## 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.

Copyright © 2013 The Apache Software Foundation