package act.util;
/*-
* #%L
* ACT Framework
* %%
* Copyright (C) 2014 - 2017 ActFramework
* %%
* 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.
* #L%
*/
import org.joda.time.DateTime;
import org.osgl.$;
import org.osgl.util.E;
import org.osgl.util.IO;
import org.osgl.util.S;
import java.io.File;
import java.util.concurrent.atomic.AtomicLong;
/**
* Generate unique ID in a cluster
*/
public class IdGenerator {
/**
* Implementation of {@code StartIdProvider} shall return a
* unique id per each system start
*/
public interface StartIdProvider {
/**
* Returns the system start ID. The start ID shall be different
* between System starts, but it shall remaining the same value
* within one system life time
*/
long startId();
/**
* Generate system start ID based on timestamp
*/
class Timestamp implements StartIdProvider {
private final long id;
public Timestamp() {
long origin = DateTime.parse("2016-05-10").getMillis();
// let's assume the system cannot be restart within 10 seconds
long l = ($.ms() - origin) / 1000 / 10;
id = l;
}
@Override
public long startId() {
return id;
}
}
/**
* Generate system start ID based on incremental sequence. The newly generated ID
* will be write to a File
*/
class FileBasedStartCounter implements StartIdProvider {
private final long id;
public FileBasedStartCounter() {
this(".act.id-global");
}
public FileBasedStartCounter(String path) {
File file = new File(path);
if (file.exists()) {
String s = IO.readContentAsString(file);
long seq = Long.parseLong(s);
seq = seq + 1;
IO.writeContent(S.str(seq), file);
id = (seq);
} else {
id = 0;
IO.writeContent(Long.toString(id), file);
}
}
@Override
public long startId() {
return id;
}
}
/**
* Default start ID provider will try to use the {@link act.util.IdGenerator.StartIdProvider.FileBasedStartCounter}. In case
* File IO is not allowed (e.g. in GAE), then it will use {@link act.util.IdGenerator.StartIdProvider.Timestamp}
*/
class DefaultStartIdProvider implements StartIdProvider {
private StartIdProvider delegate;
public DefaultStartIdProvider() {
this(".act.id-global");
}
public DefaultStartIdProvider(String path) {
try {
delegate = new FileBasedStartCounter(path);
delegate.startId();
} catch (Exception e) {
delegate = new Timestamp();
}
}
@Override
public long startId() {
return delegate.startId();
}
}
}
/**
* {@code SequenceProvider} shall generate unique ID within
* one JVM per each call
*/
public interface SequenceProvider {
long seqId();
class AtomicLongSeq implements SequenceProvider {
private final AtomicLong seq = new AtomicLong(0);
@Override
public long seqId() {
return (seq.incrementAndGet());
}
}
}
public interface NodeIdProvider {
long nodeId();
class IpProvider implements NodeIdProvider {
private enum EffectiveBytes {
ONE(1), TWO(2), THREE(3), FOUR(4);
private int value;
EffectiveBytes(int value) {
this.value = value;
}
public static EffectiveBytes valueOf(int n) {
switch (n) {
case 1: return ONE;
case 2: return TWO;
case 3: return THREE;
case 4: return FOUR;
default :
throw E.unexpected("Invalid EffectiveByte value: %s. Expected: 1 - 4", n);
}
}
}
private final EffectiveBytes effectiveBytes;
private final long id;
public IpProvider() {
this(4);
}
public IpProvider(int effectBytes) {
this.effectiveBytes = EffectiveBytes.valueOf(effectBytes);
String ip = LocalIpAddressUtil.ip();
String[] sa = ip.split("\\.");
int n = effectiveBytes.value;
long l = 0;
for (int i = 0; i < n; ++i) {
String b = sa[3 - i];
long factor = 1;
for (int j = 0; j < i; ++j) {
factor = factor * 256;
}
l += Long.valueOf(b) * factor;
}
id = (l);
}
public long nodeId() {
return id;
}
}
}
public interface LongEncoder {
String longToStr(long l);
abstract class LongEncoderBase implements LongEncoder {
private final char[] digits;
private final int MAX_RADIX;
public LongEncoderBase(char[] digits) {
this.digits = digits;
this.MAX_RADIX = digits.length;
}
/**
* Code copied from JDK Long.toString(long, String)
*/
public String longToStr(long l) {
int radix = MAX_RADIX;
char[] buf = new char[65];
int charPos = 64;
boolean negative = (l < 0);
if (!negative) {
l = -l;
}
while (l <= -radix) {
buf[charPos--] = digits[(int)(-(l % radix))];
l = l / radix;
}
buf[charPos] = digits[(int)(-l)];
if (negative) {
buf[--charPos] = '-';
}
return new String(buf, charPos, (65 - charPos));
}
}
}
public static class UnsafeLongEncoder extends LongEncoder.LongEncoderBase {
/**
* Extended char table for representing a number as a String
*/
private final static char[] digits = {
'0', '1', '2', '3', '4', '5',
'6', '7', '8', '9', 'a', 'b',
'c', 'd', 'e', 'f', 'g', 'h',
'i', 'j', 'k', 'l', 'm', 'n',
'o', 'p', 'q', 'r', 's', 't',
'u', 'v', 'w', 'x', 'y', 'z',
'A', 'B', 'C', 'D', 'E', 'F',
'G', 'H', 'I', 'J', 'K', 'L',
'M', 'N', 'O', 'P', 'Q', 'R',
'S', 'T', 'U', 'V', 'W', 'X',
