Java tutorial
/* * 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.drill.exec.rpc.user; import org.apache.drill.exec.proto.GeneralRPCProtos.Ack; import org.apache.drill.exec.proto.UserBitShared.QueryId; import org.apache.drill.exec.proto.UserProtos.CreatePreparedStatementReq; import org.apache.drill.exec.proto.UserProtos.GetCatalogsReq; import org.apache.drill.exec.proto.UserProtos.GetColumnsReq; import org.apache.drill.exec.proto.UserProtos.GetQueryPlanFragments; import org.apache.drill.exec.proto.UserProtos.GetSchemasReq; import org.apache.drill.exec.proto.UserProtos.GetServerMetaReq; import org.apache.drill.exec.proto.UserProtos.GetTablesReq; import org.apache.drill.exec.proto.UserProtos.RpcType; import org.apache.drill.exec.proto.UserProtos.RunQuery; import org.apache.drill.exec.rpc.RequestHandler; import org.apache.drill.exec.rpc.Response; import org.apache.drill.exec.rpc.ResponseSender; import org.apache.drill.exec.rpc.RpcException; import org.apache.drill.exec.rpc.user.UserServer.BitToUserConnection; import org.apache.drill.exec.work.user.UserWorker; import com.google.protobuf.InvalidProtocolBufferException; import io.netty.buffer.ByteBuf; import io.netty.buffer.ByteBufInputStream; /** * Should create only one instance of this class per Drillbit service. */ // package private class UserServerRequestHandler implements RequestHandler<BitToUserConnection> { private static final org.slf4j.Logger logger = org.slf4j.LoggerFactory .getLogger(UserServerRequestHandler.class); private final UserWorker worker; public UserServerRequestHandler(final UserWorker worker) { this.worker = worker; } @Override public void handle(BitToUserConnection connection, int rpcType, ByteBuf pBody, ByteBuf dBody, ResponseSender responseSender) throws RpcException { switch (rpcType) { case RpcType.RUN_QUERY_VALUE: logger.debug("Received query to run. Returning query handle."); try { final RunQuery query = RunQuery.PARSER.parseFrom(new ByteBufInputStream(pBody)); final QueryId queryId = worker.submitWork(connection, query); responseSender.send(new Response(RpcType.QUERY_HANDLE, queryId)); break; } catch (InvalidProtocolBufferException e) { throw new RpcException("Failure while decoding RunQuery body.", e); } case RpcType.CANCEL_QUERY_VALUE: try { final QueryId queryId = QueryId.PARSER.parseFrom(new ByteBufInputStream(pBody)); final Ack ack = worker.cancelQuery(queryId); responseSender.send(new Response(RpcType.ACK, ack)); break; } catch (InvalidProtocolBufferException e) { throw new RpcException("Failure while decoding QueryId body.", e); } case RpcType.RESUME_PAUSED_QUERY_VALUE: try { final QueryId queryId = QueryId.PARSER.parseFrom(new ByteBufInputStream(pBody)); final Ack ack = worker.resumeQuery(queryId); responseSender.send(new Response(RpcType.ACK, ack)); break; } catch (final InvalidProtocolBufferException e) { throw new RpcException("Failure while decoding QueryId body.", e); } case RpcType.GET_QUERY_PLAN_FRAGMENTS_VALUE: try { final GetQueryPlanFragments req = GetQueryPlanFragments.PARSER .parseFrom(new ByteBufInputStream(pBody)); responseSender .send(new Response(RpcType.QUERY_PLAN_FRAGMENTS, worker.getQueryPlan(connection, req))); break; } catch (final InvalidProtocolBufferException e) { throw new RpcException("Failure while decoding GetQueryPlanFragments body.", e); } case RpcType.GET_CATALOGS_VALUE: try { final GetCatalogsReq req = GetCatalogsReq.PARSER.parseFrom(new ByteBufInputStream(pBody)); worker.submitCatalogMetadataWork(connection.getSession(), req, responseSender); break; } catch (final InvalidProtocolBufferException e) { throw new RpcException("Failure while decoding GetCatalogsReq body.", e); } case RpcType.GET_SCHEMAS_VALUE: try { final GetSchemasReq req = GetSchemasReq.PARSER.parseFrom(new ByteBufInputStream(pBody)); worker.submitSchemasMetadataWork(connection.getSession(), req, responseSender); break; } catch (final InvalidProtocolBufferException e) { throw new RpcException("Failure while decoding GetSchemasReq body.", e); } case RpcType.GET_TABLES_VALUE: try { final GetTablesReq req = GetTablesReq.PARSER.parseFrom(new ByteBufInputStream(pBody)); worker.submitTablesMetadataWork(connection.getSession(), req, responseSender); break; } catch (final InvalidProtocolBufferException e) { throw new RpcException("Failure while decoding GetTablesReq body.", e); } case RpcType.GET_COLUMNS_VALUE: try { final GetColumnsReq req = GetColumnsReq.PARSER.parseFrom(new ByteBufInputStream(pBody)); worker.submitColumnsMetadataWork(connection.getSession(), req, responseSender); break; } catch (final InvalidProtocolBufferException e) { throw new RpcException("Failure while decoding GetColumnsReq body.", e); } case RpcType.CREATE_PREPARED_STATEMENT_VALUE: try { final CreatePreparedStatementReq req = CreatePreparedStatementReq.PARSER .parseFrom(new ByteBufInputStream(pBody)); worker.submitPreparedStatementWork(connection, req, responseSender); break; } catch (final InvalidProtocolBufferException e) { throw new RpcException("Failure while decoding CreatePreparedStatementReq body.", e); } case RpcType.GET_SERVER_META_VALUE: try { final GetServerMetaReq req = GetServerMetaReq.PARSER.parseFrom(new ByteBufInputStream(pBody)); worker.submitServerMetadataWork(connection.getSession(), req, responseSender); break; } catch (final InvalidProtocolBufferException e) { throw new RpcException("Failure while decoding CreatePreparedStatementReq body.", e); } default: throw new UnsupportedOperationException( String.format("UserServerRequestHandler received rpc of unknown type. Type was %d.", rpcType)); } } }