MONDRIAN: Implement "aggregate" builtin function.

[git-p4: depot-paths = "//open/mondrian/": change = 310]

src/main/mondrian/olap/Evaluator.java

@@ -57,6 +57,12 @@ public interface Evaluator {
 	 * Returns parent evaluator.
 	 */
 	Evaluator getParent();
-};
+	/**
+	 * Retrieves the value of property <code>name</code>. If more than one
+	 * member in the current context defines that property, the one with the
+	 * highest solve order has precedence.
+	 */
+	Object getProperty(String name);
+}
 
 // End Evaluator.java

src/main/mondrian/olap/Property.java

@@ -24,6 +24,22 @@ public abstract class Property {
 	public static final int TYPE_NUMERIC = 1;
 	public static final int TYPE_BOOLEAN = 2;
 
+	/** The name of the property which holds the parsed format string. Internal. **/
+	public static final String PROPERTY_FORMAT_EXP = "$format_exp";
+	/** The name of the property which holds the aggregation type. This is
+	 * automatically set for stored measures, based upon their SQL
+	 * aggregation. **/
+	public static final String PROPERTY_AGGREGATION_TYPE = "$aggregation_type";
+
+	/**
+	 * A list of the names of properties which have special meaning to the
+	 * Mondrian system.
+	 */
+	public static final String[] systemPropertyNames = {
+		PROPERTY_FORMAT_EXP,
+		PROPERTY_AGGREGATION_TYPE,
+	};
+
 	protected Property(String name, int type) {
 		this.name = name;
 		this.type = type;

src/main/mondrian/olap/fun/FunUtil.java

@@ -648,7 +648,6 @@ static Object covariance(Evaluator evaluator, Vector members, ExpBase exp1, ExpB
 		SetWrapper sw2 = evaluateSet(evaluator.push(), members, exp2);
 		//todo: because evaluateSet does not add nulls to the SetWrapper, this solution may
 		//lead to mismatched vectors and is therefore not robust
-//		return _covariance(sw1, sw2, biased);
 		return _covariance(sw1, sw2, biased);
 	}
 
@@ -674,10 +673,9 @@ private static Object _covariance(SetWrapper sw1, SetWrapper sw2, boolean biased
 	static Object stdev(Evaluator evaluator, Vector members, ExpBase exp, boolean biased) {
 		Object o = var(evaluator, members, exp, biased);
 		if (o instanceof Double) {
-				return new Double(Math.sqrt(((Double) o).doubleValue()));
-		}
-		else {
-				return o;
+			return new Double(Math.sqrt(((Double) o).doubleValue()));
+		} else {
+			return o;
 		}
 	}
 
@@ -724,27 +722,54 @@ static Object sum(Evaluator evaluator, Vector members, ExpBase exp) {
 		}
 	}
 
+	static Object count(Vector members, boolean includeEmpty) {
+		if (includeEmpty) {
+			return new Double(members.size());
+		} else {
+			int retval = 0;
+			for (int i = 0; i < members.size(); i++) {
+				final Object member = members.elementAt(i);
+				if (member != Util.nullValue && member != null) {
+					retval++;
+				}
+			}
+			return new Double(retval);
+		}
+	}
+
+	static Object aggregate(
+			Evaluator evaluator, String aggregator, Vector members, ExpBase exp) {
+		if (aggregator.equals("sum")) {
+			return sum(evaluator, members, exp);
+		} else if (aggregator.equals("count")) {
+			return count(members, false);
+		} else if (aggregator.equals("avg")) {
+			return avg(evaluator, members, exp);
+		} else if (aggregator.equals("min")) {
+			return min(evaluator, members, exp);
+		} else if (aggregator.equals("max")) {
+			return max(evaluator, members, exp);
+		} else {
+			throw newEvalException(null, "Unknown aggregator '" + aggregator + "'");
+		}
+	}
+
 	/**
 	 * Evaluates <code>exp</code> (if defined) over <code>members</code> to
 	 * generate a <code>Vector</code> of <code>SetWrapper</code>, which contains
 	 * a <code>Double</code> value and meta information, unlike
 	 * <code>evaluateMembers</code>, which only produces values
+	 *
+	 * @pre exp != null
 	 */
 	static SetWrapper evaluateSet(Evaluator evaluator, Vector members, ExpBase exp) {
+		Util.assertPrecondition(exp != null, "exp != null");
 		// todo: treat constant exps as evaluateMembers() does
 		SetWrapper retval = new SetWrapper();
 		for (int i = 0, count = members.size(); i < count; i++) {
 			Member member = (Member) members.elementAt(i);
 			evaluator.setContext(member);
-			Object o = null;
-			if (exp != null) {
-				o = exp.evaluateScalar(evaluator);
-			}
-			else { //is this right?
-				evaluator.setContext(member);
-				o = evaluator.evaluateCurrent();
-			}
-
+			Object o = exp.evaluateScalar(evaluator);
 			if (o == null || o == Util.nullValue) {
 				retval.nullCount++;
 			} else if (o instanceof Throwable) {

src/main/mondrian/rolap/RolapCalculatedMember.java

@@ -43,7 +43,7 @@ public class RolapCalculatedMember extends RolapMember {
 		if (formatExp == null) {
 			formatExp = Literal.emptyString;
 		}
-		setProperty(PROPERTY_FORMAT_EXP, formatExp);
+		setProperty(Property.PROPERTY_FORMAT_EXP, formatExp);
 	}
 
