Package io.deephaven.clientsupport.plotdownsampling

Class ByteValueTracker

java.lang.Object

io.deephaven.clientsupport.plotdownsampling.ValueTracker

io.deephaven.clientsupport.plotdownsampling.ByteValueTracker

public final class ByteValueTracker
extends ValueTracker

See ReplicateDownsamplingValueTrackers for notes on changing this file.

Constructor Summary

Constructors

Constructor	Description
ByteValueTracker()

Method Summary

Modifier and Type	Method	Description
void	append(int offset, long rowKey, Chunk<? extends Values> valuesChunk, int indexInChunk, @Nullable WritableRowSet nulls)	Indicates that a new value is being added to the original table being downsampled, and its value should be considered as possibly interesting.
protected void	ensureCapacity(int bucketCount)
String	toString(int offset)	Create a String representation of the tracked values and metadata at the given offset for logging/debugging purposes.
void	update(int offset, long rowKey, Chunk<? extends Values> valuesChunk, int indexInChunk, @Nullable WritableRowSet nulls)	Indicates that a value has changed in the original table that is being downsampled, and we should consider if the old value or the new value was interesting.
void	validate(int offset, long rowKey, Chunk<? extends Values> valuesChunk, int indexInChunk, @Nullable RowSet nulls)	Scan the given chunk and confirm that whichever values are currently selected as max and min are correct, and that the current data is now valid.

Methods inherited from class io.deephaven.clientsupport.plotdownsampling.ValueTracker

maxIndex, maxValuePosition, maxValueValid, maxValueValid, minIndex, minValuePosition, minValueValid, minValueValid, of, remove, setMaxIndex, setMinIndex, shiftMaxIndex, shiftMinIndex

Methods inherited from class java.lang.Object

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

Constructor Details

ByteValueTracker

public ByteValueTracker()

Method Details

ensureCapacity

protected void ensureCapacity(int bucketCount)

Overrides:

ensureCapacity in class ValueTracker

append

public void append(int offset,
 long rowKey,
 Chunk<? extends Values> valuesChunk,
 int indexInChunk,
 @Nullable
 @Nullable WritableRowSet nulls)

Description copied from class: ValueTracker

Indicates that a new value is being added to the original table being downsampled, and its value should be considered as possibly interesting. Implementations should read the value from the chunk and specialize based on that type of data. If it is the only value in the bucket (specified by the offset), include this value as both the max and the min. If there are other values, check to see if the new value is either the new max or the new min. In any case where this becomes the new max or the new min, mark that position as being valid, indicating that we are confident that we have the largest or smallest value at that offset. Implementations must take care to check if the value is null. If so, if nulls is present, the current row key should be added to it. If the

Specified by:

append in class ValueTracker

Parameters:

offset - the offset of the bucket state to use - use this with minValuePosition/maxValuePosition to compute the actual position in the underlying array sources

rowKey - the row key in the original table of the specified value. If the current given value is interesting in some way, record this using setMinIndex/setMaxIndex so we can construct the full downsampled table row set later

valuesChunk - the chunk that we're currently examining

indexInChunk - the index in the chunk that we're currently examining

update

public void update(int offset,
 long rowKey,
 Chunk<? extends Values> valuesChunk,
 int indexInChunk,
 @Nullable
 @Nullable WritableRowSet nulls)

Description copied from class: ValueTracker

Indicates that a value has changed in the original table that is being downsampled, and we should consider if the old value or the new value was interesting. Implementations should read the value from the chunk and specialize based on that type of data. There are three cases to consider for each min and max, so six cases in total. Here is the summary for the three "max" cases, the opposite must be likewise done for the min cases: If the updated row was the old max, then we cover two of the cases: o if the new value is greater than the old value, record the new value, but we are still the max and still valid. o if the new value is less than the old value, invalidate this row but keep the old max, we may need to rescan later Otherwise, if the new value is greater than the old max, then the current row is now the new max, and are now valid.

Specified by:

update in class ValueTracker

Parameters:

offset - the offset of the bucket state to use - use this with minValuePosition/maxValuePosition to compute the actual position in the underlying array sources

rowKey - the row key in the original table of the specified value. If the current given value is interesting in some way, record this using setMinIndex/setMaxIndex so we can construct the full downsampled table row set later

valuesChunk - the chunk that we're currently examining

indexInChunk - the index in the chunk that we're currently examining

validate

public void validate(int offset,
 long rowKey,
 Chunk<? extends Values> valuesChunk,
 int indexInChunk,
 @Nullable
 @Nullable RowSet nulls)

Description copied from class: ValueTracker

Scan the given chunk and confirm that whichever values are currently selected as max and min are correct, and that the current data is now valid.

Specified by:

validate in class ValueTracker

toString

public String toString(int offset)

Description copied from class: ValueTracker

Create a String representation of the tracked values and metadata at the given offset for logging/debugging purposes.

Specified by:

toString in class ValueTracker