This is an automated email from the ASF dual-hosted git repository.
desruisseaux pushed a commit to branch geoapi-4.0
in repository https://gitbox.apache.org/repos/asf/sis.git
commit c5ac1dc86a3caf358bc4821cee77420ccc7b1085
Author: Martin Desruisseaux <martin.desruisse...@geomatys.com>
AuthorDate: Fri Mar 28 17:30:52 2025 +0100
When only a subset of the feature properties is requested,
declare only that subset in the SQL `SELECT` statement.
---
.../apache/sis/feature/privy/FeatureUtilities.java | 39 +--
.../apache/sis/storage/sql/feature/Analyzer.java | 5 +-
.../org/apache/sis/storage/sql/feature/Column.java | 67 +++-
.../apache/sis/storage/sql/feature/Database.java | 24 +-
.../sis/storage/sql/feature/FeatureAdapter.java | 8 +-
.../sis/storage/sql/feature/FeatureAnalyzer.java | 10 +-
.../sis/storage/sql/feature/FeatureIterator.java | 49 ++-
.../sis/storage/sql/feature/FeatureStream.java | 52 ++-
.../apache/sis/storage/sql/feature/Relation.java | 48 ++-
.../apache/sis/storage/sql/feature/Resources.java | 5 +
.../sis/storage/sql/feature/Resources.properties | 1 +
.../storage/sql/feature/Resources_fr.properties | 3 +-
.../org/apache/sis/storage/sql/feature/Table.java | 140 ++++++--
.../apache/sis/storage/sql/postgis/Postgres.java | 2 +-
.../org/apache/sis/storage/sql/SQLStoreTest.java | 22 +-
.../main/org/apache/sis/storage/FeatureQuery.java | 213 ++++--------
.../main/org/apache/sis/storage/FeatureSubset.java | 37 +-
.../apache/sis/storage/base/FeatureProjection.java | 383 +++++++++++++++++++++
18 files changed, 837 insertions(+), 271 deletions(-)
diff --git
a/endorsed/src/org.apache.sis.feature/main/org/apache/sis/feature/privy/FeatureUtilities.java
b/endorsed/src/org.apache.sis.feature/main/org/apache/sis/feature/privy/FeatureUtilities.java
index c34d9b00e6..e8a2ab139b 100644
---
a/endorsed/src/org.apache.sis.feature/main/org/apache/sis/feature/privy/FeatureUtilities.java
+++
b/endorsed/src/org.apache.sis.feature/main/org/apache/sis/feature/privy/FeatureUtilities.java
@@ -16,12 +16,7 @@
*/
package org.apache.sis.feature.privy;
-import java.util.Map;
import java.util.HashMap;
-import java.util.Iterator;
-import java.util.Collection;
-import java.util.ConcurrentModificationException;
-import org.opengis.util.GenericName;
import org.opengis.metadata.Identifier;
import org.opengis.parameter.ParameterDescriptor;
import org.opengis.parameter.ParameterDescriptorGroup;
@@ -29,9 +24,6 @@ import
org.apache.sis.parameter.DefaultParameterDescriptorGroup;
import org.apache.sis.metadata.iso.citation.Citations;
import org.apache.sis.util.Static;
-// Specific to the geoapi-3.1 and geoapi-4.0 branches:
-import org.opengis.feature.PropertyType;
-
/**
* Non-public utility methods for Apache SIS internal usage.
@@ -61,38 +53,9 @@ public final class FeatureUtilities extends Static {
* @return description of the parameters group.
*/
public static ParameterDescriptorGroup parameters(final String name, final
ParameterDescriptor<?>... parameters) {
- final Map<String,Object> properties = new HashMap<>(4);
+ final var properties = new HashMap<String,Object>(4);
properties.put(ParameterDescriptorGroup.NAME_KEY, name);
properties.put(Identifier.AUTHORITY_KEY, Citations.SIS);
return new DefaultParameterDescriptorGroup(properties, 1, 1);
}
-
- /**
- * Gets the name of all given properties. If any property is null or has a
null name,
- * then the corresponding entry in the returned array will be null.
- *
- * @param properties the properties for which to get the names, or
{@code null}.
- * @return the name of all given properties, or {@code null} if the given
list was null.
- */
- public static String[] getNames(final Collection<? extends PropertyType>
properties) {
- if (properties == null) {
- return null;
- }
- final String[] names = new String[properties.size()];
- final Iterator<? extends PropertyType> it = properties.iterator();
- for (int i=0; i < names.length; i++) {
- final PropertyType property = it.next();
- if (property != null) {
- final GenericName name = property.getName();
- if (name != null) {
- names[i] = name.toString();
- }
- }
- }
- // Should not have any element left, unless collection size changed
during iteration.
- if (it.hasNext()) {
- throw new ConcurrentModificationException();
- }
- return names;
- }
}
diff --git
a/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/feature/Analyzer.java
b/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/feature/Analyzer.java
index a2333db673..406b8c9239 100644
---
a/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/feature/Analyzer.java
+++
b/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/feature/Analyzer.java
@@ -27,7 +27,6 @@ import java.util.HashMap;
import java.util.Objects;
import java.util.Locale;
import java.util.logging.Level;
-import java.util.logging.LogRecord;
import java.util.concurrent.locks.ReadWriteLock;
import java.sql.SQLException;
import java.sql.DatabaseMetaData;
@@ -427,9 +426,7 @@ public final class Analyzer {
table.setDeferredSearchTables(this, featureTables);
}
if (featureNotSupported != null) {
- LogRecord record = resources().getLogRecord(Level.WARNING,
Resources.Keys.CanNotAnalyzeFully);
- record.setThrown(featureNotSupported);
- database.log(record);
+ database.warning(Resources.Keys.CanNotAnalyzeFully,
featureNotSupported);
}
for (final ResourceInternationalString warning : warnings) {
database.log(warning.toLogRecord(Level.WARNING));
diff --git
a/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/feature/Column.java
b/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/feature/Column.java
index 0ed50f5cbc..e4a2393e17 100644
---
a/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/feature/Column.java
+++
b/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/feature/Column.java
@@ -51,25 +51,31 @@ import org.apache.sis.util.resources.Errors;
* @see ResultSet#getMetaData()
* @see DatabaseMetaData#getColumns(String, String, String, String)
*/
-public final class Column {
+public final class Column implements Cloneable {
/**
- * Name of the column.
+ * Name of the column as declared in the table.
*
* @see Reflection#COLUMN_NAME
+ * @see ResultSetMetaData#getColumnName(int)
*/
public final String name;
/**
- * Title to use for displays. This is the name specified by the {@code AS}
keyword in a {@code SELECT} clause.
- * This is never null but may be identical to {@link #name} if no label
was specified.
+ * Name of the column as declared in with a {@code AS} clause in the
<abbr>SQL</abbr> statement.
+ * This is never null but may be identical to {@link #name} if no {@code
AS} clause was specified.
+ *
+ * @see ResultSetMetaData#getColumnLabel(int)
*/
public final String label;
/**
* Name to use for feature property. This is the same as {@link #label}
unless there is a name collision.
* In that case the property name is modified for avoiding the collision.
+ *
+ * @see #getPropertyName()
+ * @see #setPropertyName(AttributeTypeBuilder)
*/
- String propertyName;
+ private String propertyName;
/**
* Type of values as one of the constants enumerated in {@link Types}
class.
@@ -233,6 +239,42 @@ public final class Column {
.getString(Errors.Keys.ValueAlreadyDefined_1,
property));
}
+ /**
+ * Returns a column identical to this column except for the property name.
+ * This method does not modify this column, but may return {@code this} if
+ * there is no name change to apply.
+ *
+ * @param property the new property name.
+ * @return a column with the given property name (may be {@code this}).
+ */
+ final Column rename(final String property) {
+ if (property.equals(propertyName)) {
+ return this;
+ }
+ final Column c = clone();
+ c.propertyName = property;
+ return c;
+ }
+
+ /**
+ * Returns the name to use for feature property.
+ * This is often, but not necessarily, the column {@linkplain #name}.
+ *
+ * @return the name of the feature property where to store the value.
+ */
+ public final String getPropertyName() {
+ return propertyName;
+ }
+
+ /**
+ * Sets the property name.
+ *
+ * @param attribute the builder which is creating the attribute for this
column.
+ */
+ final void setPropertyName(final AttributeTypeBuilder<?> attribute) {
+ propertyName = attribute.getName().toString();
+ }
+
/**
* If this column is a geometry column, returns the type of the geometry
objects.
* Otherwise returns empty (including the case where this is a raster
column).
@@ -300,4 +342,19 @@ public final class Column {
"name", name, "propertyName", propertyName, "type", type,
"typeName", typeName,
"geometryType", geometryType, "precision", precision,
"isNullable", isNullable);
}
+
+ /**
+ * Returns a shallow clone of this column.
+ * Used by this {@code Column} implementation only and should not be
invoked directly.
+ *
+ * @see #rename(String)
+ */
+ @Override
+ protected final Column clone() {
+ try {
+ return (Column) super.clone();
+ } catch (CloneNotSupportedException e) {
+ throw new AssertionError(e);
+ }
+ }
}
diff --git
a/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/feature/Database.java
b/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/feature/Database.java
index fbb62c850b..940afb0440 100644
---
a/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/feature/Database.java
+++
b/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/feature/Database.java
@@ -24,6 +24,7 @@ import java.util.WeakHashMap;
import java.util.LinkedHashMap;
import java.util.Locale;
import java.util.Optional;
+import java.util.logging.Level;
import java.util.logging.LogRecord;
import java.util.concurrent.locks.ReadWriteLock;
import java.sql.Array;
@@ -273,6 +274,10 @@ public class Database<G> extends Syntax {
throws SQLException
{
super(metadata, true);
+ this.source = source;
+ this.geomLibrary = geomLibrary;
+ this.contentLocale = contentLocale;
+ this.listeners = listeners; // Need to be set before code
below.
/*
* Get information about whether byte are unsigned.
* According JDBC specification, the rows shall be ordered by
DATA_TYPE.
