Package org.apache.druid.frame.field
Interface FieldReader
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- All Known Implementing Classes:
ComplexFieldReader
,DoubleArrayFieldReader
,DoubleFieldReader
,FloatArrayFieldReader
,FloatFieldReader
,LongArrayFieldReader
,LongFieldReader
,NumericArrayFieldReader
,NumericFieldReader
,StringArrayFieldReader
,StringFieldReader
public interface FieldReader
Embeds the logic to read a specific field from row-based frames or fromRowKey
. Most callers should useFrameReader
orRowKeyReader
rather than using this interface directly. Stateless and immutable.
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Method Summary
All Methods Instance Methods Abstract Methods Modifier and Type Method Description boolean
isComparable()
Whether this field is comparable.boolean
isNull(org.apache.datasketches.memory.Memory memory, long position)
Whether the provided memory position points to a null value.ColumnValueSelector<?>
makeColumnValueSelector(org.apache.datasketches.memory.Memory memory, ReadableFieldPointer fieldPointer)
Create aColumnValueSelector
backed by some memory and a moveable pointer.DimensionSelector
makeDimensionSelector(org.apache.datasketches.memory.Memory memory, ReadableFieldPointer fieldPointer, ExtractionFn extractionFn)
Create aDimensionSelector
backed by some memory and a moveable pointer.
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Method Detail
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makeColumnValueSelector
ColumnValueSelector<?> makeColumnValueSelector(org.apache.datasketches.memory.Memory memory, ReadableFieldPointer fieldPointer)
Create aColumnValueSelector
backed by some memory and a moveable pointer.
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makeDimensionSelector
DimensionSelector makeDimensionSelector(org.apache.datasketches.memory.Memory memory, ReadableFieldPointer fieldPointer, @Nullable ExtractionFn extractionFn)
Create aDimensionSelector
backed by some memory and a moveable pointer.
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isNull
boolean isNull(org.apache.datasketches.memory.Memory memory, long position)
Whether the provided memory position points to a null value.
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isComparable
boolean isComparable()
Whether this field is comparable. Comparable fields can be compared as unsigned bytes.
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