Package org.apache.druid.frame.write.columnar

Class ColumnarFrameWriter

java.lang.Object

org.apache.druid.frame.write.columnar.ColumnarFrameWriter

All Implemented Interfaces:

Closeable, AutoCloseable, FrameWriter

public class ColumnarFrameWriter
extends Object
implements FrameWriter

Constructor Summary

Constructors

Constructor	Description
ColumnarFrameWriter(RowSignature signature, List<KeyColumn> keyColumns, AppendableMemory rowOrderMemory, List<FrameColumnWriter> columnWriters)

Method Summary

Modifier and Type	Method	Description
boolean	addSelection()	Write the current row to the frame that is under construction, if there is enough space to do so.
void	close()
int	getNumRows()	Returns the number of rows written so far.
long	getTotalSize()	Returns the number of bytes that would be written by FrameWriter.writeTo(org.apache.datasketches.memory.WritableMemory, long) if called now.
long	writeTo(org.apache.datasketches.memory.WritableMemory memory, long startPosition)	Writes the frame to the provided memory location, which must have at least FrameWriter.getTotalSize() bytes available.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.druid.frame.write.FrameWriter

toByteArray

Constructor Detail

ColumnarFrameWriter

public ColumnarFrameWriter(RowSignature signature,
                           List<KeyColumn> keyColumns,
                           @Nullable
                           AppendableMemory rowOrderMemory,
                           List<FrameColumnWriter> columnWriters)

Method Detail

addSelection

public boolean addSelection()

Description copied from interface: FrameWriter

Write the current row to the frame that is under construction, if there is enough space to do so.

If this method returns false on an empty frame, or in a situation where starting a new frame is impractical, it is conventional (although not required) for the caller to throw FrameRowTooLargeException.

Specified by:

addSelection in interface FrameWriter

Returns:

true if the row was written, false if there was not enough space

getNumRows

public int getNumRows()

Description copied from interface: FrameWriter

Returns the number of rows written so far.

Specified by:

getNumRows in interface FrameWriter

getTotalSize

public long getTotalSize()

Description copied from interface: FrameWriter

Returns the number of bytes that would be written by FrameWriter.writeTo(org.apache.datasketches.memory.WritableMemory, long) if called now.

Specified by:

getTotalSize in interface FrameWriter

writeTo

public long writeTo(org.apache.datasketches.memory.WritableMemory memory,
                    long startPosition)

Description copied from interface: FrameWriter

Writes the frame to the provided memory location, which must have at least FrameWriter.getTotalSize() bytes available. Once this method is called, the frame writer is no longer usable and must be closed. Returns the number of bytes written, which will equal FrameWriter.getTotalSize().

Specified by:

writeTo in interface FrameWriter

close

public void close()

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Specified by:

close in interface FrameWriter