DummyScalarWriter (Drill : 1.20.3 API)

java.lang.Object
- org.apache.drill.exec.vector.accessor.writer.AbstractScalarWriter
- - org.apache.drill.exec.vector.accessor.writer.AbstractScalarWriterImpl
  - - org.apache.drill.exec.vector.accessor.writer.dummy.DummyScalarWriter

All Implemented Interfaces:

ColumnWriter, ScalarWriter, ValueWriter, WriterEvents, WriterPosition

Direct Known Subclasses:

DummyArrayWriter.DummyOffsetVectorWriter
```
public class DummyScalarWriter
extends AbstractScalarWriterImpl
```
Represents a non-projected column. The writer accepts data, but discards it. The writer does not participate in writer events, nor is it backed by a real vector, index or type.

Nested Class Summary
- Nested classes/interfaces inherited from class org.apache.drill.exec.vector.accessor.writer.AbstractScalarWriterImpl
  AbstractScalarWriterImpl.ScalarObjectWriter
- Nested classes/interfaces inherited from interface org.apache.drill.exec.vector.accessor.writer.WriterEvents
  WriterEvents.ColumnWriterListener, WriterEvents.State

Field Summary
- Fields inherited from class org.apache.drill.exec.vector.accessor.writer.AbstractScalarWriterImpl
  schema, vectorIndex

Constructor Summary

Constructors
Constructor and Description

DummyScalarWriter(ColumnMetadata schema)

Constructors
Constructor and Description
`DummyScalarWriter(ColumnMetadata schema)`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`appendBytes(byte[] value, int len)`
`void`	`bindIndex(ColumnWriterIndex index)` Bind the writer to a writer index.
`void`	`bindListener(WriterEvents.ColumnWriterListener listener)` Bind a listener to the underlying vector writer.
`void`	`copy(ColumnReader from)` Copy a single value from the given reader, which must be of the same type as this writer.
`void`	`endWrite()` End a batch: finalize any vector values.
`boolean`	`isProjected()` Whether this writer is projected (is backed by a materialized vector), or is unprojected (is just a dummy writer.) In most cases, clients can ignore whether the column is projected and just write to the writer.
`int`	`lastWriteIndex()` Return the last write position in the vector.
`boolean`	`nullable()` Whether this writer allows nulls.
`void`	`postRollover()` The vectors backing this writer rolled over.
`void`	`preRollover()` The vectors backing this vector are about to roll over.
`void`	`restartRow()` During a writer to a row, rewind the the current index position to restart the row.
`int`	`rowStartIndex()` Position within the vector of the first value for the current row.
`void`	`setBoolean(boolean value)`
`void`	`setBytes(byte[] value, int len)`
`void`	`setDate(LocalDate value)`
`void`	`setDecimal(BigDecimal value)`
`void`	`setDefaultValue(Object value)` Set the default value to be used to fill empties for this writer.
`void`	`setDouble(double value)`
`void`	`setFloat(float value)`
`void`	`setInt(int value)`
`void`	`setLong(long value)`
`void`	`setNull()` Set the current value to null.
`void`	`setPeriod(org.joda.time.Period value)`
`void`	`setString(String value)`
`void`	`setTime(LocalTime value)`
`void`	`setTimestamp(Instant value)`
`void`	`setValue(Object value)` Write value to a vector as a Java object of the "native" type for the column.
`ValueType`	`valueType()` Describe the type of the value.
`BaseDataValueVector`	`vector()`

Methods inherited from class org.apache.drill.exec.vector.accessor.writer.AbstractScalarWriterImpl
bindSchema, dump, endArrayValue, saveRow, schema, startRow, startWrite, type, writeIndex

Methods inherited from class org.apache.drill.exec.vector.accessor.writer.AbstractScalarWriter
conversionError, extendedType, setObject, toString

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - DummyScalarWriter
```
public DummyScalarWriter(ColumnMetadata schema)
```
- Method Detail
  - bindListener
```
public void bindListener(WriterEvents.ColumnWriterListener listener)
```
    Description copied from interface: WriterEvents
    
    Bind a listener to the underlying vector writer. This listener reports on vector events (overflow, growth), and so is called only when the writer is backed by a vector. The listener is ignored (and never called) for dummy (non-projected) columns. If the column is compound (such as for a nullable or repeated column, or for a map), then the writer is bound to the individual components.
    
    Specified by:
    
    bindListener in interface WriterEvents
    
    Overrides:
    
    bindListener in class AbstractScalarWriter
    
    Parameters:
    
    listener - the vector event listener to bind
  - valueType
```
public ValueType valueType()
```
    Description copied from interface: ScalarWriter
    
    Describe the type of the value. This is a compression of the value vector type: it describes which method will return the vector value.
    
    Returns:
    
    the value type which indicates which get method is valid for the column
  - nullable
```
public boolean nullable()
```
    Description copied from interface: ColumnWriter
    
    Whether this writer allows nulls. This is not as simple as checking for the TypeProtos.DataMode.OPTIONAL type in the schema. List entries are nullable, if they are primitive, but not if they are maps or lists. Unions are nullable, regardless of cardinality.
    
