org.apache.hadoop.hive.common

Class StringInternUtils

java.lang.Object

org.apache.hadoop.hive.common.StringInternUtils

public class StringInternUtils
extends java.lang.Object

Collection of utilities for string interning, common across Hive. We use the standard String.intern() call, that performs very well (no problems with PermGen overflowing, etc.) starting from JDK 7.

Constructor Summary

Constructors

Constructor and Description
StringInternUtils()

Method Summary

Modifier and Type	Method and Description
static java.lang.String	internIfNotNull(java.lang.String s)
static java.lang.String[]	internStringsInArray(java.lang.String[] strings) Interns all the strings in the given array in place, returning the same array
static java.util.List<java.lang.String>	internStringsInList(java.util.List<java.lang.String> list) This method interns all the strings in the given list in place.
static java.net.URI	internStringsInUri(java.net.URI uri)
static org.apache.hadoop.fs.Path	internUriStringsInPath(org.apache.hadoop.fs.Path path)
static org.apache.hadoop.fs.Path[]	internUriStringsInPathArray(org.apache.hadoop.fs.Path[] paths)
static <K> java.util.Map<K,java.lang.String>	internValuesInMap(java.util.Map<K,java.lang.String> map)

Methods inherited from class java.lang.Object

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

Constructor Detail

StringInternUtils

public StringInternUtils()

Method Detail

internStringsInUri

public static java.net.URI internStringsInUri(java.net.URI uri)

internUriStringsInPath

public static org.apache.hadoop.fs.Path internUriStringsInPath(org.apache.hadoop.fs.Path path)

internUriStringsInPathArray

public static org.apache.hadoop.fs.Path[] internUriStringsInPathArray(org.apache.hadoop.fs.Path[] paths)

internStringsInList

public static java.util.List<java.lang.String> internStringsInList(java.util.List<java.lang.String> list)

This method interns all the strings in the given list in place. That is, it iterates over the list, replaces each element with the interned copy and eventually returns the same list. Note that the provided List implementation should return an iterator (via list.listIterator()) method, and that iterator should implement the set(Object) method. That's what all List implementations in the JDK provide. However, if some custom List implementation doesn't have this functionality, this method will return without interning its elements.

internStringsInArray

public static java.lang.String[] internStringsInArray(java.lang.String[] strings)

Interns all the strings in the given array in place, returning the same array

internValuesInMap

public static <K> java.util.Map<K,java.lang.String> internValuesInMap(java.util.Map<K,java.lang.String> map)

internIfNotNull

public static java.lang.String internIfNotNull(java.lang.String s)