NullableNumericBufferAggregator (druid-processing 0.20.1 API)

java.lang.Object
- org.apache.druid.query.aggregation.NullableNumericBufferAggregator

All Implemented Interfaces:

BufferAggregator, HotLoopCallee
```
public final class NullableNumericBufferAggregator
extends Object
implements BufferAggregator
```
Null-aware numeric BufferAggregator. The result of this aggregator will be null if all the values to be aggregated are null values or no values are aggregated at all. If any of the values are non-null, the result will be the aggregated value of the delegate aggregator. When wrapped by this class, the underlying aggregator's required storage space is increased by one byte. The extra byte is a boolean that stores whether or not any non-null values have been seen. The extra byte is placed before the underlying aggregator's normal state. (Buffer layout = [nullability byte] [delegate storage bytes]) Used by NullableNumericAggregatorFactory.factorizeBuffered(ColumnSelectorFactory) to wrap non-null aware aggregators. This class is only used when SQL compatible null handling is enabled.

See Also:

NullableNumericAggregatorFactory.factorizeBuffered(ColumnSelectorFactory), the vectorized version.

Constructor Summary

Constructors
Constructor and Description

NullableNumericBufferAggregator(BufferAggregator delegate, BaseNullableColumnValueSelector nullSelector)

Constructors
Constructor and Description
`NullableNumericBufferAggregator(BufferAggregator delegate, BaseNullableColumnValueSelector nullSelector)`

Method Summary

All Methods Instance Methods Concrete Methods
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.
`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.getMaxIntermediateSizeWithNulls()` in the corresponding `AggregatorFactory`
`void`	`inspectRuntimeShape(RuntimeShapeInspector inspector)` Implementations of this method should call `inspector.visit()` with all fields of this class, which meet two conditions: 1.
`boolean`	`isNull(ByteBuffer buf, int position)` returns true if aggregator's output type is primitive long/double/float and aggregated value is null, but when aggregated output type is Object, this method always returns false, and users are advised to check nullability for the object returned by `BufferAggregator.get(ByteBuffer, int)` method.
`void`	`relocate(int oldPosition, int newPosition, ByteBuffer oldBuffer, ByteBuffer newBuffer)` Relocates any cached objects.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - NullableNumericBufferAggregator
```
public NullableNumericBufferAggregator(BufferAggregator delegate,
                                       BaseNullableColumnValueSelector nullSelector)
```
- Method Detail
  - init
```
public void init(ByteBuffer buf,
                 int position)
```
    Description copied from interface: BufferAggregator
    
    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.getMaxIntermediateSizeWithNulls() in the corresponding AggregatorFactory
    
    Specified by:
    
    init in interface BufferAggregator
    
    Parameters:
    
    buf - byte buffer to initialize
    
    position - offset within the byte buffer for initialization
  - aggregate
```
public void aggregate(ByteBuffer buf,
                      int position)
```
    Description copied from interface: BufferAggregator
    
    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. Implementations must not change the position, limit or mark of the given buffer
    
    Specified by:
    
    aggregate in interface BufferAggregator
    
    Parameters:
    
    buf - byte buffer storing the byte array representation of the aggregate
    
    position - offset within the byte buffer at which the current aggregate value is stored
  - get
```
@Nullable
public Object get(ByteBuffer buf,
                            int position)
```
    Description copied from interface: BufferAggregator
    
    Returns the intermediate object representation of the given aggregate. Converts the given byte buffer representation into an intermediate aggregate Object Implementations must not change the position, limit or mark of the given buffer. The object returned must not have any references to the given buffer (i.e., make a copy), since the underlying buffer is a shared resource and may be given to another processing thread while the objects returned by this aggregator are still in use. If the corresponding AggregatorFactory.combine(Object, Object) method for this aggregator expects its inputs to be mutable, then the object returned by this method must be mutable.
    
    Specified by:
    
    get in interface BufferAggregator
    
    Parameters:
    
    buf - byte buffer storing the byte array representation of the aggregate
    
    position - offset within the byte buffer at which the aggregate value is stored
    
    Returns:
    
    the Object representation of the aggregate
  - getFloat
```
public float getFloat(ByteBuffer buf,
                      int position)
```
    Description copied from interface: BufferAggregator
    
    Returns the float representation of the given aggregate byte array Converts the given byte buffer representation into the intermediate aggregate value. Implementations must not change the position, limit or mark of the given buffer Implementations are only required to support this method if they are aggregations which have an AggregatorFactory.getType() ()} of ValueType.FLOAT. If unimplemented, throwing an UnsupportedOperationException is common and recommended.
    
