/**
* Copyright 2011 The Apache Software Foundation
*
* 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 java.util.Collection;
import java.util.regex.Pattern;
import org.apache.hadoop.hbase.util.Addressing;
import org.apache.hadoop.hbase.util.Bytes;
/**
* 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><hostname> '{@link #SERVERNAME_SEPARATOR}' <port> '{@link #SERVERNAME_SEPARATOR}' <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.
*/
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 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 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><hostname> ',' <port> ',' <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 <hostname> ':' <port>
* @param startcode
* @return Server name made of the concatenation of hostname, port and
* startcode formatted as <code><hostname> ',' <port> ',' <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;
}
/**
* @return ServerName with matching hostname and port.
*/
public static ServerName findServerWithSameHostnamePort(final Collection<ServerName> names,
final ServerName serverName) {
for (ServerName sn: names) {
if (isSameHostnameAndPort(serverName, sn)) return sn;
}
return null;
}
/**
* @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);
}
}