/**
    *
    * 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.hadoop.hbase;
  
  import com.google.protobuf.InvalidProtocolBufferException;
  import org.apache.hadoop.classification.InterfaceAudience;
  import org.apache.hadoop.classification.InterfaceStability;
  import org.apache.hadoop.hbase.exceptions.DeserializationException;
  import org.apache.hadoop.hbase.protobuf.ProtobufUtil;
  import org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos.RootRegionServer;
  import org.apache.hadoop.hbase.util.Addressing;
  import org.apache.hadoop.hbase.util.Bytes;
  
  import java.util.ArrayList;
  import java.util.List;
  import java.util.regex.Pattern;
  
  /**
   * Instance of an HBase ServerName.
   * A server name is used uniquely identifying a server instance and is made
   * of the combination of hostname, port, and startcode. The startcode
   * distingushes restarted servers on same hostname and port (startcode is
   * usually timestamp of server startup). The {@link #toString()} format of
   * ServerName is safe to use in the  filesystem and as znode name up in
   * ZooKeeper.  Its format is:
   * <code>&lt;hostname> '{@link #SERVERNAME_SEPARATOR}' &lt;port> '{@link #SERVERNAME_SEPARATOR}' &lt;startcode></code>.
   * For example, if hostname is <code>example.org</code>, port is <code>1234</code>,
   * and the startcode for the regionserver is <code>1212121212</code>, then
   * the {@link #toString()} would be <code>example.org,1234,1212121212</code>.
   * 
   * <p>You can obtain a versioned serialized form of this class by calling
   * {@link #getVersionedBytes()}.  To deserialize, call {@link #parseVersionedServerName(byte[])}
   * 
   * <p>Immutable.
   */
  @InterfaceAudience.Public
  @InterfaceStability.Evolving
  public class ServerName implements Comparable<ServerName> {
    /**
     * Version for this class.
     * Its a short rather than a byte so I can for sure distinguish between this
     * version of this class and the version previous to this which did not have
     * a version.
     */
    private static final short VERSION = 0;
    static final byte [] VERSION_BYTES = Bytes.toBytes(VERSION);
  
    /**
     * What to use if no startcode supplied.
     */
    public static final int NON_STARTCODE = -1;
  
    /**
     * This character is used as separator between server hostname, port and
     * startcode.
     */
    public static final String SERVERNAME_SEPARATOR = ",";
  
    public static final Pattern SERVERNAME_PATTERN =
      Pattern.compile("[^" + SERVERNAME_SEPARATOR + "]+" +
        SERVERNAME_SEPARATOR + Addressing.VALID_PORT_REGEX +
        SERVERNAME_SEPARATOR + Addressing.VALID_PORT_REGEX + "$");
  
    /**
     * What to use if server name is unknown.
     */
    public static final String UNKNOWN_SERVERNAME = "#unknown#";
  
    private final String servername;
    private final String hostname;
    private final int port;
    private final long startcode;
  
    /**
     * Cached versioned bytes of this ServerName instance.
     * @see #getVersionedBytes()
     */
    private byte [] bytes;
    public static final List<ServerName> EMPTY_SERVER_LIST = new ArrayList<ServerName>(0);
  
    public ServerName(final String hostname, final int port, final long startcode) {
      this.hostname = hostname;
      this.port = port;
     this.startcode = startcode;
     this.servername = getServerName(hostname, port, startcode);
   }
 
   public ServerName(final String serverName) {
     this(parseHostname(serverName), parsePort(serverName),
       parseStartcode(serverName));
   }
 
   public ServerName(final String hostAndPort, final long startCode) {
     this(Addressing.parseHostname(hostAndPort),
       Addressing.parsePort(hostAndPort), startCode);
   }
 
   public static String parseHostname(final String serverName) {
     if (serverName == null || serverName.length() <= 0) {
       throw new IllegalArgumentException("Passed hostname is null or empty");
     }
     int index = serverName.indexOf(SERVERNAME_SEPARATOR);
     return serverName.substring(0, index);
   }
 
   public static int parsePort(final String serverName) {
     String [] split = serverName.split(SERVERNAME_SEPARATOR);
     return Integer.parseInt(split[1]);
   }
 
   public static long parseStartcode(final String serverName) {
     int index = serverName.lastIndexOf(SERVERNAME_SEPARATOR);
     return Long.parseLong(serverName.substring(index + 1));
   }
 
