bug 57840: move XSSFTable cache from XSSFWorkbook to XSSFEvaluationWorkbook where staleness is less likely to cause problems for users

git-svn-id: https://svn.apache.org/repos/asf/poi/branches/xssf_structured_references@1747615 13f79535-47bb-0310-9956-ffa450edef68

src/ooxml/java/org/apache/poi/xssf/streaming/SXSSFEvaluationWorkbook.java

@@ -28,7 +28,7 @@ import org.apache.poi.xssf.usermodel.BaseXSSFEvaluationWorkbook;
  * SXSSF wrapper around the SXSSF and XSSF workbooks
  */
 public final class SXSSFEvaluationWorkbook extends BaseXSSFEvaluationWorkbook {
-    private SXSSFWorkbook _uBook;
+    private final SXSSFWorkbook _uBook;
     
     public static SXSSFEvaluationWorkbook create(SXSSFWorkbook book) {
         if (book == null) {
@@ -42,15 +42,18 @@ public final class SXSSFEvaluationWorkbook extends BaseXSSFEvaluationWorkbook {
         _uBook = book;
     }
 
+    @Override
     public int getSheetIndex(EvaluationSheet evalSheet) {
         SXSSFSheet sheet = ((SXSSFEvaluationSheet)evalSheet).getSXSSFSheet();
         return _uBook.getSheetIndex(sheet);
     }
 
+    @Override
     public EvaluationSheet getSheet(int sheetIndex) {
         return new SXSSFEvaluationSheet(_uBook.getSheetAt(sheetIndex));
     }
 
+    @Override
     public Ptg[] getFormulaTokens(EvaluationCell evalCell) {
         SXSSFCell cell = ((SXSSFEvaluationCell)evalCell).getSXSSFCell();
         SXSSFEvaluationWorkbook frBook = SXSSFEvaluationWorkbook.create(_uBook);

src/ooxml/java/org/apache/poi/xssf/usermodel/BaseXSSFEvaluationWorkbook.java

@@ -17,7 +17,10 @@
 
 package org.apache.poi.xssf.usermodel;
 
+import java.util.HashMap;
 import java.util.List;
+import java.util.Locale;
+import java.util.Map;
 
 import org.apache.poi.ss.SpreadsheetVersion;
 import org.apache.poi.ss.formula.EvaluationName;
@@ -37,6 +40,7 @@ import org.apache.poi.ss.formula.ptg.Ref3DPxg;
 import org.apache.poi.ss.formula.udf.IndexedUDFFinder;
 import org.apache.poi.ss.formula.udf.UDFFinder;
 import org.apache.poi.ss.usermodel.Table;
+import org.apache.poi.ss.usermodel.Sheet;
 import org.apache.poi.ss.util.AreaReference;
 import org.apache.poi.ss.util.CellReference;
 import org.apache.poi.util.NotImplemented;
@@ -311,8 +315,46 @@ public abstract class BaseXSSFEvaluationWorkbook implements FormulaRenderingWork
         return _uBook.createName();
     }
 
-    public Table getTable(String name) {
+    /*
-        return _uBook.getTable(name);
+     * TODO: data tables are stored at the workbook level in XSSF, but are bound to a single sheet.
+     *       The current code structure has them hanging off XSSFSheet, but formulas reference them
+     *       only by name (names are global, and case insensitive).
+     *       This map stores names as lower case for case-insensitive lookups.
+     *
+     * FIXME: Caching tables by name here for fast formula lookup means the map is out of date if
+     *       a table is renamed or added/removed to a sheet after the map is created.
+     *
+     *       Perhaps tables can be managed similar to PivotTable references above?
+     */
+    private Map<String, XSSFTable> _tableCache = null;
+    private Map<String, XSSFTable> getTableCache() {
+        if ( _tableCache != null ) {
+            return _tableCache;
+        }
+        // FIXME: use org.apache.commons.collections.map.CaseInsensitiveMap
+        _tableCache = new HashMap<String, XSSFTable>();
+
+        for (Sheet sheet : _uBook) {
+            for (XSSFTable tbl : ((XSSFSheet)sheet).getTables()) {
+                String lname = tbl.getName().toLowerCase(Locale.ROOT);
+                _tableCache.put(lname, tbl);
+            }
+        }
+        return _tableCache;
+    }
+
+    /**
+     * Returns the data table with the given name (case insensitive).
+     * Tables are cached for performance (formula evaluation looks them up by name repeatedly).
+     * After the first table lookup, adding or removing a table from the document structure will cause trouble.
+     * This is meant to be used on documents whose structure is essentially static at the point formulas are evaluated.
+     * 
+     * @param name the data table name (case-insensitive)
+     * @return The Data table in the workbook named <tt>name</tt>, or <tt>null</tt> if no table is named <tt>name</tt>.
+     * @since 3.15 beta 2
+     */
+    public XSSFTable getTable(String name) {
+        return getTableCache().get(name.toLowerCase(Locale.ROOT));
     }
     
     public UDFFinder getUDFFinder(){

src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFEvaluationWorkbook.java

@@ -27,7 +27,6 @@ import org.apache.poi.ss.formula.ptg.Ptg;
  * Internal POI use only
  */
 public final class XSSFEvaluationWorkbook extends BaseXSSFEvaluationWorkbook {
-    @Override
     public static XSSFEvaluationWorkbook create(XSSFWorkbook book) {
         if (book == null) {
             return null;