Package org.pipecraft.pipes.terminal

Class MapWriterPipe<T,K,V>

java.lang.Object

org.pipecraft.pipes.terminal.TerminalPipe

org.pipecraft.pipes.terminal.MapWriterPipe<T,K,V>

Type Parameters:

T - The type of items in the input pipe

K - The key type in the output map. Must be suitable as a key map (i.e. equal items must have the same hashcode).

V - The value type in the output map

All Implemented Interfaces:

Closeable, AutoCloseable, BasePipe

public class MapWriterPipe<T,K,V>
extends TerminalPipe

A terminal pipe writing all contents from an input pipe into a given Map. Thread safety: It's the responsibility of the caller to make sure access to the output map is thread safe. For example, if the map itself is thread safe, or if a single thread creates, runs and queries the results (using getItems()) then there's no concurrency problem.

Author:

Eyal Schneider

Constructor Summary

Constructors

Constructor	Description
MapWriterPipe(Pipe<T> inputPipe, FailableFunction<T,K,ValidationPipeException> keyExtractor, FailableFunction<T,V,ValidationPipeException> valueExtractor)	Constructor Creates a writer that populates a new HashMap.
MapWriterPipe(Pipe<T> inputPipe, FailableFunction<T,K,ValidationPipeException> keyExtractor, FailableFunction<T,V,ValidationPipeException> valueExtractor, Map<K,V> outputMap)	Constructor

Method Summary

Modifier and Type	Method	Description
void	close()
Map<K,V>	getItems()
void	start()	Performs pre-processing prior to item flow throw the pipe.

Methods inherited from class org.pipecraft.pipes.terminal.TerminalPipe

getProgress

Methods inherited from class java.lang.Object

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

Constructor Detail

MapWriterPipe

public MapWriterPipe(Pipe<T> inputPipe,
                     FailableFunction<T,K,ValidationPipeException> keyExtractor,
                     FailableFunction<T,V,ValidationPipeException> valueExtractor)

Constructor Creates a writer that populates a new HashMap.

Parameters:

inputPipe - The input pipe to consume

keyExtractor - The logic for extracting the map key from an input item. In case that two different items produce the same key, the latter (in input pipe appearance order) will override the results of the former.

valueExtractor - The logic for extracting the map value from an input item

MapWriterPipe

public MapWriterPipe(Pipe<T> inputPipe,
                     FailableFunction<T,K,ValidationPipeException> keyExtractor,
                     FailableFunction<T,V,ValidationPipeException> valueExtractor,
                     Map<K,V> outputMap)

Constructor

Parameters:

inputPipe - The input pipe to consume

keyExtractor - The logic for extracting the map key from an input item. In case that two different items produce the same key, the latter (in input pipe appearance order) will override the results of the former.

valueExtractor - The logic for extracting the map value from an input item

outputMap - The map to populate

Method Detail

start

public void start()
           throws PipeException,
                  InterruptedException

Description copied from interface: BasePipe

Performs pre-processing prior to item flow throw the pipe. Implementations must call the same method for all their input pipes before accessing their items. This is typically done here.

Throws:

PipeException - In case of pipe errors in this pipe or somewhere up-stream.

InterruptedException - In case that the operation has been interrupted by another thread.

close

public void close()
           throws IOException

Throws:

IOException

getItems

public Map<K,V> getItems()

Returns:

The output map