   @Override
   public String toString() {
     return getServerName();
   }
 
   /**
    * @return {@link #getServerName()} as bytes with a short-sized prefix with
    * the ServerName#VERSION of this class.
    */
   public synchronized byte [] getVersionedBytes() {
     if (this.bytes == null) {
       this.bytes = Bytes.add(VERSION_BYTES, Bytes.toBytes(getServerName()));
     }
     return this.bytes;
   }
 
   public String getServerName() {
     return servername;
   }
 
   public String getHostname() {
     return hostname;
   }
 
   public int getPort() {
     return port;
   }
 
   public long getStartcode() {
     return startcode;
   }
 
   /**
    * @param hostName
    * @param port
    * @param startcode
    * @return Server name made of the concatenation of hostname, port and
    * startcode formatted as <code>&lt;hostname> ',' &lt;port> ',' &lt;startcode></code>
    */
   public static String getServerName(String hostName, int port, long startcode) {
     final StringBuilder name = new StringBuilder(hostName.length() + 1 + 5 + 1 + 13);
     name.append(hostName);
     name.append(SERVERNAME_SEPARATOR);
     name.append(port);
     name.append(SERVERNAME_SEPARATOR);
     name.append(startcode);
     return name.toString();
   }
 
   /**
    * @param hostAndPort String in form of &lt;hostname> ':' &lt;port>
    * @param startcode
    * @return Server name made of the concatenation of hostname, port and
    * startcode formatted as <code>&lt;hostname> ',' &lt;port> ',' &lt;startcode></code>
    */
   public static String getServerName(final String hostAndPort,
       final long startcode) {
     int index = hostAndPort.indexOf(":");
     if (index <= 0) throw new IllegalArgumentException("Expected <hostname> ':' <port>");
     return getServerName(hostAndPort.substring(0, index),
       Integer.parseInt(hostAndPort.substring(index + 1)), startcode);
   }
 
   /**
    * @return Hostname and port formatted as described at
    * {@link Addressing#createHostAndPortStr(String, int)}
    */
   public String getHostAndPort() {
     return Addressing.createHostAndPortStr(this.hostname, this.port);
   }
 
   /**
    * @param serverName ServerName in form specified by {@link #getServerName()}
    * @return The server start code parsed from <code>servername</code>
    */
   public static long getServerStartcodeFromServerName(final String serverName) {
     int index = serverName.lastIndexOf(SERVERNAME_SEPARATOR);
     return Long.parseLong(serverName.substring(index + 1));
   }
 
   /**
    * Utility method to excise the start code from a server name
    * @param inServerName full server name
    * @return server name less its start code
    */
   public static String getServerNameLessStartCode(String inServerName) {
     if (inServerName != null && inServerName.length() > 0) {
       int index = inServerName.lastIndexOf(SERVERNAME_SEPARATOR);
       if (index > 0) {
         return inServerName.substring(0, index);
       }
     }
     return inServerName;
   }
 
   @Override
   public int compareTo(ServerName other) {
     int compare = this.getHostname().toLowerCase().
       compareTo(other.getHostname().toLowerCase());
     if (compare != 0) return compare;
     compare = this.getPort() - other.getPort();
     if (compare != 0) return compare;
     return (int)(this.getStartcode() - other.getStartcode());
   }
 
   @Override
   public int hashCode() {
     return getServerName().hashCode();
   }
 
   @Override
   public boolean equals(Object o) {
     if (this == o) return true;
     if (o == null) return false;
     if (!(o instanceof ServerName)) return false;
     return this.compareTo((ServerName)o) == 0;
   }
 
