Package org.apache.hadoop.hdfs.server.federation.resolver.order

Class HashResolver

java.lang.Object

org.apache.hadoop.hdfs.server.federation.resolver.order.HashResolver

All Implemented Interfaces:

OrderedResolver

Direct Known Subclasses:

HashFirstResolver

public class HashResolver
extends java.lang.Object
implements OrderedResolver

Order the destinations based on consistent hashing.

Field Summary

Fields

Modifier and Type	Field	Description
protected static org.slf4j.Logger	LOG

Constructor Summary

Constructors

Constructor	Description
HashResolver()

Method Summary

Modifier and Type	Method	Description
static java.lang.String	extractTempFileName(java.lang.String input)	Some files use a temporary naming pattern.
java.lang.String	getFirstNamespace(java.lang.String path, PathLocation loc)	Use the result from consistent hashing locator to prioritize the locations for a path.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

LOG

protected static final org.slf4j.Logger LOG

Constructor Detail

HashResolver

public HashResolver()

Method Detail

getFirstNamespace

public java.lang.String getFirstNamespace(java.lang.String path,
                                          PathLocation loc)

Use the result from consistent hashing locator to prioritize the locations for a path.

Specified by:

getFirstNamespace in interface OrderedResolver

Parameters:

path - Path to check.

loc - Federated location with multiple destinations.

Returns:

First namespace based on hash.

extractTempFileName

@VisibleForTesting
public static java.lang.String extractTempFileName(java.lang.String input)

Some files use a temporary naming pattern. Extract the final name from the temporary name. For example, files *._COPYING_ will be renamed, so we remove that chunk.

Parameters:

input - Input string.

Returns:

Final file name.