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desruisseaux pushed a commit to branch geoapi-4.0
in repository https://gitbox.apache.org/repos/asf/sis.git
The following commit(s) were added to refs/heads/geoapi-4.0 by this push:
new 8e338b7 Resolve links during the optimization phase of a filter
expression. It allows SQL statements where we previously missed opportunities.
8e338b7 is described below
commit 8e338b7cf5d7e3737873770b769af0a2664bbbb7
Author: Martin Desruisseaux <martin.desruisse...@geomatys.com>
AuthorDate: Sun Dec 26 21:51:30 2021 +0100
Resolve links during the optimization phase of a filter expression.
It allows SQL statements where we previously missed opportunities.
---
.../java/org/apache/sis/filter/PropertyValue.java | 63 ++++++++++++++++++++--
.../sis/internal/sql/feature/FeatureStream.java | 19 +++++--
.../org/apache/sis/storage/sql/SQLStoreTest.java | 21 ++++++++
3 files changed, 96 insertions(+), 7 deletions(-)
diff --git
a/core/sis-feature/src/main/java/org/apache/sis/filter/PropertyValue.java
b/core/sis-feature/src/main/java/org/apache/sis/filter/PropertyValue.java
index 594999a..8a20ddc 100644
--- a/core/sis-feature/src/main/java/org/apache/sis/filter/PropertyValue.java
+++ b/core/sis-feature/src/main/java/org/apache/sis/filter/PropertyValue.java
@@ -16,8 +16,10 @@
*/
package org.apache.sis.filter;
+import java.util.Optional;
import java.util.Collection;
import java.util.Collections;
+import org.apache.sis.feature.Features;
import org.apache.sis.util.ArgumentChecks;
import org.apache.sis.util.ObjectConverter;
import org.apache.sis.util.ObjectConverters;
@@ -45,7 +47,7 @@ import org.opengis.filter.ValueReference;
*
* @author Johann Sorel (Geomatys)
* @author Martin Desruisseaux (Geomatys)
- * @version 1.1
+ * @version 1.2
*
* @param <V> the type of value computed by the expression.
*
@@ -136,7 +138,9 @@ abstract class PropertyValue<V> extends
LeafExpression<Feature,V> implements Val
* An expression fetching property values as {@code Object}.
* This expression does not need to apply any type conversion.
*/
- private static final class AsObject extends PropertyValue<Object> {
+ private static final class AsObject extends PropertyValue<Object>
+ implements Optimization.OnExpression<Feature,Object>
+ {
/** For cross-version compatibility. */
private static final long serialVersionUID = 2854731969723006038L;
@@ -161,6 +165,21 @@ abstract class PropertyValue<V> extends
LeafExpression<Feature,V> implements Val
}
return null;
}
+
+ /**
+ * If the evaluated property is a link, replaces this expression
+ * by a more direct reference to the target property.
+ */
+ @Override
+ public Expression<Feature,?> optimize(final Optimization optimization)
{
+ final FeatureType type = optimization.getFeatureType();
+ if (type != null) try {
+ return
Features.getLinkTarget(type.getProperty(name)).map(AsObject::new).orElse(this);
+ } catch (PropertyNotFoundException e) {
+ warning(e, true);
+ }
+ return this;
+ }
}
@@ -189,6 +208,14 @@ abstract class PropertyValue<V> extends
LeafExpression<Feature,V> implements Val
}
/**
+ * Creates a new {@code Converted} fetching values for a property of
different name.
+ * The given name should be the target of a link that the caller has
resolved.
+ */
+ protected Converted<V> rename(final String target) {
+ return new Converted<>(type, target);
+ }
+
+ /**
* Returns the type of values computed by this expression.
*/
@Override
@@ -222,13 +249,25 @@ abstract class PropertyValue<V> extends
LeafExpression<Feature,V> implements Val
public final Expression<Feature, ? extends V> optimize(final
Optimization optimization) {
final FeatureType featureType = optimization.getFeatureType();
if (featureType != null) try {
- final PropertyType property = featureType.getProperty(name);
+ String targetName = name;
+ PropertyType property = featureType.getProperty(targetName);
+ Optional<String> target = Features.getLinkTarget(property);
+ if (target.isPresent()) try {
+ targetName = target.get();
+ property = featureType.getProperty(targetName);
+ } catch (PropertyNotFoundException e) {
+ targetName = name;
+ warning(e, true);
+ }
if (property instanceof AttributeType<?>) {
final Class<?> source = ((AttributeType<?>)
property).getValueClass();
if (source != null && source != Object.class &&
!source.isAssignableFrom(getSourceClass())) {
- return new CastedAndConverted<>(source, type, name);
+ return new CastedAndConverted<>(source, type,
targetName);
}
}
+ if (!targetName.equals(name)) {
+ return rename(targetName);
+ }
} catch (PropertyNotFoundException e) {
warning(e, true);
}
@@ -301,6 +340,22 @@ abstract class PropertyValue<V> extends
LeafExpression<Feature,V> implements Val
converter = ObjectConverters.find(source, type);
}
+ /** Creates a new expression derived from an existing one except for
the target name. */
+ private CastedAndConverted(final CastedAndConverted<S,V> other, final
String name) {
+ super(other.type, name);
+ source = other.source;
+ converter = other.converter;
+ }
+
+ /**
+ * Creates a new {@code CastedAndConverted} fetching values for a
property of different name.