    Specified by:
    
    getFloat in interface BufferAggregator
    
    Parameters:
    
    buf - byte buffer storing the byte array representation of the aggregate
    
    position - offset within the byte buffer at which the aggregate value is stored
    
    Returns:
    
    the float representation of the aggregate
  - getLong
```
public long getLong(ByteBuffer buf,
                    int position)
```
    Description copied from interface: BufferAggregator
    
    Returns the long representation of the given aggregate byte array Converts the given byte buffer representation into the intermediate aggregate value. Implementations must not change the position, limit or mark of the given buffer Implementations are only required to support this method if they are aggregations which have an AggregatorFactory.getType() of of ValueType.LONG. If unimplemented, throwing an UnsupportedOperationException is common and recommended.
    
    Specified by:
    
    getLong in interface BufferAggregator
    
    Parameters:
    
    buf - byte buffer storing the byte array representation of the aggregate
    
    position - offset within the byte buffer at which the aggregate value is stored
    
    Returns:
    
    the long representation of the aggregate
  - getDouble
```
public double getDouble(ByteBuffer buf,
                        int position)
```
    Description copied from interface: BufferAggregator
    
    Returns the double representation of the given aggregate byte array Converts the given byte buffer representation into the intermediate aggregate value. Implementations must not change the position, limit or mark of the given buffer Implementations are only required to support this method if they are aggregations which have an AggregatorFactory.getType() of of ValueType.DOUBLE. If unimplemented, throwing an UnsupportedOperationException is common and recommended. The default implementation casts BufferAggregator.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.
    
    Specified by:
    
    getDouble in interface BufferAggregator
    
    Parameters:
    
    buf - byte buffer storing the byte array representation of the aggregate
    
    position - offset within the byte buffer at which the aggregate value is stored
    
    Returns:
    
    the double representation of the aggregate
  - isNull
```
public boolean isNull(ByteBuffer buf,
                      int position)
```
    Description copied from interface: BufferAggregator
    
    returns true if aggregator's output type is primitive long/double/float and aggregated value is null, but when aggregated output type is Object, this method always returns false, and users are advised to check nullability for the object returned by BufferAggregator.get(ByteBuffer, int) method. The default implementation always return false to enable smooth backward compatibility, re-implement if your aggregator is nullable.
    
    Specified by:
    
    isNull in interface BufferAggregator
    
    Parameters:
    
    buf - byte buffer storing the byte array representation of the aggregate
    
    position - offset within the byte buffer at which the aggregate value is stored
    
    Returns:
    
    true if the aggregated value is primitive long/double/float and aggregated value is null otherwise false.
  - relocate
```
public void relocate(int oldPosition,
                     int newPosition,
                     ByteBuffer oldBuffer,
                     ByteBuffer newBuffer)
```
    Description copied from interface: BufferAggregator
    
    Relocates any cached objects. If underlying ByteBuffer used for aggregation buffer relocates to a new ByteBuffer, positional caches(if any) built on top of old ByteBuffer can not be used for further BufferAggregator.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 buffer
    
    Specified by:
    
    relocate in interface BufferAggregator
    
    Parameters:
    
    oldPosition - 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.
  - close
```
public void close()
```
    Description copied from interface: BufferAggregator
    
    Release any resources used by the aggregator
    
    Specified by:
    
    close in interface BufferAggregator
  - inspectRuntimeShape
```
public void inspectRuntimeShape(RuntimeShapeInspector inspector)
```
    Description copied from interface: BufferAggregator
    
    Implementations of this method should call 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(org.apache.druid.query.monomorphicprocessing.RuntimeShapeInspector).
    
    Specified by:
    
    inspectRuntimeShape in interface BufferAggregator
    
    Specified by:
    
    inspectRuntimeShape in interface HotLoopCallee

Class NullableNumericBufferAggregator

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

NullableNumericBufferAggregator

Method Detail

init

aggregate

get

getFloat

getLong

getDouble

isNull

relocate

close

inspectRuntimeShape