@@ -298,14 +303,9 @@ public class Database<G> extends Syntax {
cause = e;
}
if (cause != null || wasNull) {
- listeners.warning(Resources.forLocale(listeners.getLocale())
-
.getString(Resources.Keys.AssumeUnsigned), cause);
+ warning(Resources.Keys.AssumeUnsigned, cause);
}
- this.source = source;
this.isByteSigned = !unsigned;
- this.geomLibrary = geomLibrary;
- this.contentLocale = contentLocale;
- this.listeners = listeners;
this.cacheOfCRS = new Cache<>(7, 2, false);
this.cacheOfSRID = new WeakHashMap<>();
this.tablesByNames = new FeatureNaming<>();
@@ -845,6 +845,18 @@ public class Database<G> extends Syntax {
return new InfoStatements(this, connection);
}
+ /**
+ * Logs a warning with a localized message and an optional cause.
+ *
+ * @param resourceKey one of {@code Resources.Keys} constants.
+ * @param cause the cause, or {@code null} if none.
+ */
+ final void warning(final short resourceKey, final Exception cause) {
+ LogRecord record =
Resources.forLocale(listeners.getLocale()).getLogRecord(Level.WARNING,
resourceKey);
+ record.setThrown(cause);
+ log(record);
+ }
+
/**
* Sets the logger, class and method names of the given record, then logs
it.
* This method declares {@link SQLStore#components()} as the public source
of the log.
diff --git
a/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/feature/FeatureAdapter.java
b/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/feature/FeatureAdapter.java
index 5ce00aa6f8..7cb4b6e8f7 100644
---
a/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/feature/FeatureAdapter.java
+++
b/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/feature/FeatureAdapter.java
@@ -198,13 +198,13 @@ final class FeatureAdapter {
if (dependency.excluded) continue;
if (dependency != noFollow) {
dependency.startFollowing(following); //
Safety against never-ending recursion.
- associationNames [count] = dependency.propertyName;
+ associationNames [count] = dependency.getPropertyName();
foreignerKeyIndices[count] = getColumnIndices(sql,
dependency, columnIndices);
dependencies [count] = new
FeatureAdapter(dependency.getSearchTable(), metadata, following, noFollow);
dependency.endFollowing(following);
count++;
} else {
- deferredAssociation = dependency.propertyName;
+ deferredAssociation = dependency.getPropertyName();
}
}
importCount = count;
@@ -219,7 +219,7 @@ final class FeatureAdapter {
dependency.startFollowing(following); //
Safety against never-ending recursion.
final Table foreigner = dependency.getSearchTable();
final Relation inverse = foreigner.getInverseOf(dependency,
table.name);
- associationNames [count] = dependency.propertyName;
+ associationNames [count] = dependency.getPropertyName();
foreignerKeyIndices[count] = getColumnIndices(sql, dependency,
columnIndices);
dependencies [count] = new FeatureAdapter(foreigner,
metadata, following, inverse);
dependency.endFollowing(following);
@@ -327,7 +327,7 @@ final class FeatureAdapter {
final Column column = attributes[i];
final Object value = column.valueGetter.getValue(stmts, result,
i+1);
if (value != null) {
- feature.setPropertyValue(column.propertyName, value);
+ feature.setPropertyValue(column.getPropertyName(), value);
}
}
return feature;
diff --git
a/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/feature/FeatureAnalyzer.java
b/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/feature/FeatureAnalyzer.java
index 169df707e0..7918ac1fd5 100644
---
a/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/feature/FeatureAnalyzer.java
+++
b/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/feature/FeatureAnalyzer.java
@@ -261,7 +261,7 @@ abstract class FeatureAnalyzer {
* do not know which column describes better the
association (often there is none).
* In such case we use the foreigner key name as a
fallback.
*/
- dependency.setPropertyName(column.propertyName, count++);
+ dependency.setPropertyName(column.getPropertyName(),
count++);
final AssociationRoleBuilder association;
if (table != null) {
dependency.setSearchTable(analyzer, table,
table.primaryKey, Relation.Direction.IMPORT);
@@ -269,7 +269,7 @@ abstract class FeatureAnalyzer {
} else {
association = feature.addAssociation(typeName); //
May happen in case of cyclic dependency.
}
- association.setName(dependency.propertyName);
+ association.setName(dependency.getPropertyName());
if (column.isNullable) {
association.setMinimumOccurs(0);
}
@@ -280,8 +280,8 @@ abstract class FeatureAnalyzer {
* column should rarely be used directly.
*/
if (attribute != null) {
-
attribute.setName(analyzer.nameFactory.createGenericName(null, "pk",
column.propertyName));
- column.propertyName = attribute.getName().toString();
+
attribute.setName(analyzer.nameFactory.createGenericName(null, "pk",
column.getPropertyName()));
+ column.setPropertyName(attribute);
attribute = null;
}
}
@@ -322,7 +322,7 @@ abstract class FeatureAnalyzer {
while (feature.isNameUsed(propertyName)) {
propertyName = base + '-' + ++count;
}
- dependency.propertyName = propertyName;
+ dependency.setPropertyName(propertyName);
final Table table = analyzer.table(dependency, typeName, id);
final AssociationRoleBuilder association;
if (table != null) {
diff --git
a/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/feature/FeatureIterator.java
b/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/feature/FeatureIterator.java
index 450f625a5b..428b947eac 100644
---
a/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/feature/FeatureIterator.java
+++
b/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/feature/FeatureIterator.java
@@ -25,6 +25,7 @@ import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import org.apache.sis.metadata.sql.privy.SQLBuilder;
+import org.apache.sis.storage.base.FeatureProjection;
import org.apache.sis.util.collection.WeakValueHashMap;
// Specific to the geoapi-3.1 and geoapi-4.0 branches:
@@ -102,6 +103,25 @@ final class FeatureIterator implements
Spliterator<Feature>, AutoCloseable {
*/
private final FeatureIterator[] dependencies;
+ /**
+ * Additional properties to compute from the main properties, or {@code
null} if none.
+ * This is usually {@code null}. It may be non-null if the user specified
a query with
+ * operations other than {@code ValueReference} or {@code Literal}.
+ *
+ * <h4>Completion</h4>
+ * Usually, the expressions are executed on a source feature instance and
the results
+ * are copied in a target feature instance. However, if {@link
#completion} is true,
+ * then the source and target features are the same instance. The
completion mode is
+ * used when the target feature have all information needed for computing
the query
+ * expressions, so that the projection is only a completion.
+ */
+ private final FeatureProjection projection;
+
+ /**
+ * Whether the {@linkplain #projection} should be applied on the same
+ */
+ private final boolean completion;
+
/**
* Creates a new iterator over features.
*
@@ -112,6 +132,7 @@ final class FeatureIterator implements
Spliterator<Feature>, AutoCloseable {
* @param sort the {@code ORDER BY} clauses, or {@code null} if
none.
* @param offset number of rows to skip in underlying SQL query, or ≤
0 for none.
* @param count maximum number of rows to return, or ≤ 0 for no
limit.
+ * @param projection additional properties to compute, or {@code null} if
none.
*/
FeatureIterator(final Table table,
final Connection connection,
@@ -119,7 +140,8 @@ final class FeatureIterator implements
Spliterator<Feature>, AutoCloseable {
final SelectionClause selection,
final SortBy<? super Feature> sort,
final long offset,
- final long count)
+ final long count,
+ final FeatureProjection projection)
throws Exception
{
adapter = table.adapter(connection);
@@ -162,9 +184,11 @@ final class FeatureIterator implements
Spliterator<Feature>, AutoCloseable {
} else {
estimatedSize = 0; // Cannot estimate the size if
there is filtering conditions.
}
- result = connection.createStatement().executeQuery(sql);
- dependencies = new FeatureIterator[adapter.dependencies.length];
- statement = null;
+ this.result = connection.createStatement().executeQuery(sql);
+ this.dependencies = new FeatureIterator[adapter.dependencies.length];
+ this.completion = projection != null && projection.featureType ==
table.featureType;
+ this.projection = projection;
+ this.statement = null;
}
/**
@@ -185,6 +209,8 @@ final class FeatureIterator implements
Spliterator<Feature>, AutoCloseable {
this.adapter = adapter;
statement = connection.prepareStatement(adapter.sql);
dependencies = new FeatureIterator[adapter.dependencies.length];
+ completion = false;
+ projection = null;
estimatedSize = 0;
}
@@ -260,7 +286,7 @@ final class FeatureIterator implements
Spliterator<Feature>, AutoCloseable {
*/
private boolean fetch(final Consumer<? super Feature> action, final
boolean all) throws Exception {
while (result.next()) {
- final Feature feature = adapter.createFeature(spatialInformation,
result);
+ Feature feature = adapter.createFeature(spatialInformation,
result);
for (int i=0; i < dependencies.length; i++) {
WeakValueHashMap<?,Object> instances = null;
Object key = null, value = null;
@@ -294,6 +320,19 @@ final class FeatureIterator implements
Spliterator<Feature>, AutoCloseable {
}
feature.setPropertyValue(adapter.associationNames[i], value);
}
+ /*
+ * At this point, we have done everything we could do using SQL
statements.
+ * Those statements were derived (among others) from expressions
that have
+ * been recognized as `ValueReference` instances. If the user
specified more
+ * complex expressions, we need to handle them in Java code.
+ */
+ if (projection != null) {
+ if (completion) {
+ projection.applySelf(feature);
+ } else {
+ feature = projection.apply(feature);
+ }
+ }
action.accept(feature);
if (!all) return true;
}
diff --git
a/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/feature/FeatureStream.java
b/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/feature/FeatureStream.java
index 1cbd99ae93..c2a226c459 100644
---
a/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/feature/FeatureStream.java
+++
b/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/feature/FeatureStream.java
@@ -16,6 +16,9 @@
*/
package org.apache.sis.storage.sql.feature;
+import java.util.Set;
+import java.util.HashSet;
+import java.util.LinkedHashMap;
import java.util.Objects;
import java.util.Comparator;
import java.util.Spliterator;
@@ -29,6 +32,7 @@ import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import org.apache.sis.filter.Optimization;
+import org.apache.sis.filter.privy.ListingPropertyVisitor;
import org.apache.sis.metadata.sql.privy.SQLBuilder;
import org.apache.sis.util.ArgumentChecks;
import org.apache.sis.util.privy.Strings;
@@ -37,9 +41,11 @@ import org.apache.sis.util.stream.PaginedStream;
import org.apache.sis.filter.privy.SortByComparator;
import org.apache.sis.filter.privy.WarningEvent;
import org.apache.sis.storage.DataStoreException;
+import org.apache.sis.storage.base.FeatureProjection;
// Specific to the geoapi-3.1 and geoapi-4.0 branches:
import org.opengis.feature.Feature;
+import org.opengis.filter.Expression;
import org.opengis.filter.Filter;
import org.opengis.filter.SortBy;
@@ -63,6 +69,14 @@ final class FeatureStream extends DeferredStream<Feature> {
*/
private final Table table;
+ /**
+ * The columns that the user wants to keep, or {@code null} for all
columns.
