org.apache.parquet.column.values

Class ValuesWriter

java.lang.Object

org.apache.parquet.column.values.ValuesWriter

Direct Known Subclasses:

BitPackingValuesWriter, BooleanPlainValuesWriter, ByteBitPackingValuesWriter, DeltaBinaryPackingValuesWriter, DeltaByteArrayWriter, DeltaLengthByteArrayValuesWriter, DevNullValuesWriter, DictionaryValuesWriter, FallbackValuesWriter, FixedLenByteArrayPlainValuesWriter, PlainValuesWriter, RunLengthBitPackingHybridValuesWriter

public abstract class ValuesWriter
extends Object

base class to implement an encoding for a given column

Author:

Julien Le Dem

Constructor Summary

Constructors

Constructor and Description
ValuesWriter()

Method Summary

Methods

Modifier and Type	Method and Description
void	close() Called to close the values writer.
abstract long	getAllocatedSize() ( > getBufferedSize() )
abstract long	getBufferedSize() used to decide if we want to work to the next page
abstract BytesInput	getBytes()
abstract Encoding	getEncoding() called after getBytes() and before reset()
abstract String	memUsageString(String prefix)
abstract void	reset() called after getBytes() to reset the current buffer and start writing the next page
void	resetDictionary() reset the dictionary when a new block starts
DictionaryPage	toDictPageAndClose() Returns the dictionary generated by this writer if one was created.
void	writeBoolean(boolean v)
void	writeByte(int value)
void	writeBytes(Binary v)
void	writeDouble(double v)
void	writeFloat(float v)
void	writeInteger(int v)
void	writeLong(long v)

Methods inherited from class java.lang.Object

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

Constructor Detail

ValuesWriter

public ValuesWriter()

Method Detail

getBufferedSize

public abstract long getBufferedSize()

used to decide if we want to work to the next page

Returns:

the size of the currently buffered data (in bytes)

getBytes

public abstract BytesInput getBytes()

Returns:

the bytes buffered so far to write to the current page

getEncoding

public abstract Encoding getEncoding()

called after getBytes() and before reset()

Returns:

the encoding that was used to encode the bytes

reset

public abstract void reset()

called after getBytes() to reset the current buffer and start writing the next page

close

public void close()

Called to close the values writer. Any output stream is closed and can no longer be used. All resources are released.

toDictPageAndClose

public DictionaryPage toDictPageAndClose()

Returns the dictionary generated by this writer if one was created. As part of this operation the dictionary is closed and will not have any new values written into it.

Returns:

the dictionary page or null if not dictionary based

resetDictionary

public void resetDictionary()

reset the dictionary when a new block starts

getAllocatedSize

public abstract long getAllocatedSize()

( > getBufferedSize() )

Returns:

the allocated size of the buffer

writeByte

public void writeByte(int value)

Parameters:

value - the value to encode

writeBoolean

public void writeBoolean(boolean v)

Parameters:

v - the value to encode

writeBytes

public void writeBytes(Binary v)

Parameters:

v - the value to encode

writeInteger

public void writeInteger(int v)

Parameters:

v - the value to encode

writeLong

public void writeLong(long v)

Parameters:

v - the value to encode

writeDouble

public void writeDouble(double v)

Parameters:

v - the value to encode

writeFloat

public void writeFloat(float v)

Parameters:

v - the value to encode

memUsageString

public abstract String memUsageString(String prefix)