    Returns:
    
    true if a call to ColumnWriter.setNull() is supported, false if not
  - setNull
```
public void setNull()
```
    Description copied from interface: ColumnWriter
    
    Set the current value to null. Support depends on the underlying implementation: only nullable types support this operation. throws IllegalStateException if called on a non-nullable value.
  - setBoolean
```
public void setBoolean(boolean value)
```
  - setInt
```
public void setInt(int value)
```
  - setLong
```
public void setLong(long value)
```
  - setFloat
```
public void setFloat(float value)
```
  - setDouble
```
public void setDouble(double value)
```
  - setString
```
public void setString(String value)
```
  - setBytes
```
public void setBytes(byte[] value,
                     int len)
```
  - appendBytes
```
public void appendBytes(byte[] value,
                        int len)
```
  - setDecimal
```
public void setDecimal(BigDecimal value)
```
  - setPeriod
```
public void setPeriod(org.joda.time.Period value)
```
  - bindIndex
```
public void bindIndex(ColumnWriterIndex index)
```
    Description copied from interface: WriterEvents
    
    Bind the writer to a writer index.
    
    Specified by:
    
    bindIndex in interface WriterEvents
    
    Overrides:
    
    bindIndex in class AbstractScalarWriterImpl
    
    Parameters:
    
    index - the writer index (top level or nested for arrays)
  - restartRow
```
public void restartRow()
```
    Description copied from interface: WriterEvents
    
    During a writer to a row, rewind the the current index position to restart the row. Done when abandoning the current row, such as when filtering out a row at read time.
  - endWrite
```
public void endWrite()
```
    Description copied from interface: WriterEvents
    
    End a batch: finalize any vector values.
  - preRollover
```
public void preRollover()
```
    Description copied from interface: WriterEvents
    
    The vectors backing this vector are about to roll over. Finish the current batch up to, but not including, the current row.
  - postRollover
```
public void postRollover()
```
    Description copied from interface: WriterEvents
    
    The vectors backing this writer rolled over. This means that data for the current row has been rolled over into a new vector. Offsets and indexes should be shifted based on the understanding that data for the current row now resides at the start of a new vector instead of its previous location elsewhere in an old vector.
  - lastWriteIndex
```
public int lastWriteIndex()
```
    Description copied from interface: WriterPosition
    
    Return the last write position in the vector. This may be the same as the writer index position (if the vector was written at that point), or an earlier point. In either case, this value points to the last valid value in the vector.
    
    Returns:
    
    index of the last valid value in the vector
  - vector
```
public BaseDataValueVector vector()
```
    Specified by:
    
    vector in class AbstractScalarWriterImpl
  - rowStartIndex
```
public int rowStartIndex()
```
    Description copied from interface: WriterPosition
    
    Position within the vector of the first value for the current row. Note that this is always the first value for the row, even for a writer deeply nested within a hierarchy of arrays. (The first position for the current array is not exposed in this API.)
    
    Specified by:
    
    rowStartIndex in interface WriterPosition
    
    Overrides:
    
    rowStartIndex in class AbstractScalarWriterImpl
    
    Returns:
    
    the vector offset of the first value for the current row
  - setDate
```
public void setDate(LocalDate value)
```
  - setTime
```
public void setTime(LocalTime value)
```
  - setTimestamp
```
public void setTimestamp(Instant value)
```
  - setValue
```
public void setValue(Object value)
```
    Description copied from interface: ValueWriter
    
    Write value to a vector as a Java object of the "native" type for the column. This form is available only on scalar writers. The object must be of the form for the primary write method above.
    Primarily to be used when the code already knows the object type.
    
    Parameters:
    
    value - a value that matches the primary setter above, or null to set the column to null
    
    See Also:
    
    for the generic case
  - setDefaultValue
```
public void setDefaultValue(Object value)
```
    Description copied from interface: ScalarWriter
    
    Set the default value to be used to fill empties for this writer. Only valid for required writers: null writers set this is-set bit to 0 and set the data value to 0.
    
    Parameters:
    
    value - the value to set. Cannot be null. The type of the value must match that legal for ValueWriter.setValue(Object)
  - isProjected
```
public boolean isProjected()
```
    Description copied from interface: ColumnWriter
    
    Whether this writer is projected (is backed by a materialized vector), or is unprojected (is just a dummy writer.) In most cases, clients can ignore whether the column is projected and just write to the writer. This flag handles those special cases where it is helpful to know if the column is projected or not.
    
    Specified by:
    
    isProjected in interface ColumnWriter
    
    Overrides:
    
    isProjected in class AbstractScalarWriterImpl
  - copy
```
public void copy(ColumnReader from)
```
    Description copied from interface: ColumnWriter
    
    Copy a single value from the given reader, which must be of the same type as this writer.
    
    Parameters:
    
    from - reader to provide the data

Class DummyScalarWriter

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.drill.exec.vector.accessor.writer.AbstractScalarWriterImpl

Nested classes/interfaces inherited from interface org.apache.drill.exec.vector.accessor.writer.WriterEvents

Field Summary

Fields inherited from class org.apache.drill.exec.vector.accessor.writer.AbstractScalarWriterImpl

Constructor Summary

Method Summary

Methods inherited from class org.apache.drill.exec.vector.accessor.writer.AbstractScalarWriterImpl

Methods inherited from class org.apache.drill.exec.vector.accessor.writer.AbstractScalarWriter

Methods inherited from class java.lang.Object

Constructor Detail

DummyScalarWriter

Method Detail

bindListener

valueType

nullable

setNull

setBoolean

setInt

setLong

setFloat

setDouble

setString

setBytes

appendBytes

setDecimal

setPeriod

bindIndex

restartRow

endWrite

preRollover

postRollover

lastWriteIndex

vector

rowStartIndex

setDate

setTime

setTimestamp

setValue

setDefaultValue

isProjected

copy