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.server.library.server.ssl;
  
  import io.netty.buffer.ByteBufAllocator;
  import io.netty.handler.ssl.ApplicationProtocolNegotiator;
  import io.netty.handler.ssl.SslContext;
  import java.util.List;
  import javax.net.ssl.SSLEngine;
  import javax.net.ssl.SSLSessionContext;
  import lombok.AccessLevel;
  import lombok.Setter;
  import org.apache.skywalking.oap.server.library.util.MultipleFilesChangeMonitor;
  
  public abstract class AbstractSslContext extends SslContext {
      private final MultipleFilesChangeMonitor monitor;
  
      @Setter(AccessLevel.PROTECTED)
      private volatile SslContext ctx;
  
      protected AbstractSslContext(final String privateKeyFile, final String certChainFile, final String trustedCAsFile) {
          updateContext(privateKeyFile, certChainFile, trustedCAsFile);
          monitor = new MultipleFilesChangeMonitor(
              10,
              readableContents -> updateContext(privateKeyFile, certChainFile, trustedCAsFile),
              certChainFile,
              privateKeyFile,
              trustedCAsFile);
      }
  
      protected AbstractSslContext(final String caFile) {
          updateContext(caFile);
          monitor = new MultipleFilesChangeMonitor(
              10,
              readableContents -> updateContext(caFile),
              caFile);
      }
  
      protected abstract void updateContext(String caFile);
  
      protected abstract void updateContext(final String privateKeyFile, final String certChainFile, final String trustedCAsFile);
  
      public void start() {
          monitor.start();
      }
  
      @Override
      public final boolean isClient() {
          return ctx.isClient();
      }
  
      @Override
      public final List<String> cipherSuites() {
          return ctx.cipherSuites();
      }
  
      @Override
      public final long sessionCacheSize() {
          return ctx.sessionCacheSize();
      }
  
      @Override
      public final long sessionTimeout() {
          return ctx.sessionTimeout();
      }
  
      @Override
      public final ApplicationProtocolNegotiator applicationProtocolNegotiator() {
          return ctx.applicationProtocolNegotiator();
      }
  
      @Override
      public final SSLEngine newEngine(ByteBufAllocator alloc) {
          return ctx.newEngine(alloc);
      }
  
      @Override
      public final SSLEngine newEngine(ByteBufAllocator alloc, String peerHost, int peerPort) {
          return ctx.newEngine(alloc, peerHost, peerPort);
      }
  
      @Override
      public final SSLSessionContext sessionContext() {
          return ctx.sessionContext();
      }
  }
  