/*
    * ====================================================================
    * 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.
   * ====================================================================
   *
   * This software consists of voluntary contributions made by many
   * individuals on behalf of the Apache Software Foundation.  For more
   * information on the Apache Software Foundation, please see
   * <http://www.apache.org/>.
   *
   */
  
  package org.apache.http.impl.execchain;
  
  import java.io.Closeable;
  import java.io.IOException;
  import java.util.concurrent.TimeUnit;
  import java.util.concurrent.atomic.AtomicBoolean;
  
  import org.apache.commons.logging.Log;
  import org.apache.http.HttpClientConnection;
  import org.apache.http.annotation.Contract;
  import org.apache.http.annotation.ThreadingBehavior;
  import org.apache.http.concurrent.Cancellable;
  import org.apache.http.conn.ConnectionReleaseTrigger;
  import org.apache.http.conn.HttpClientConnectionManager;
  
  /**
   * Internal connection holder.
   *
   * @since 4.3
   */
  @Contract(threading = ThreadingBehavior.SAFE)
  class ConnectionHolder implements ConnectionReleaseTrigger, Cancellable, Closeable {
  
      private final Log log;
  
      private final HttpClientConnectionManager manager;
      private final HttpClientConnection managedConn;
      private final AtomicBoolean released;
      private volatile boolean reusable;
      private volatile Object state;
      private volatile long validDuration;
      private volatile TimeUnit timeUnit;
  
      public ConnectionHolder(
              final Log log,
              final HttpClientConnectionManager manager,
              final HttpClientConnection managedConn) {
          super();
          this.log = log;
          this.manager = manager;
          this.managedConn = managedConn;
          this.released = new AtomicBoolean(false);
      }
  
      public boolean isReusable() {
          return this.reusable;
      }
  
      public void markReusable() {
          this.reusable = true;
      }
  
      public void markNonReusable() {
          this.reusable = false;
      }
  
      public void setState(final Object state) {
          this.state = state;
      }
  
      public void setValidFor(final long duration, final TimeUnit timeUnit) {
          synchronized (this.managedConn) {
              this.validDuration = duration;
              this.timeUnit = timeUnit;
          }
      }
  
      private void releaseConnection(final boolean reusable) {
          if (this.released.compareAndSet(false, true)) {
              synchronized (this.managedConn) {
                  if (reusable) {
                      this.manager.releaseConnection(this.managedConn,
                             this.state, this.validDuration, this.timeUnit);
                 } else {
                     try {
                         this.managedConn.close();
                         log.debug("Connection discarded");
                     } catch (final IOException ex) {
                         if (this.log.isDebugEnabled()) {
                             this.log.debug(ex.getMessage(), ex);
                         }
                     } finally {
                         this.manager.releaseConnection(
                                 this.managedConn, null, 0, TimeUnit.MILLISECONDS);
                     }
                 }
             }
         }
     }
 
     @Override
     public void releaseConnection() {
         releaseConnection(this.reusable);
     }
 
     @Override
     public void abortConnection() {
         if (this.released.compareAndSet(false, true)) {
             synchronized (this.managedConn) {
                 try {
                     this.managedConn.shutdown();
                     log.debug("Connection discarded");
                 } catch (final IOException ex) {
                     if (this.log.isDebugEnabled()) {
                         this.log.debug(ex.getMessage(), ex);
                     }
                 } finally {
                     this.manager.releaseConnection(
                             this.managedConn, null, 0, TimeUnit.MILLISECONDS);
                 }
             }
         }
     }
 
     @Override
     public boolean cancel() {
         final boolean alreadyReleased = this.released.get();
         log.debug("Cancelling request execution");
         abortConnection();
         return !alreadyReleased;
     }
 
     public boolean isReleased() {
         return this.released.get();
     }
 
     @Override
     public void close() throws IOException {
         releaseConnection(false);
     }
 
 }