IncomingLinkImpl.java

/*
 * Copyright 2011 the original author or authors.
 *
 * Licensed 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 io.vertx.ext.amqp.impl.protocol;

import io.vertx.ext.amqp.impl.CreditMode;
import io.vertx.ext.amqp.ErrorCode;
import io.vertx.ext.amqp.MessagingException;
import io.vertx.ext.amqp.ReliabilityMode;
import org.apache.qpid.proton.engine.Link;
import org.apache.qpid.proton.engine.Receiver;

import java.util.concurrent.atomic.AtomicInteger;

import static io.vertx.ext.amqp.impl.util.Functions.print;

class IncomingLinkImpl extends BaseLink implements IncomingLink {
  private static int DEFAULT_CREDITS = 1;

  private final CreditMode _creditMode;

  private final ReliabilityMode _receiverMode;

  private int _credits = 0;

  private AtomicInteger _unsettled = new AtomicInteger(0);

  IncomingLinkImpl(SessionImpl ssn, String address, Link link, ReliabilityMode receiverMode, CreditMode creditMode) {
    super(ssn, address, link);
    _creditMode = creditMode;
    _receiverMode = receiverMode;
  }

  void init() {
    _link.open();
        /*if (_creditMode == CreditMode.AUTO && DEFAULT_CREDITS > 0)
        {
            _credits = DEFAULT_CREDITS;
            ((Receiver) _link).flow(_credits);
        }*/
    _ssn.getConnection().write();
  }

  void issueCredits(int credits, boolean drain) {
    Receiver receiver = (Receiver) _link;
    if (drain) {
      // receiver.setDrain(true);
    }
    receiver.flow(credits);
    /*print("\n==============================");
    print("\nSetting credits=%s, for link '%s'", credits, this.getName());
    print("\n==============================");*/
    _ssn.getConnection().write();
  }

  void decrementUnsettledCount() {
    _unsettled.decrementAndGet();
  }

  void issuePostReceiveCredit() {
    if (_creditMode == CreditMode.AUTO) {
      if (_credits == 1) {
        issueCredits(1, false);
      } else if (_unsettled.get() < _credits / 2) {
        issueCredits(_credits - _unsettled.get(), false);
      }
    }
  }

  @Override
  public ReliabilityMode getReceiverMode() {
    return _receiverMode;
  }

  @Override
  public CreditMode getCreditMode() {
    return _creditMode;
  }

  @Override
  public int getUnsettled() throws MessagingException {
    checkClosed();
    return _unsettled.get();
  }

  @Override
  public void setCredits(int credits) throws MessagingException {
    checkClosed();
    if (credits < 0) {
      throw new MessagingException("Capacity cannot be negative", ErrorCode.INTERNAL_ERROR);
    }
    _credits = credits;
    issueCredits(_credits, _creditMode == CreditMode.AUTO);
  }

  @Override
  public boolean isInbound() {
    return true;
  }
}