+ * The word "projection" in this context is in the <abbr>SQL</abbr>
database sense.
+ *
+ * @see #map(Function)
+ */
+ private FeatureProjection projection;
+
/**
* The visitor to use for converting filters/expressions to SQL statements.
* This is used for writing the content of the {@link SelectionClause}.
@@ -183,7 +197,7 @@ final class FeatureStream extends DeferredStream<Feature> {
WarningEvent.LISTENER.set(selection);
final var optimization = new Optimization();
optimization.setFeatureType(table.featureType);
- for (final Filter<? super Feature> filter :
optimization.applyAndDecompose((Filter<? super Feature>) predicate)) {
+ for (final var filter : optimization.applyAndDecompose((Filter<?
super Feature>) predicate)) {
if (filter == Filter.include()) continue;
if (filter == Filter.exclude()) return empty();
if (!selection.tryAppend(filterToSQL, filter)) {
@@ -295,7 +309,12 @@ final class FeatureStream extends DeferredStream<Feature> {
* be optimized.
*/
@Override
+ @SuppressWarnings("unchecked")
public <R> Stream<R> map(final Function<? super Feature, ? extends R>
mapper) {
+ if (projection == null && mapper instanceof FeatureProjection) {
+ projection = (FeatureProjection) mapper;
+ return (Stream) this;
+ }
return new PaginedStream<>(super.map(mapper), this);
}
@@ -403,11 +422,38 @@ final class FeatureStream extends DeferredStream<Feature>
{
*/
@Override
protected Spliterator<Feature> createSourceIterator() throws Exception {
- lock(table.database.transactionLocks);
+ Table projected = table;
+ FeatureProjection completion = null;
+ if (projection != null) {
+ final var unhandled = new LinkedHashMap<String, Expression<? super
Feature, ?>>();
+ final var reusedNames = new HashSet<String>();
+ projected = new Table(projected, projection, reusedNames,
unhandled);
+ if (!unhandled.isEmpty()) {
+ /*
+ * Some properties may not be handled by the projection. Check
if the projected feature contains
+ * enough information for computing missing properties without
the need for the original feature.
+ */
+ Set<String> references = null;
+ for (var expression : unhandled.values()) {
+ references = ListingPropertyVisitor.xpaths(expression,
references);
+ }
+ if (references == null || reusedNames.containsAll(references))
{
+ completion = new FeatureProjection(projected.featureType,
unhandled);
+ } else {
+ /*
+ * Cannot use `projected` because some expressions need
properties
+ * available only in the original features.
+ */
+ projected = table;
+ completion = projection;
+ }
+ }
+ }
+ lock(projected.database.transactionLocks);
final Connection connection = getConnection();
setCloseHandler(connection); // Executed only if `FeatureIterator`
creation fails, discarded later otherwise.
makeReadOnly(connection);
- final var features = new FeatureIterator(table, connection, distinct,
selection, sort, offset, count);
+ final var features = new FeatureIterator(projected, connection,
distinct, selection, sort, offset, count, completion);
setCloseHandler(features);
selection = null; // Let the garbage collector do its work.
return features;
diff --git
a/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/feature/Relation.java
b/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/feature/Relation.java
index 8471b3ccbc..6cd050cd52 100644
---
a/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/feature/Relation.java
+++
b/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/feature/Relation.java
@@ -54,7 +54,7 @@ import org.apache.sis.util.resources.Errors;
* @author Johann Sorel (Geomatys)
* @author Martin Desruisseaux (Geomatys)
*/
-final class Relation extends TableReference {
+final class Relation extends TableReference implements Cloneable {
/**
* An empty array used when there are no relations.
*/
@@ -154,8 +154,11 @@ final class Relation extends TableReference {
/**
* The name of the feature property where the association to {@link
#searchTable} table will be stored.
* If the foreigner key uses exactly one column, then this is the name of
that column.
+ *
+ * @see #getPropertyName()
+ * @see #setPropertyName(String)
*/
- String propertyName;
+ private String propertyName;
/**
* Whether the {@link #columns} map include all primary key columns. This
field is set to {@code false}
@@ -247,6 +250,23 @@ final class Relation extends TableReference {
}
}
+ /**
+ * Returns a relation identical to this relation except for the property
name.
+ * This method does not modify this relation, but may return {@code this}
if
+ * there is no name change to apply.
+ *
+ * @param property the new property name.
+ * @return a relation with the given property name (may be {@code this}).
+ */
+ final Relation rename(final String property) {
+ if (property.equals(propertyName)) {
+ return this;
+ }
+ final Relation c = clone();
+ c.propertyName = property;
+ return c;
+ }
+
/**
* Invoked after construction for setting the name of the feature property
of the enclosing table where to
* store association to the feature instances read from the {@linkplain
#getSearchTable() search table}.
@@ -265,6 +285,15 @@ final class Relation extends TableReference {
}
}
+ /**
+ * Sets the property name. This method should be invoked during
{@linkplain FeatureAnalyzer analysis time} only.
+ *
+ * @param name the new property name.
+ */
+ final void setPropertyName(final String name) {
+ propertyName = name;
+ }
+
/**
* Returns the name of the feature property where the association to the
search table will be stored.
* If the foreigner key uses exactly one column, then this is the name of
that column.
@@ -471,4 +500,19 @@ final class Relation extends TableReference {
public String toString() {
return toString(this, (n) -> appendTo(n, " — "));
}
+
+ /**
+ * Returns a shallow clone of this relation.
+ * Used by this {@code Relation} implementation only and should not be
invoked directly.
+ *
+ * @see #rename(String)
+ */
+ @Override
+ protected final Relation clone() {
+ try {
+ return (Relation) super.clone();
+ } catch (CloneNotSupportedException e) {
+ throw new AssertionError(e);
+ }
+ }
}
diff --git
a/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/feature/Resources.java
b/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/feature/Resources.java
index 7ea58675af..000c657f73 100644
---
a/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/feature/Resources.java
+++
b/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/feature/Resources.java
@@ -63,6 +63,11 @@ public class Resources extends IndexedResourceBundle {
*/
public static final short CanNotAnalyzeFully = 17;
+ /**
+ * Error while building the SQL query. Fallback partially on pure Java
implementation.
+ */
+ public static final short CanNotBuildSQL = 19;
+
/**
* Cannot fetch a Coordinate Reference System (CRS) for SRID code {0}.
*/
diff --git
a/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/feature/Resources.properties
b/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/feature/Resources.properties
index 1060cb1e1c..15eaa17134 100644
---
a/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/feature/Resources.properties
+++
b/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/feature/Resources.properties
@@ -21,6 +21,7 @@
#
AssumeUnsigned = Assume database byte/tinyint unsigned, due
to a lack of metadata.
CanNotAnalyzeFully = Cannot analyze fully the database schema
because of incomplete metadata.
+CanNotBuildSQL = Error while building the SQL query.
Fallback partially on pure Java implementation.
CanNotFetchCRS_1 = Cannot fetch a Coordinate Reference System
(CRS) for SRID code {0}.
CanNotFindSRID_1 = Cannot find an identifier in the database
for the reference system \u201c{0}\u201d.
DataSource = Provider of connections to the database.
diff --git
a/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/feature/Resources_fr.properties
b/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/feature/Resources_fr.properties
index 3d6a4a87f0..6f7724df8d 100644
---
a/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/feature/Resources_fr.properties
+++
b/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/feature/Resources_fr.properties
@@ -26,13 +26,14 @@
#
AssumeUnsigned = Les valeurs de type
\u2018tinyint\u2019/\u2018byte\u2019 seront consid\u00e9r\u00e9es comme non
sign\u00e9es, car la base de donn\u00e9es ne fournit pas d\u2019information
\u00e0 ce sujet.
CanNotAnalyzeFully = Ne peut pas analyser compl\u00e8tement le
sch\u00e9ma de la base de donn\u00e9es parce que les m\u00e9ta-donn\u00e9es
sont incompl\u00e8tes.
+CanNotBuildSQL = Erreur lors de la construction de la
requ\u00eate SQL. Ex\u00e9cute partiellement en Java comme solution de rechange.
CanNotFetchCRS_1 = Ne peut pas obtenir un syst\u00e8me de
r\u00e9f\u00e9rence des coordonn\u00e9es pour le code SRID {0}.
CanNotFindSRID_1 = Ne peut pas trouver un identifiant dans la
base de donn\u00e9es pour le syst\u00e8me de r\u00e9f\u00e9rence
\u00ab\u202f{0}\u202f\u00bb.
DataSource = Fournisseur de connexions \u00e0 la base
de donn\u00e9es.
DuplicatedColumn_1 = Doublon inattendu d\u2019une colonne
nomm\u00e9e \u00ab\u202f{0}\u202f\u00bb.
DuplicatedSRID_2 = L\u2019identifiant de r\u00e9f\u00e9rence
spatiale (SRID) {1} a plusieurs entr\u00e9s dans la table
\u00ab\u202f{0}\u202f\u00bb.
IllegalQualifiedName_1 = \u00ab\u202f{0}\u202f\u00bb n\u2019est pas
un nom qualifi\u00e9 de table valide.
-IncompatibleLiteralCRS_2 = Le litt\u00e9ral de la fonction
\u00ab\u202f{0}\u202f\u00bb n'est pas compatible avec le syst\u00e8me de
r\u00e9f\u00e9rence de la propri\u00e9t\u00e9 \u00ab\u202f{1}\u202f\u00bb.
