYPT)) {
		meta->dbmeta.encrypt_alg =
		    ((DB_CIPHER *)dbp->dbenv->crypto_handle)->alg;
		DB_ASSERT(meta->dbmeta.encrypt_alg != 0);
		meta->crypto_magic = meta->dbmeta.magic;
	}
	meta->dbmeta.type = P_BTREEMETA;
	meta->dbmeta.free = PGNO_INVALID;
	meta->dbmeta.last_pgno = pgno;
	if (F_ISSET(dbp, DB_AM_DUP))
		F_SET(&meta->dbmeta, BTM_DUP);
	if (F_ISSET(dbp, DB_AM_FIXEDLEN))
		F_SET(&meta->dbmeta, BTM_FIXEDLEN);
	if (F_ISSET(dbp, DB_AM_RECNUM))
		F_SET(&meta->dbmeta, BTM_RECNUM);
	if (F_ISSET(dbp, DB_AM_RENUMBER))
		F_SET(&meta->dbmeta, BTM_RENUMBER);
	if (F_ISSET(dbp, DB_AM_SUBDB))
		F_SET(&meta->dbmeta, BTM_SUBDB);
	if (dbp->dup_compare != NULL)
		F_SET(&meta->dbmeta, BTM_DUPSORT);
	if (dbp->type == DB_RECNO)
		F_SET(&meta->dbmeta, BTM_RECNO);
	memcpy(meta->dbmeta.uid, dbp->fileid, DB_FILE_ID_LEN);

	t = dbp->bt_internal;
	meta->maxkey = t->bt_maxkey;
	meta->minkey = t->bt_minkey;
	meta->re_len = t->re_len;
	meta->re_pad = t->re_pad;
}

/*
 * __bam_new_file --
 * Create the necessary pages to begin a new database file.
 *
 * This code appears more complex than it is because of the two cases (named
 * and unnamed).  The way to read the code is that for each page being created,
 * there are three parts: 1) a "get page" chunk (which either uses malloc'd
 * memory or calls mpf->get), 2) the initialization, and 3) the "put page"
 * chunk which either does a fop write or an mpf->put.
 *
 * PUBLIC: int __bam_new_file __P((DB *, DB_TXN *, DB_FH *, const char *));
 */
int
__bam_new_file(dbp, txn, fhp, name)
	DB *dbp;
	DB_TXN *txn;
	DB_FH *fhp;
	const char *name;
{
	BTMETA *meta;
	DB_ENV *dbenv;
	DB_LSN lsn;
	DB_MPOOLFILE *mpf;
	DB_PGINFO pginfo;
	DBT pdbt;
	PAGE *root;
	db_pgno_t pgno;
	int ret;
	void *buf;

	dbenv = dbp->dbenv;
	mpf = dbp->mpf;
	root = NULL;
	meta = NULL;
	memset(&pdbt, 0, sizeof(pdbt));

	/* Build meta-data page. */

	if (name == NULL) {
		pgno = PGNO_BASE_MD;
		ret = mpf->get(mpf, &pgno, DB_MPOOL_CREATE, &meta);
	} else {
		pginfo.db_pagesize = dbp->pgsize;
		pginfo.flags =
		    F_ISSET(dbp, (DB_AM_CHKSUM | DB_AM_ENCRYPT | DB_AM_SWAP));
		pginfo.type = dbp->type;
		pdbt.data = &pginfo;
		pdbt.size = sizeof(pginfo);
		ret = __os_calloc(dbp->dbenv, 1, dbp->pgsize, &buf);
		meta = (BTMETA *)buf;
	}
	if (ret != 0)
		return (ret);

	LSN_NOT_LOGGED(lsn);
	__bam_init_meta(dbp, meta, PGNO_BASE_MD, &lsn);
	meta->root = 1;
	meta->dbmeta.last_pgno = 1;

	if (name == NULL)
		ret = mpf->put(mpf, meta, DB_MPOOL_DIRTY);
	else {
		if ((ret = __db_pgout(dbenv, PGNO_BASE_MD, meta, &pdbt)) != 0)
			goto err;
		ret = __fop_write(dbenv,
		    txn, name, DB_APP_DATA, fhp, 0, buf, dbp->pgsize, 1);
	}
	if (ret != 0)
		goto err;
	meta = NULL;

