org.apache.calcite.rel.metadata

Class JaninoRelMetadataProvider

java.lang.Object

org.apache.calcite.rel.metadata.JaninoRelMetadataProvider

All Implemented Interfaces:

RelMetadataProvider

public class JaninoRelMetadataProvider
extends Object
implements RelMetadataProvider

Implementation of the RelMetadataProvider interface that generates a class that dispatches to the underlying providers.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
private static class	JaninoRelMetadataProvider.Key Key for the cache.
static class	JaninoRelMetadataProvider.NoHandler Exception that indicates there there should be a handler for this class but there is not.

Field Summary

Fields

Modifier and Type	Field and Description
private static Set<Class<? extends RelNode>>	ALL_RELS
static JaninoRelMetadataProvider	DEFAULT
private static com.google.common.cache.LoadingCache<JaninoRelMetadataProvider.Key,MetadataHandler>	HANDLERS Cache of pre-generated handlers by provider and kind of metadata.
private RelMetadataProvider	provider

Constructor Summary

Constructors

Modifier	Constructor and Description
private	JaninoRelMetadataProvider(RelMetadataProvider provider) Private constructor; use of(org.apache.calcite.rel.metadata.RelMetadataProvider).

Method Summary

Modifier and Type	Method and Description
<M extends Metadata> UnboundMetadata<M>	apply(Class<? extends RelNode> relClass, Class<? extends M> metadataClass) Retrieves metadata of a particular type and for a particular sub-class of relational expression.
private static StringBuilder	argList(StringBuilder buff, Method method) Returns e.g.
(package private) static <M extends Metadata> MetadataHandler<M>	compile(String className, String classBody, MetadataDef<M> def, List<Object> argList)
(package private) <M extends Metadata,H extends MetadataHandler<M>> H	create(MetadataDef<M> def)
boolean	equals(Object obj)
private static String	findProvider(List<Pair<String,MetadataHandler>> providerList, Class<?> declaringClass)
<M extends Metadata> com.google.common.collect.Multimap<Method,MetadataHandler<M>>	handlers(MetadataDef<M> def)
int	hashCode()
private static <M extends Metadata> MetadataHandler<M>	load3(MetadataDef<M> def, com.google.common.collect.Multimap<Method,MetadataHandler<M>> map, com.google.common.collect.ImmutableList<Class<? extends RelNode>> relClasses)
private static <K,V> com.google.common.cache.CacheBuilder<K,V>	maxSize(com.google.common.cache.CacheBuilder<K,V> builder, int size)
static JaninoRelMetadataProvider	of(RelMetadataProvider provider) Creates a JaninoRelMetadataProvider.
private static StringBuilder	paramList(StringBuilder buff, Method method) Returns e.g.
void	register(Iterable<Class<? extends RelNode>> classes) Registers some classes.
(package private) <M extends Metadata,H extends MetadataHandler<M>> H	revise(Class<? extends RelNode> rClass, MetadataDef<M> def)
private static StringBuilder	safeArgList(StringBuilder buff, Method method) Returns e.g.

Methods inherited from class java.lang.Object

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

Field Detail

provider

private final RelMetadataProvider provider

DEFAULT

public static final JaninoRelMetadataProvider DEFAULT

ALL_RELS

private static final Set<Class<? extends RelNode>> ALL_RELS

HANDLERS

private static final com.google.common.cache.LoadingCache<JaninoRelMetadataProvider.Key,MetadataHandler> HANDLERS

Cache of pre-generated handlers by provider and kind of metadata. For the cache to be effective, providers should implement identity correctly.

Constructor Detail

JaninoRelMetadataProvider

private JaninoRelMetadataProvider(RelMetadataProvider provider)

Private constructor; use of(org.apache.calcite.rel.metadata.RelMetadataProvider).

Method Detail

of

public static JaninoRelMetadataProvider of(RelMetadataProvider provider)

Creates a JaninoRelMetadataProvider.

Parameters:

provider - Underlying provider

maxSize

private static <K,V> com.google.common.cache.CacheBuilder<K,V> maxSize(com.google.common.cache.CacheBuilder<K,V> builder,
                                                                       int size)

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

apply

public <M extends Metadata> UnboundMetadata<M> apply(Class<? extends RelNode> relClass,
                                                     Class<? extends M> metadataClass)

Description copied from interface: RelMetadataProvider

Retrieves metadata of a particular type and for a particular sub-class of relational expression.

The object returned is a function. It can be applied to a relational expression of the given type to create a metadata object.

For example, you might call

 RelMetadataProvider provider;
 LogicalFilter filter;
 RexNode predicate;
 Function<RelNode, Metadata> function =
   provider.apply(LogicalFilter.class, Selectivity.class};
 Selectivity selectivity = function.apply(filter);
 Double d = selectivity.selectivity(predicate);
 

Specified by:

apply in interface RelMetadataProvider

Parameters:

relClass - Type of relational expression

metadataClass - Type of metadata

Returns:

Function that will field a metadata instance; or null if this provider cannot supply metadata of this type

handlers

public <M extends Metadata> com.google.common.collect.Multimap<Method,MetadataHandler<M>> handlers(MetadataDef<M> def)

Specified by:

handlers in interface RelMetadataProvider

load3

private static <M extends Metadata> MetadataHandler<M> load3(MetadataDef<M> def,
                                                             com.google.common.collect.Multimap<Method,MetadataHandler<M>> map,
                                                             com.google.common.collect.ImmutableList<Class<? extends RelNode>> relClasses)

findProvider

private static String findProvider(List<Pair<String,MetadataHandler>> providerList,
                                   Class<?> declaringClass)

argList

private static StringBuilder argList(StringBuilder buff,
                                     Method method)

Returns e.g. ", ignoreNulls".

safeArgList

private static StringBuilder safeArgList(StringBuilder buff,
                                         Method method)

Returns e.g. ", ignoreNulls".

paramList

private static StringBuilder paramList(StringBuilder buff,
                                       Method method)

Returns e.g. ",\n boolean ignoreNulls".

compile

static <M extends Metadata> MetadataHandler<M> compile(String className,
                                                       String classBody,
                                                       MetadataDef<M> def,
                                                       List<Object> argList)
                                                throws org.codehaus.commons.compiler.CompileException,
                                                       IOException

Throws:

org.codehaus.commons.compiler.CompileException

IOException

create

<M extends Metadata,H extends MetadataHandler<M>> H create(MetadataDef<M> def)

revise

<M extends Metadata,H extends MetadataHandler<M>> H revise(Class<? extends RelNode> rClass,
                                                           MetadataDef<M> def)

register

public void register(Iterable<Class<? extends RelNode>> classes)

Registers some classes. Does not flush the providers, but next time we need to generate a provider, it will handle all of these classes. So, calling this method reduces the number of times we need to re-generate.