--- /dev/null
+/*\r
+\r
+ Derby - Class org.apache.derby.impl.store.access.conglomerate.OpenConglomerateScratchSpace\r
+\r
+ Licensed to the Apache Software Foundation (ASF) under one or more\r
+ contributor license agreements. See the NOTICE file distributed with\r
+ this work for additional information regarding copyright ownership.\r
+ The ASF licenses this file to you under the Apache License, Version 2.0\r
+ (the "License"); you may not use this file except in compliance with\r
+ the License. You may obtain a copy of the License at\r
+\r
+ http://www.apache.org/licenses/LICENSE-2.0\r
+\r
+ Unless required by applicable law or agreed to in writing, software\r
+ distributed under the License is distributed on an "AS IS" BASIS,\r
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\r
+ See the License for the specific language governing permissions and\r
+ limitations under the License.\r
+\r
+ */\r
+\r
+package org.apache.derby.impl.store.access.conglomerate;\r
+\r
+import org.apache.derby.iapi.error.StandardException; \r
+\r
+import org.apache.derby.iapi.store.access.DynamicCompiledOpenConglomInfo;\r
+import org.apache.derby.iapi.store.access.RowUtil;\r
+\r
+import org.apache.derby.iapi.store.raw.Transaction;\r
+\r
+import org.apache.derby.iapi.types.DataValueDescriptor;\r
+\r
+import org.apache.derby.iapi.services.io.FormatableBitSet;\r
+import org.apache.derby.iapi.services.loader.InstanceGetter;\r
+\r
+/**\r
+\r
+A utility class to store and use temporary scratch space associated with\r
+a conglomerate.\r
+\r
+**/\r
+\r
+public class OpenConglomerateScratchSpace \r
+ implements DynamicCompiledOpenConglomInfo\r
+{\r
+\r
+ /**************************************************************************\r
+ * Fields of the class\r
+ **************************************************************************\r
+ */\r
+\r
+ /**\r
+ * A template of info about the classes in the returned row.\r
+ * <p>\r
+ * This template is allocated on demand, and is used to efficiently\r
+ * create new rows for export from this class. This variable is for\r
+ * use by get_row_for_export().\r
+ **/\r
+ private FormatableBitSet row_for_export_column_list;\r
+ private DataValueDescriptor[] row_for_export_template;\r
+\r
+ /**\r
+ * A Scratch template used for searching and qualifying rows in the \r
+ * conglomerate. This is a full template, independent of the \r
+ * FormatableBitSet used for access.\r
+ **/\r
+ private DataValueDescriptor[] scratch_template;\r
+\r
+ /**\r
+ * A Scratch row used for qualifying rows in the \r
+ * conglomerate. This is a row which matches the FormatableBitSet of rows\r
+ * being returned.\r
+ **/\r
+ private DataValueDescriptor[] scratch_row;\r
+\r
+ /**\r
+ * A complete array of format id's and collation_ids for this conglomerate.\r
+ **/\r
+ private int[] format_ids;\r
+ private int[] collation_ids;\r
+\r
+\r
+ /* scratch space used by ConglomerateController.delete and replace */\r
+ private RowPosition scratch_row_position;\r
+\r
+ /**************************************************************************\r
+ * Constructors for This class:\r
+ **************************************************************************\r
+ */\r
+ public OpenConglomerateScratchSpace(\r
+ int[] format_ids,\r
+ int[] collation_ids)\r
+ {\r
+ this.format_ids = format_ids;\r
+ this.collation_ids = collation_ids;\r
+ }\r
+\r
+ /**************************************************************************\r
+ * Private/Protected methods of This class:\r
+ **************************************************************************\r
+ */\r
+\r