+IncompatibleLiteralCRS_2 = Le litt\u00e9ral de la fonction
\u00ab\u202f{0}\u202f\u00bb n\u2019est pas compatible avec le syst\u00e8me de
r\u00e9f\u00e9rence de la propri\u00e9t\u00e9 \u00ab\u202f{1}\u202f\u00bb.
InternalError = Erreur inattendue pendant l\u2019analyse
du sch\u00e9ma de la base de donn\u00e9es.
MalformedForeignerKey_2 = Colonne \u00ab\u202f{1}\u202f\u00bb
inattendue dans la cl\u00e9 \u00e9trang\u00e8re \u00ab\u202f{0}\u202f\u00bb.
MappedSQLQueries = Noms de ressources associ\u00e9s \u00e0
des requ\u00eates SQL.
diff --git
a/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/feature/Table.java
b/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/feature/Table.java
index 13856b4c89..808c4b80b7 100644
---
a/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/feature/Table.java
+++
b/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/feature/Table.java
@@ -17,6 +17,8 @@
package org.apache.sis.storage.sql.feature;
import java.util.Map;
+import java.util.Set;
+import java.util.List;
import java.util.Optional;
import java.util.stream.Stream;
import java.sql.Connection;
@@ -29,20 +31,25 @@ import org.opengis.geometry.Envelope;
import org.apache.sis.storage.AbstractFeatureSet;
import org.apache.sis.storage.DataStoreException;
import org.apache.sis.storage.InternalDataStoreException;
+import org.apache.sis.storage.base.FeatureProjection;
import org.apache.sis.metadata.sql.privy.Reflection;
import org.apache.sis.metadata.sql.privy.SQLBuilder;
import org.apache.sis.pending.jdk.JDK19;
+import org.apache.sis.util.ArraysExt;
import org.apache.sis.util.Debug;
import org.apache.sis.util.Exceptions;
import org.apache.sis.util.collection.WeakValueHashMap;
import org.apache.sis.util.collection.TreeTable;
import org.apache.sis.util.iso.DefaultNameSpace;
+import org.apache.sis.util.resources.Errors;
// Specific to the geoapi-3.1 and geoapi-4.0 branches:
import org.opengis.feature.Feature;
import org.opengis.feature.FeatureType;
import org.opengis.feature.AttributeType;
import org.opengis.feature.FeatureAssociationRole;
+import org.opengis.filter.Expression;
+import org.opengis.filter.InvalidFilterValueException;
/**
@@ -186,25 +193,94 @@ final class Table extends AbstractFeatureSet {
/**
* Creates a new table as a projection (subset of columns) of the given
table.
+ * The columns to retain, potentially under different names, are specified
in {@code projection}.
+ * The projection may also contain complex expressions that cannot be
handled by this constructor.
+ * Such expressions are stored in the {@code unhandled} map.
*
- * @todo This constructor is not yet used because it is an unfinished work.
- * We need to invent some mechanism for using a subset of the
columns.
- * A starting point is {@link
org.apache.sis.storage.FeatureQuery#expectedType(FeatureType)}.
+ * @param table the source table.
+ * @param projection description of the columns to keep.
+ * @param reusedNames an initially empty set where to store the names of
attributes that are not renamed.
+ * @param unhandled an initially empty map where to add expressions
that are not handled by the new table.
+ * @throws InvalidFilterValueException if there is an error in the
declaration of property values.
*/
- Table(final Table parent) {
- super(parent.listeners, false);
- database = parent.database;
- query = parent.query;
- name = parent.name;
-
- // TODO: filter the columns.
- primaryKey = parent.primaryKey;
- attributes = parent.attributes;
- importedKeys = parent.importedKeys;
- exportedKeys = parent.exportedKeys;
- featureType = parent.featureType;
- hasGeometry = parent.hasGeometry;
- hasRaster = parent.hasRaster;
+ @SuppressWarnings("LocalVariableHidesMemberVariable")
+ Table(final Table source,
+ final FeatureProjection projection,
+ final Set<String> reusedNames,
+ final Map<String, Expression<? super Feature, ?>> unhandled)
+ {
+ super(source.listeners, false);
+ database = source.database;
+ query = source.query;
+ name = source.name;
+ featureType = projection.featureType;
+ /*
+ * Temporary values the fields, before assignment to final fields.
+ * The final number of attributes and foreigner keys may be smaller.
+ */
+ final var attributes = new Column [source.attributes .length];
+ final var importedKeys = new Relation[source.importedKeys.length];
+ final var exportedKeys = new Relation[source.exportedKeys.length];
+ int attributesCount = 0;
+ int importedKeysCount = 0;
+ int exportedKeysCount = 0;
+ boolean hasGeometry = false;
+ /*
+ * Take all columns that we can put in the `WHERE` clause of the SQL
statement.
+ * The columns that we cannot take will be declared in the `unhandled`
bit set.
+ */
+ final List<String> storedProperties =
projection.getStoredPropertyNames();
+ final int count = storedProperties.size();
+ for (int i=0; i<count; i++) {
+ final String xpath = projection.getSourcePropertyName(i, false);
+ if (xpath == null) {
+ unhandled.put(storedProperties.get(i),
projection.getExpression(i));
+ continue;
+ }
+ final Column column = source.getColumn(xpath);
+ if (column != null) {
+ hasGeometry |= column.getGeometryType().isPresent();
+ final String name = storedProperties.get(i);
+ final Column renamed = column.rename(name);
+ attributes[attributesCount++] = renamed;
+ if (renamed == column) {
+ reusedNames.add(name);
+ }
+ continue;
+ }
+ Relation relation = source.getRelation(xpath, false);
+ if (relation != null) {
+ importedKeys[importedKeysCount++] = relation;
+ continue;
+ }
+ relation = source.getRelation(xpath, false);
+ if (relation != null) {
+ exportedKeys[exportedKeysCount++] = relation;
+ continue;
+ }
+ throw new
InvalidFilterValueException(Errors.forLocale(listeners.getLocale())
+ .getString(Errors.Keys.PropertyNotFound_2,
source.featureType.getName(), xpath));
+ }
+ /*
+ * Save the columns and foreigner keys that this table handles.
+ * Take the primary key only if we have all the needed columns
+ * and those columns have the same names as in the source table.
+ */
+ this.hasGeometry = hasGeometry;
+ this.hasRaster = source.hasRaster; // Not yet accurately
determined.
+ this.attributes = ArraysExt.resize(attributes, attributesCount);
+ this.importedKeys = ArraysExt.resize(importedKeys, importedKeysCount);
+ this.exportedKeys = ArraysExt.resize(exportedKeys, exportedKeysCount);
+ if (source.primaryKey != null) {
+ for (String column : source.primaryKey.getColumns()) {
+ final int i = storedProperties.indexOf(column);
+ if (i < 0 ||
!column.equals(projection.getSourcePropertyName(i, true))) {
+ primaryKey = null;
+ return;
+ }
+ }
+ }
+ this.primaryKey = source.primaryKey;
}
/**
@@ -229,7 +305,7 @@ final class Table extends AbstractFeatureSet {
* have been set to association names. If
`ClassCastException` occurs here, it is a bug
* in our object constructions.
*/
- final var association = (FeatureAssociationRole)
featureType.getProperty(relation.propertyName);
+ final var association = (FeatureAssociationRole)
featureType.getProperty(relation.getPropertyName());
final Table table =
tables.get(association.getValueType().getName());
if (table == null) {
throw new
InternalDataStoreException(association.toString());
@@ -278,7 +354,7 @@ final class Table extends AbstractFeatureSet {
final void appendTo(TreeTable.Node parent) {
parent = Relation.newChild(parent, featureType.getName().toString());
for (final Column attribute : attributes) {
- TableReference.newChild(parent, attribute.propertyName);
+ TableReference.newChild(parent, attribute.getPropertyName());
}
appendAll(parent, importedKeys, " → ");
appendAll(parent, exportedKeys, " ← ");
@@ -367,7 +443,7 @@ final class Table extends AbstractFeatureSet {
if (m == null) {
m = JDK19.newHashMap(attributes.length);
for (final Column c : attributes) {
- String label = c.propertyName;
+ String label = c.getPropertyName();
m.put(label, c);
final int s =
label.lastIndexOf(DefaultNameSpace.DEFAULT_SEPARATOR);
if (s >= 0) {
@@ -380,6 +456,30 @@ final class Table extends AbstractFeatureSet {
return m.get(xpath);
}
+ /**
+ * Returns the relation from an attribute name specified as XPath.
+ * See {@link #getColumn(String)} for a note on the wat that {@code xpath}
is interpreted.
+ *
+ * @param xpath the XPath (currently only attribute name).
+ * @param exports {@code true} for searching in exported keys, or {@code
false} for searching in imported keys.
+ * @return relation for the given XPath, or {@code null} if the specified
attribute is not found.
+ */
+ private Relation getRelation(final String xpath, final boolean exports) {
+ boolean tip = false;
+ do { // Execute 1 or 2 times: check tips only if no exact match.
+ for (final Relation c : (exports ? exportedKeys : importedKeys)) {
+ String label = c.getPropertyName();
+ if (tip) {
+ label =
label.substring(label.lastIndexOf(DefaultNameSpace.DEFAULT_SEPARATOR) + 1);
+ }
+ if (label.equals(xpath)) {
+ return c;
+ }
+ }
+ } while ((tip = !tip) == true);
+ return null;
+ }
+
/**
* If this table imports the inverse of the given relation, returns the
imported relation.
