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.celeborn.common.network.util;
  
  import java.io.IOException;
  import java.io.InputStream;
  
  import io.netty.buffer.ByteBuf;
  import io.netty.buffer.ByteBufHolder;
  import io.netty.channel.ChannelHandlerContext;
  import io.netty.handler.logging.LogLevel;
  import io.netty.handler.logging.LoggingHandler;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * A Netty logger that constructs a log handler depending on the log level.
   *
   * <p>Note: code copied from Apache Spark.
   */
  public class NettyLogger {
    private static final Logger logger = LoggerFactory.getLogger(NettyLogger.class);
  
    /** A Netty LoggingHandler which does not dump the message contents. */
    private static class NoContentLoggingHandler extends LoggingHandler {
  
      NoContentLoggingHandler(Class<?> clazz, LogLevel level) {
        super(clazz, level);
      }
  
      @Override
      protected String format(ChannelHandlerContext ctx, String eventName, Object arg) {
        if (arg instanceof ByteBuf) {
          return format(ctx, eventName) + " " + ((ByteBuf) arg).readableBytes() + "B";
        } else if (arg instanceof ByteBufHolder) {
          return format(ctx, eventName) + " " + ((ByteBufHolder) arg).content().readableBytes() + "B";
        } else if (arg instanceof InputStream) {
          int available = -1;
          try {
            available = ((InputStream) arg).available();
          } catch (IOException ex) {
            // Swallow, but return -1 to indicate an error happened
          }
          return format(ctx, eventName, arg) + " " + available + "B";
        } else {
          return super.format(ctx, eventName, arg);
        }
      }
    }
  
    private final LoggingHandler loggingHandler;
  
    public NettyLogger() {
      if (logger.isTraceEnabled()) {
        loggingHandler = new LoggingHandler(NettyLogger.class, LogLevel.TRACE);
      } else if (logger.isDebugEnabled()) {
        loggingHandler = new NoContentLoggingHandler(NettyLogger.class, LogLevel.DEBUG);
      } else {
        loggingHandler = null;
      }
    }
  
    public LoggingHandler getLoggingHandler() {
      return loggingHandler;
    }
  }
  