	/* Now build root page. */
	if (name == NULL) {
		pgno = 1;
		if ((ret = mpf->get(mpf, &pgno, DB_MPOOL_CREATE, &root)) != 0)
			goto err;
	} else {
#ifdef DIAGNOSTIC
		memset(buf, 0, dbp->pgsize);
#endif
		root = (PAGE *)buf;
	}

	P_INIT(root, dbp->pgsize, 1, PGNO_INVALID, PGNO_INVALID,
	    LEAFLEVEL, dbp->type == DB_RECNO ? P_LRECNO : P_LBTREE);
	LSN_NOT_LOGGED(root->lsn);

	if (name == NULL)
		ret = mpf->put(mpf, root, DB_MPOOL_DIRTY);
	else {
		if ((ret = __db_pgout(dbenv, root->pgno, root, &pdbt)) != 0)
			goto err;
		ret = __fop_write(dbenv, txn,
		    name, DB_APP_DATA, fhp, dbp->pgsize, buf, dbp->pgsize, 1);
	}
	if (ret != 0)
		goto err;
	root = NULL;

err:	if (name != NULL)
		__os_free(dbenv, buf);
	else {
		if (meta != NULL)
			(void)mpf->put(mpf, meta, 0);
		if (root != NULL)
			(void)mpf->put(mpf, root, 0);
	}
	return (ret);
}

/*
 * __bam_new_subdb --
 *	Create a metadata page and a root page for a new btree.
 *
 * PUBLIC: int __bam_new_subdb __P((DB *, DB *, DB_TXN *));
 */
int
__bam_new_subdb(mdbp, dbp, txn)
	DB *mdbp, *dbp;
	DB_TXN *txn;
{
	BTMETA *meta;
	DBC *dbc;
	DB_ENV *dbenv;
	DB_LOCK metalock;
	DB_LSN lsn;
	DB_MPOOLFILE *mpf;
	PAGE *root;
	int ret, t_ret;

	dbenv = mdbp->dbenv;
	mpf = mdbp->mpf;
	dbc = NULL;
	meta = NULL;
	root = NULL;

	if ((ret = mdbp->cursor(mdbp, txn,
	    &dbc, CDB_LOCKING(dbenv) ?  DB_WRITECURSOR : 0)) != 0)
		return (ret);

	/* Get, and optionally create the metadata page. */
	if ((ret = __db_lget(dbc,
	    0, dbp->meta_pgno, DB_LOCK_WRITE, 0, &metalock)) != 0)
		goto err;
	if ((ret = mpf->get(mpf, &dbp->meta_pgno, DB_MPOOL_CREATE, &meta)) != 0)
		goto err;

	/* Build meta-data page. */
	lsn = meta->dbmeta.lsn;
	__bam_init_meta(dbp, meta, dbp->meta_pgno, &lsn);
	if ((ret = __db_log_page(mdbp,
	    txn, &meta->dbmeta.lsn, dbp->meta_pgno, (PAGE *)meta)) != 0)
		goto err;

	/* Create and initialize a root page. */
	if ((ret = __db_new(dbc,
	    dbp->type == DB_RECNO ? P_LRECNO : P_LBTREE, &root)) != 0)
		goto err;
	root->level = LEAFLEVEL;

	if (DBENV_LOGGING(dbenv) &&
	    (ret = __bam_root_log(mdbp, txn, &meta->dbmeta.lsn, 0,
	    meta->dbmeta.pgno, root->pgno, &meta->dbmeta.lsn)) != 0)
		goto err;

	meta->root = root->pgno;
	if ((ret =
	    __db_log_page(mdbp, txn, &root->lsn, root->pgno, root)) != 0)
		goto err;

	/* Release the metadata and root pages. */
	if ((ret = mpf->put(mpf, meta, DB_MPOOL_DIRTY)) != 0)
		goto err;
	meta = NULL;
	if ((ret = mpf->put(mpf, root, DB_MPOOL_DIRTY)) != 0)
		goto err;
	root = NULL;
err:
	if (meta != NULL)
		if ((t_ret = mpf->put(mpf, meta, 0)) != 0 && ret == 0)
			ret = t_ret;
	if (root != NULL)
		if ((t_ret = mpf->put(mpf, root, 0)) != 0 && ret == 0)
			ret = t_ret;
	if (LOCK_ISSET(metalock))
		if ((t_ret = __LPUT(dbc, metalock)) != 0 && ret == 0)
			ret = t_ret;
	if (dbc != NULL)
		if ((t_ret = dbc->c_close(dbc)) != 0 && ret == 0)
			ret = t_ret;
	return (ret);
}