Implement streamRelationColumns in BlackHole

Author: chenjian2664

plugin/trino-blackhole/src/main/java/io/trino/plugin/blackhole/BlackHoleMetadata.java

@@ -35,6 +35,7 @@
 import io.trino.spi.connector.ConnectorTableMetadata;
 import io.trino.spi.connector.ConnectorTableVersion;
 import io.trino.spi.connector.ConnectorViewDefinition;
+import io.trino.spi.connector.RelationColumnsMetadata;
 import io.trino.spi.connector.RetryMode;
 import io.trino.spi.connector.RowChangeParadigm;
 import io.trino.spi.connector.SaveMode;
@@ -54,6 +55,7 @@
 
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.HashMap;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
@@ -62,6 +64,7 @@
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.function.Function;
+import java.util.function.UnaryOperator;
 
 import static com.google.common.base.Preconditions.checkArgument;
 import static com.google.common.base.Verify.verify;
@@ -185,9 +188,32 @@ public Map<SchemaTableName, List<ColumnMetadata>> listTableColumns(ConnectorSess
     @Override
     public Iterator<TableColumnsMetadata> streamTableColumns(ConnectorSession session, SchemaTablePrefix prefix)
     {
-        return tables.values().stream()
+        throw new UnsupportedOperationException("The deprecated streamTableColumns is not supported because streamRelationColumns is implemented instead");
+    }
+
+    @Override
+    public Iterator<RelationColumnsMetadata> streamRelationColumns(
+            ConnectorSession session,
+            Optional<String> schemaName,
+            UnaryOperator<Set<SchemaTableName>> relationFilter)
+    {
+        Map<SchemaTableName, RelationColumnsMetadata> relationColumns = new HashMap<>();
+        SchemaTablePrefix prefix = schemaName.map(SchemaTablePrefix::new).orElseGet(SchemaTablePrefix::new);
+
+        tables.values().stream()
                 .filter(table -> prefix.matches(table.toSchemaTableName()))
-                .map(handle -> TableColumnsMetadata.forTable(handle.toSchemaTableName(), handle.toTableMetadata().getColumns()))
+                .map(BlackHoleTableHandle::toTableMetadata)
+                .forEach(columnsMetadata -> {
+                    SchemaTableName name = columnsMetadata.getTable();
+                    relationColumns.put(name, RelationColumnsMetadata.forTable(name, columnsMetadata.getColumns()));
+                });
+
+        for (Map.Entry<SchemaTableName, ConnectorViewDefinition> entry : getViews(session, schemaName).entrySet()) {
+            relationColumns.put(entry.getKey(), RelationColumnsMetadata.forView(entry.getKey(), entry.getValue().getColumns()));
+        }
+
+        return relationFilter.apply(relationColumns.keySet()).stream()
+                .map(relationColumns::get)
                 .iterator();
     }