Package io.deephaven.extensions.barrage.chunk

Class LocalDictionaryWriterState

java.lang.Object

io.deephaven.extensions.barrage.chunk.LocalDictionaryWriterState

All Implemented Interfaces:

DictionaryWriterState

public final class LocalDictionaryWriterState
extends Object
implements DictionaryWriterState

DictionaryWriterState implementation for viewport subscriptions and snapshots. A single DictionaryWriterValueMap holds all distinct values in insertion order; deltaStartOffset marks the boundary between values already flushed to the subscriber and values that still need to be sent.

Thread-safety: not thread-safe; single-threaded barrage stream serialization is assumed.

Constructor Summary

Constructors

Constructor	Description
LocalDictionaryWriterState(long dictId, ChunkType valuesChunkType)

Method Summary

Modifier and Type	Method	Description
@NotNull WritableChunk<Values>	buildDeltaChunk()	Builds and returns a typed chunk containing the current delta values (values added since the last DictionaryWriterState.resetDelta() call, or all values if this is the first batch for this subscriber).
void	fillIndexChunk(@NotNull Chunk<Values> source, @Nullable RowSet subset, @NotNull BarrageOptions options, @NotNull WritableIntChunk<Values> out)	Fills out with one dictionary index per logical row in source/subset.
long	getDictId()
boolean	hasDelta()	Returns true if a DictionaryBatch message needs to be emitted before the current RecordBatch — either because this is the first batch for this subscriber (isDelta=false) or because new values have been added since the last reset.
boolean	needsFullBatch()
void	reset()	Resets the dictionary to an empty state, as if no values had ever been seen.
void	resetDelta()	Advances the delta boundary after a DictionaryBatch has been successfully emitted.
int	totalSize()	Current number of distinct values in the dictionary (resets to zero after DictionaryWriterState.reset()).

Methods inherited from class java.lang.Object

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

Constructor Details

LocalDictionaryWriterState

public LocalDictionaryWriterState(long dictId,
 ChunkType valuesChunkType)

Method Details

getDictId

public long getDictId()

Specified by:

getDictId in interface DictionaryWriterState

fillIndexChunk

public void fillIndexChunk(@NotNull
 @NotNull Chunk<Values> source,
 @Nullable
 @Nullable RowSet subset,
 @NotNull
 @NotNull BarrageOptions options,
 @NotNull
 @NotNull WritableIntChunk<Values> out)

Description copied from interface: DictionaryWriterState

Fills out with one dictionary index per logical row in source/subset. Null rows (in non-deephaven-nulls mode) produce QueryConstants.NULL_INT; non-null rows produce a non-negative dictionary index, registering new values as needed.

Specified by:

fillIndexChunk in interface DictionaryWriterState

Parameters:

source - the source chunk containing column values

subset - row positions within source to include; null means all rows

options - barrage serialization options (e.g. useDeephavenNulls)

out - pre-sized output chunk to fill with dictionary indices

hasDelta

public boolean hasDelta()

Description copied from interface: DictionaryWriterState

Returns true if a DictionaryBatch message needs to be emitted before the current RecordBatch — either because this is the first batch for this subscriber (isDelta=false) or because new values have been added since the last reset.

Specified by:

hasDelta in interface DictionaryWriterState

needsFullBatch

public boolean needsFullBatch()

Specified by:

needsFullBatch in interface DictionaryWriterState

buildDeltaChunk

@NotNull
public @NotNull WritableChunk<Values> buildDeltaChunk()

Description copied from interface: DictionaryWriterState

Builds and returns a typed chunk containing the current delta values (values added since the last DictionaryWriterState.resetDelta() call, or all values if this is the first batch for this subscriber). The returned chunk is owned by the caller and must be closed when no longer needed.

Specified by:

buildDeltaChunk in interface DictionaryWriterState

resetDelta

public void resetDelta()

Description copied from interface: DictionaryWriterState

Advances the delta boundary after a DictionaryBatch has been successfully emitted. Unlike DictionaryWriterState.reset(), this does not discard the accumulated value-to-index mapping — it only moves the boundary so that already-sent values are excluded from future delta batches. The client's cached dictionary remains valid after this call.

Specified by:

resetDelta in interface DictionaryWriterState

totalSize

public int totalSize()

Description copied from interface: DictionaryWriterState

Current number of distinct values in the dictionary (resets to zero after DictionaryWriterState.reset()).

Specified by:

totalSize in interface DictionaryWriterState

reset

public void reset()

Description copied from interface: DictionaryWriterState

Resets the dictionary to an empty state, as if no values had ever been seen. The next DictionaryBatch emitted will be isDelta=false with only the values encountered in the next batch. Call this when the cumulative dictionary size exceeds the live row count and compaction is needed.

Specified by:

reset in interface DictionaryWriterState