1 files changed, 73 insertions, 0 deletions
diff --git a/src/mongo/db/pipeline/accumulator_push.cpp b/src/mongo/db/pipeline/accumulator_push.cpp
new file mode 100755
index 00000000000..2640bc4ecfd
--- /dev/null
+++ b/src/mongo/db/pipeline/accumulator_push.cpp
@@ -0,0 +1,73 @@
+/**
+ * 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/expression_context.h"
+#include "db/pipeline/value.h"
+
+namespace mongo {
+    intrusive_ptr<const Value> AccumulatorPush::evaluate(
+        const intrusive_ptr<Document> &pDocument) const {
+        assert(vpOperand.size() == 1);
+	intrusive_ptr<const Value> prhs(vpOperand[0]->evaluate(pDocument));
+
+	if (prhs->getType() == Undefined)
+	    ; /* nothing to add to the array */
+	else if (!pCtx->getInRouter())
+	    vpValue.push_back(prhs);
+	else {
+	    /*
+	      If we're in the router, we need to take apart the arrays we
+	      receive and put their elements into the array we are collecting.
+	      If we didn't, then we'd get an array of arrays, with one array
+	      from each shard that responds.
+	     */
+	    assert(prhs->getType() == Array);
+	    
+	    intrusive_ptr<ValueIterator> pvi(prhs->getArray());
+	    while(pvi->more()) {
+		intrusive_ptr<const Value> pElement(pvi->next());
+		vpValue.push_back(pElement);
+	    }
+	}
+
+        return Value::getNull();
+    }
+
+    intrusive_ptr<const Value> AccumulatorPush::getValue() const {
+        return Value::createArray(vpValue);
+    }
+
+    AccumulatorPush::AccumulatorPush(
+	const intrusive_ptr<ExpressionContext> &pTheCtx):
+        Accumulator(),
+        vpValue(),
+        pCtx(pTheCtx) {
+    }
+
+    intrusive_ptr<Accumulator> AccumulatorPush::create(
+	const intrusive_ptr<ExpressionContext> &pCtx) {
+	intrusive_ptr<AccumulatorPush> pAccumulator(
+	    new AccumulatorPush(pCtx));
+        return pAccumulator;
+    }
+
+    const char *AccumulatorPush::getOpName() const {
+	return "$push";
+    }
+}