geode-core/src/main/java/org/apache/geode/internal/cache/Node.java

/*
 * 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.geode.internal.cache;

import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;

import org.apache.geode.cache.CacheLoader;
import org.apache.geode.cache.CacheWriter;
import org.apache.geode.distributed.internal.membership.InternalDistributedMember;
import org.apache.geode.internal.ExternalizableDSFID;
import org.apache.geode.internal.InternalDataSerializer;
import org.apache.geode.internal.serialization.DeserializationContext;
import org.apache.geode.internal.serialization.SerializationContext;
import org.apache.geode.internal.serialization.Version;

/**
 * Stores information about a PartitionedRegion singleton instance running inside a virtual machine.
 * This Node is said to be a participant, cooperating with other Nodes to physically manage a
 * logically named PartitionedRegion.
 * <p>
 * Nodes are stored in a list within PartitionedRegionConfig which is stored globally as the value
 * of an named entry in the <code>DistributedHashMap.PARTITIONED_REGION_NAME</code>. Node must be
 * Serializable and have a no args Constructor. Since Nodes are used as keys in each Thread's
 * ThreadLocal map of Nodes to Connections, Node must implement hashCode and equals.
 * <p>
 * Node maintains a field for maxMemory (fixed) to enable other Nodes to determine whether the Node
 * should be the target of a canRebalance request. If the Node's maxMemory is 0, then the Node is
 * advertising that it never should receive a request to rebalance.
 *
 */
public class Node extends ExternalizableDSFID {
  private InternalDistributedMember memberId;

  public static final int NONE = 0;
  public static final int ACCESSOR = 1;
  public static final int DATASTORE = 2;
  public static final int ACCESSOR_DATASTORE = 3;
  public static final int FIXED_PR_ACCESSOR = 4;
  public static final int FIXED_PR_DATASTORE = 5;

  private int prType = Node.NONE;

  private boolean isPersistent = false;

  private byte cacheLoaderWriterByte;

  private int serialNumber;

  public Node(InternalDistributedMember id, int serialNumber) {
    this.memberId = id;
    this.serialNumber = serialNumber;
  }

  public Node(Node node) {
    this.memberId = node.getMemberId();
    this.serialNumber = node.serialNumber;
  }

  public Node(DataInput in) throws IOException, ClassNotFoundException {
    fromData(in, InternalDataSerializer.createDeserializationContext(in));
  }

  // for Externalizable
  public Node() {}

  public InternalDistributedMember getMemberId() {
    return this.memberId;
  }

  public boolean isPersistent() {
    return this.isPersistent;
  }

  public void setPersistence(boolean isPersistent) {
    this.isPersistent = isPersistent;
  }

  @Override
  public String toString() {
    return ("Node=[memberId=" + this.memberId + "; prType=" + prType + "; isPersistent="
        + isPersistent + "]");
  }

  @Override
  public int hashCode() {
    return this.memberId.hashCode() + 31 * serialNumber;
  }

  public int getPRType() {
    return prType;
  }

  public void setPRType(int type) {
    this.prType = type;
  }

  void setLoaderAndWriter(CacheLoader loader, CacheWriter writer) {
    byte loaderByte = (byte) (loader != null ? 0x01 : 0x00);
    byte writerByte = (byte) (writer != null ? 0x02 : 0x00);
    this.cacheLoaderWriterByte = (byte) (loaderByte + writerByte);
  }

  public boolean isCacheLoaderAttached() {
    if (this.cacheLoaderWriterByte == 0x01 || this.cacheLoaderWriterByte == 0x03) {
      return true;
    } else {
      return false;
    }
  }

  public boolean isCacheWriterAttached() {
    if (this.cacheLoaderWriterByte == 0x02 || this.cacheLoaderWriterByte == 0x03) {
      return true;
    } else {
      return false;
    }
  }

  @Override
  public boolean equals(Object obj) {
    if (obj == this) {
      return true;
    }
    if (obj instanceof Node) {
      Node n = (Node) obj;
      if (this.memberId.equals(n.memberId) && this.serialNumber == n.serialNumber) {
        return true;
      }
    }
    return false;
  }

  @Override
  public int getDSFID() {
    return PR_NODE;
  }

  @Override
  public void toData(DataOutput out,
      SerializationContext context) throws IOException {
    InternalDataSerializer.invokeToData(this.memberId, out);
    out.writeInt(this.prType);
    out.writeBoolean(this.isPersistent);
    out.writeByte(this.cacheLoaderWriterByte);
    out.writeInt(serialNumber);
  }

  @Override
  public void fromData(DataInput in,
      DeserializationContext context) throws IOException, ClassNotFoundException {
    this.memberId = new InternalDistributedMember();
    InternalDataSerializer.invokeFromData(this.memberId, in);
    this.prType = in.readInt();
    this.isPersistent = in.readBoolean();
    this.cacheLoaderWriterByte = in.readByte();
    this.serialNumber = in.readInt();
  }

  @Override
  public Version[] getSerializationVersions() {
    return null;
  }
}