public interface BufferAggregator extends HotLoopCallee
Modifier and Type | Method and Description |
---|---|
void |
aggregate(ByteBuffer buf,
int position)
Aggregates metric values into the given aggregate byte representation
Implementations of this method must read in the aggregate value from the buffer at the given position,
aggregate the next element of data and write the updated aggregate value back into the buffer.
|
void |
close()
Release any resources used by the aggregator
|
Object |
get(ByteBuffer buf,
int position)
Returns the intermediate object representation of the given aggregate.
|
default double |
getDouble(ByteBuffer buf,
int position)
Returns the double representation of the given aggregate byte array
Converts the given byte buffer representation into the intermediate aggregate value.
|
float |
getFloat(ByteBuffer buf,
int position)
Returns the float representation of the given aggregate byte array
Converts the given byte buffer representation into the intermediate aggregate value.
|
long |
getLong(ByteBuffer buf,
int position)
Returns the long representation of the given aggregate byte array
Converts the given byte buffer representation into the intermediate aggregate value.
|
void |
init(ByteBuffer buf,
int position)
Initializes the buffer location
Implementations of this method must initialize the byte buffer at the given position
Implementations must not change the position, limit or mark of the given buffer
This method must not exceed the number of bytes returned by
AggregatorFactory.getMaxIntermediateSize()
in the corresponding AggregatorFactory |
default void |
inspectRuntimeShape(RuntimeShapeInspector inspector)
Implementations of this method should call
inspector.visit() with all fields of this class, which meet two
conditions:
1. |
default void |
relocate(int oldPosition,
int newPosition,
ByteBuffer oldBuffer,
ByteBuffer newBuffer)
Relocates any cached objects.
|
@CalledFromHotLoop void init(ByteBuffer buf, int position)
AggregatorFactory.getMaxIntermediateSize()
in the corresponding AggregatorFactory
buf
- byte buffer to initializeposition
- offset within the byte buffer for initialization@CalledFromHotLoop void aggregate(ByteBuffer buf, int position)
buf
- byte buffer storing the byte array representation of the aggregateposition
- offset within the byte buffer at which the current aggregate value is storedObject get(ByteBuffer buf, int position)
buf
- byte buffer storing the byte array representation of the aggregateposition
- offset within the byte buffer at which the aggregate value is storedfloat getFloat(ByteBuffer buf, int position)
AggregatorFactory.getTypeName()
of "float".
If unimplemented, throwing an UnsupportedOperationException
is common and recommended.buf
- byte buffer storing the byte array representation of the aggregateposition
- offset within the byte buffer at which the aggregate value is storedlong getLong(ByteBuffer buf, int position)
AggregatorFactory.getTypeName()
of "long".
If unimplemented, throwing an UnsupportedOperationException
is common and recommended.buf
- byte buffer storing the byte array representation of the aggregateposition
- offset within the byte buffer at which the aggregate value is storeddefault double getDouble(ByteBuffer buf, int position)
AggregatorFactory.getTypeName()
of "double".
If unimplemented, throwing an UnsupportedOperationException
is common and recommended.
The default implementation casts getFloat(ByteBuffer, int)
to double.
This default method is added to enable smooth backward compatibility, please re-implement it if your aggregators
work with numeric double columns.buf
- byte buffer storing the byte array representation of the aggregateposition
- offset within the byte buffer at which the aggregate value is storedvoid close()
default void inspectRuntimeShape(RuntimeShapeInspector inspector)
inspector.visit()
with all fields of this class, which meet two
conditions:
1. They are used in methods of this class, annotated with CalledFromHotLoop
2. They are either:
a. Nullable objects
b. Instances of HotLoopCallee
c. Objects, which don't always have a specific class in runtime. For example, a field of type Set
could be HashSet
or TreeSet
in runtime, depending on how
this instance (the instance on which inspectRuntimeShape() is called) is configured.
d. ByteBuffer or similar objects, where byte order matters
e. boolean flags, affecting branch taking
f. Arrays of objects, meeting any of conditions a-e.
The default implementation inspects nothing. Classes that implement BufferAggregator
are encouraged to
override this method, following the specification of HotLoopCallee.inspectRuntimeShape(io.druid.query.monomorphicprocessing.RuntimeShapeInspector)
.
inspectRuntimeShape
in interface HotLoopCallee
default void relocate(int oldPosition, int newPosition, ByteBuffer oldBuffer, ByteBuffer newBuffer)
aggregate(ByteBuffer, int)
calls. This method tells the BufferAggregator that the cached objects at a certain location has been relocated to
a different location.
Only used if there is any positional caches/objects in the BufferAggregator implementation.
If relocate happens to be across multiple new ByteBuffers (say n ByteBuffers), this method should be called
multiple times(n times) given all the new positions/old positions should exist in newBuffer/OldBuffer.
Implementations must not change the position, limit or mark of the given bufferoldPosition
- old position of a cached object before aggregation buffer relocates to a new ByteBuffer.newPosition
- new position of a cached object after aggregation buffer relocates to a new ByteBuffer.oldBuffer
- old aggregation buffer.newBuffer
- new aggregation buffer.Copyright © 2011–2018. All rights reserved.