* Otherwise returns {@code null}. This method is used for preventing
infinite recursion.
diff --git
a/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/postgis/Postgres.java
b/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/postgis/Postgres.java
index 7507ebf31d..a68494cd8f 100644
---
a/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/postgis/Postgres.java
+++
b/endorsed/src/org.apache.sis.storage.sql/main/org/apache/sis/storage/sql/postgis/Postgres.java
@@ -84,7 +84,7 @@ public final class Postgres<G> extends Database<G> {
}
}
} catch (SQLException e) {
- log(Resources.forLocale(null).getLogRecord(Level.CONFIG,
+
log(Resources.forLocale(listeners.getLocale()).getLogRecord(Level.CONFIG,
Resources.Keys.SpatialExtensionNotFound_1, "PostGIS"));
}
}
diff --git
a/endorsed/src/org.apache.sis.storage.sql/test/org/apache/sis/storage/sql/SQLStoreTest.java
b/endorsed/src/org.apache.sis.storage.sql/test/org/apache/sis/storage/sql/SQLStoreTest.java
index 80a484c799..989576bb5b 100644
---
a/endorsed/src/org.apache.sis.storage.sql/test/org/apache/sis/storage/sql/SQLStoreTest.java
+++
b/endorsed/src/org.apache.sis.storage.sql/test/org/apache/sis/storage/sql/SQLStoreTest.java
@@ -174,9 +174,9 @@ public final class SQLStoreTest extends TestOnAllDatabases {
* Creates a {@link SQLStore} instance with the specified table as a
resource, then tests some queries.
*/
private void testTableQuery(final StorageConnector connector, final
ResourceDefinition table) throws Exception {
- try (SimpleFeatureStore store = new SimpleFeatureStore(new
SQLStoreProvider(), connector, table)) {
+ try (var store = new SimpleFeatureStore(new SQLStoreProvider(),
connector, table)) {
verifyFeatureTypes(store);
- final Map<String,Integer> countryCount = new HashMap<>();
+ final var countryCount = new HashMap<String,Integer>();
try (Stream<Feature> features =
store.findResource("Cities").features(false)) {
features.forEach((f) -> verifyContent(f, countryCount));
}
@@ -287,7 +287,7 @@ public final class SQLStoreTest extends TestOnAllDatabases {
*/
assertEquals(c.countryName, getIndirectPropertyValue(feature,
"country", "native_name"));
if (isCanada) {
- final Feature f = (Feature) feature.getPropertyValue("country");
+ final var f = (Feature) feature.getPropertyValue("country");
if (canada == null) {
canada = f;
} else {
@@ -424,8 +424,8 @@ public final class SQLStoreTest extends TestOnAllDatabases {
private void verifyWhereOnLink(SimpleFeatureStore dataset) throws
Exception {
final String desiredProperty = "native_name";
final String[] expectedValues = {"Canada"};
- final FeatureSet countries = dataset.findResource("Countries");
- final FeatureQuery query = new FeatureQuery();
+ final FeatureSet countries = dataset.findResource("Countries");
+ final var query = new FeatureQuery();
query.setSelection(FF.equal(FF.property("sis:identifier"),
FF.literal("CAN")));
final String executionMode;
final Object[] names;
@@ -452,8 +452,8 @@ public final class SQLStoreTest extends TestOnAllDatabases {
*/
private void verifyStreamOperations(final FeatureSet cities) throws
DataStoreException {
try (Stream<Feature> features = cities.features(false)) {
- final AtomicInteger peekCount = new AtomicInteger();
- final AtomicInteger mapCount = new AtomicInteger();
+ final var peekCount = new AtomicInteger();
+ final var mapCount = new AtomicInteger();
final long actualPopulations = features.peek(f ->
peekCount.incrementAndGet())
.peek(f -> peekCount.incrementAndGet())
.map (f -> {mapCount.incrementAndGet(); return f;})
@@ -487,7 +487,7 @@ public final class SQLStoreTest extends TestOnAllDatabases {
"SELECT * FROM " + SCHEMA + ".\"Cities\" WHERE \"population\"
>= 1000000")))
{
final FeatureSet cities = store.findResource("LargeCities");
- final Map<String,Integer> countryCount = new HashMap<>();
+ final var countryCount = new HashMap<String,Integer>();
try (Stream<Feature> features = cities.features(false)) {
features.forEach((f) -> verifyContent(f, countryCount));
}
@@ -510,7 +510,7 @@ public final class SQLStoreTest extends TestOnAllDatabases {
/*
* Add a filter for parks in France.
*/
- final FeatureQuery query = new FeatureQuery();
+ final var query = new FeatureQuery();
query.setSortBy(FF.sort(FF.property("native_name"),
SortOrder.DESCENDING));
query.setSelection(FF.equal(FF.property("country"),
FF.literal("FRA")));
query.setProjection(FF.property("native_name"));
@@ -546,7 +546,7 @@ public final class SQLStoreTest extends TestOnAllDatabases {
{
final FeatureSet parks = store.findResource("MyQuery");
final FeatureType type = parks.getType();
- final AttributeType<?> property = (AttributeType<?>)
TestUtilities.getSingleton(type.getProperties(true));
+ final var property = (AttributeType<?>)
TestUtilities.getSingleton(type.getProperties(true));
assertEquals("title", property.getName().toString(), "Property
name should be label defined in query");
assertEquals(String.class, property.getValueClass(), "Attribute
should be a string");
assertEquals(0, property.getMinimumOccurs(), "Column should be
nullable.");
@@ -581,7 +581,7 @@ public final class SQLStoreTest extends TestOnAllDatabases {
*/
private void verifyDistinctQuery(final StorageConnector connector) throws
Exception {
final Object[] expected;
- try (SimpleFeatureStore store = new SimpleFeatureStore(null,
connector, ResourceDefinition.query("Countries",
+ try (var store = new SimpleFeatureStore(null, connector,
ResourceDefinition.query("Countries",
"SELECT \"country\" FROM " + SCHEMA + ".\"Parks\" ORDER BY
\"country\"")))
{
final FeatureSet countries = store.findResource("Countries");
diff --git
a/endorsed/src/org.apache.sis.storage/main/org/apache/sis/storage/FeatureQuery.java
b/endorsed/src/org.apache.sis.storage/main/org/apache/sis/storage/FeatureQuery.java
index 675104c8c7..7a961f9af1 100644
---
a/endorsed/src/org.apache.sis.storage/main/org/apache/sis/storage/FeatureQuery.java
+++
b/endorsed/src/org.apache.sis.storage/main/org/apache/sis/storage/FeatureQuery.java
@@ -27,29 +27,21 @@ import javax.measure.Quantity;
import javax.measure.quantity.Length;
import org.opengis.util.GenericName;
import org.opengis.geometry.Envelope;
-import org.apache.sis.feature.AbstractOperation;
import org.apache.sis.feature.FeatureOperations;
-import org.apache.sis.feature.builder.FeatureTypeBuilder;
-import org.apache.sis.feature.builder.PropertyTypeBuilder;
-import org.apache.sis.feature.builder.AttributeTypeBuilder;
import org.apache.sis.feature.privy.AttributeConvention;
-import org.apache.sis.feature.privy.FeatureExpression;
import org.apache.sis.filter.DefaultFilterFactory;
import org.apache.sis.filter.Optimization;
import org.apache.sis.filter.privy.ListingPropertyVisitor;
import org.apache.sis.filter.privy.SortByComparator;
-import org.apache.sis.filter.privy.XPath;
import org.apache.sis.storage.internal.Resources;
import org.apache.sis.pending.jdk.JDK19;
import org.apache.sis.util.ArgumentChecks;
-import org.apache.sis.util.ArraysExt;
import org.apache.sis.util.CharSequences;
+import org.apache.sis.util.Emptiable;
import org.apache.sis.util.iso.Names;
-import org.apache.sis.util.resources.Vocabulary;
// Specific to the geoapi-3.1 and geoapi-4.0 branches:
import org.opengis.feature.Feature;
-import org.opengis.feature.FeatureType;
import org.opengis.feature.Attribute;
import org.opengis.feature.AttributeType;
import org.opengis.feature.Operation;
@@ -60,7 +52,6 @@ import org.opengis.filter.Literal;
import org.opengis.filter.ValueReference;
import org.opengis.filter.SortBy;
import org.opengis.filter.SortProperty;
-import org.opengis.filter.InvalidFilterValueException;
/**
@@ -86,7 +77,7 @@ import org.opengis.filter.InvalidFilterValueException;
* @version 1.5
* @since 1.1
*/
-public class FeatureQuery extends Query implements Cloneable, Serializable {
+public class FeatureQuery extends Query implements Cloneable, Emptiable,
Serializable {
/**
* For cross-version compatibility.
*/
@@ -109,7 +100,7 @@ public class FeatureQuery extends Query implements
Cloneable, Serializable {
private NamedExpression[] projection;
/**
- * The filter for trimming feature instances.
+ * The filter for trimming feature instances, or {@code null} if none.
* In a database, "feature instances" are table rows.
* Subset of rows is called <dfn>selection</dfn> in relational database
terminology.
*
@@ -140,7 +131,7 @@ public class FeatureQuery extends Query implements
Cloneable, Serializable {
private long limit;
/**
- * The expressions to use for sorting the feature instances.
+ * The expressions to use for sorting the feature instances, or {@code
null} if none.
*
* @see #getSortBy()
* @see #setSortBy(SortBy)
@@ -149,7 +140,7 @@ public class FeatureQuery extends Query implements
Cloneable, Serializable {
private SortBy<Feature> sortBy;
/**
- * Hint used by resources to optimize returned features.
+ * Hint used by resources to optimize returned features, or {@code null}
for full resolution.
* Different stores make use of vector tiles of different scales.
* A {@code null} value means to query data at their full resolution.
*
@@ -166,19 +157,53 @@ public class FeatureQuery extends Query implements
Cloneable, Serializable {
limit = UNLIMITED;
}
+ /**
+ * Creates a new query initialized to the same values than the given query.
+ * This is an alternative to the {@link #clone()} method when the caller
+ * wants to change the implementation class.
+ *
+ * @param other the other query from which to copy the configuration.
+ *
+ * @see #clone()
+ *
+ * @since 1.5
+ */
+ public FeatureQuery(final FeatureQuery other) {
+ projection = other.projection;
+ selection = other.selection;
+ skip = other.skip;
+ limit = other.limit;
+ sortBy = other.sortBy;
+ linearResolution = other.linearResolution;
+ }
+
+ /**
+ * Returns {@code true} if this query do not specify any filtering.
+ *
+ * @return if this query performs no filtering.
+ *
+ * @since 1.5
+ */
+ @Override
+ public boolean isEmpty() {
+ return (projection == null) && (selection == null) && (skip == 0) &&
(limit < 0) && (sortBy == null)
+ && (linearResolution == null);
+ }
+
/**
* Sets the properties to retrieve by their names. This convenience method
wraps the
* given names in {@link ValueReference} expressions without alias and
delegates to
* {@link #setProjection(NamedExpression...)}.
