How to use

ReflectiveRelMetadataProvider

in

org.apache.calcite.rel.metadata

public RelMetadataProvider getMetadataProvider() {
 return ReflectiveRelMetadataProvider.reflectiveSource(this,
       BuiltInMethod.IS_PHASE_TRANSITION.method,
       BuiltInMethod.SPLIT_COUNT.method);
}

public <M extends Metadata> UnboundMetadata<M> apply(
  Class<? extends RelNode> relClass, Class<? extends M> metadataClass) {
 if (metadataClass == metadataClass0) {
  return apply(relClass);
 } else {
  return null;
 }
}

 methodsMap.put(key, function);
return new ReflectiveRelMetadataProvider(methodsMap, space.metadataClass0,
  space.providerMap);

public <M extends Metadata> UnboundMetadata<M> apply(
  Class<? extends RelNode> relClass, Class<? extends M> metadataClass) {
 if (metadataClass == metadataClass0) {
  return apply(relClass);
 } else {
  return null;
 }
}

 methodsMap.put(key, function);
return new ReflectiveRelMetadataProvider(methodsMap, space.metadataClass0,
  space.providerMap);

public RelMetadataProvider getMetadataProvider() {
 return ReflectiveRelMetadataProvider.reflectiveSource(this,
       BuiltInMethod.IS_PHASE_TRANSITION.method,
       BuiltInMethod.SPLIT_COUNT.method);
}

public RelMetadataProvider getMetadataProvider() {
 return ChainedRelMetadataProvider.of(
       ImmutableList.of(
         ReflectiveRelMetadataProvider.reflectiveSource(this,
           BuiltInMethod.NON_CUMULATIVE_COST.method),
         RelMdPercentageOriginalRows.SOURCE));
}

public RelMetadataProvider getMetadataProvider() {
 return ChainedRelMetadataProvider.of(
       ImmutableList.of(
         ReflectiveRelMetadataProvider.reflectiveSource(this,
           BuiltInMethod.NON_CUMULATIVE_COST.method),
         RelMdPercentageOriginalRows.SOURCE));
}

public RelMetadataProvider getMetadataProvider() {
 return ReflectiveRelMetadataProvider.reflectiveSource(this,
       BuiltInMethod.IS_PHASE_TRANSITION.method,
       BuiltInMethod.SPLIT_COUNT.method);
}

/** Returns a reflective metadata provider that implements several
 * methods. */
public static RelMetadataProvider reflectiveSource(MetadataHandler target,
  Method... methods) {
 return reflectiveSource(target, ImmutableList.copyOf(methods));
}

/** Returns a reflective metadata provider that implements several
 * methods. */
public static RelMetadataProvider reflectiveSource(MetadataHandler target,
  Method... methods) {
 return reflectiveSource(target, ImmutableList.copyOf(methods));
}

/** Returns an implementation of {@link RelMetadataProvider} that scans for
 * methods with a preceding argument.
 *
 * <p>For example, {@link BuiltInMetadata.Selectivity} has a method
 * {@link BuiltInMetadata.Selectivity#getSelectivity(RexNode)}.
 * A class</p>
 *
 * <blockquote><pre><code>
 * class RelMdSelectivity {
 *   public Double getSelectivity(Union rel, RexNode predicate) { }
 *   public Double getSelectivity(Filter rel, RexNode predicate) { }
 * </code></pre></blockquote>
 *
 * <p>provides implementations of selectivity for relational expressions
 * that extend {@link org.apache.calcite.rel.core.Union}
 * or {@link org.apache.calcite.rel.core.Filter}.</p>
 */
public static RelMetadataProvider reflectiveSource(Method method,
  MetadataHandler target) {
 return reflectiveSource(target, ImmutableList.of(method));
}

/** Returns an implementation of {@link RelMetadataProvider} that scans for
 * methods with a preceding argument.
 *
 * <p>For example, {@link BuiltInMetadata.Selectivity} has a method
 * {@link BuiltInMetadata.Selectivity#getSelectivity(RexNode)}.
 * A class</p>
 *
 * <blockquote><pre><code>
 * class RelMdSelectivity {
 *   public Double getSelectivity(Union rel, RexNode predicate) { }
 *   public Double getSelectivity(Filter rel, RexNode predicate) { }
 * </code></pre></blockquote>
 *
 * <p>provides implementations of selectivity for relational expressions
 * that extend {@link org.apache.calcite.rel.core.Union}
 * or {@link org.apache.calcite.rel.core.Filter}.</p>
 */
public static RelMetadataProvider reflectiveSource(Method method,
  MetadataHandler target) {
 return reflectiveSource(target, ImmutableList.of(method));
}

public RelMetadataProvider getMetadataProvider() {
 return ChainedRelMetadataProvider.of(
       ImmutableList.of(
         ReflectiveRelMetadataProvider.reflectiveSource(this,
           BuiltInMethod.NON_CUMULATIVE_COST.method),
         RelMdPercentageOriginalRows.SOURCE));
}

ChainedRelMetadataProvider.of(
  ImmutableList.of(
    ReflectiveRelMetadataProvider.reflectiveSource(
      BuiltInMethod.PERCENTAGE_ORIGINAL_ROWS.method, INSTANCE),
    ReflectiveRelMetadataProvider.reflectiveSource(
      BuiltInMethod.CUMULATIVE_COST.method, INSTANCE),
    ReflectiveRelMetadataProvider.reflectiveSource(
      BuiltInMethod.NON_CUMULATIVE_COST.method, INSTANCE)));

ChainedRelMetadataProvider.of(
  ImmutableList.of(
    ReflectiveRelMetadataProvider.reflectiveSource(
      BuiltInMethod.PERCENTAGE_ORIGINAL_ROWS.method, INSTANCE),
    ReflectiveRelMetadataProvider.reflectiveSource(
      BuiltInMethod.CUMULATIVE_COST.method, INSTANCE),
    ReflectiveRelMetadataProvider.reflectiveSource(
      BuiltInMethod.NON_CUMULATIVE_COST.method, INSTANCE)));

 implements MetadataHandler<BuiltInMetadata.ColumnUniqueness> {
public static final RelMetadataProvider SOURCE =
  ReflectiveRelMetadataProvider.reflectiveSource(
    BuiltInMethod.COLUMN_UNIQUENESS.method, new RelMdColumnUniqueness());

 implements MetadataHandler<BuiltInMetadata.ColumnUniqueness> {
public static final RelMetadataProvider SOURCE =
  ReflectiveRelMetadataProvider.reflectiveSource(
    BuiltInMethod.COLUMN_UNIQUENESS.method, new RelMdColumnUniqueness());