org.apache.giraph.block_app.framework.block

Interface Block

All Superinterfaces:

Iterable<AbstractPiece>

All Known Subinterfaces:

BlockWithApiHandle

All Known Implementing Classes:

AbstractPiece, DefaultParentPiece, DelegatePiece, EmptyBlock, FilteringBlock, FilteringPiece, IfBlock, IterationCounterPiece, MigrationPiece, Piece, PieceWithWorkerContext, RepeatBlock, RepeatUntilBlock, SendMessagePiece, SendMessageWithCombinerPiece, SequenceBlock, WorkerGCPiece

public interface Block
extends Iterable<AbstractPiece>

Composable unit of execution. Used to combine other Blocks into bigger units. Each Piece represents a Block itself. Execution is represented as an iterator across Pieces. The whole application run is represented by a single block at the end.

Method Summary

Modifier and Type	Method and Description
void	forAllPossiblePieces(Consumer<AbstractPiece> consumer) Calls consumer for each Piece: - in no particular order - potentially calling multiple times on same Piece - even if Piece might never be returned in the iterator - it will be called at least once for every piece that is going to be returned by iterator Can be used for static analysis/introspection of the block, without actually executing them.
PieceCount	getPieceCount() How many pieces are in this block.
Iterator<AbstractPiece>	iterator() Create iterator representing all pieces needed to be executed in this block.

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Method Detail

iterator

Iterator<AbstractPiece> iterator()

Create iterator representing all pieces needed to be executed in this block. After Iterator.next call returns, master compute of returned Piece is guaranteed to be called before calling hasNext/next on the iterator. (allows for iterators logic to depend on the execution dynamically, and not be only static)

Specified by:

iterator in interface Iterable<AbstractPiece>

forAllPossiblePieces

void forAllPossiblePieces(Consumer<AbstractPiece> consumer)

Calls consumer for each Piece: - in no particular order - potentially calling multiple times on same Piece - even if Piece might never be returned in the iterator - it will be called at least once for every piece that is going to be returned by iterator Can be used for static analysis/introspection of the block, without actually executing them.

getPieceCount

PieceCount getPieceCount()

How many pieces are in this block. Sometimes we don't know (eg RepeatBlock).

Returns:

How many pieces are in this block.