Singleton (ImgLib2 Javadocs 0-SNAPSHOT API)

java.lang.Object
- net.imglib2.algorithm.util.Singleton

public class Singleton
extends Object

Manage named singleton instances. Useful for sharing instances of objects between threads. Our most relevant use case for this is to share cached ImgLib2 cell images such as N5 datasets and lazily generated cell images between tasks of a Spark cluster running on the same executor. Example:


 final String url = "https://janelia-cosem.s3.amazonaws.com/jrc_hela-2/jrc_hela-2.n5";
 final String dataset = "/em/fibsem-uint16/s4";

 final N5Reader n5 = Singleton.get(
 		url,
 		() -> new N5Factory().openReader( url ) );

 final RandomAccessibleInterval< T > img = Singleton.get(
 		url + ":" + dataset,
 		() -> N5Utils.open( n5, dataset ) );

Author:: Stephan Saalfeld

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

static interface Singleton.ThrowingSupplier<T,E extends Exception>

Nested Classes
Modifier and Type	Class and Description
`static interface`	`Singleton.ThrowingSupplier<T,E extends Exception>`

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`static void`	`clear()` Clear all named singletons.
`static <T,E extends Exception> T`	`get(String key, Singleton.ThrowingSupplier<T,E> supplier)` Get or create the named singleton instance of T.
`static Object`	`remove(String key)` Remove and retrieve a named singleton instance.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

remove
```
public static Object remove(String key)
```
Remove and retrieve a named singleton instance.

Parameters:

key -

Returns:

get

public static <T,E extends Exception> T get(String key,
                                            Singleton.ThrowingSupplier<T,E> supplier)
                                     throws E extends Exception

Get or create the named singleton instance of T.

Type Parameters:: T -; E -
Parameters:: key -; supplier -
Returns:
Throws:: E; E extends Exception

clear
```
public static void clear()
```
Clear all named singletons.

Class Singleton

Nested Class Summary

Method Summary

Methods inherited from class java.lang.Object

Method Detail

remove

get

clear