org.apache.cassandra.db.context
Interface IContext

All Known Implementing Classes:

CounterContext

public interface IContext

An opaque commutative context. Maintains a ByteBuffer context that represents a partitioned commutative value.

Nested Class Summary

static class

IContext.ContextRelationship

Method Summary

IContext.ContextRelationship	diff(java.nio.ByteBuffer left, java.nio.ByteBuffer right) Determine the relationship between two contexts.
java.nio.ByteBuffer	merge(java.nio.ByteBuffer left, java.nio.ByteBuffer right, Allocator allocator) Return a context w/ an aggregated count for each node id.
java.lang.String	toString(java.nio.ByteBuffer context) Human-readable String from context.

Method Detail

diff

IContext.ContextRelationship diff(java.nio.ByteBuffer left,
                                  java.nio.ByteBuffer right)

Determine the relationship between two contexts. EQUAL: Equal set of nodes and every count is equal. GREATER_THAN: Superset of nodes and every count is equal or greater than its corollary. LESS_THAN: Subset of nodes and every count is equal or less than its corollary. DISJOINT: Node sets are not equal and/or counts are not all greater or less than.

Parameters:

left - context.

right - context.

Returns:

the ContextRelationship between the contexts.

merge

java.nio.ByteBuffer merge(java.nio.ByteBuffer left,
                          java.nio.ByteBuffer right,
                          Allocator allocator)

Return a context w/ an aggregated count for each node id.

Parameters:

left - context.

right - context.

allocator - an allocator to allocate the new context from.

toString

java.lang.String toString(java.nio.ByteBuffer context)

Human-readable String from context.

Parameters:

context - context.

Returns:

a human-readable String of the context.