org.apache.hadoop.hive.ql.io.protobuf

Class ProtobufMessageInputFormat<K,V extends com.google.protobuf.MessageLite>

java.lang.Object

org.apache.hadoop.mapred.FileInputFormat<K,V>

org.apache.hadoop.mapred.SequenceFileInputFormat<K,ProtoMessageWritable<V>>

org.apache.hadoop.hive.ql.io.protobuf.ProtobufMessageInputFormat<K,V>

Type Parameters:

K - K for the sequence file.

V - The proto message type stored in the sequence file. Just to keep java compiler happy.

All Implemented Interfaces:

org.apache.hadoop.mapred.InputFormat<K,ProtoMessageWritable<V>>

public class ProtobufMessageInputFormat<K,V extends com.google.protobuf.MessageLite>
extends org.apache.hadoop.mapred.SequenceFileInputFormat<K,ProtoMessageWritable<V>>

InputFormat to support reading ProtoWritable stored in a sequence file. You cannot use the sequence file directly since the createValue method uses default constructor. But ProtoWritable has a package protected constructor which takes a parser. By reading the proto class name from job conf which is copied from table properties by Hive this class manages to give a generic implementation where only can set the proto.class in table properties and load the file. It is also enhanced to ignore EOF exception while opening a file, so as to ignore 0 bytes files in the table. Maybe we should allow this to be configured.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.hadoop.mapred.FileInputFormat

org.apache.hadoop.mapred.FileInputFormat.Counter

Field Summary

Fields inherited from class org.apache.hadoop.mapred.FileInputFormat

INPUT_DIR_NONRECURSIVE_IGNORE_SUBDIRS, INPUT_DIR_RECURSIVE, LOG, NUM_INPUT_FILES

Constructor Summary

Constructors

Constructor and Description
ProtobufMessageInputFormat()

Method Summary

Modifier and Type	Method and Description
org.apache.hadoop.mapred.RecordReader<K,ProtoMessageWritable<V>>	getRecordReader(org.apache.hadoop.mapred.InputSplit split, org.apache.hadoop.mapred.JobConf job, org.apache.hadoop.mapred.Reporter reporter)

Methods inherited from class org.apache.hadoop.mapred.SequenceFileInputFormat

listStatus

Methods inherited from class org.apache.hadoop.mapred.FileInputFormat

addInputPath, addInputPathRecursively, addInputPaths, computeSplitSize, getBlockIndex, getInputPathFilter, getInputPaths, getSplitHosts, getSplits, isSplitable, makeSplit, makeSplit, setInputPathFilter, setInputPaths, setInputPaths, setMinSplitSize

Methods inherited from class java.lang.Object

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

Constructor Detail

ProtobufMessageInputFormat

public ProtobufMessageInputFormat()

Method Detail

getRecordReader

public org.apache.hadoop.mapred.RecordReader<K,ProtoMessageWritable<V>> getRecordReader(org.apache.hadoop.mapred.InputSplit split,
                                                                                        org.apache.hadoop.mapred.JobConf job,
                                                                                        org.apache.hadoop.mapred.Reporter reporter)
                                                                                 throws IOException

Specified by:

getRecordReader in interface org.apache.hadoop.mapred.InputFormat<K,ProtoMessageWritable<V extends com.google.protobuf.MessageLite>>

Overrides:

getRecordReader in class org.apache.hadoop.mapred.SequenceFileInputFormat<K,ProtoMessageWritable<V extends com.google.protobuf.MessageLite>>

Throws:

IOException