content: /*
   * Copyright 2020 Alibaba Group Holding Limited.
   *
   * Licensed 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 com.alibaba.graphscope.frontend;
  
  import com.alibaba.graphscope.GraphServer;
  import com.alibaba.graphscope.common.client.channel.ChannelFetcher;
  import com.alibaba.graphscope.common.client.channel.HostsRpcChannelFetcher;
  import com.alibaba.graphscope.common.config.Configs;
  import com.alibaba.graphscope.common.ir.meta.fetcher.StaticIrMetaFetcher;
  import com.alibaba.graphscope.common.ir.planner.GraphRelOptimizer;
  import com.alibaba.graphscope.common.ir.tools.QueryCache;
  import com.alibaba.graphscope.common.manager.IrMetaQueryCallback;
  import com.alibaba.graphscope.gremlin.integration.result.TestGraphFactory;
  import com.google.common.collect.ImmutableList;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.io.IOException;
  import java.util.concurrent.CountDownLatch;
  
  public class Frontend implements AutoCloseable {
      private static final Logger logger = LoggerFactory.getLogger(Frontend.class);
      private GraphServer graphServer;
      private Configs configs;
  
      public Frontend(String configFile) throws IOException {
          this(new Configs(configFile));
      }
  
      public Frontend(Configs configs) {
          this.configs = configs;
      }
  
      public void start() throws Exception {
          ChannelFetcher channelFetcher = new HostsRpcChannelFetcher(configs);
          GraphRelOptimizer optimizer = new GraphRelOptimizer(configs);
          QueryCache cache = new QueryCache(configs);
          IrMetaQueryCallback queryCallback =
                  new IrMetaQueryCallback(
                          new StaticIrMetaFetcher(
                                  new VineyardIrMetaReader(configs),
                                  ImmutableList.of(optimizer, cache)));
          this.graphServer =
                  new GraphServer(
                          this.configs,
                          channelFetcher,
                          queryCallback,
                          TestGraphFactory.VINEYARD,
                          optimizer,
                          cache);
          this.graphServer.start();
      }
  
      @Override
      public void close() throws Exception {
          if (this.graphServer != null) {
              this.graphServer.close();
          }
      }
  
      public static void main(String[] args) {
          logger.info("start to run Frontend.");
          if (args == null || args.length < 1) {
              logger.error("Please give the path of config file.");
              System.exit(1);
          }
          try (Frontend frontend = new Frontend(args[0])) {
              frontend.start();
              CountDownLatch shutdown = new CountDownLatch(1);
              shutdown.await();
          } catch (Throwable t) {
              logger.error("Error in frontend main:", t);
              System.exit(1);
          }
          System.exit(0);
      }
  }
  