 	// override RolapMember

src/main/mondrian/rolap/RolapEvaluator.java

@@ -30,7 +30,6 @@ class RolapEvaluator implements Evaluator
 	Evaluator parent;
 	CellReader cellReader;
 	int depth;
-	private static final RolapMember[] emptyMembers = {};
 
 	RolapEvaluator(RolapCube cube, RolapConnection connection)
 	{
@@ -80,29 +79,27 @@ public Evaluator getParent() {
 	}
 
 	public Evaluator push(Member[] members) {
-		RolapMember[] cloneCurrentMembers = new RolapMember[
-			this.currentMembers.length];
-		for (int i = 0; i < this.currentMembers.length; i++) {
-			cloneCurrentMembers[i] = this.currentMembers[i];
-		}
-		for (int i = 0; i < members.length; i++) {
-			RolapMember member = (RolapMember) members[i];
-			int ordinal = member.getDimension().getOrdinal(cube);
-			cloneCurrentMembers[ordinal] = member;
-		}
-		return new RolapEvaluator(cube, connection, cloneCurrentMembers, this);
+		final RolapEvaluator evaluator = _push();
+		evaluator.setContext(members);
+		return evaluator;
+	}
+
+	public Evaluator push(Member member) {
+		final RolapEvaluator evaluator = _push();
+		evaluator.setContext(member);
+		return evaluator;
 	}
 
 	public Evaluator push() {
-		return push(emptyMembers);
+		return _push();
 	}
 
-	public Evaluator push(Member member) {
-		return push(new Member[] {member});
+	private final RolapEvaluator _push() {
+		RolapMember[] cloneCurrentMembers = (RolapMember[]) this.currentMembers.clone();
+		return new RolapEvaluator(cube, connection, cloneCurrentMembers, this);
 	}
 
-	public Evaluator pop()
-	{
+	public Evaluator pop() {
 		return parent;
 	}
 	public Object xx(Literal literal) {
@@ -199,12 +196,7 @@ private String getContextString() {
 		return sb.toString();
 	}
 
-	/**
-	 * Retrieves the value of property <code>name</code>. If more than one
-	 * member in the current context defines that property, the one with the
-	 * highest solve order has precedence.
-	 */
-	Object getProperty(String name)
+	public Object getProperty(String name)
 	{
 		Object o = null;
 		int maxSolve = Integer.MIN_VALUE;
@@ -223,7 +215,7 @@ Object getProperty(String name)
 	}
 	private String getFormatString()
 	{
-		Exp formatExp = (Exp) getProperty(RolapMember.PROPERTY_FORMAT_EXP);
+		Exp formatExp = (Exp) getProperty(Property.PROPERTY_FORMAT_EXP);
 		Object o = formatExp.evaluate(this);
 		return o.toString();
 	}

src/main/mondrian/rolap/RolapMeasure.java

@@ -11,10 +11,7 @@
 */
 
 package mondrian.rolap;
-import mondrian.olap.MondrianDef;
-import mondrian.olap.Evaluator;
-import mondrian.olap.Literal;
-import mondrian.olap.Exp;
+import mondrian.olap.*;
 
 /**
  * todo:
@@ -42,7 +39,7 @@ abstract class RolapMeasure extends RolapMember
 		}
 		RolapConnection connection = ((RolapDimension) getDimension()).schema.getInternalConnection();
 		Exp formatExp = connection.parseExpression("'" + formatString + "'");
-		setProperty(PROPERTY_FORMAT_EXP, formatExp);
+		setProperty(Property.PROPERTY_FORMAT_EXP, formatExp);
 	}
 
 }

src/main/mondrian/rolap/RolapMember.java

@@ -87,15 +87,15 @@ public void setName(String name)
 	{
 		throw new Error("unsupported");
 	}
-	/** The name of the property which holds the parsed format string. Internal. **/
-	public static final String PROPERTY_FORMAT_EXP = "$format_exp";
+	/** Sets a property of this member to a given value. */
 	public synchronized void setProperty(String name, Object value) {
 		if (mapPropertyNameToValue.isEmpty()) {
 			// the empty map is shared and immutable; create our own
 			mapPropertyNameToValue = new HashMap();
 		}
 		mapPropertyNameToValue.put(name, value);
 	}
+
 	public synchronized Object getPropertyValue(String name) {
 		return mapPropertyNameToValue.get(name);
 	}

src/main/mondrian/rolap/RolapStoredMeasure.java

@@ -13,6 +13,7 @@
 package mondrian.rolap;
 import mondrian.olap.Util;
 import mondrian.olap.MondrianDef;
+import mondrian.olap.Property;
 
 /**
  * todo:
@@ -36,8 +37,21 @@ class RolapStoredMeasure extends RolapMeasure
 		super(parentMember, level, name, formatString);
 		this.cube = cube;
 		this.expression = expression;
-		//Util.assertTrue(aggregator.equals("sum") || aggregator.equals("count"));
+		Util.assertTrue(aggregatorIsValid(aggregator));
 		this.aggregator = aggregator;
+		setProperty(Property.PROPERTY_AGGREGATION_TYPE, aggregator);
+	}
+
+	private static final String[] aggregators = new String[] {
+		"sum", "count", "min", "max", "avg"
+	};
+	private static boolean aggregatorIsValid(String aggregator) {
+		for (int i = 0; i < aggregators.length; i++) {
+			if (aggregator.equals(aggregators[i])) {
+				return true;
+			}
+		}
+		return false;
 	}
 
 	RolapStoredMeasure(