1 files changed, 114 insertions, 0 deletions
diff --git a/src/java/org/apache/poi/ss/formula/CellCacheEntry.java b/src/java/org/apache/poi/ss/formula/CellCacheEntry.java
new file mode 100644
index 0000000000..861874c25b
--- /dev/null
+++ b/src/java/org/apache/poi/ss/formula/CellCacheEntry.java
@@ -0,0 +1,114 @@
+/* ====================================================================
+   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.poi.ss.formula;
+
+import java.util.HashSet;
+import java.util.Set;
+
+import org.apache.poi.hssf.record.formula.eval.BoolEval;
+import org.apache.poi.hssf.record.formula.eval.ErrorEval;
+import org.apache.poi.hssf.record.formula.eval.NumberEval;
+import org.apache.poi.hssf.record.formula.eval.StringEval;
+import org.apache.poi.hssf.record.formula.eval.ValueEval;
+
+/**
+ * Stores the parameters that identify the evaluation of one cell.<br/>
+ */
+final class CellCacheEntry {
+	private ValueEval _value;
+	private final Set _consumingCells;
+	private CellLocation[] _usedCells;
+	private boolean _isPlainValueCell;
+	
+	public CellCacheEntry() {
+		_consumingCells = new HashSet();
+	}
+	public boolean updatePlainValue(ValueEval value) {
+		boolean wasChanged = false;
+		if (!_isPlainValueCell) {
+			wasChanged = true;
+		}
+		if (!areValuesEqual(_value, value)) {
+			wasChanged = true;
+		}
+		_isPlainValueCell = true;
+		_value = value;
+		_usedCells = null;
+		return wasChanged;
+	}
+	private boolean areValuesEqual(ValueEval a, ValueEval b) {
+		if (a == null) {
+			return false;
+		}
+		Class cls = a.getClass();
+		if (cls != b.getClass()) {
+			// value type is changing
+			return false;
+		}
+		if (cls == NumberEval.class) {
+			return ((NumberEval)a).getNumberValue() == ((NumberEval)b).getNumberValue();
+		}
+		if (cls == StringEval.class) {
+			return ((StringEval)a).getStringValue().equals(((StringEval)b).getStringValue());
+		}
+		if (cls == BoolEval.class) {
+			return ((BoolEval)a).getBooleanValue() == ((BoolEval)b).getBooleanValue();
+		}
+		if (cls == ErrorEval.class) {
+			return ((ErrorEval)a).getErrorCode() == ((ErrorEval)b).getErrorCode();
+		}
+		throw new IllegalStateException("Unexpected value class (" + cls.getName() + ")");
+	}
+	public void setFormulaResult(ValueEval value, CellLocation[] usedCells) {
+		_isPlainValueCell = false;
+		_value = value;
+		_usedCells = usedCells;
+	}
+	public void addConsumingCell(CellLocation cellLoc) {
+		_consumingCells.add(cellLoc);
+		
+	}
+	public CellLocation[] getConsumingCells() {
+		int nItems = _consumingCells.size();
+		if (nItems < 1) {
+			return CellLocation.EMPTY_ARRAY;
+		}
+		CellLocation[] result = new CellLocation[nItems];
+		_consumingCells.toArray(result);
+		return result;
+	}
+	public CellLocation[] getUsedCells() {
+		return _usedCells;
+	}
+	public void clearConsumingCell(CellLocation fc) {
+		if(!_consumingCells.remove(fc)) {
+			throw new IllegalStateException("Cell '" + fc.formatAsString() + "' does not use this cell");
+		}
+		
+	}
+	public ValueEval getValue() {
+		ValueEval result = _value;
+		if (result == null) {
+			if (_isPlainValueCell) {
+				throw new IllegalStateException("Plain value cell should always have a value");
+				
+			}
+		}
+		return result;
+	}
+}
+\ No newline at end of file