gh-yzou commented on code in PR #1303: URL: https://github.com/apache/polaris/pull/1303#discussion_r2039962078
########## plugins/spark/v3.5/src/main/java/org/apache/polaris/spark/utils/DeltaHelper.java: ########## @@ -0,0 +1,108 @@ +/* + * 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.polaris.spark.utils; + +import com.esotericsoftware.minlog.Log; +import java.lang.reflect.Field; +import java.lang.reflect.Method; +import org.apache.iceberg.common.DynConstructors; +import org.apache.polaris.spark.PolarisSparkCatalog; +import org.apache.spark.sql.connector.catalog.DelegatingCatalogExtension; +import org.apache.spark.sql.connector.catalog.TableCatalog; +import org.apache.spark.sql.util.CaseInsensitiveStringMap; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +public class DeltaHelper { + private static final Logger LOG = LoggerFactory.getLogger(DeltaHelper.class); + + public static final String DELTA_CATALOG_IMPL_KEY = "delta-catalog-impl"; + private static final String DEFAULT_DELTA_CATALOG_CLASS = + "org.apache.spark.sql.delta.catalog.DeltaCatalog"; + + private TableCatalog deltaCatalog = null; + private String deltaCatalogImpl = DEFAULT_DELTA_CATALOG_CLASS; + + public DeltaHelper(CaseInsensitiveStringMap options) { + if (options.get(DELTA_CATALOG_IMPL_KEY) != null) { + this.deltaCatalogImpl = options.get(DELTA_CATALOG_IMPL_KEY); + } + } + + public TableCatalog loadDeltaCatalog(PolarisSparkCatalog polarisSparkCatalog) { + if (this.deltaCatalog != null) { + return this.deltaCatalog; + } + + DynConstructors.Ctor<TableCatalog> ctor; + try { + ctor = DynConstructors.builder(TableCatalog.class).impl(deltaCatalogImpl).buildChecked(); + } catch (NoSuchMethodException e) { + throw new IllegalArgumentException( + String.format("Cannot initialize Delta Catalog %s: %s", deltaCatalogImpl, e.getMessage()), + e); + } + + try { + this.deltaCatalog = ctor.newInstance(); + } catch (ClassCastException e) { + throw new IllegalArgumentException( + String.format( + "Cannot initialize Delta Catalog, %s does not implement Table Catalog.", + deltaCatalogImpl), + e); + } + + // set the polaris spark catalog as the delegate catalog of delta catalog + ((DelegatingCatalogExtension) this.deltaCatalog).setDelegateCatalog(polarisSparkCatalog); + + // We want to behave exactly the same as unity catalog for Delta. However, DeltaCatalog + // implementation today is hard coded for unity catalog. Following issue is used to track + // the extension of the usage https://github.com/delta-io/delta/issues/4306. + // Here, we use reflection to set the isUnityCatalog to true for exactly same behavior as + // unity catalog for now. + try { + // isUnityCatalog is a lazy val, access the compute method for the lazy val + // make sure the method is triggered before the value is set, otherwise, the + // value will be overwritten later when the method is triggered. + String methodGetName = "isUnityCatalog" + "$lzycompute"; + Method method = this.deltaCatalog.getClass().getDeclaredMethod(methodGetName); + method.setAccessible(true); + // invoke the lazy methods before it is set + method.invoke(this.deltaCatalog); + } catch (NoSuchMethodException e) { + Log.warn("No lazy compute method found for variable isUnityCatalog"); Review Comment: that is a mistake, thanks for catching that! updated -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
