Package com.clickhouse.client

Class ClickHouseDataProcessor

java.lang.Object

com.clickhouse.client.ClickHouseDataProcessor

Direct Known Subclasses:

ClickHouseRowBinaryProcessor, ClickHouseTabSeparatedProcessor

public abstract class ClickHouseDataProcessor
extends Object

This defines a data processor for dealing with one or multiple ClickHouseFormat.

Field Summary

Fields

Modifier and Type	Field	Description
protected List<ClickHouseColumn>	columns
protected ClickHouseConfig	config
static List<ClickHouseColumn>	DEFAULT_COLUMNS
protected static String	ERROR_UNKNOWN_DATA_TYPE
protected ClickHouseInputStream	input
protected OutputStream	output
protected Map<String,Object>	settings

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	ClickHouseDataProcessor(ClickHouseConfig config, ClickHouseInputStream input, OutputStream output, List<ClickHouseColumn> columns, Map<String,Object> settings)	Default constructor.

Method Summary

Modifier and Type	Method	Description
protected static void	buildAggMappings(Map<ClickHouseAggregateFunction,ClickHouseDeserializer<ClickHouseValue>> deserializers, Map<ClickHouseAggregateFunction,ClickHouseSerializer<ClickHouseValue>> serializers, ClickHouseDeserializer<ClickHouseValue> d, ClickHouseSerializer<ClickHouseValue> s, ClickHouseAggregateFunction... types)
protected static <E extends Enum<E>,T extends ClickHouseValue> void	buildMappings(Map<E,ClickHouseDeserializer<? extends ClickHouseValue>> deserializers, Map<E,ClickHouseSerializer<? extends ClickHouseValue>> serializers, ClickHouseDeserializer<T> d, ClickHouseSerializer<T> s, E... types)
List<ClickHouseColumn>	getColumns()	Gets list of columns to process.
protected abstract List<ClickHouseColumn>	readColumns()	Read columns from input stream.
abstract Iterable<ClickHouseRecord>	records()	Returns an iterable collection of records which can be walked through in a foreach loop.

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_COLUMNS

public static final List<ClickHouseColumn> DEFAULT_COLUMNS

ERROR_UNKNOWN_DATA_TYPE

protected static final String ERROR_UNKNOWN_DATA_TYPE

See Also:

Constant Field Values

config

protected final ClickHouseConfig config

input

protected final ClickHouseInputStream input

output

protected final OutputStream output

columns

protected final List<ClickHouseColumn> columns

settings

protected final Map<String,Object> settings

Constructor Detail

ClickHouseDataProcessor

protected ClickHouseDataProcessor(ClickHouseConfig config,
                                  ClickHouseInputStream input,
                                  OutputStream output,
                                  List<ClickHouseColumn> columns,
                                  Map<String,Object> settings)
                           throws IOException

Default constructor.

Parameters:

config - non-null confinguration contains information like format

input - input stream for deserialization, can be null when output is not

output - outut stream for serialization, can be null when input is not

columns - nullable columns

settings - nullable settings

Throws:

IOException - when failed to read columns from input stream

Method Detail

buildAggMappings

protected static void buildAggMappings(Map<ClickHouseAggregateFunction,ClickHouseDeserializer<ClickHouseValue>> deserializers,
                                       Map<ClickHouseAggregateFunction,ClickHouseSerializer<ClickHouseValue>> serializers,
                                       ClickHouseDeserializer<ClickHouseValue> d,
                                       ClickHouseSerializer<ClickHouseValue> s,
                                       ClickHouseAggregateFunction... types)

buildMappings

protected static <E extends Enum<E>,T extends ClickHouseValue> void buildMappings(Map<E,ClickHouseDeserializer<? extends ClickHouseValue>> deserializers,
                                                                                        Map<E,ClickHouseSerializer<? extends ClickHouseValue>> serializers,
                                                                                        ClickHouseDeserializer<T> d,
                                                                                        ClickHouseSerializer<T> s,
                                                                                        E... types)

readColumns

protected abstract List<ClickHouseColumn> readColumns()
                                               throws IOException

Read columns from input stream. Usually this will be only called once during instantiation.

Returns:

list of columns

Throws:

IOException - when failed to read columns from input stream

getColumns

public final List<ClickHouseColumn> getColumns()

Gets list of columns to process.

Returns:

list of columns to process

records

public abstract Iterable<ClickHouseRecord> records()

Returns an iterable collection of records which can be walked through in a foreach loop. Please pay attention that: 1) UncheckedIOException might be thrown when iterating through the collection; and 2) it's not supposed to be called for more than once.

Returns:

non-null iterable collection