org.apache.pig.data

Enum SchemaTupleClassGenerator.GenContext

java.lang.Object

java.lang.Enum<SchemaTupleClassGenerator.GenContext>

org.apache.pig.data.SchemaTupleClassGenerator.GenContext

All Implemented Interfaces:

Serializable, Comparable<SchemaTupleClassGenerator.GenContext>

Enclosing class:

SchemaTupleClassGenerator

public static enum SchemaTupleClassGenerator.GenContext
extends Enum<SchemaTupleClassGenerator.GenContext>

The GenContext mechanism provides a level of control in where SchemaTupleFactories are used. By attaching a GenContext enum type to the registration of a Schema, the code can express the intent of where a SchemaTupleFactory is intended to be used. In this way, if a load func and a join both involve Tuples of the same Schema, it's possible to use SchemaTupleFactories in one but not in the other.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	SchemaTupleClassGenerator.GenContext.GenerateForceLoad
static interface	SchemaTupleClassGenerator.GenContext.GenerateForeach
static interface	SchemaTupleClassGenerator.GenContext.GenerateFrJoin
static interface	SchemaTupleClassGenerator.GenContext.GenerateMergeJoin
static interface	SchemaTupleClassGenerator.GenContext.GenerateUdf These annotations are used to mark a given SchemaTuple with the context in which is was intended to be generated.

Enum Constant Summary

Enum Constants

Enum Constant and Description
FORCE_LOAD All registered Schemas will also be registered in one additional context.
FOREACH This context is for POForEach.
FR_JOIN This context controls whether or not SchemaTuples will be used in FR joins.
MERGE_JOIN This context controls whether or not SchemaTuples will be used in merge joins.
UDF This context is used in UDF code.

Method Summary

Modifier and Type	Method and Description
String	getAnnotationCanonicalName()
String	key()
boolean	shouldGenerate(Class clazz) Checks the generated class to see if the annotation associated with this enum is present.
boolean	shouldGenerate(org.apache.hadoop.conf.Configuration conf) Given a job configuration file, this checks to see if the default value has been overriden.
static SchemaTupleClassGenerator.GenContext	valueOf(String name) Returns the enum constant of this type with the specified name.
static SchemaTupleClassGenerator.GenContext[]	values() Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

UDF

public static final SchemaTupleClassGenerator.GenContext UDF

This context is used in UDF code. Currently, this is only used for the inputs to UDF's.

FOREACH

public static final SchemaTupleClassGenerator.GenContext FOREACH

This context is for POForEach. This will use the expected output of a ForEach to return a typed Tuple.

FR_JOIN

public static final SchemaTupleClassGenerator.GenContext FR_JOIN

This context controls whether or not SchemaTuples will be used in FR joins. Currently, they will be used in the HashMap that FR Joins construct.

MERGE_JOIN

public static final SchemaTupleClassGenerator.GenContext MERGE_JOIN

This context controls whether or not SchemaTuples will be used in merge joins.

FORCE_LOAD

public static final SchemaTupleClassGenerator.GenContext FORCE_LOAD

All registered Schemas will also be registered in one additional context. This context will allow users to "force" the load of a SchemaTupleFactory if one is present in any context.

Method Detail

values

public static SchemaTupleClassGenerator.GenContext[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (SchemaTupleClassGenerator.GenContext c : SchemaTupleClassGenerator.GenContext.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static SchemaTupleClassGenerator.GenContext valueOf(String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum type has no constant with the specified name

NullPointerException - if the argument is null

key

public String key()

getAnnotationCanonicalName

public String getAnnotationCanonicalName()

shouldGenerate

public boolean shouldGenerate(Class clazz)

Checks the generated class to see if the annotation associated with this enum is present.

Parameters:

clazz -

Returns:

boolean type value

shouldGenerate

public boolean shouldGenerate(org.apache.hadoop.conf.Configuration conf)

Given a job configuration file, this checks to see if the default value has been overriden.

Parameters:

conf -

Returns:

boolean type value