/*

 * Copyright (c) 1999, 2011, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

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 */

package com.sun.jndi.ldap;

import java.io.IOException;

import java.util.concurrent.BlockingQueue;

import java.util.concurrent.LinkedBlockingQueue;

import javax.naming.CommunicationException;

final class LdapRequest {

    LdapRequest next;   // Set/read in synchronized Connection methods

    int msgId;          // read-only

    private int gotten = 0;

    private BlockingQueue<BerDecoder> replies;

    private int highWatermark = -1;

    private boolean cancelled = false;

    private boolean pauseAfterReceipt = false;

    private boolean completed = false;

    LdapRequest(int msgId, boolean pause) {

        this(msgId, pause, -1);

    }

    LdapRequest(int msgId, boolean pause, int replyQueueCapacity) {

        this.msgId = msgId;

        this.pauseAfterReceipt = pause;

        if (replyQueueCapacity == -1) {

            this.replies = new LinkedBlockingQueue<BerDecoder>();

        } else {

            this.replies =

                new LinkedBlockingQueue<BerDecoder>(replyQueueCapacity);

            highWatermark = (replyQueueCapacity * 80) / 100; // 80% capacity

        }

    }

    synchronized void cancel() {

        cancelled = true;

        // Unblock reader of pending request

        // Should only ever have at most one waiter

        notify();

    }

    synchronized boolean addReplyBer(BerDecoder ber) {

        if (cancelled) {

            return false;

        }

        // Add a new reply to the queue of unprocessed replies.

        try {

            replies.put(ber);

        } catch (InterruptedException e) {

            // ignore

        }

        // peek at the BER buffer to check if it is a SearchResultDone PDU

        try {

            ber.parseSeq(null);

            ber.parseInt();

            completed = (ber.peekByte() == LdapClient.LDAP_REP_RESULT);

        } catch (IOException e) {

            // ignore

        }

        ber.reset();

        notify(); // notify anyone waiting for reply

        /*

         * If a queue capacity has been set then trigger a pause when the

         * queue has filled to 80% capacity. Later, when the queue has drained

         * then the reader gets unpaused.

         */

        if (highWatermark != -1 && replies.size() >= highWatermark) {

            return true; // trigger the pause

        }

        return pauseAfterReceipt;

    }

    synchronized BerDecoder getReplyBer() throws CommunicationException {

        if (cancelled) {

            throw new CommunicationException("Request: " + msgId +

                " cancelled");

        }

        /*

         * Remove a reply if the queue is not empty.

         * poll returns null if queue is empty.

         */

        BerDecoder reply = replies.poll();

        return reply;

    }

    synchronized boolean hasSearchCompleted() {

        return completed;

    }

}