*
* @param properties properties to retrieve, or {@code null} to retrieve
all properties.
- * @throws IllegalArgumentException if a property is duplicated.
+ * @throws IllegalArgumentException if the given array is empty of if a
property is duplicated.
*/
@Override
public void setProjection(final String... properties) {
NamedExpression[] wrappers = null;
if (properties != null) {
- final FilterFactory<Feature,?,?> ff =
DefaultFilterFactory.forFeatures();
+ ArgumentChecks.ensureNonEmpty("properties", properties);
+ final var ff = DefaultFilterFactory.forFeatures();
wrappers = new NamedExpression[properties.length];
for (int i=0; i<wrappers.length; i++) {
final String p = properties[i];
@@ -195,12 +220,14 @@ public class FeatureQuery extends Query implements
Cloneable, Serializable {
* delegates to {@link #setProjection(NamedExpression...)}.
*
* @param properties properties to retrieve, or {@code null} to retrieve
all properties.
- * @throws IllegalArgumentException if a property is duplicated.
+ * @throws IllegalArgumentException if the given array is empty of if a
property is duplicated.
*/
@SafeVarargs
+ @SuppressWarnings("varargs")
public final void setProjection(final Expression<? super Feature, ?>...
properties) {
NamedExpression[] wrappers = null;
if (properties != null) {
+ ArgumentChecks.ensureNonEmpty("properties", properties);
wrappers = new NamedExpression[properties.length];
for (int i=0; i<wrappers.length; i++) {
final Expression<? super Feature, ?> e = properties[i];
@@ -227,7 +254,7 @@ public class FeatureQuery extends Query implements
Cloneable, Serializable {
if (properties != null) {
ArgumentChecks.ensureNonEmpty("properties", properties);
properties = properties.clone();
- final Map<Object,Integer> uniques =
JDK19.newLinkedHashMap(properties.length);
+ final var uniques =
JDK19.<Object,Integer>newLinkedHashMap(properties.length);
for (int i=0; i<properties.length; i++) {
final NamedExpression c = properties[i];
ArgumentChecks.ensureNonNullElement("properties", i, c);
@@ -255,25 +282,6 @@ public class FeatureQuery extends Query implements
Cloneable, Serializable {
return (projection != null) ? projection.clone() : null;
}
- /**
- * Returns the properties to be stored in the target feature.
- */
- final NamedExpression[] getStoredProjection() {
- final NamedExpression[] stored = getProjection();
- if (stored != null) {
- int count = 0;
- for (final NamedExpression p : stored) {
- if (p.type == ProjectionType.STORED) {
- stored[count++] = p;
- }
- }
- if (count != 0) {
- return ArraysExt.resize(stored, count);
- }
- }
- return null;
- }
-
/**
* Sets the approximate area of feature instances to include in the subset.
* This convenience method creates a filter that checks if the bounding box
@@ -620,7 +628,7 @@ public class FeatureQuery extends Query implements
Cloneable, Serializable {
return true;
}
if (obj != null && getClass() == obj.getClass()) {
- final NamedExpression other = (NamedExpression) obj;
+ final var other = (NamedExpression) obj;
return expression.equals(other.expression) &&
Objects.equals(alias, other.alias) && type == other.type;
}
return false;
@@ -633,7 +641,7 @@ public class FeatureQuery extends Query implements
Cloneable, Serializable {
*/
@Override
public String toString() {
- final StringBuilder buffer = new StringBuilder("SELECT ");
+ final var buffer = new StringBuilder("SELECT ");
appendTo(buffer);
return buffer.toString();
}
@@ -719,125 +727,40 @@ public class FeatureQuery extends Query implements
Cloneable, Serializable {
* @since 1.2
*/
protected FeatureSet execute(final FeatureSet source) throws
DataStoreException {
- Objects.requireNonNull(source);
- final FeatureQuery query = clone();
- if (query.selection != null) {
- final Optimization optimization = new Optimization();
- optimization.setFeatureType(source.getType());
- query.selection = optimization.apply(query.selection);
+ if (isEmpty()) {
+ return source;
}
+ final FeatureQuery query = clone();
+ query.optimize(source);
return new FeatureSubset(source, query);
}
/**
- * Returns the type of values evaluated by this query when executed on
features of the given type.
- * If some expressions have no name, default names are computed as below:
+ * Optimizes this query before execution. This method is invoked by {@link
#execute(FeatureSet)}
+ * on a {@linkplain #clone() clone} of the user-provided query. The
default implementations tries
+ * to optimize the {@linkplain #getSelection() selection} filter using
{@link Optimization}.
+ * Subclasses can override for modifying the optimization algorithm.
*
- * <ul>
- * <li>If the expression is an instance of {@link ValueReference}, the
name of the
- * property referenced by the {@linkplain ValueReference#getXPath()
XPath}.</li>
- * <li>Otherwise the localized string "Unnamed #1" with increasing
numbers.</li>
- * </ul>
+ * @param source the set of features given to the {@code
execute(FeatureSet)} method.
+ * @throws DataStoreException if an error occurred during the optimization
of this query.
*
- * @param valueType the type of features to be evaluated by the
expressions in this query.
- * @return type resulting from expressions evaluation (never null).
- * @throws IllegalArgumentException if this method can operate only on
some feature types
- * and the given type is not one of them.
- * @throws InvalidFilterValueException if this method cannot determine the
result type of an expression
- * in this query. It may be because that expression is backed by
an unsupported implementation.
+ * @since 1.5
*/
- final FeatureType expectedType(final FeatureType valueType) {
- if (projection == null) {
- return valueType; // All columns included: result is of
the same type.
- }
- int unnamedNumber = 0; // Sequential number for unnamed
expressions.
- Set<String> names = null; // Names already used, for avoiding
collisions.
- final FeatureTypeBuilder ftb = new
FeatureTypeBuilder().setName(valueType.getName());
- for (int column = 0; column < projection.length; column++) {
- final NamedExpression item = projection[column];
- /*
- * For each property, get the expected type (mandatory) and its
name (optional).
- * A default name will be computed if no alias was explicitly
given by the user.
- */
- final Expression<? super Feature,?> expression = item.expression;
- final FeatureExpression<?,?> fex =
FeatureExpression.castOrCopy(expression);
- final PropertyTypeBuilder resultType;
- if (fex == null || (resultType = fex.expectedType(valueType, ftb))
== null) {
- throw new
InvalidFilterValueException(Resources.format(Resources.Keys.InvalidExpression_2,
-
expression.getFunctionName().toInternationalString(), column));
- }
- GenericName name = item.alias;
- if (name == null) {
- /*
- * Build a list of aliases declared by the user, for making
sure that we do not collide with them.
- * No check for `GenericName` collision here because it was
already verified by `setProjection(…)`.
- * We may have collision of their `String` representations
however, which is okay.
- */
- if (names == null) {
- names = JDK19.newHashSet(projection.length);
- for (final NamedExpression p : projection) {
- if (p.alias != null) {
- names.add(p.alias.toString());
- }
- }
- }
- /*
- * If the expression is a `ValueReference`, the `PropertyType`
instance can be taken directly
- * from the source feature (the Apache SIS implementation does
just that). If the name is set,
- * then we assume that it is correct. Otherwise we take the
tip of the XPath.
- */
- String tip = null;
- if (expression instanceof ValueReference<?,?>) {
- tip = XPath.toPropertyName(((ValueReference<?,?>)
expression).getXPath());
- /*
- * Take the existing `GenericName` instance from the
property. It should be equivalent to
- * creating a name from the tip, except that it may be a
`ScopedName` instead of `LocalName`.
- * We do not take `resultType.getName()` because the
latter is different if the property
- * is itself a link to another property (in which case
`resultType` is the final target).
- */
- name = valueType.getProperty(tip).getName();
- if (name == null || !names.add(name.toString())) {
- name = null;
- if (tip.isEmpty() || names.contains(tip)) {
- tip = null;
- }
- }
- }
- /*
- * If we still have no name at this point, create a name like
"Unnamed #1".
- * Note that despite the use of `Vocabulary` resources, the
name will be unlocalized
- * (for easier programmatic use) because `GenericName`
implementation is designed for
- * providing localized names only if explicitly requested.
- */
- if (name == null) {
- CharSequence text = tip;
- if (text == null) do {
- text =
Vocabulary.formatInternational(Vocabulary.Keys.Unnamed_1, ++unnamedNumber);
- } while (!names.add(text.toString()));
- name = Names.createLocalName(null, null, text);
- }
- }
- /*
- * If the attribute that we just added should be virtual, replace
the attribute by an operation.
- */
- if (item.type == ProjectionType.COMPUTING && resultType instanceof
AttributeTypeBuilder<?>) {
- final var ab = (AttributeTypeBuilder<?>) resultType;
- final AttributeType<?> storedType = ab.build();
- if (ftb.properties().remove(resultType)) {
- final var properties = Map.of(AbstractOperation.NAME_KEY,
name);
- ftb.addProperty(FeatureOperations.expression(properties,
expression, storedType));
- }
- } else {
- resultType.setName(name);
- }
+ protected void optimize(final FeatureSet source) throws DataStoreException
{
+ if (selection != null) {
+ final var optimization = new Optimization();
+ optimization.setFeatureType(source.getType());
+ selection = optimization.apply(selection);
}
- return ftb.build();
}
/**
* Returns a clone of this query.
*
* @return a clone of this query.
