geode-core/src/main/java/org/apache/geode/distributed/internal/StartupMessageData.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.distributed.internal;

import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Properties;
import java.util.StringTokenizer;

import org.apache.geode.DataSerializer;

/**
 * Provides optional data fields as properties for StartupMessage and StartupResponseMessage. This
 * is handled by serializing and deserializing a new Properties instance if and only if the member
 * version is 6.6.3 or greater. New fields can be added to the Properties without breaking backwards
 * compatibility. All new fields added should be written to allow for version compatibility.
 *
 * @since GemFire 7.0
 */
class StartupMessageData {

  static final String HOSTED_LOCATORS = "HL";
  static final String COMMA_DELIMITER = ",";
  static final String MCAST_PORT = "MP";
  static final String MCAST_HOST_ADDRESS = "MHA";
  static final String IS_SHARED_CONFIG_ENABLED = "ISCE";

  private Properties optionalFields;

  /**
   * Constructs a new instance with empty Properties. After construction the instance should
   * optionally invoke one or more "write" methods such as {@link #writeHostedLocators(Collection)}
   * before invoking <code>toData(DataOutput)</code> to marshal the Properties into the DataOutput
   * (onto the wire).
   */
  StartupMessageData() {
    this.optionalFields = new Properties();
  }

  public void readFrom(DataInput in) throws ClassNotFoundException, IOException {
    this.optionalFields = DataSerializer.readObject(in);
  }

  /**
   * Check for the optional field {@link #HOSTED_LOCATORS} and return the value or null.
   */
  Collection<String> readHostedLocators() {
    if (this.optionalFields == null || this.optionalFields.isEmpty()) {
      return null;
    }
    Collection<String> hostedLocators = null;
    String hostedLocatorsString = this.optionalFields.getProperty(HOSTED_LOCATORS);
    if (hostedLocatorsString != null && !hostedLocatorsString.isEmpty()) {
      StringTokenizer st = new StringTokenizer(hostedLocatorsString, COMMA_DELIMITER);
      hostedLocators = new ArrayList<String>();
      while (st.hasMoreTokens()) {
        String locatorString = st.nextToken();
        if (locatorString != null && !locatorString.isEmpty()) {
          hostedLocators.add(locatorString);
        }
      }
      if (hostedLocators.isEmpty()) {
        hostedLocators = null;
      }
    }
    return hostedLocators;
  }

  // /**
  // * Check for the optional field {@link #HOSTED_LOCATORS_WITH_SHARED_CONFIGURATION} and return
  // the
  // * value or null.
  // */
  // Collection<String> readHostedLocatorsWithSharedConfiguration() {
  // if (this.optionalFields == null || this.optionalFields.isEmpty()) {
  // return null;
  // }
  // Collection<String> hostedLocatorsWithSharedConfiguration = null;
  // String hostedLocatorsString =
  // this.optionalFields.getProperty(HOSTED_LOCATORS_WITH_SHARED_CONFIGURATION);
  // if (hostedLocatorsString != null && !hostedLocatorsString.isEmpty()) {
  // StringTokenizer st = new StringTokenizer(hostedLocatorsString, COMMA_DELIMITER);
  // hostedLocatorsWithSharedConfiguration = new ArrayList<String>();
  // while (st.hasMoreTokens()) {
  // String locatorString = st.nextToken();
  // if (locatorString != null && !locatorString.isEmpty()) {
  // hostedLocatorsWithSharedConfiguration.add(locatorString);
  // }
  // }
  // if (hostedLocatorsWithSharedConfiguration.isEmpty()) {
  // hostedLocatorsWithSharedConfiguration = null;
  // }
  // }
  // return hostedLocatorsWithSharedConfiguration;
  // }

  boolean readIsSharedConfigurationEnabled() {
    if (this.optionalFields == null || this.optionalFields.isEmpty()) {
      return false;
    }
    return Boolean.parseBoolean((this.optionalFields.getProperty(IS_SHARED_CONFIG_ENABLED)));
  }

  /**
   * Write the value for the optional field {@link #HOSTED_LOCATORS}.
   */
  void writeHostedLocators(Collection<String> hostedLocators) {
    if (this.optionalFields == null) {
      return;
    }
    if (hostedLocators != null && !hostedLocators.isEmpty()) {
      String hostedLocatorsString = asCommaDelimitedString(hostedLocators);
      if (hostedLocatorsString != null && !hostedLocatorsString.isEmpty()) {
        this.optionalFields.setProperty(HOSTED_LOCATORS, hostedLocatorsString);
      }
    }
  }

  // void writeHostedLocatorsWithSharedConfiguration(Collection<String>
  // hostedLocatorsWithSharedConfiguration) {
  // if (this.optionalFields == null) {
  // return;
  // }
  // if (hostedLocatorsWithSharedConfiguration != null &&
  // !hostedLocatorsWithSharedConfiguration.isEmpty()) {
  // String hostedLocatorsString = asCommaDelimitedString(hostedLocatorsWithSharedConfiguration);
  // if (hostedLocatorsString != null && !hostedLocatorsString.isEmpty()) {
  // this.optionalFields.setProperty(HOSTED_LOCATORS_WITH_SHARED_CONFIGURATION,
  // hostedLocatorsString);
  // }
  // }
  // }
  //
  void writeIsSharedConfigurationEnabled(boolean isSharedConfigurationEnabled) {
    if (this.optionalFields == null) {
      return;
    }
    this.optionalFields.setProperty(IS_SHARED_CONFIG_ENABLED,
        Boolean.toString(isSharedConfigurationEnabled));
  }

  int readMcastPort() {
    int result = 0;
    if (this.optionalFields != null) {
      String resultString = this.optionalFields.getProperty(MCAST_PORT);
      if (resultString != null && !resultString.isEmpty()) {
        result = Integer.parseInt(resultString);
      }
    }
    return result;
  }

  void writeMcastPort(int mcastPort) {
    if (this.optionalFields != null) {
      if (mcastPort != 0) {
        this.optionalFields.setProperty(MCAST_PORT, Integer.toString(mcastPort));
      }
    }
  }

  String readMcastHostAddress() {
    String result = null;
    if (this.optionalFields != null) {
      result = this.optionalFields.getProperty(MCAST_HOST_ADDRESS);
    }
    return result;
  }

  void writeMcastHostAddress(String addr) {
    if (this.optionalFields != null) {
      if (addr != null && !addr.isEmpty()) {
        this.optionalFields.setProperty(MCAST_HOST_ADDRESS, addr);
      }
    }
  }

  /**
   * Writes all optional fields to the DataOutput or null for minimal wire footprint.
   *
   */
  void writeTo(DataOutput out) throws IOException {
    if (this.optionalFields.isEmpty()) {
      DataSerializer.writeObject(null, out);
    } else {
      DataSerializer.writeObject(this.optionalFields, out);
    }
  }

  /**
   * Returns {@link #optionalFields} for testing.
   */
  Properties getOptionalFields() {
    return this.optionalFields;
  }

  /**
   * Marshals a collection of strings to a single comma-delimited string. Returns null if collection
   * is null or empty.
   */
  public static String asCommaDelimitedString(Collection<String> strings) {
    StringBuilder sb = new StringBuilder();
    for (String string : strings) {
      if (sb.length() > 0) {
        sb.append(COMMA_DELIMITER);
      }
      sb.append(string);
    }
    return sb.toString();
  }
}