content: /*
   * 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.index.sasi.analyzer.filter;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * Executes all linked Pipeline Tasks serially and returns
   * output (if exists) from the executed logic
   */
  public class FilterPipelineExecutor
  {
      private static final Logger logger = LoggerFactory.getLogger(FilterPipelineExecutor.class);
  
      public static <F,T> T execute(FilterPipelineTask<F, T> task, T initialInput)
      {
          FilterPipelineTask<?, ?> taskPtr = task;
          T result = initialInput;
          try
          {
              while (true)
              {
                  FilterPipelineTask<F,T> taskGeneric = (FilterPipelineTask<F,T>) taskPtr;
                  result = taskGeneric.process((F) result);
                  taskPtr = taskPtr.next;
                  if(taskPtr == null)
                      return result;
              }
          }
          catch (Exception e)
          {
              logger.info("An unhandled exception to occurred while processing " +
                      "pipeline [{}]", task.getName(), e);
          }
          return null;
      }
  }
  