1 files changed, 74 insertions, 0 deletions
diff --git a/src/mongo/db/pipeline/accumulator_sum.cpp b/src/mongo/db/pipeline/accumulator_sum.cpp
new file mode 100755
index 00000000000..e6526ac254a
--- /dev/null
+++ b/src/mongo/db/pipeline/accumulator_sum.cpp
@@ -0,0 +1,74 @@
+/**
+ * Copyright (c) 2011 10gen Inc.
+ *
+ * This program is free software: you can redistribute it and/or  modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "pch.h"
+#include "accumulator.h"
+
+#include "db/pipeline/value.h"
+
+namespace mongo {
+
+    intrusive_ptr<const Value> AccumulatorSum::evaluate(
+        const intrusive_ptr<Document> &pDocument) const {
+        assert(vpOperand.size() == 1);
+	intrusive_ptr<const Value> prhs(vpOperand[0]->evaluate(pDocument));
+
+        /* upgrade to the widest type required to hold the result */
+	totalType = Value::getWidestNumeric(totalType, prhs->getType());
+
+        if (totalType == NumberInt) {
+            int v = prhs->coerceToInt();
+            longTotal += v;
+            doubleTotal += v;
+        }
+        else if (totalType == NumberLong) {
+            long long v = prhs->coerceToLong();
+            longTotal += v;
+            doubleTotal += v;
+        }
+        else { /* (totalType == NumberDouble) */
+            double v = prhs->coerceToDouble();
+            doubleTotal += v;
+        }
+
+        return Value::getZero();
+    }
+
+    intrusive_ptr<Accumulator> AccumulatorSum::create(
+	const intrusive_ptr<ExpressionContext> &pCtx) {
+	intrusive_ptr<AccumulatorSum> pSummer(new AccumulatorSum());
+        return pSummer;
+    }
+
+    intrusive_ptr<const Value> AccumulatorSum::getValue() const {
+        if (totalType == NumberInt)
+            return Value::createInt((int)longTotal);
+        if (totalType == NumberLong)
+            return Value::createLong(longTotal);
+        return Value::createDouble(doubleTotal);
+    }
+
+    AccumulatorSum::AccumulatorSum():
+        Accumulator(),
+        totalType(NumberInt),
+        longTotal(0),
+        doubleTotal(0) {
+    }
+
+    const char *AccumulatorSum::getOpName() const {
+	return "$sum";
+    }
+}