+ * The given name should be the target of a link that the caller has
resolved.
+ */
+ @Override
+ protected Converted<V> rename(final String target) {
+ return new CastedAndConverted<>(this, target);
+ }
+
/**
* Returns the type of values fetched from {@link Feature} instance.
*/
diff --git
a/storage/sis-sqlstore/src/main/java/org/apache/sis/internal/sql/feature/FeatureStream.java
b/storage/sis-sqlstore/src/main/java/org/apache/sis/internal/sql/feature/FeatureStream.java
index 2b4ab6b..2660249 100644
---
a/storage/sis-sqlstore/src/main/java/org/apache/sis/internal/sql/feature/FeatureStream.java
+++
b/storage/sis-sqlstore/src/main/java/org/apache/sis/internal/sql/feature/FeatureStream.java
@@ -32,6 +32,7 @@ import org.apache.sis.internal.metadata.sql.SQLBuilder;
import org.apache.sis.internal.stream.DeferredStream;
import org.apache.sis.internal.stream.PaginedStream;
import org.apache.sis.internal.filter.SortByComparator;
+import org.apache.sis.internal.util.Strings;
import org.apache.sis.storage.DataStoreException;
import org.apache.sis.util.collection.BackingStoreException;
import org.apache.sis.util.ArgumentChecks;
@@ -75,7 +76,7 @@ final class FeatureStream extends DeferredStream<Feature> {
/**
* The SQL fragment on the right side of the {@code WHERE} keyword.
* This buffer does not including the {@code WHERE} keyword.
- * IT is created when first needed.
+ * It is created when first needed and discarded after the iterator is
created.
*/
private SelectionClause selection;
@@ -392,8 +393,7 @@ final class FeatureStream extends DeferredStream<Feature> {
@Override
protected Spliterator<Feature> createSourceIterator() throws Exception {
final String filter = (selection != null && !selection.isEmpty()) ?
selection.toString() : null;
- selection = null; // Let the garbage collector do its work.
- filterToSQL = null;
+ selection = null; // Let the garbage collector do its work.
final Connection connection = getConnection();
setCloseHandler(connection); // Executed only if `FeatureIterator`
creation fails, discarded later otherwise.
@@ -402,4 +402,17 @@ final class FeatureStream extends DeferredStream<Feature> {
setCloseHandler(features);
return features;
}
+
+ /**
+ * Returns a string representation of this stream for debugging purposes.
+ */
+ @Override
+ public String toString() {
+ return Strings.toString(getClass(), "table", table.name.table,
+ "predicates", hasPredicates ? (filterToSQL != null ? "mixed" :
"Java") : (filterToSQL != null ? "SQL" : null),
+ "comparator", hasComparator ? (sort != null ? "mixed" :
"Java") : (sort != null ? "SQL" : null),
+ "distinct", distinct ? Boolean.TRUE : null,
+ "offset", offset != 0 ? offset : null,
+ "count", count != 0 ? count : null);
+ }
}
diff --git
a/storage/sis-sqlstore/src/test/java/org/apache/sis/storage/sql/SQLStoreTest.java
b/storage/sis-sqlstore/src/test/java/org/apache/sis/storage/sql/SQLStoreTest.java
index b4111b1..a1ee95e 100644
---
a/storage/sis-sqlstore/src/test/java/org/apache/sis/storage/sql/SQLStoreTest.java
+++
b/storage/sis-sqlstore/src/test/java/org/apache/sis/storage/sql/SQLStoreTest.java
@@ -207,6 +207,7 @@ public final strictfp class SQLStoreTest extends TestCase {
verifySimpleQuerySorting(store);
verifySimpleQueryWithLimit(store);
verifySimpleWhere(store);
+ verifyWhereOnLink(store);
verifyStreamOperations(store.findResource("Cities"));
}
canada = null;
@@ -432,6 +433,26 @@ public final strictfp class SQLStoreTest extends TestCase {
}
/**
+ * Requests a new set of features filtered by a condition on the
"sis:identifier" property.
+ * The optimizer should replace that link by a condition on the actual
column.
+ *
+ * @param dataset the store on which to query the features.
+ * @throws DataStoreException if an error occurred during query execution.
+ */
+ private void verifyWhereOnLink(SQLStore dataset) throws Exception {
+ final String desiredProperty = "native_name";
+ final String[] expectedValues = {"Canada"};
+ final FeatureSet countries = dataset.findResource("Countries");
+ final FeatureQuery query = new FeatureQuery();
+ query.setSelection(FF.equal(FF.property("sis:identifier"),
FF.literal("CAN")));
+ final Object[] names;
+ try (Stream<Feature> features =
countries.subset(query).features(false)) {
+ names = features.map(f ->
f.getPropertyValue(desiredProperty)).toArray();
+ }
+ assertArrayEquals(expectedValues, names);
+ }
+
+ /**
* Checks that operations stacked on feature stream are well executed.
* This test focuses on mapping and peeking actions overloaded by SQL
streams.
* Operations used here are meaningless; we just want to ensure that the
pipeline does not skip any operation.