+ *
+ * @see #FeatureQuery(FeatureQuery)
+ * @see #optimize(FeatureSet)
*/
@Override
public FeatureQuery clone() {
@@ -876,7 +799,7 @@ public class FeatureQuery extends Query implements
Cloneable, Serializable {
return true;
}
if (obj != null && getClass() == obj.getClass()) {
- final FeatureQuery other = (FeatureQuery) obj;
+ final var other = (FeatureQuery) obj;
return skip == other.skip &&
limit == other.limit &&
Objects.equals(selection, other.selection) &&
@@ -895,7 +818,7 @@ public class FeatureQuery extends Query implements
Cloneable, Serializable {
*/
@Override
public String toString() {
- final StringBuilder sb = new StringBuilder(80);
+ final var sb = new StringBuilder(80);
sb.append("SELECT ");
if (projection != null) {
for (int i=0; i<projection.length; i++) {
diff --git
a/endorsed/src/org.apache.sis.storage/main/org/apache/sis/storage/FeatureSubset.java
b/endorsed/src/org.apache.sis.storage/main/org/apache/sis/storage/FeatureSubset.java
index ce6e9563bc..32159973bd 100644
---
a/endorsed/src/org.apache.sis.storage/main/org/apache/sis/storage/FeatureSubset.java
+++
b/endorsed/src/org.apache.sis.storage/main/org/apache/sis/storage/FeatureSubset.java
@@ -19,7 +19,7 @@ package org.apache.sis.storage;
import java.util.OptionalLong;
import java.util.stream.Stream;
import org.opengis.metadata.Metadata;
-import org.apache.sis.feature.privy.FeatureUtilities;
+import org.apache.sis.storage.base.FeatureProjection;
import org.apache.sis.storage.base.MetadataBuilder;
import org.apache.sis.storage.base.StoreUtilities;
import org.apache.sis.storage.internal.Resources;
@@ -28,7 +28,6 @@ import org.apache.sis.storage.internal.Resources;
import org.opengis.feature.Feature;
import org.opengis.feature.FeatureType;
import org.opengis.filter.Filter;
-import org.opengis.filter.Expression;
import org.opengis.filter.SortBy;
@@ -52,6 +51,12 @@ final class FeatureSubset extends AbstractFeatureSet {
*/
private final FeatureQuery query;
+ /**
+ * A function applying projections (with "projected" in the
<abbr>SQL</abbr> database sense) of features.
+ * This is computed together with {@link #resultType}. May stay {@code
null} if there is no projection.
+ */
+ private FeatureProjection projection;
+
/**
* The type of features in this set. May or may not be the same as {@link
#source}.
* This is computed when first needed.
@@ -74,7 +79,7 @@ final class FeatureSubset extends AbstractFeatureSet {
*/
@Override
protected Metadata createMetadata() throws DataStoreException {
- final MetadataBuilder builder = new MetadataBuilder();
+ final var builder = new MetadataBuilder();
builder.addDefaultMetadata(this, listeners);
builder.addLineage(Resources.formatInternational(Resources.Keys.UnfilteredData));
builder.addProcessDescription(Resources.formatInternational(Resources.Keys.SubsetQuery_1,
StoreUtilities.getLabel(source)));
@@ -90,7 +95,8 @@ final class FeatureSubset extends AbstractFeatureSet {
if (resultType == null) {
final FeatureType type = source.getType();
try {
- resultType = query.expectedType(type);
+ projection = FeatureProjection.create(type,
query.getProjection());
+ resultType = (projection != null) ? projection.featureType :
type;
} catch (IllegalArgumentException e) {
throw new
DataStoreContentException(Resources.forLocale(listeners.getLocale())
.getString(Resources.Keys.CanNotDeriveTypeFromFeature_1, type.getName()), e);
@@ -134,25 +140,14 @@ final class FeatureSubset extends AbstractFeatureSet {
stream = stream.limit(limit.getAsLong());
}
/*
- * Transform feature instances.
- * Note: "projection" here is in relational database sense, not map
projection.
+ * Transform feature instances, usually for keeping only a subset of
the properties.
+ * Note: "projection" here is in relational database sense (SQL), not
map projection.
+ * This operation should be last, because the filter applied above may
need properties
+ * that are excluded by this projection.
*/
- final FeatureQuery.NamedExpression[] projection =
query.getStoredProjection();
+ getType(); // Force the computation of `projection` if not
already done.
if (projection != null) {
- @SuppressWarnings({"unchecked", "rawtypes"})
- final Expression<? super Feature,?>[] expressions = new
Expression[projection.length];
- for (int i=0; i<expressions.length; i++) {
- expressions[i] = projection[i].expression;
- }
- final FeatureType type = getType();
- final String[] names =
FeatureUtilities.getNames(type.getProperties(false));
- stream = stream.map(t -> {
- final Feature f = type.newInstance();
- for (int i=0; i < expressions.length; i++) {
- f.setPropertyValue(names[i], expressions[i].apply(t));
- }
- return f;
- });
+ stream = stream.map(projection);
}
return stream;
}
diff --git
a/endorsed/src/org.apache.sis.storage/main/org/apache/sis/storage/base/FeatureProjection.java
b/endorsed/src/org.apache.sis.storage/main/org/apache/sis/storage/base/FeatureProjection.java
new file mode 100644
index 0000000000..5a25571e28
--- /dev/null
+++
b/endorsed/src/org.apache.sis.storage/main/org/apache/sis/storage/base/FeatureProjection.java
@@ -0,0 +1,383 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.sis.storage.base;
+
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.ConcurrentModificationException;
+import java.util.function.UnaryOperator;
+import org.opengis.util.GenericName;
+import org.apache.sis.feature.AbstractOperation;
+import org.apache.sis.feature.FeatureOperations;
+import org.apache.sis.feature.builder.FeatureTypeBuilder;
+import org.apache.sis.feature.builder.PropertyTypeBuilder;
+import org.apache.sis.feature.builder.AttributeTypeBuilder;
+import org.apache.sis.feature.privy.FeatureExpression;
+import org.apache.sis.filter.privy.XPath;
+import org.apache.sis.storage.FeatureQuery;
+import org.apache.sis.storage.internal.Resources;
+import org.apache.sis.pending.jdk.JDK19;
+import org.apache.sis.util.ArraysExt;
+import org.apache.sis.util.iso.Names;
+import org.apache.sis.util.logging.Logging;
+import org.apache.sis.util.privy.UnmodifiableArrayList;
+import org.apache.sis.util.resources.Vocabulary;
+
+// Specific to the geoapi-3.1 and geoapi-4.0 branches:
+import org.opengis.feature.Feature;
+import org.opengis.feature.FeatureType;
+import org.opengis.feature.PropertyNotFoundException;
+import org.opengis.filter.InvalidFilterValueException;
+import org.opengis.filter.Expression;
+import org.opengis.filter.ValueReference;
+
+
+/**
+ * A function applying projections (with "projected" in the <abbr>SQL</abbr>
database sense) of features.
+ * Given full feature instances in input, this method returns feature
instances containing only a subset
+ * of the properties. The property values may also be different if they are
computed by the expressions.
+ *
+ * @author Guilhem Legal (Geomatys)
+ * @author Martin Desruisseaux (Geomatys)
+ */
+public class FeatureProjection implements UnaryOperator<Feature> {
+ /**
+ * The type of features created by this mapper.
+ */
+ public final FeatureType featureType;
+
+ /**
+ * Names of the properties to be stored in the target features. This is
inferred from the {@code properties}
+ * given at construction time, retaining only the elements of type {@link
FeatureQuery.ProjectionType#STORED}.
+ * Properties that are computed on-the-fly from other properties are not
included in this list.
+ * This array is arbitrarily set to {@code null} if this projection is an
identity operation.
+ *
+ * <p>When a new {@code Feature} instance needs to be created with a
subset of the properties
+ * of the original feature instance, usually only the stored properties
need to be copied.
+ * Other properties computed on-the-fly from stored properties may not
need copy.</p>
+ *
+ * @see #isIdentity()
+ */
+ private final String[] storedProperties;
+
+ /**
+ * Expressions to apply on the source feature for fetching the property
values of the projected feature.
+ * Shall have the same length as {@link #storedProperties} and the
properties shall be in the same order.
+ * This array is arbitrarily set to {@code null} if this projection is an
identity operation.
+ *
+ * @see #isIdentity()
+ */
+ private final Expression<? super Feature, ?>[] expressions;
+
+ /**
+ * Infers the type of values evaluated by a query when executed on
features of the given type.
+ * If some expressions have no name, default names are computed as below:
+ *
+ * <ul>
+ * <li>If the expression is an instance of {@link ValueReference}, the
name of the
+ * property referenced by the {@linkplain ValueReference#getXPath()
XPath}.</li>
+ * <li>Otherwise the localized string "Unnamed #1" with increasing
numbers.</li>
+ * </ul>
+ *
+ * <h4>Identity operation</h4>
+ * If the result is a feature type with all the properties of the source
feature,
+ * with the same property names in the same order, and if the expressions
are only
+ * fetching the values (no computation), then this method returns {@code
null} for
+ * meaning that this projection does nothing.
+ *
+ * @param sourceType the type of features to be converted to projected
features.
+ * @param projection descriptions of the properties to keep in the
projected features, or {@code null} if none.
+ * @return a function for projecting the feature instances, or {@code
null} if none.
+ * @throws IllegalArgumentException if this method can operate only on
some feature types
+ * and the given type is not one of them.
+ * @throws InvalidFilterValueException if this method cannot determine the
result type of an expression.
+ * It may be because that expression is backed by an unsupported
implementation.
+ */
+ public static FeatureProjection create(final FeatureType sourceType, final
FeatureQuery.NamedExpression[] projection) {
+ if (projection != null) {
+ var fp = new FeatureProjection(sourceType, projection);
+ if (!fp.isIdentity()) {
+ return fp;
+ }
+ }
+ return null;
+ }
+
+ /**
+ * Creates a new feature projection. If some expressions have no name,
+ * default names are computed as described in {@link #create create(…)}.
+ *
+ * <p>Callers shall invoke {@link #isIdentity()} after construction.
+ * This instance shall not be used if it is the identity operation.</p>
+ *
+ * @param sourceType the type of features to be converted to projected
features.
+ * @param projection descriptions of the properties to keep in the
projected features, or {@code null} if none.
+ * @throws IllegalArgumentException if this method can operate only on
some feature types
+ * and the given type is not one of them.
+ * @throws InvalidFilterValueException if this method cannot determine the
result type of an expression.
+ * It may be because that expression is backed by an unsupported
implementation.
+ */
+ protected FeatureProjection(final FeatureType sourceType, final
FeatureQuery.NamedExpression[] projection) {
+ int storedCount = 0;
+ int unnamedNumber = 0; // Sequential number for unnamed
expressions.
