Package org.apache.druid.query.aggregation

Class SerializablePairLongStringDeltaEncodedStagedSerde

java.lang.Object

org.apache.druid.query.aggregation.AbstractSerializablePairLongObjectDeltaEncodedStagedSerde<SerializablePairLongString>

org.apache.druid.query.aggregation.SerializablePairLongStringDeltaEncodedStagedSerde

All Implemented Interfaces:

StagedSerde<SerializablePairLongString>

public class SerializablePairLongStringDeltaEncodedStagedSerde
extends AbstractSerializablePairLongObjectDeltaEncodedStagedSerde<SerializablePairLongString>

serializes a Long/String pair in the context of a column/segment. Uses the minValue to perform delta encoding/decoding and if the range of the segment fits in an integer (useIntegerDelta), the format is Integer:Integer:bytes otherwise Long:Integer:bytes The StringSize can be following: -1 : Denotes an empty string 0 : Denotes a null string >0 : Denotes a non-empty string Mapping of null and empty string is done weirdly to preserve backward compatibility when nulls were returned all the time, and there was no distinction between empty and null string

Constructor Summary

Constructors

Constructor	Description
SerializablePairLongStringDeltaEncodedStagedSerde(long minValue, boolean useIntegerDelta)

Method Summary

Modifier and Type	Method	Description
SerializablePairLongString	deserialize(ByteBuffer byteBuffer)
StorableBuffer	serializeDelayed(SerializablePairLongString value)	Useful method when some computation is necessary to prepare for serialization without actually writing out all the bytes in order to determine the serialized size.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.druid.segment.serde.cell.StagedSerde

deserialize, serialize

Constructor Detail

SerializablePairLongStringDeltaEncodedStagedSerde

public SerializablePairLongStringDeltaEncodedStagedSerde(long minValue,
                                                         boolean useIntegerDelta)

Method Detail

serializeDelayed

public StorableBuffer serializeDelayed(@Nullable
                                       SerializablePairLongString value)

Description copied from interface: StagedSerde

Useful method when some computation is necessary to prepare for serialization without actually writing out all the bytes in order to determine the serialized size. It allows encapsulation of the size computation and the final logical to actually store into a ByteBuffer. It also allows for callers to pack multiple serialized objects into a single ByteBuffer without extra copies of a byte[]/ByteBuffer by using the StorableBuffer instance returned

Specified by:

serializeDelayed in interface StagedSerde<SerializablePairLongString>

Overrides:

serializeDelayed in class AbstractSerializablePairLongObjectDeltaEncodedStagedSerde<SerializablePairLongString>

Parameters:

value - - object to serialize

Returns:

an object that reports its serialized size and how to serialize the object to a ByteBuffer

deserialize

@Nullable
public SerializablePairLongString deserialize(ByteBuffer byteBuffer)