Package org.apache.druid.frame.field

Class ComplexFieldReader

java.lang.Object

org.apache.druid.frame.field.ComplexFieldReader

All Implemented Interfaces:

FieldReader

public class ComplexFieldReader
extends Object
implements FieldReader

Reads values written by ComplexFieldWriter.

Format:

- 1 byte: ComplexFieldWriter.NULL_BYTE or ComplexFieldWriter.NOT_NULL_BYTE - 4 bytes: length of serialized complex value, little-endian int - N bytes: serialized complex value

Method Summary

Modifier and Type	Method	Description
static ComplexFieldReader	createFromType(ColumnType columnType)
boolean	isNull(org.apache.datasketches.memory.Memory memory, long position)	Whether the provided memory position points to a null value.
ColumnValueSelector<?>	makeColumnValueSelector(org.apache.datasketches.memory.Memory memory, ReadableFieldPointer fieldPointer)	Create a ColumnValueSelector backed by some memory and a moveable pointer.
DimensionSelector	makeDimensionSelector(org.apache.datasketches.memory.Memory memory, ReadableFieldPointer fieldPointer, ExtractionFn extractionFn)	Create a DimensionSelector backed by some memory and a moveable pointer.
Column	makeRACColumn(Frame frame, RowSignature signature, String columnName)	Create a Column which provides accses to the rows in the frame, via the Column.toAccessor().
static Object	readFieldFromByteArray(ComplexMetricSerde serde, byte[] bytes, int position)	Alternative interface to read the field from the byte array without creating a selector and field pointer.
static <T> T	readFieldFromMemory(ComplexMetricSerde serde, org.apache.datasketches.memory.Memory memory, long position)	Alternative interface to read the field from the memory without creating a selector and field pointer

Methods inherited from class java.lang.Object

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

Method Details

createFromType

public static ComplexFieldReader createFromType(ColumnType columnType)

makeColumnValueSelector

public ColumnValueSelector<?> makeColumnValueSelector(org.apache.datasketches.memory.Memory memory,
 ReadableFieldPointer fieldPointer)

Description copied from interface: FieldReader

Create a ColumnValueSelector backed by some memory and a moveable pointer.

Specified by:

makeColumnValueSelector in interface FieldReader

makeDimensionSelector

public DimensionSelector makeDimensionSelector(org.apache.datasketches.memory.Memory memory,
 ReadableFieldPointer fieldPointer,
 @Nullable
 ExtractionFn extractionFn)

Description copied from interface: FieldReader

Create a DimensionSelector backed by some memory and a moveable pointer.

Specified by:

makeDimensionSelector in interface FieldReader

isNull

public boolean isNull(org.apache.datasketches.memory.Memory memory,
 long position)

Description copied from interface: FieldReader

Whether the provided memory position points to a null value.

Specified by:

isNull in interface FieldReader

readFieldFromByteArray

@Nullable
public static Object readFieldFromByteArray(ComplexMetricSerde serde,
 byte[] bytes,
 int position)

Alternative interface to read the field from the byte array without creating a selector and field pointer. It is much faster than wrapping the byte array in Memory for reading.

readFieldFromMemory

@Nullable
public static <T> T readFieldFromMemory(ComplexMetricSerde serde,
 org.apache.datasketches.memory.Memory memory,
 long position)

Alternative interface to read the field from the memory without creating a selector and field pointer

makeRACColumn

public Column makeRACColumn(Frame frame,
 RowSignature signature,
 String columnName)

Description copied from interface: FieldReader

Create a Column which provides accses to the rows in the frame, via the Column.toAccessor().

Specified by:

makeRACColumn in interface FieldReader