// Code source of this file:
// http://grepcode.com/file/repo1.maven.org/maven2/
// org.apache.maven/maven-artifact/3.1.1/
// org/apache/maven/artifact/versioning/ComparableVersion.java/
//
// Modifications made on top of the source:
// 1. Changed
// package org.apache.maven.artifact.versioning;
// to
// package org.apache.hadoop.util;
// 2. Removed author tags to clear hadoop author tag warning
// author <a href="mailto:kenney@apache.org">Kenney Westerhof</a>
// author <a href="mailto:hboutemy@apache.org">Hervé Boutemy</a>
//
package org.apache.hadoop.util;
/*
* 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.
*/
import java.math.BigInteger;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Iterator;
import java.util.List;
import java.util.ListIterator;
import java.util.Locale;
import java.util.Properties;
import java.util.Stack;
/**
* Generic implementation of version comparison.
*
* <p>Features:
* <ul>
* <li>mixing of '<code>-</code>' (dash) and '<code>.</code>' (dot) separators,</li>
* <li>transition between characters and digits also constitutes a separator:
* <code>1.0alpha1 => [1, 0, alpha, 1]</code></li>
* <li>unlimited number of version components,</li>
* <li>version components in the text can be digits or strings,</li>
* <li>strings are checked for well-known qualifiers and the qualifier ordering is used for version ordering.
* Well-known qualifiers (case insensitive) are:<ul>
* <li><code>alpha</code> or <code>a</code></li>
* <li><code>beta</code> or <code>b</code></li>
* <li><code>milestone</code> or <code>m</code></li>
* <li><code>rc</code> or <code>cr</code></li>
* <li><code>snapshot</code></li>
* <li><code>(the empty string)</code> or <code>ga</code> or <code>final</code></li>
* <li><code>sp</code></li>
* </ul>
* Unknown qualifiers are considered after known qualifiers, with lexical order (always case insensitive),
* </li>
* <li>a dash usually precedes a qualifier, and is always less important than something preceded with a dot.</li>
* </ul></p>
*
* @see <a href="https://cwiki.apache.org/confluence/display/MAVENOLD/Versioning">"Versioning" on Maven Wiki</a>
*/
public class ComparableVersion
implements Comparable<ComparableVersion>
{
private String value;
private String canonical;
private ListItem items;
private interface Item
{
int INTEGER_ITEM = 0;
int STRING_ITEM = 1;
int LIST_ITEM = 2;
int compareTo( Item item );
int getType();
boolean isNull();
}
/**
* Represents a numeric item in the version item list.
*/
private static class IntegerItem
implements Item
{
private static final BigInteger BIG_INTEGER_ZERO = new BigInteger( "0" );
private final BigInteger value;
public static final IntegerItem ZERO = new IntegerItem();
private IntegerItem()
{
this.value = BIG_INTEGER_ZERO;
}
public IntegerItem( String str )
{
this.value = new BigInteger( str );
}
public int getType()
{
return INTEGER_ITEM;
}
public boolean isNull()
{
return BIG_INTEGER_ZERO.equals( value );
}
public int compareTo( Item item )
{
if ( item == null )
{
return BIG_INTEGER_ZERO.equals( value ) ? 0 : 1; // 1.0 == 1, 1.1 > 1
}
switch ( item.getType() )
{
case INTEGER_ITEM:
return value.compareTo( ( (IntegerItem) item ).value );
case STRING_ITEM:
return 1; // 1.1 > 1-sp
case LIST_ITEM:
return 1; // 1.1 > 1-1
default:
throw new RuntimeException( "invalid item: " + item.getClass() );
}
}
public String toString()
{
return value.toString();
}
}
/**
* Represents a string in the version item list, usually a qualifier.
*/
private static class StringItem
implements Item
{
private static final String[] QUALIFIERS = { "alpha", "beta", "milestone", "rc", "snapshot", "", "sp" };
private static final List<String> _QUALIFIERS = Arrays.asList( QUALIFIERS );
private static final Properties ALIASES = new Properties();
static
{
ALIASES.put( "ga", "" );
ALIASES.put( "final", "" );
ALIASES.put( "cr", "rc" );
}
/**
* A comparable value for the empty-string qualifier. This one is used to determine if a given qualifier makes
* the version older than one without a qualifier, or more recent.
*/
private static final String RELEASE_VERSION_INDEX = String.valueOf( _QUALIFIERS.indexOf( "" ) );
private String value;
public StringItem( String value, boolean followedByDigit )
{
if ( followedByDigit && value.length() == 1 )
{
// a1 = alpha-1, b1 = beta-1, m1 = milestone-1
switch ( value.charAt( 0 ) )
{
case 'a':
value = "alpha";
break;
case 'b':
value = "beta";
break;
case 'm':
value = "milestone";
break;
}
}
this.value = ALIASES.getProperty( value , value );
}
public int getType()
{
return STRING_ITEM;
}
public boolean isNull()
{
return ( comparableQualifier( value ).compareTo( RELEASE_VERSION_INDEX ) == 0 );
}
/**
* Returns a comparable value for a qualifier.
*
* This method takes into account the ordering of known qualifiers then unknown qualifiers with lexical ordering.
*
* just returning an Integer with the index here is faster, but requires a lot of if/then/else to check for -1
* or QUALIFIERS.size and then resort to lexical ordering. Most comparisons are decided by the first character,
* so this is still fast. If more characters are needed then it requires a lexical sort anyway.