'Y', 'Z', '!', '$', '%', '&',
'.', ',', ';', ':', '=', '?',
'+', '-', '*', '/', '<', '>',
'_', '~', '#', '^', '@', '|',
'(', ')', '[', ']', '{', '}'
};
public UnsafeLongEncoder() {
super(digits);
}
}
public static class SafeLongEncoder extends LongEncoder.LongEncoderBase {
/**
* Extended char table for representing a number as a String
*/
private final static char[] digits = {
'0', '1', '2', '3', '4', '5',
'6', '7', '8', '9', 'a', 'b',
'c', 'd', 'e', 'f', 'g', 'h',
'i', 'j', 'k', 'l', 'm', 'n',
'o', 'p', 'q', 'r', 's', 't',
'u', 'v', 'w', 'x', 'y', 'z',
'A', 'B', 'C', 'D', 'E', 'F',
'G', 'H', 'I', 'J', 'K', 'L',
'M', 'N', 'O', 'P', 'Q', 'R',
'S', 'T', 'U', 'V', 'W', 'X',
'Y', 'Z', '.', '-', '_', '~',
};
public SafeLongEncoder() {
super(digits);
}
}
public static final LongEncoder SAFE_ENCODER = new SafeLongEncoder();
public static final LongEncoder UNSAFE_ENCODER = new UnsafeLongEncoder();
private final NodeIdProvider nodeIdProvider;
private final StartIdProvider startIdProvider;
private final SequenceProvider sequenceProvider;
private LongEncoder longEncoder;
/**
* Create a default IdGenerator with following configuration:
* <ul>
* <li>Node ID provider: four byte IP address</li>
* <li>Start ID provider: stored in <code>.act.id-global</code> file</li>
* <li>Sequence ID provider: Atomic Long sequence</li>
* <li>Long Encoder: {@link SafeLongEncoder}</li>
* </ul>
*/
public IdGenerator() {
this(new NodeIdProvider.IpProvider(), new StartIdProvider.DefaultStartIdProvider(),
new SequenceProvider.AtomicLongSeq(), SAFE_ENCODER);
}
/**
* Create a default IdGenerator with following configuration:
* <ul>
* <li>Node ID provider: four byte IP address</li>
* <li>Start ID provider: stored in <code>.act.id-global</code> file</li>
* <li>Sequence ID provider: Atomic Long sequence</li>
* <li>
* Long Encoder: {@link UnsafeLongEncoder} when `useUnsafeLongEncoder` is set to
* `true` or {@link SafeLongEncoder} otherwise
* </li>
* </ul>
* @param useUnsafeLongEncoder indicate use safe or unsafe long encoder
*/
public IdGenerator(boolean useUnsafeLongEncoder) {
this(new NodeIdProvider.IpProvider(), new StartIdProvider.DefaultStartIdProvider(),
new SequenceProvider.AtomicLongSeq(), useUnsafeLongEncoder ? UNSAFE_ENCODER : SAFE_ENCODER);
}
/**
* Create a default IdGenerator with specified node id provider, start id provider and sequence provider:
*/
public IdGenerator(NodeIdProvider nodeIdProvider, StartIdProvider startIdProvider, SequenceProvider sequenceProvider, LongEncoder longEncoder) {
this.nodeIdProvider = $.notNull(nodeIdProvider);
this.startIdProvider = $.notNull(startIdProvider);
this.sequenceProvider = $.notNull(sequenceProvider);
this.longEncoder = $.notNull(longEncoder);
}
/**
* Create a default IdGenerator with following configuration:
* <ul>
* <li>Node ID provider: N byte IP address, where N is specified by effectiveIpBytes argument</li>
* <li>Start ID provider: stored in <code>.act.id-global</code> file</li>
* <li>Sequnce ID provider: Atomic Long sequence</li>
* </ul>
*/
public IdGenerator(int effectiveIpBytes) {
this.nodeIdProvider = new NodeIdProvider.IpProvider(effectiveIpBytes);
this.startIdProvider = new StartIdProvider.DefaultStartIdProvider();
this.sequenceProvider = new SequenceProvider.AtomicLongSeq();
this.longEncoder = SAFE_ENCODER;
}
/**
* Create a default IdGenerator with following configuration:
* <ul>
* <li>Node ID provider: N byte IP address, where N is specified by effectiveIpBytes argument</li>
* <li>Start ID provider: use start ID file specified by startIdFile argument</li>
* <li>Sequnce ID provider: Atomic Long sequence</li>
* </ul>
*/
public IdGenerator(int effectiveIpBytes, String startIdFile) {
this.nodeIdProvider = new NodeIdProvider.IpProvider(effectiveIpBytes);
this.startIdProvider = new StartIdProvider.DefaultStartIdProvider(startIdFile);
this.sequenceProvider = new SequenceProvider.AtomicLongSeq();
this.longEncoder = SAFE_ENCODER;
}
/**
* Create a default IdGenerator with following configuration:
* <ul>
* <li>Node ID provider: 4 byte IP address</li>
* <li>Start ID provider: use start ID file specified by startIdFile argument</li>
* <li>Sequnce ID provider: Atomic Long sequence</li>
* </ul>
*/
public IdGenerator(String startIdFile) {
this.nodeIdProvider = new NodeIdProvider.IpProvider();
this.startIdProvider = new StartIdProvider.DefaultStartIdProvider(startIdFile);
this.sequenceProvider = new SequenceProvider.AtomicLongSeq();
this.longEncoder = SAFE_ENCODER;
}
/**
* Generate a unique ID across the cluster
* @return generated ID
*/
public String genId() {
S.Buffer sb = S.newBuffer();
sb.a(longEncoder.longToStr(nodeIdProvider.nodeId()))
.a(longEncoder.longToStr(startIdProvider.startId()))
.a(longEncoder.longToStr(sequenceProvider.seqId()));
return sb.toString();
}
}