com.ning.metrics.serialization.hadoop.pig
Class ThriftStorage

java.lang.Object
  org.apache.pig.LoadFunc
      com.ning.metrics.serialization.hadoop.pig.ThriftStorage

All Implemented Interfaces:

org.apache.pig.LoadMetadata

public class ThriftStorage
extends org.apache.pig.LoadFunc
implements org.apache.pig.LoadMetadata

Constructor Summary

ThriftStorage(String schemaName)

ThriftStorage(String schemaName, String goodwillHost, int goodwillPort)

Method Summary

org.apache.hadoop.mapreduce.InputFormat	getInputFormat() This will be called during planning on the front end.
org.apache.pig.data.Tuple	getNext()
String[]	getPartitionKeys(String location, org.apache.hadoop.mapreduce.Job job) Find what columns are partition keys for this input.
org.apache.pig.ResourceSchema	getSchema(String location, org.apache.hadoop.mapreduce.Job job) Get a schema for the data to be loaded.
org.apache.pig.ResourceStatistics	getStatistics(String location, org.apache.hadoop.mapreduce.Job job) Get statistics about the data to be loaded.
void	prepareToRead(org.apache.hadoop.mapreduce.RecordReader reader, org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigSplit split) Initializes LoadFunc for reading data.
void	setLocation(String location, org.apache.hadoop.mapreduce.Job job) Communicate to the loader the location of the object(s) being loaded.
void	setPartitionFilter(org.apache.pig.Expression partitionFilter) Set the filter for partitioning.

Methods inherited from class org.apache.pig.LoadFunc

getAbsolutePath, getLoadCaster, getPathStrings, join, relativeToAbsolutePath, setUDFContextSignature

Methods inherited from class java.lang.Object

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

Constructor Detail

ThriftStorage

public ThriftStorage(String schemaName)
              throws IOException

Throws:

IOException

ThriftStorage

public ThriftStorage(String schemaName,
                     String goodwillHost,
                     int goodwillPort)
              throws IOException

Throws:

IOException

Method Detail

setLocation

public void setLocation(String location,
                        org.apache.hadoop.mapreduce.Job job)
                 throws IOException

Communicate to the loader the location of the object(s) being loaded. The location string passed to the LoadFunc here is the return value of LoadFunc.relativeToAbsolutePath(String, org.apache.hadoop.fs.Path). Implementations should use this method to communicate the location (and any other information) to its underlying InputFormat through the Job object.

This method will be called in the backend multiple times. Implementations should bear in mind that this method is called multiple times and should ensure there are no inconsistent side effects due to the multiple calls.

Specified by:

setLocation in class org.apache.pig.LoadFunc

Parameters:

location - Location as returned by LoadFunc.relativeToAbsolutePath(String, org.apache.hadoop.fs.Path)

job - the Job object store or retrieve earlier stored information from the org.apache.pig.impl.util.UDFContext

Throws:

IOException - if the location is not valid.

getInputFormat

public org.apache.hadoop.mapreduce.InputFormat getInputFormat()
                                                       throws IOException

This will be called during planning on the front end. This is the instance of InputFormat (rather than the class name) because the load function may need to instantiate the InputFormat in order to control how it is constructed.

Specified by:

getInputFormat in class org.apache.pig.LoadFunc

Returns:

the InputFormat associated with this loader.

Throws:

IOException - if there is an exception during InputFormat construction

prepareToRead

public void prepareToRead(org.apache.hadoop.mapreduce.RecordReader reader,
                          org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigSplit split)
                   throws IOException

Initializes LoadFunc for reading data. This will be called during execution before any calls to getNext. The RecordReader needs to be passed here because it has been instantiated for a particular InputSplit.

Specified by:

prepareToRead in class org.apache.pig.LoadFunc

Parameters:

reader - RecordReader to be used by this instance of the LoadFunc

split - The input PigSplit to process

Throws:

IOException - if there is an exception during initialization

getNext

public org.apache.pig.data.Tuple getNext()
                                  throws IOException

Specified by:

getNext in class org.apache.pig.LoadFunc

Throws:

IOException

getSchema

public org.apache.pig.ResourceSchema getSchema(String location,
                                               org.apache.hadoop.mapreduce.Job job)
                                        throws IOException

Get a schema for the data to be loaded.

Specified by:

getSchema in interface org.apache.pig.LoadMetadata

Parameters:

location - Location as returned by LoadFunc.relativeToAbsolutePath(String, org.apache.hadoop.fs.Path)

job - The Job object - this should be used only to obtain cluster properties through JobContext.getConfiguration() and not to set/query any runtime job information.

Returns:

schema for the data to be loaded. This schema should represent all tuples of the returned data. If the schema is unknown or it is not possible to return a schema that represents all returned data, then null should be returned. The schema should not be affected by pushProjection, ie. getSchema should always return the original schema even after pushProjection

Throws:

IOException - if an exception occurs while determining the schema

getStatistics

public org.apache.pig.ResourceStatistics getStatistics(String location,
                                                       org.apache.hadoop.mapreduce.Job job)
                                                throws IOException

Get statistics about the data to be loaded. If no statistics are available, then null should be returned.

Specified by:

getStatistics in interface org.apache.pig.LoadMetadata

Parameters:

location - Location as returned by LoadFunc.relativeToAbsolutePath(String, org.apache.hadoop.fs.Path)

job - The Job object - this should be used only to obtain cluster properties through JobContext.getConfiguration() and not to set/query any runtime job information.

Returns:

statistics about the data to be loaded. If no statistics are available, then null should be returned.

Throws:

IOException - if an exception occurs while retrieving statistics

getPartitionKeys

public String[] getPartitionKeys(String location,
                                 org.apache.hadoop.mapreduce.Job job)
                          throws IOException

Find what columns are partition keys for this input.

Specified by:

getPartitionKeys in interface org.apache.pig.LoadMetadata

Parameters:

location - Location as returned by LoadFunc.relativeToAbsolutePath(String, org.apache.hadoop.fs.Path)

job - The Job object - this should be used only to obtain cluster properties through JobContext.getConfiguration() and not to set/query any runtime job information.

Returns:

array of field names of the partition keys. Implementations should return null to indicate that there are no partition keys

Throws:

IOException - if an exception occurs while retrieving partition keys

setPartitionFilter

public void setPartitionFilter(org.apache.pig.Expression partitionFilter)
                        throws IOException

Set the filter for partitioning. It is assumed that this filter will only contain references to fields given as partition keys in getPartitionKeys. So if the implementation returns null in getPartitionKeys(String, org.apache.hadoop.mapreduce.Job), then this method is not called by Pig runtime. This method is also not called by the Pig runtime if there are no partition filter conditions.

Specified by:

setPartitionFilter in interface org.apache.pig.LoadMetadata

Parameters:

partitionFilter - that describes filter for partitioning

Throws:

IOException - if the filter is not compatible with the storage mechanism or contains non-partition fields.