+ Set<String> names = null; // Names already used, for avoiding
collisions.
+
+ // For detecting if the projection would be an identity operation.
+ var propertiesOfIdentity = sourceType.getProperties(true).iterator();
+
+ @SuppressWarnings({"LocalVariableHidesMemberVariable", "unchecked",
"rawtypes"})
+ final Expression<? super Feature,?>[] expressions = new
Expression[projection.length];
+
+ @SuppressWarnings("LocalVariableHidesMemberVariable")
+ final String[] storedProperties = new String[projection.length];
+
+ final FeatureTypeBuilder ftb = new
FeatureTypeBuilder().setName(sourceType.getName());
+ for (int column = 0; column < projection.length; column++) {
+ final FeatureQuery.NamedExpression item = projection[column];
+ /*
+ * For each property, get the expected type (mandatory) and its
name (optional).
+ * A default name will be computed if no alias was explicitly
given by the user.
+ */
+ final var expression = item.expression;
+ final var fex = FeatureExpression.castOrCopy(expression);
+ final PropertyTypeBuilder resultType;
+ if (fex == null || (resultType = fex.expectedType(sourceType,
ftb)) == null) {
+ throw new
InvalidFilterValueException(Resources.format(Resources.Keys.InvalidExpression_2,
+
expression.getFunctionName().toInternationalString(), column));
+ }
+ GenericName name = item.alias;
+ if (name == null) {
+ /*
+ * Build a list of aliases declared by the user, for making
sure that we do not collide with them.
+ * No check for `GenericName` collision here because it was
already verified by `setProjection(…)`.
+ * We may have collision of their `String` representations
however, which is okay.
+ */
+ if (names == null) {
+ names = JDK19.newHashSet(projection.length);
+ for (final FeatureQuery.NamedExpression p : projection) {
+ if (p.alias != null) {
+ names.add(p.alias.toString());
+ }
+ }
+ }
+ /*
+ * If the expression is a `ValueReference`, the `PropertyType`
instance can be taken directly
+ * from the source feature (the Apache SIS implementation does
just that). If the name is set,
+ * then we assume that it is correct. Otherwise we take the
tip of the XPath.
+ */
+ String tip = reference(expression, true);
+ if (tip != null) {
+ /*
+ * Take the existing `GenericName` instance from the
property. It should be equivalent to
+ * creating a name from the tip, except that it may be a
`ScopedName` instead of `LocalName`.
+ * We do not take `resultType.getName()` because the
latter is different if the property
+ * is itself a link to another property (in which case
`resultType` is the final target).
+ */
+ name = sourceType.getProperty(tip).getName();
+ if (name == null || !names.add(name.toString())) {
+ name = null;
+ if (tip.isBlank() || names.contains(tip)) {
+ tip = null;
+ }
+ }
+ }
+ /*
+ * If we still have no name at this point, create a name like
"Unnamed #1".
+ * Note that despite the use of `Vocabulary` resources, the
name will be unlocalized
+ * (for easier programmatic use) because `GenericName`
implementation is designed for
+ * providing localized names only if explicitly requested.
+ */
+ if (name == null) {
+ CharSequence text = tip;
+ if (text == null) do {
+ text =
Vocabulary.formatInternational(Vocabulary.Keys.Unnamed_1, ++unnamedNumber);
+ } while (!names.add(text.toString()));
+ name = Names.createLocalName(null, null, text);
+ }
+ }
+ /*
+ * If the attribute that we just added should be virtual, replace
the attribute by an operation.
+ * When `FeatureProjection` contains at least one such virtual
attributes, the result cannot be
+ * an identity operation.
+ */
+ if (item.type != FeatureQuery.ProjectionType.STORED) {
+ propertiesOfIdentity = null; // No longer an identity
operation.
+ if (resultType instanceof AttributeTypeBuilder<?>) {
+ final var ab = (AttributeTypeBuilder<?>) resultType;
+ final var storedType = ab.build();
+ if (ftb.properties().remove(resultType)) {
+ final var identification =
Map.of(AbstractOperation.NAME_KEY, name);
+
ftb.addProperty(FeatureOperations.expression(identification, expression,
storedType));
+ }
+ }
+ continue;
+ }
+ /*
+ * This is the usual case where the property value is copied in
the "projected" feature.
+ * If the target property name is equal to the source property
name, in the same order,
+ * and the expression is just fetching the value from a property
of the same name, then
+ * we consider that the projection is an identity operation.
+ */
+ resultType.setName(name);
+ storedProperties[storedCount] = name.toString();
+ expressions[storedCount++] = expression;
+isIdentity: if (propertiesOfIdentity != null) {
+ if (propertiesOfIdentity.hasNext()) {
+ final var property = propertiesOfIdentity.next();
+ if (name.equals(property.getName())) {
+ final String tip = name.tip().toString();
+ if (tip.equals(reference(expression, true))) try {
+ if (property.equals(sourceType.getProperty(tip))) {
+ break isIdentity; // Continue to consider
that we may have an identity projection.
+ }
+ } catch (PropertyNotFoundException e) {
+ // It may be because the property name is
ambiguous.
+ Logging.ignorableException(StoreUtilities.LOGGER,
FeatureProjection.class, "create", e);
+ }
+ }
+ }
+ propertiesOfIdentity = null;
+ }
+ }
+ /*
+ * End of the construction of properties from the given expressions.
If all properties
+ * are just copying values of properties of the same name from the
source, returns `null`.
+ */
+ if (propertiesOfIdentity == null || propertiesOfIdentity.hasNext()) {
+ this.featureType = ftb.build();
+ this.storedProperties = ArraysExt.resize(storedProperties,
storedCount);
+ this.expressions = ArraysExt.resize(expressions, storedCount);
+ } else {
+ this.featureType = sourceType;
+ this.storedProperties = null;
+ this.expressions = null; // Means "identity operation".
+ }
+ }
+
+ /**
+ * Creates a new projection with the given properties.
+ *
+ * @param type the type of feature instances created by this
projection.
+ * @param projection all properties by name, associated to expressions
for getting values from source features.
+ */
+ @SuppressWarnings({"rawtypes", "unchecked"})
+ public FeatureProjection(final FeatureType type, final Map<String,
Expression<? super Feature, ?>> projection) {
+ featureType = type;
+ expressions = new Expression[projection.size()];
+ storedProperties = new String[expressions.length];
+ int i = 0;
+ for (var entry : projection.entrySet()) {
+ storedProperties[i] = entry.getKey();
+ expressions[i++] = entry.getValue();
+ }
+ if (i != expressions.length) {
+ // Should never happen, unless the `Map` has been modified
concurrently.
+ throw new ConcurrentModificationException();
+ }
+ }
+
+ /**
+ * If the given expression is a value reference, returns the tip of the
referenced property.
+ * Otherwise, returns {@code null}.
+ *
+ * @param expression the expression from which to get the referenced
property name.
+ * @param decode whether to decode the XPath syntax (e.g. {@code {@code
"Q{namespace}"}} syntax).
+ * @return the referenced property name, or {@code null} if none.
+ */
+ private static String reference(final Expression<? super Feature, ?>
expression, final boolean decode) {
+ if (expression instanceof ValueReference<?,?>) {
+ String xpath = ((ValueReference<?,?>) expression).getXPath();
+ return decode ? XPath.toPropertyName(xpath) : xpath;
+ }
+ return null;
+ }
+
+ /**
+ * Returns whether this projection performs no operation.
+ * If this method returns {@code true}, then this instance shall
<strong>not</strong> be used.
+ *
+ * @return whether this projection performs no operation.
+ */
+ public final boolean isIdentity() {
+ return expressions == null;
+ }
+
+ /**
+ * Returns the names of all stored properties. This list may be shorter
than the list of properties
+ * of the {@linkplain #featureType feature type} if some feature
properties are computed on-the-fly.
+ *
+ * @return the name of all stored properties.
+ */
+ public final List<String> getStoredPropertyNames() {
+ return UnmodifiableArrayList.wrap(storedProperties);
+ }
+
+ /**
+ * Returns the name of a property in the source features.
+ * The given index corresponds to an index in the list returned by {@link
#getStoredPropertyNames()}.
+ * The return value is often the same name as {@code
getStoredPropertyNames().get(index)}.
+ *
+ * @param index index of the stored property for which to get the name
in the source feature.
+ * @param decode whether to decode the XPath syntax (e.g. {@code {@code
"Q{namespace}"}} syntax).
+ * @return name in the source features, or {@code null} if the property is
not a {@link ValueReference}.
+ * @throws NullPointerException if {@link #isIdentity()} is {@code true}.
+ */
+ public final String getSourcePropertyName(final int index, final boolean
decode) {
+ return reference(expressions[index], decode);
+ }
+
+ /**
+ * Returns the expression at the given index.
+ *
+ * @param index index of the stored property for which to get the
expression.
+ * @return expression at the given index.
+ * @throws NullPointerException if {@link #isIdentity()} is {@code true}.
+ */
+ public final Expression<? super Feature, ?> getExpression(final int index)
{
+ return expressions[index];
+ }
+
+ /**
+ * Derives a new projected feature instance from the given source.
+ *
+ * @param source the source feature instance.
+ * @return the "projected" (<abbr>SQL</abbr> database sense) feature
instance.
+ * @throws NullPointerException if {@link #isIdentity()} is {@code true}.
+ */
+ @Override
+ public final Feature apply(final Feature source) {
+ final var feature = featureType.newInstance();
+ for (int i=0; i < expressions.length; i++) {
+ feature.setPropertyValue(storedProperties[i],
expressions[i].apply(source));
+ }
+ return feature;
+ }
+
+ /**
+ * Applies the expressions with the given feature as both the source and
the target.
+ * IT can be useful when all expressions are computing values derived from
other attributes.
+ *
+ * @param feature the feature on which to apply the expressions.
+ * @throws NullPointerException if {@link #isIdentity()} is {@code true}.
+ */
+ public final void applySelf(final Feature feature) {
+ for (int i=0; i < expressions.length; i++) {
+ feature.setPropertyValue(storedProperties[i],
expressions[i].apply(feature));
+ }
+ }
+}
