Package io.deephaven.extensions.barrage.chunk

Class RunEndEncodedChunkWriter

java.lang.Object

io.deephaven.extensions.barrage.chunk.BaseChunkWriter<Chunk<Values>>

io.deephaven.extensions.barrage.chunk.RunEndEncodedChunkWriter

All Implemented Interfaces:

ChunkWriter<Chunk<Values>>

public class RunEndEncodedChunkWriter
extends BaseChunkWriter<Chunk<Values>>

Serializes a flat column chunk as Arrow Run-End Encoded (REE) on the wire.

The REE parent array has logical length numRows, null_count 0, and zero buffers. It has two children:

1. run_ends — a non-nullable Int16/Int32/Int64 array of numRuns cumulative 1-based end indices (last == numRows)
2. values — the encoded value type of length numRuns, one representative value per run

Runs are computed over the selected subset. Consecutive equal values (including null == null) collapse into a single run.

Nested Class Summary

Nested classes/interfaces inherited from class io.deephaven.extensions.barrage.chunk.BaseChunkWriter

BaseChunkWriter.ChunkTransformer<SOURCE_CHUNK_TYPE extends Chunk<Values>>, BaseChunkWriter.SerContext

Nested classes/interfaces inherited from interface io.deephaven.extensions.barrage.chunk.ChunkWriter

ChunkWriter.BufferListener, ChunkWriter.Context, ChunkWriter.DrainableColumn, ChunkWriter.Factory, ChunkWriter.FieldNodeInfo, ChunkWriter.FieldNodeListener

Field Summary

Fields inherited from class io.deephaven.extensions.barrage.chunk.BaseChunkWriter

BULK_WRITE_BUFFER_BYTES, dhNullable, elementSize, fieldNullable, PADDING_BUFFER, REMAINDER_MOD_8_MASK

Constructor Summary

Constructors

Constructor	Description
RunEndEncodedChunkWriter(@NotNull ChunkWriter<IntChunk<Values>> runEndsWriter, @NotNull ChunkWriter<Chunk<Values>> valuesWriter, @NotNull ChunkType runEndsChunkType, @NotNull ChunkType valuesChunkType, boolean fieldNullable)

Method Summary

Modifier and Type	Method	Description
protected int	computeNullCount(ChunkWriter.Context context, @NotNull RowSequence subset)	Compute the number of nulls in the subset.
ChunkWriter.DrainableColumn	getInputStream(ChunkWriter.Context context, @Nullable RowSet subset, @NotNull BarrageOptions options)	Get an input stream optionally position-space filtered using the provided RowSet.
ChunkWriter.DrainableColumn	getInputStream(ChunkWriter.Context context, @Nullable RowSet subset, @NotNull BarrageOptions options, @Nullable DictionaryWriterRegistry dictionaryRegistry)	Get an input stream, threading a DictionaryWriterRegistry down to any dictionary-encoded writers nested within this writer (e.g.
protected void	writeValidityBufferInternal(ChunkWriter.Context context, @NotNull RowSequence subset, @NotNull BaseChunkWriter.SerContext serContext)	Update the validity buffer for the subset.

Methods inherited from class io.deephaven.extensions.barrage.chunk.BaseChunkWriter

getEmptyInputStream, getEmptyInputStream, getNumLongsForBitPackOfSize, getValidityMapSerializationSizeFor, isFieldNullable, makeContext

Methods inherited from class java.lang.Object

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

Constructor Details

RunEndEncodedChunkWriter

public RunEndEncodedChunkWriter(@NotNull
 @NotNull ChunkWriter<IntChunk<Values>> runEndsWriter,
 @NotNull
 @NotNull ChunkWriter<Chunk<Values>> valuesWriter,
 @NotNull
 @NotNull ChunkType runEndsChunkType,
 @NotNull
 @NotNull ChunkType valuesChunkType,
 boolean fieldNullable)

Method Details

computeNullCount

protected int computeNullCount(@NotNull
 ChunkWriter.Context context,
 @NotNull
 @NotNull RowSequence subset)

Description copied from class: BaseChunkWriter

Compute the number of nulls in the subset.

Specified by:

computeNullCount in class BaseChunkWriter<Chunk<Values>>

Parameters:

context - the context for the chunk

subset - the subset of rows to consider

Returns:

the number of nulls in the subset

writeValidityBufferInternal

protected void writeValidityBufferInternal(@NotNull
 ChunkWriter.Context context,
 @NotNull
 @NotNull RowSequence subset,
 @NotNull
 @NotNull BaseChunkWriter.SerContext serContext)

Description copied from class: BaseChunkWriter

Update the validity buffer for the subset.

Specified by:

writeValidityBufferInternal in class BaseChunkWriter<Chunk<Values>>

Parameters:

context - the context for the chunk

subset - the subset of rows to consider

serContext - the serialization context

getInputStream

public ChunkWriter.DrainableColumn getInputStream(@NotNull
 ChunkWriter.Context context,
 @Nullable
 @Nullable RowSet subset,
 @NotNull
 @NotNull BarrageOptions options)
                                           throws IOException

Description copied from interface: ChunkWriter

Get an input stream optionally position-space filtered using the provided RowSet.

Parameters:

context - the chunk writer context holding the data to be drained to the client

subset - if provided, is a position-space filter of source data

options - options for writing to the stream

Returns:

a single-use DrainableColumn ready to be drained via grpc

Throws:

IOException

getInputStream

public ChunkWriter.DrainableColumn getInputStream(@NotNull
 ChunkWriter.Context context,
 @Nullable
 @Nullable RowSet subset,
 @NotNull
 @NotNull BarrageOptions options,
 @Nullable
 @Nullable DictionaryWriterRegistry dictionaryRegistry)
                                           throws IOException

Get an input stream, threading a DictionaryWriterRegistry down to any dictionary-encoded writers nested within this writer (e.g. the values child of a run-end-encoded column). Writers that contain no dictionary encoding ignore the registry and behave identically to ChunkWriter.getInputStream(Context, RowSet, BarrageOptions).

A DictionaryChunkWriter uses the registry to obtain (and register) its per-id DictionaryWriterState, so that the enclosing message writer emits the corresponding DictionaryBatch. Composite writers forward the registry to their children.

Forwards dictionaryRegistry to the values child writer so that a dictionary-encoded values child (yielding a RunEndEncoded<Dictionary<...>> column) can resolve and register its dictionary state. The run_ends child is never dictionary-encoded, so it ignores the registry.

Parameters:

context - the chunk writer context holding the data to be drained to the client

subset - if provided, is a position-space filter of source data

options - options for writing to the stream

dictionaryRegistry - the per-stream dictionary registry; may be null when the caller does not support dictionary encoding (a nested dictionary-encoded writer will then throw)

Returns:

a single-use DrainableColumn ready to be drained via grpc

Throws:

IOException