org.apache.hadoop.hbase.client.coprocessor

Class AggregationHelper

java.lang.Object

org.apache.hadoop.hbase.client.coprocessor.AggregationHelper

@InterfaceAudience.Private
public final class AggregationHelper
extends Object

Helper class for constructing aggregation request and response.

Constructor Summary

Constructors

Modifier	Constructor and Description
private	AggregationHelper()

Method Summary

Modifier and Type	Method and Description
static <T extends com.google.protobuf.Message> T	getParsedGenericInstance(Class<?> runtimeClass, int position, com.google.protobuf.ByteString b) Get an instance of the argument type declared in a class's signature.
(package private) static <R,S,P extends com.google.protobuf.Message,Q extends com.google.protobuf.Message,T extends com.google.protobuf.Message> org.apache.hadoop.hbase.protobuf.generated.AggregateProtos.AggregateRequest	validateArgAndGetPB(Scan scan, ColumnInterpreter<R,S,P,Q,T> ci, boolean canFamilyBeAbsent)
private static void	validateParameters(Scan scan, boolean canFamilyBeAbsent)

Methods inherited from class java.lang.Object

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

Constructor Detail

AggregationHelper

private AggregationHelper()

Method Detail

validateParameters

private static void validateParameters(Scan scan,
                                       boolean canFamilyBeAbsent)
                                throws IOException

Parameters:

scan - the HBase scan object to use to read data from HBase

canFamilyBeAbsent - whether column family can be absent in familyMap of scan

Throws:

IOException

validateArgAndGetPB

static <R,S,P extends com.google.protobuf.Message,Q extends com.google.protobuf.Message,T extends com.google.protobuf.Message> org.apache.hadoop.hbase.protobuf.generated.AggregateProtos.AggregateRequest validateArgAndGetPB(Scan scan,
                                                                                                                                                                                                                               ColumnInterpreter<R,S,P,Q,T> ci,
                                                                                                                                                                                                                               boolean canFamilyBeAbsent)
                                                                                                                                                                                                                        throws IOException

Throws:

IOException

getParsedGenericInstance

public static <T extends com.google.protobuf.Message> T getParsedGenericInstance(Class<?> runtimeClass,
                                                                                 int position,
                                                                                 com.google.protobuf.ByteString b)
                                                                          throws IOException

Get an instance of the argument type declared in a class's signature. The argument type is assumed to be a PB Message subclass, and the instance is created using parseFrom method on the passed ByteString.

Parameters:

runtimeClass - the runtime type of the class

position - the position of the argument in the class declaration

b - the ByteString which should be parsed to get the instance created

Returns:

the instance

Throws:

IOException - Either we couldn't instantiate the method object, or "parseFrom" failed.