+ /**************************************************************************\r
+ * Public Methods of This class:\r
+ **************************************************************************\r
+ */\r
+\r
+ /**\r
+ * Return an empty template (possibly partial) row to be given back to \r
+ * a client.\r
+ * <p>\r
+ * The main use of this is for fetchSet() and fetchNextGroup() which\r
+ * allocate rows and then give them back entirely to the caller.\r
+ * <p>\r
+ *\r
+ * @return The row to use.\r
+ *\r
+ * @exception StandardException Standard exception policy.\r
+ **/\r
+ public DataValueDescriptor[] get_row_for_export(Transaction rawtran)\r
+ throws StandardException\r
+ {\r
+ // Create a partial row class template template from the initial scan\r
+ // parameters.\r
+ if (row_for_export_template == null)\r
+ {\r
+ row_for_export_template = \r
+ RowUtil.newTemplate(\r
+ rawtran.getDataValueFactory(), \r
+ row_for_export_column_list, format_ids, collation_ids);\r
+ }\r
+\r
+ // Allocate a new row based on the class template.\r
+ return(RowUtil.newRowFromTemplate(row_for_export_template));\r
+ }\r
+\r
+ /**\r
+ * Return an empty template (possibly partial) row to be used and \r
+ * reused internally for processing.\r
+ * <p>\r
+ * The main use of this is for qualifying rows where a row has not been\r
+ * provided by the client. This routine cache's a single row for reuse\r
+ * by the caller, if the caller needs 2 concurrent scratch rows, some other\r
+ * mechanism must be used.\r
+ * <p>\r
+ *\r
+ * @return The row to use.\r
+ *\r
+ * @exception StandardException Standard exception policy.\r
+ **/\r
+ public DataValueDescriptor[] get_scratch_row(Transaction rawtran)\r
+ throws StandardException\r
+ {\r
+ // Create a partial row class template template from the initial scan\r
+ // parameters.\r
+ if (scratch_row == null)\r
+ {\r
+ scratch_row = get_row_for_export(rawtran);\r
+ }\r
+\r
+ // Allocate a new row based on the class template.\r
+ return(scratch_row);\r
+ }\r
+\r
+ /**\r
+ * Return a complete empty row. \r
+ * <p>\r
+ * The main use of this is for searching a tree where a complete copy of\r
+ * the row is needed for searching.\r
+ * <p>\r
+ *\r
+ * @return The template to use.\r
+ *\r
+ * @exception StandardException Standard exception policy.\r
+ **/\r
+ public DataValueDescriptor[] get_template(Transaction rawtran)\r
+ throws StandardException\r
+ {\r
+ // Create a partial row class template from the initial scan parameters.\r
+ if (scratch_template == null)\r
+ {\r
+ scratch_template = \r
+ TemplateRow.newRow(\r
+ rawtran, \r
+ (FormatableBitSet) null, format_ids, collation_ids);\r
+ }\r
+\r
+ return(scratch_template);\r
+ }\r
+\r
+ /**\r
+ * Return a scratch RowPosition.\r
+ * <p>\r
+ * Used by GenericConglomerateController.delete() and \r
+ * GenericConglomerateController.replace(). It may be reused so callers\r
+ * must insure that object no longer needed before next possible call\r
+ * to get it again.\r
+ * <p>\r
+ *\r
+ * @return a scratch RowPosition.\r
+ *\r
+ * @exception StandardException Standard exception policy.\r
+ **/\r
+ public RowPosition get_scratch_row_position()\r
+ {\r
+ if (scratch_row_position == null)\r
+ {\r
+ scratch_row_position = new RowPosition();\r
+ }\r
+\r
+ return(scratch_row_position);\r
+ }\r
+\r
+ /**\r
+ * Initialize scratch space for reuse by possibly different template.\r
+ * <p>\r
+ * Some data is only valid per statement.\r
+ **/\r
+ public void init(\r
+ FormatableBitSet export_column_list)\r
+ {\r
+ row_for_export_template = null;\r
+ row_for_export_column_list = null;\r
+ }\r
+}\r
projects / Benchmarks_CSolver.git / blobdiff