| /* |
| * 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.cassandra.sidecar.routes; |
| |
| import com.datastax.driver.core.KeyspaceMetadata; |
| import com.datastax.driver.core.Metadata; |
| import com.google.inject.Inject; |
| import com.google.inject.Singleton; |
| import io.netty.handler.codec.http.HttpResponseStatus; |
| import io.vertx.core.Future; |
| import io.vertx.core.http.HttpServerRequest; |
| import io.vertx.core.net.SocketAddress; |
| import io.vertx.ext.web.RoutingContext; |
| import org.apache.cassandra.sidecar.cluster.CassandraAdapterDelegate; |
| import org.apache.cassandra.sidecar.common.data.SchemaResponse; |
| import org.apache.cassandra.sidecar.concurrent.ExecutorPools; |
| import org.apache.cassandra.sidecar.data.SchemaRequest; |
| import org.apache.cassandra.sidecar.utils.CassandraInputValidator; |
| import org.apache.cassandra.sidecar.utils.InstanceMetadataFetcher; |
| |
| import static org.apache.cassandra.sidecar.utils.HttpExceptions.cassandraServiceUnavailable; |
| import static org.apache.cassandra.sidecar.utils.HttpExceptions.wrapHttpException; |
| |
| /** |
| * The {@link SchemaHandler} class handles schema requests |
| */ |
| @Singleton |
| public class SchemaHandler extends AbstractHandler<SchemaRequest> |
| { |
| /** |
| * Constructs a handler with the provided {@code metadataFetcher} |
| * |
| * @param metadataFetcher the interface to retrieve metadata |
| * @param executorPools executor pools for blocking executions |
| * @param validator a validator instance to validate Cassandra-specific input |
| */ |
| @Inject |
| protected SchemaHandler(InstanceMetadataFetcher metadataFetcher, ExecutorPools executorPools, |
| CassandraInputValidator validator) |
| { |
| super(metadataFetcher, executorPools, validator); |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public void handleInternal(RoutingContext context, |
| HttpServerRequest httpRequest, |
| String host, |
| SocketAddress remoteAddress, |
| SchemaRequest request) |
| { |
| metadata(host) |
| .onFailure(cause -> processFailure(cause, context, host, remoteAddress, request)) |
| .onSuccess(metadata -> handleWithMetadata(context, request, metadata)); |
| } |
| |
| /** |
| * Handles the request with the Cassandra {@link Metadata metadata}. |
| * |
| * @param context the event to handle |
| * @param requestParams the {@link SchemaRequest} parsed from the request |
| * @param metadata the metadata on the connected cluster, including known nodes and schema definitions |
| */ |
| private void handleWithMetadata(RoutingContext context, SchemaRequest requestParams, Metadata metadata) |
| { |
| if (metadata == null) |
| { |
| // set request as failed and return |
| logger.error("Failed to obtain metadata on the connected cluster for request '{}'", requestParams); |
| context.fail(cassandraServiceUnavailable()); |
| return; |
| } |
| |
| if (requestParams.keyspace() == null) |
| { |
| SchemaResponse schemaResponse = new SchemaResponse(metadata.exportSchemaAsString()); |
| context.json(schemaResponse); |
| return; |
| } |
| |
| // retrieve keyspace metadata |
| KeyspaceMetadata ksMetadata = metadata.getKeyspace(requestParams.keyspace()); |
| if (ksMetadata == null) |
| { |
| // set request as failed and return |
| // keyspace does not exist |
| String errorMessage = String.format("Keyspace '%s' does not exist.", |
| requestParams.keyspace()); |
| context.fail(wrapHttpException(HttpResponseStatus.NOT_FOUND, errorMessage)); |
| return; |
| } |
| |
| SchemaResponse schemaResponse = new SchemaResponse(requestParams.keyspace(), ksMetadata.exportAsString()); |
| context.json(schemaResponse); |
| } |
| |
| /** |
| * Gets cluster metadata asynchronously. |
| * |
| * @param host the Cassandra instance host |
| * @return {@link Future} containing {@link Metadata} |
| */ |
| private Future<Metadata> metadata(String host) |
| { |
| return executorPools.service().executeBlocking(promise -> { |
| CassandraAdapterDelegate delegate = metadataFetcher.delegate(host); |
| // metadata can block so we need to run in a blocking thread |
| promise.complete(delegate.metadata()); |
| }); |
| } |
| |
| /** |
| * Parses the request parameters |
| * |
| * @param context the event to handle |
| * @return the {@link SchemaRequest} parsed from the request |
| */ |
| @Override |
| protected SchemaRequest extractParamsOrThrow(RoutingContext context) |
| { |
| return new SchemaRequest(keyspace(context, false)); |
| } |
| } |