org.apache.arrow.vector.dictionary

Class StructSubfieldEncoder

java.lang.Object

org.apache.arrow.vector.dictionary.StructSubfieldEncoder

public class StructSubfieldEncoder
extends Object

Sub fields encoder/decoder for Dictionary encoded StructVector. Notes that child vectors within struct vector can either be dictionary encodable or not.

Constructor Summary

Constructors

Constructor and Description
StructSubfieldEncoder(BufferAllocator allocator, DictionaryProvider.MapDictionaryProvider provider) Construct an instance.
StructSubfieldEncoder(BufferAllocator allocator, DictionaryProvider.MapDictionaryProvider provider, ArrowBufHasher hasher) Construct an instance.

Method Summary

Modifier and Type	Method and Description
StructVector	decode(StructVector vector) Decodes a dictionary subfields encoded vector using the provided dictionary.
StructVector	encode(StructVector vector, Map<Integer,Long> columnToDictionaryId) Dictionary encodes subfields for complex vector with a provided dictionary.

Methods inherited from class java.lang.Object

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

Constructor Detail

StructSubfieldEncoder

public StructSubfieldEncoder(BufferAllocator allocator,
                             DictionaryProvider.MapDictionaryProvider provider)

Construct an instance.

StructSubfieldEncoder

public StructSubfieldEncoder(BufferAllocator allocator,
                             DictionaryProvider.MapDictionaryProvider provider,
                             ArrowBufHasher hasher)

Construct an instance.

Method Detail

encode

public StructVector encode(StructVector vector,
                           Map<Integer,Long> columnToDictionaryId)

Dictionary encodes subfields for complex vector with a provided dictionary. The dictionary must contain all values in the sub fields vector.

Parameters:

vector - vector to encode

columnToDictionaryId - the mappings between child vector index and dictionary id. A null dictionary id indicates the child vector is not encodable.

Returns:

dictionary encoded vector

decode

public StructVector decode(StructVector vector)

Decodes a dictionary subfields encoded vector using the provided dictionary.

Parameters:

vector - dictionary encoded vector, its child vector must be int type

Returns:

vector with values restored from dictionary