org.apache.accumulo.tserver

Class NativeMap

java.lang.Object

org.apache.accumulo.tserver.NativeMap

All Implemented Interfaces:

Iterable<Map.Entry<Key,Value>>

public class NativeMap
extends Object
implements Iterable<Map.Entry<Key,Value>>

This class stores data in a C++ map. Doing this allows us to store more in memory and avoid pauses caused by Java GC. The strategy for dealing with native memory allocated for the native map is that java code using the native map should call delete() as soon as it is finished using the native map. When the NativeMap object is garbage collected its native resources will be released if needed. However waiting for java GC would be a mistake for long lived NativeMaps. Long lived objects are not garbage collected quickly, therefore a process could easily use too much memory.

Constructor Summary

Constructors

Constructor and Description
NativeMap()

Method Summary

Modifier and Type	Method and Description
void	delete()
protected void	finalize()
Value	get(Key key)
long	getMemoryUsed()
static boolean	isLoaded() Check if native libraries are loaded.
Iterator<Map.Entry<Key,Value>>	iterator()
Iterator<Map.Entry<Key,Value>>	iterator(Key startKey)
static void	loadNativeLib(List<File> searchPath) If native libraries are not loaded, the specified search path will be used to attempt to load them.
void	mutate(Mutation mutation, int mutationCount)
void	put(Key key, Value value)
int	size()
SortedKeyValueIterator<Key,Value>	skvIterator()

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Detail

NativeMap

public NativeMap()

Method Detail

loadNativeLib

public static void loadNativeLib(List<File> searchPath)

If native libraries are not loaded, the specified search path will be used to attempt to load them. Directories will be searched by using the system-specific library naming conventions. A path directly to a file can also be provided. Loading will continue until the search path is exhausted, or until the native libraries are found and successfully loaded, whichever occurs first.

Parameters:

searchPath - a list of files and directories to search

isLoaded

public static boolean isLoaded()

Check if native libraries are loaded.

Returns:

true if they are loaded; false otherwise

finalize

protected void finalize()
                 throws Throwable

Overrides:

finalize in class Object

Throws:

Throwable

mutate

public void mutate(Mutation mutation,
                   int mutationCount)

put

public void put(Key key,
                Value value)

get

public Value get(Key key)

size

public int size()

getMemoryUsed

public long getMemoryUsed()

iterator

public Iterator<Map.Entry<Key,Value>> iterator()

Specified by:

iterator in interface Iterable<Map.Entry<Key,Value>>

iterator

public Iterator<Map.Entry<Key,Value>> iterator(Key startKey)

delete

public void delete()

skvIterator

public SortedKeyValueIterator<Key,Value> skvIterator()