com.facebook.drift.codec

Class DelegateCodec<T>

java.lang.Object

com.facebook.drift.codec.DelegateCodec<T>

All Implemented Interfaces:

ThriftCodec<T>

public class DelegateCodec<T>
extends Object
implements ThriftCodec<T>

A placeholder for aThriftCodec that defers computation of the real codec until it is actually used, and then just delegates to that codec.

This is used to break the cycle when computing the codec for a recursive type tries to compute codecs for all of its fields.

Constructor Summary

Constructors

Constructor and Description
DelegateCodec(ThriftCodecManager codecManager, Type javaType)

Method Summary

Modifier and Type	Method and Description
ThriftType	getType() The Thrift type this codec supports.
boolean	isNull(T value) If the value is effectively null and should not be written.
T	read(TProtocolReader protocol) Reads a value from supplied Thrift protocol reader.
void	write(T value, TProtocolWriter protocol) Writes a value to the supplied Thrift protocol writer.

Methods inherited from class java.lang.Object

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

Constructor Detail

DelegateCodec

public DelegateCodec(ThriftCodecManager codecManager,
                     Type javaType)

Method Detail

getType

public ThriftType getType()

Description copied from interface: ThriftCodec

The Thrift type this codec supports. The Thrift type contains the Java generic Type of the codec.

Specified by:

getType in interface ThriftCodec<T>

read

public T read(TProtocolReader protocol)
       throws Exception

Description copied from interface: ThriftCodec

Reads a value from supplied Thrift protocol reader.

Specified by:

read in interface ThriftCodec<T>

Parameters:

protocol - the protocol to read from

Returns:

the value; not null

Throws:

Exception - if any problems occurred when reading or coercing the value

write

public void write(T value,
                  TProtocolWriter protocol)
           throws Exception

Description copied from interface: ThriftCodec

Writes a value to the supplied Thrift protocol writer.

Specified by:

write in interface ThriftCodec<T>

Parameters:

value - the value to write; not null

protocol - the protocol to write to

Throws:

Exception - if any problems occurred when writing or coercing the value

isNull

public boolean isNull(T value)

Description copied from interface: ThriftCodec

If the value is effectively null and should not be written.

Specified by:

isNull in interface ThriftCodec<T>

Parameters:

value - the value to test

Returns:

true if the value should not be written