code: /*
   * 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.skywalking.oap.log.analyzer.provider.log.listener;
  
  import com.google.protobuf.Message;
  import java.util.Collection;
  import java.util.List;
  import java.util.Map;
  import java.util.stream.Collectors;
  import lombok.RequiredArgsConstructor;
  import lombok.extern.slf4j.Slf4j;
  
  import java.util.HashMap;
  import org.apache.skywalking.apm.network.logging.v3.LogData;
  import org.apache.skywalking.oap.log.analyzer.dsl.Binding;
  import org.apache.skywalking.oap.log.analyzer.dsl.DSL;
  import org.apache.skywalking.oap.log.analyzer.provider.LALConfig;
  import org.apache.skywalking.oap.log.analyzer.provider.LALConfigs;
  import org.apache.skywalking.oap.log.analyzer.provider.LogAnalyzerModuleConfig;
  
  import org.apache.skywalking.oap.server.core.analysis.Layer;
  import org.apache.skywalking.oap.server.library.module.ModuleManager;
  import org.apache.skywalking.oap.server.library.module.ModuleStartException;
  
  @Slf4j
  @RequiredArgsConstructor
  public class LogFilterListener implements LogAnalysisListener {
      private final Collection<DSL> dsls;
  
      @Override
      public void build() {
          dsls.forEach(dsl -> {
              try {
                  dsl.evaluate();
              } catch (final Exception e) {
                  log.warn("Failed to evaluate dsl: {}", dsl, e);
              }
          });
      }
  
      @Override
      public LogAnalysisListener parse(final LogData.Builder logData,
                                       final Message extraLog) {
          dsls.forEach(dsl -> dsl.bind(new Binding().log(logData.build())
                                                    .extraLog(extraLog)));
          return this;
      }
  
      public static class Factory implements LogAnalysisListenerFactory {
          private final Map<Layer, Map<String, DSL>> dsls;
  
          public Factory(final ModuleManager moduleManager, final LogAnalyzerModuleConfig config) throws Exception {
              dsls = new HashMap<>();
  
              final List<LALConfig> configList = LALConfigs.load(config.getLalPath(), config.lalFiles())
                                                           .stream()
                                                           .flatMap(it -> it.getRules().stream())
                                                           .collect(Collectors.toList());
              for (final LALConfig c : configList) {
                  Layer layer = Layer.nameOf(c.getLayer());
                  Map<String, DSL> dsls = this.dsls.computeIfAbsent(layer, k -> new HashMap<>());
                  if (dsls.put(c.getName(), DSL.of(moduleManager, config, c.getDsl())) != null) {
                      throw new ModuleStartException("Layer " + layer.name() + " has already set " + c.getName() + " rule.");
                  }
              }
          }
  
          @Override
          public LogAnalysisListener create(Layer layer) {
              if (layer == null) {
                  return null;
              }
              final Map<String, DSL> dsl = dsls.get(layer);
              if (dsl == null) {
                  return null;
              }
              return new LogFilterListener(dsl.values());
          }
      }
  }
  