org.apache.solr.util.hll

Interface ISchemaVersion

public interface ISchemaVersion

A serialization schema for HLLs. Reads and writes HLL metadata to and from byte[] representations.

Method Summary

Modifier and Type	Method and Description
IWordDeserializer	getDeserializer(HLLType type, int wordLength, byte[] bytes) Builds an HLL deserializer that matches this schema version.
org.apache.solr.util.hll.IWordSerializer	getSerializer(HLLType type, int wordLength, int wordCount) Builds an HLL serializer that matches this schema version.
int	paddingBytes(HLLType type) The number of metadata bytes required for a serialized HLL of the specified type.
org.apache.solr.util.hll.IHLLMetadata	readMetadata(byte[] bytes) Reads the metadata bytes of the serialized HLL.
int	schemaVersionNumber()
void	writeMetadata(byte[] bytes, org.apache.solr.util.hll.IHLLMetadata metadata) Writes metadata bytes to serialized HLL.

Method Detail

paddingBytes

int paddingBytes(HLLType type)

The number of metadata bytes required for a serialized HLL of the specified type.

Parameters:

type - the type of the serialized HLL

Returns:

the number of padding bytes needed in order to fully accommodate the needed metadata.

writeMetadata

void writeMetadata(byte[] bytes,
                   org.apache.solr.util.hll.IHLLMetadata metadata)

Writes metadata bytes to serialized HLL.

Parameters:

bytes - the padded data bytes of the HLL

metadata - the metadata to write to the padding bytes

readMetadata

org.apache.solr.util.hll.IHLLMetadata readMetadata(byte[] bytes)

Reads the metadata bytes of the serialized HLL.

Parameters:

bytes - the serialized HLL

Returns:

the HLL metadata

getSerializer

org.apache.solr.util.hll.IWordSerializer getSerializer(HLLType type,
                                                       int wordLength,
                                                       int wordCount)

Builds an HLL serializer that matches this schema version.

Parameters:

type - the HLL type that will be serialized. This cannot be null.

wordLength - the length of the 'words' that comprise the data of the HLL. Words must be at least 5 bits and at most 64 bits long.

wordCount - the number of 'words' in the HLL's data.

Returns:

a byte array serializer used to serialize a HLL according to this schema version's specification.

See Also:

paddingBytes(HLLType), IWordSerializer

getDeserializer

IWordDeserializer getDeserializer(HLLType type,
                                  int wordLength,
                                  byte[] bytes)

Builds an HLL deserializer that matches this schema version.

Parameters:

type - the HLL type that will be deserialized. This cannot be null.

wordLength - the length of the 'words' that comprise the data of the serialized HLL. Words must be at least 5 bits and at most 64 bits long.

bytes - the serialized HLL to deserialize. This cannot be null.

Returns:

a byte array deserializer used to deserialize a HLL serialized according to this schema version's specification.

schemaVersionNumber

int schemaVersionNumber()

Returns:

the schema version number.