Package io.confluent.parallelconsumer.offsets

Class OffsetSimultaneousEncoder

java.lang.Object

io.confluent.parallelconsumer.offsets.OffsetSimultaneousEncoder

public class OffsetSimultaneousEncoder
extends Object

Encode with multiple strategies at the same time.

Have results in an accessible structure, easily selecting the highest compression.

See Also:

• invoke()

Field Summary

Fields

Modifier and Type	Field	Description
static final String	COMPRESSION_FORCED_RESOURCE_LOCK	Used to prevent tests running in parallel that depends on setting static state in this class.
static boolean	compressionForced	Force the encoder to also add the compressed versions.
static final int	LARGE_INPUT_MAP_SIZE_THRESHOLD	Size threshold in bytes after which compressing the encodings will be compared, as it seems to be typically worth the extra compression step when beyond this size in the source array.

Constructor Summary

Constructors

Constructor	Description
OffsetSimultaneousEncoder(long baseOffsetToCommit, long highestSucceededOffset, Set<Long> incompleteOffsets)

Method Summary

Modifier and Type	Method	Description
Map<OffsetEncoding,byte[]>	getEncodingMap()	Map of different encoding types for the same offset data, used for retrieving the data for the encoding type
Set<Long>	getIncompleteOffsets()	The offsets which have not yet been fully completed and can't have their offset committed
SortedSet<EncodedOffsetPair>	getSortedEncodings()	Ordered set of the different encodings, used to quickly retrieve the most compressed encoding
OffsetSimultaneousEncoder	invoke()	Highwater mark already encoded in string - OffsetMapCodecManager.makeOffsetMetadataPayload(long, io.confluent.parallelconsumer.state.PartitionState<K, V>) - so encoding BitSet run length may not be needed, or could be swapped
byte[]	packSmallest()	Select the smallest encoding, and pack it.

Methods inherited from class java.lang.Object

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

Field Details

LARGE_INPUT_MAP_SIZE_THRESHOLD

public static final int LARGE_INPUT_MAP_SIZE_THRESHOLD

Size threshold in bytes after which compressing the encodings will be compared, as it seems to be typically worth the extra compression step when beyond this size in the source array.

See Also:

• Constant Field Values

compressionForced

public static boolean compressionForced

Force the encoder to also add the compressed versions. Useful for testing.

Visible for testing.

COMPRESSION_FORCED_RESOURCE_LOCK

public static final String COMPRESSION_FORCED_RESOURCE_LOCK

Used to prevent tests running in parallel that depends on setting static state in this class. Manipulation of static state in tests needs to be removed to this isn't necessary.

See Also:

• Constant Field Values

Constructor Details

OffsetSimultaneousEncoder

public OffsetSimultaneousEncoder(long baseOffsetToCommit,
 long highestSucceededOffset,
 Set<Long> incompleteOffsets)

Method Details

invoke

public OffsetSimultaneousEncoder invoke()

Highwater mark already encoded in string - OffsetMapCodecManager.makeOffsetMetadataPayload(long, io.confluent.parallelconsumer.state.PartitionState<K, V>) - so encoding BitSet run length may not be needed, or could be swapped

Simultaneously encodes:

• OffsetEncoding.BitSet
• OffsetEncoding.RunLength

Conditionaly encodes compression variants:

• OffsetEncoding.BitSetCompressed
• OffsetEncoding.RunLengthCompressed

Currently commented out is OffsetEncoding.ByteArray as there doesn't seem to be an advantage over BitSet encoding.

TODO: optimisation - inline this into the partition iteration loop in WorkManager

TODO: optimisation - could double the run-length range from Short.MAX_VALUE (~33,000) to Short.MAX_VALUE * 2 (~66,000) by using unsigned shorts instead (higest representable relative offset is Short.MAX_VALUE because each runlength entry is a Short)

TODO VERY large offests ranges are slow (Integer.MAX_VALUE) - encoding scans could be avoided if passing in map of incompletes which should already be known

packSmallest

public byte[] packSmallest()
                    throws NoEncodingPossibleException

Select the smallest encoding, and pack it.

Throws:

NoEncodingPossibleException

See Also:

• packEncoding(EncodedOffsetPair)

getIncompleteOffsets

public Set<Long> getIncompleteOffsets()

The offsets which have not yet been fully completed and can't have their offset committed

getEncodingMap

public Map<OffsetEncoding,byte[]> getEncodingMap()

Map of different encoding types for the same offset data, used for retrieving the data for the encoding type

getSortedEncodings

public SortedSet<EncodedOffsetPair> getSortedEncodings()

Ordered set of the different encodings, used to quickly retrieve the most compressed encoding

See Also:

• packSmallest()