*
* @param qualifier
* @return an equivalent value that can be used with lexical comparison
*/
public static String comparableQualifier( String qualifier )
{
int i = _QUALIFIERS.indexOf( qualifier );
return i == -1 ? ( _QUALIFIERS.size() + "-" + qualifier ) : String.valueOf( i );
}
public int compareTo( Item item )
{
if ( item == null )
{
// 1-rc < 1, 1-ga > 1
return comparableQualifier( value ).compareTo( RELEASE_VERSION_INDEX );
}
switch ( item.getType() )
{
case INTEGER_ITEM:
return -1; // 1.any < 1.1 ?
case STRING_ITEM:
return comparableQualifier( value ).compareTo( comparableQualifier( ( (StringItem) item ).value ) );
case LIST_ITEM:
return -1; // 1.any < 1-1
default:
throw new RuntimeException( "invalid item: " + item.getClass() );
}
}
public String toString()
{
return value;
}
}
/**
* Represents a version list item. This class is used both for the global item list and for sub-lists (which start
* with '-(number)' in the version specification).
*/
private static class ListItem
extends ArrayList<Item>
implements Item
{
public int getType()
{
return LIST_ITEM;
}
public boolean isNull()
{
return ( size() == 0 );
}
void normalize()
{
for ( ListIterator<Item> iterator = listIterator( size() ); iterator.hasPrevious(); )
{
Item item = iterator.previous();
if ( item.isNull() )
{
iterator.remove(); // remove null trailing items: 0, "", empty list
}
else
{
break;
}
}
}
public int compareTo( Item item )
{
if ( item == null )
{
if ( size() == 0 )
{
return 0; // 1-0 = 1- (normalize) = 1
}
Item first = get( 0 );
return first.compareTo( null );
}
switch ( item.getType() )
{
case INTEGER_ITEM:
return -1; // 1-1 < 1.0.x
case STRING_ITEM:
return 1; // 1-1 > 1-sp
case LIST_ITEM:
Iterator<Item> left = iterator();
Iterator<Item> right = ( (ListItem) item ).iterator();
while ( left.hasNext() || right.hasNext() )
{
Item l = left.hasNext() ? left.next() : null;
Item r = right.hasNext() ? right.next() : null;
// if this is shorter, then invert the compare and mul with -1
int result = l == null ? -1 * r.compareTo( l ) : l.compareTo( r );
if ( result != 0 )
{
return result;
}
}
return 0;
default:
throw new RuntimeException( "invalid item: " + item.getClass() );
}
}
public String toString()
{
StringBuilder buffer = new StringBuilder( "(" );
for ( Iterator<Item> iter = iterator(); iter.hasNext(); )
{
buffer.append( iter.next() );
if ( iter.hasNext() )
{
buffer.append( ',' );
}
}
buffer.append( ')' );
return buffer.toString();
}
}
public ComparableVersion( String version )
{
parseVersion( version );
}
public final void parseVersion( String version )
{
this.value = version;
items = new ListItem();
version = version.toLowerCase( Locale.ENGLISH );
ListItem list = items;
Stack<Item> stack = new Stack<Item>();
stack.push( list );
boolean isDigit = false;
int startIndex = 0;
for ( int i = 0; i < version.length(); i++ )
{
char c = version.charAt( i );
if ( c == '.' )
{
if ( i == startIndex )
{
list.add( IntegerItem.ZERO );
}
else
{
list.add( parseItem( isDigit, version.substring( startIndex, i ) ) );
}
startIndex = i + 1;
}
else if ( c == '-' )
{
if ( i == startIndex )
{
list.add( IntegerItem.ZERO );
}
else
{
list.add( parseItem( isDigit, version.substring( startIndex, i ) ) );
}
startIndex = i + 1;
if ( isDigit )
{
list.normalize(); // 1.0-* = 1-*
if ( ( i + 1 < version.length() ) && Character.isDigit( version.charAt( i + 1 ) ) )
{
// new ListItem only if previous were digits and new char is a digit,
// ie need to differentiate only 1.1 from 1-1
list.add( list = new ListItem() );
stack.push( list );
}
}
}
else if ( Character.isDigit( c ) )
{
if ( !isDigit && i > startIndex )
{
list.add( new StringItem( version.substring( startIndex, i ), true ) );
startIndex = i;
}
isDigit = true;
}
else
{
if ( isDigit && i > startIndex )
{
list.add( parseItem( true, version.substring( startIndex, i ) ) );
startIndex = i;
}
isDigit = false;
}
}
if ( version.length() > startIndex )
{
list.add( parseItem( isDigit, version.substring( startIndex ) ) );
}
while ( !stack.isEmpty() )
{
list = (ListItem) stack.pop();
list.normalize();
}
canonical = items.toString();
}
private static Item parseItem( boolean isDigit, String buf )
{
return isDigit ? new IntegerItem( buf ) : new StringItem( buf, false );
}
public int compareTo( ComparableVersion o )
{
return items.compareTo( o.items );
}
public String toString()
{
return value;
}
public boolean equals( Object o )
{
return ( o instanceof ComparableVersion ) && canonical.equals( ( (ComparableVersion) o ).canonical );
}
public int hashCode()
{
return canonical.hashCode();
}
}