1 files changed, 79 insertions, 0 deletions
diff --git a/src/mongo/db/pipeline/accumulator_add_to_set.cpp b/src/mongo/db/pipeline/accumulator_add_to_set.cpp
new file mode 100755
index 00000000000..86d4366ff0c
--- /dev/null
+++ b/src/mongo/db/pipeline/accumulator_add_to_set.cpp
@@ -0,0 +1,79 @@
+/**
+ * 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> AccumulatorAddToSet::evaluate(
+        const intrusive_ptr<Document> &pDocument) const {
+        verify(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->getDoingMerge())
+            set.insert(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.
+             */
+            verify(prhs->getType() == Array);
+            
+            intrusive_ptr<ValueIterator> pvi(prhs->getArray());
+            while(pvi->more()) {
+                intrusive_ptr<const Value> pElement(pvi->next());
+                set.insert(pElement);
+            }
+        }
+
+        return Value::getNull();
+    }
+
+    intrusive_ptr<const Value> AccumulatorAddToSet::getValue() const {
+        vector<intrusive_ptr<const Value> > valVec;
+
+        for (itr = set.begin(); itr != set.end(); ++itr) {
+            valVec.push_back(*itr);
+        }
+        /* there is no issue of scope since createArray copy constructs */
+        return Value::createArray(valVec);
+    }
+
+    AccumulatorAddToSet::AccumulatorAddToSet(
+        const intrusive_ptr<ExpressionContext> &pTheCtx):
+        Accumulator(),
+        set(),
+        pCtx(pTheCtx) {
+    }
+
+    intrusive_ptr<Accumulator> AccumulatorAddToSet::create(
+        const intrusive_ptr<ExpressionContext> &pCtx) {
+        intrusive_ptr<AccumulatorAddToSet> pAccumulator(
+            new AccumulatorAddToSet(pCtx));
+        return pAccumulator;
+    }
+
+    const char *AccumulatorAddToSet::getOpName() const {
+        return "$addToSet";
+    }
+}