Package com.illumon.iris.db.v2.sources.chunk.kernels

Class BlockZipper

java.lang.Object

com.illumon.iris.db.v2.sources.chunk.kernels.BlockZipper

public class BlockZipper
extends Object

Collects the location for entries matching a given block

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
class	BlockZipper.Context

Field Summary

Fields

Modifier and Type	Field	Description
int	inputChunkIndexMask
int	posInChunkLogShift

Constructor Summary

Constructors

Constructor	Description
BlockZipper(int inputChunksLogSize)

Method Summary

Modifier and Type	Method	Description
IntChunk	eval(BlockZipper.Context context, int blockNumber, IntChunk... hashChunks)	Collects the elements from a set of input chunks that match to a given expected block Elements are collected in the order they appear on each chunk (i.e.
BlockZipper.Context	getContext(int chunkSize, int logBlockCount)	Constructs a context reflecting the size for the current session

Methods inherited from class java.lang.Object

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

Field Details

posInChunkLogShift

public final int posInChunkLogShift

inputChunkIndexMask

public final int inputChunkIndexMask

Constructor Details

BlockZipper

public BlockZipper(int inputChunksLogSize)

Method Details

eval

public IntChunk eval(BlockZipper.Context context, int blockNumber, IntChunk... hashChunks)

Collects the elements from a set of input chunks that match to a given expected block Elements are collected in the order they appear on each chunk (i.e. all elements apearing at position k in each chunk, followed by all elements at position k+1 etc. Elements are first collected from a range of positions corresponding to the block, and then, for each chunk we search past the end of the range until we find an empty entry, this guarantees we are not missing any elements that we placed outside the range due to colisions. In the event all the elements don't fit in the destination chunk, the function can be called with context lastRegistered pos pointing to the last element examined.

Parameters:

context - The context

blockNumber - The number of the target block for which we are collecting values

hashChunks - List of hash value chunks.

Returns:

A chunk with the element's position encoded as (element position in chunk,chunk number)

getContext

public BlockZipper.Context getContext(int chunkSize, int logBlockCount)

Constructs a context reflecting the size for the current session

Parameters:

chunkSize - - The size of the hash input chunks

logBlockCount - - Log base 2 of the number of blocks in the target hash table