   /**
    * @param left
    * @param right
    * @return True if <code>other</code> has same hostname and port.
    */
   public static boolean isSameHostnameAndPort(final ServerName left,
       final ServerName right) {
     if (left == null) return false;
     if (right == null) return false;
     return left.getHostname().equals(right.getHostname()) &&
       left.getPort() == right.getPort();
   }
 
   /**
    * Use this method instantiating a {@link ServerName} from bytes
    * gotten from a call to {@link #getVersionedBytes()}.  Will take care of the
    * case where bytes were written by an earlier version of hbase.
    * @param versionedBytes Pass bytes gotten from a call to {@link #getVersionedBytes()}
    * @return A ServerName instance.
    * @see #getVersionedBytes()
    */
   public static ServerName parseVersionedServerName(final byte [] versionedBytes) {
     // Version is a short.
     short version = Bytes.toShort(versionedBytes);
     if (version == VERSION) {
       int length = versionedBytes.length - Bytes.SIZEOF_SHORT;
       return new ServerName(Bytes.toString(versionedBytes, Bytes.SIZEOF_SHORT, length));
     }
     // Presume the bytes were written with an old version of hbase and that the
     // bytes are actually a String of the form "'<hostname>' ':' '<port>'".
     return new ServerName(Bytes.toString(versionedBytes), NON_STARTCODE);
   }
 
   /**
    * @param str Either an instance of {@link ServerName#toString()} or a
    * "'<hostname>' ':' '<port>'".
    * @return A ServerName instance.
    */
   public static ServerName parseServerName(final String str) {
     return SERVERNAME_PATTERN.matcher(str).matches()? new ServerName(str):
       new ServerName(str, NON_STARTCODE);
   }
 
 
   /**
    * @return true if the String follows the pattern of {@link ServerName#toString()}, false
    *  otherwise.
    */
   public static boolean isFullServerName(final String str){
     if (str == null ||str.isEmpty()) return false;
     return SERVERNAME_PATTERN.matcher(str).matches();
   }
 
   /**
    * Get a ServerName from the passed in data bytes.
    * @param data Data with a serialize server name in it; can handle the old style
    * servername where servername was host and port.  Works too with data that
    * begins w/ the pb 'PBUF' magic and that is then followed by a protobuf that
    * has a serialized {@link ServerName} in it.
    * @return Returns null if <code>data</code> is null else converts passed data
    * to a ServerName instance.
    * @throws DeserializationException 
    */
   public static ServerName parseFrom(final byte [] data) throws DeserializationException {
     if (data == null || data.length <= 0) return null;
     if (ProtobufUtil.isPBMagicPrefix(data)) {
       int prefixLen = ProtobufUtil.lengthOfPBMagic();
       try {
         RootRegionServer rss =
           RootRegionServer.newBuilder().mergeFrom(data, prefixLen, data.length - prefixLen).build();
         org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.ServerName sn = rss.getServer();
         return new ServerName(sn.getHostName(), sn.getPort(), sn.getStartCode());
       } catch (InvalidProtocolBufferException e) {
         // A failed parse of the znode is pretty catastrophic. Rather than loop
         // retrying hoping the bad bytes will changes, and rather than change
         // the signature on this method to add an IOE which will send ripples all
         // over the code base, throw a RuntimeException.  This should "never" happen.
         // Fail fast if it does.
         throw new DeserializationException(e);
       }
     }
     // The str returned could be old style -- pre hbase-1502 -- which was
     // hostname and port seperated by a colon rather than hostname, port and
     // startcode delimited by a ','.
     String str = Bytes.toString(data);
     int index = str.indexOf(ServerName.SERVERNAME_SEPARATOR);
     if (index != -1) {
       // Presume its ServerName serialized with versioned bytes.
       return ServerName.parseVersionedServerName(data);
     }
     // Presume it a hostname:port format.
     String hostname = Addressing.parseHostname(str);
     int port = Addressing.parsePort(str);
     return new ServerName(hostname, port, -1L);
   }
 }