modules/client-handler/src/main/java/org/apache/ignite/client/handler/requests/table/ClientSchemasGetRequest.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.ignite.client.handler.requests.table;

import java.util.concurrent.CompletableFuture;
import org.apache.ignite.client.proto.ClientMessagePacker;
import org.apache.ignite.client.proto.ClientMessageUnpacker;
import org.apache.ignite.lang.IgniteException;
import org.apache.ignite.table.manager.IgniteTables;
import org.msgpack.core.MessageFormat;

import static org.apache.ignite.client.handler.requests.table.ClientTableCommon.readTable;
import static org.apache.ignite.client.handler.requests.table.ClientTableCommon.writeSchema;

/**
 * Client schemas retrieval request.
 */
public class ClientSchemasGetRequest {
    /**
     * Processes the request.
     *
     * @param in Unpacker.
     * @param out Packer.
     * @param tables Ignite tables.
     * @return Future.
     * @throws IgniteException When schema registry is no initialized.
     */
    public static CompletableFuture<Object> process(
            ClientMessageUnpacker in,
            ClientMessagePacker out,
            IgniteTables tables
    ) {
        var table = readTable(in, tables);

        if (in.getNextFormat() == MessageFormat.NIL) {
            // Return the latest schema.
            out.packMapHeader(1);

            var schema = table.schemaView().schema();

            if (schema == null)
                throw new IgniteException("Schema registry is not initialized.");

            writeSchema(out, schema.version(), schema);
        }
        else {
            var cnt = in.unpackArrayHeader();
            out.packMapHeader(cnt);

            for (var i = 0; i < cnt; i++) {
                var schemaVer = in.unpackInt();
                var schema = table.schemaView().schema(schemaVer);
                writeSchema(out, schemaVer, schema);
            }
        }

        return null;
    }
}