1 /*
   2  * Copyright (c) 1999, 2011, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package com.sun.jndi.ldap;
  27 
  28 import java.io.IOException;
  29 import java.util.concurrent.BlockingQueue;
  30 import java.util.concurrent.LinkedBlockingQueue;
  31 import javax.naming.CommunicationException;
  32 import java.util.concurrent.TimeUnit;
  33 
  34 final class LdapRequest {
  35 
  36     private final static BerDecoder EOF = new BerDecoder(new byte[]{}, -1, 0);
  37 
  38     LdapRequest next;   // Set/read in synchronized Connection methods
  39     final int msgId;          // read-only
  40 
  41     private final BlockingQueue<BerDecoder> replies;
  42     private volatile boolean cancelled;
  43     private boolean completed;
  44     private final boolean pauseAfterReceipt;
  45 
  46     LdapRequest(int msgId, boolean pause, int replyQueueCapacity) {
  47         this.msgId = msgId;
  48         this.pauseAfterReceipt = pause;
  49         if (replyQueueCapacity == -1) {
  50             this.replies = new LinkedBlockingQueue<>();
  51         } else {
  52             this.replies = new LinkedBlockingQueue<>(8 * replyQueueCapacity / 10);
  53         }
  54     }
  55 
  56     void cancel() {
  57         cancelled = true;
  58         replies.offer(EOF);
  59     }
  60 
  61     synchronized void close() {
  62         try {
  63             replies.put(EOF);
  64         } catch (InterruptedException e) {
  65             Thread.currentThread().interrupt();
  66         }
  67     }
  68 
  69     synchronized boolean addReplyBer(BerDecoder ber) {
  70         if (cancelled) {
  71             return false;
  72         }
  73 
  74         // Add a new reply to the queue of unprocessed replies.
  75         try {
  76             replies.put(ber);
  77         } catch (InterruptedException e) {
  78             // ignore
  79         }
  80 
  81         // peek at the BER buffer to check if it is a SearchResultDone PDU
  82         try {
  83             ber.parseSeq(null);
  84             ber.parseInt();
  85             completed = (ber.peekByte() == LdapClient.LDAP_REP_RESULT);
  86         } catch (IOException e) {
  87             // ignore
  88         }
  89         ber.reset();
  90         return pauseAfterReceipt;
  91     }
  92 
  93     BerDecoder getReplyBer(long millis) throws CommunicationException,
  94                                                InterruptedException {
  95         if (cancelled) {
  96             throw new CommunicationException("Request: " + msgId +
  97                 " cancelled");
  98         }
  99 
 100         BerDecoder result = millis > 0 ?
 101                 replies.poll(millis, TimeUnit.MILLISECONDS) : replies.take();
 102 
 103         if (cancelled) {
 104             throw new CommunicationException("Request: " + msgId +
 105                 " cancelled");
 106     }
 107 
 108         if (result == LdapRequest.EOF) {
 109             return null; 
 110         }
 111 
 112         return result;
 113     }
 114 
 115     boolean hasSearchCompleted() {
 116         return completed;
 117     }
 118 }