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diff --git a/src/mongo/db/pipeline/document_source_coll_stats.h b/src/mongo/db/pipeline/document_source_coll_stats.h
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+/**
+ * Copyright (C) 2016 MongoDB 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/>.
+ *
+ * As a special exception, the copyright holders give permission to link the
+ * code of portions of this program with the OpenSSL library under certain
+ * conditions as described in each individual source file and distribute
+ * linked combinations including the program with the OpenSSL library. You
+ * must comply with the GNU Affero General Public License in all respects
+ * for all of the code used other than as permitted herein. If you modify
+ * file(s) with this exception, you may extend this exception to your
+ * version of the file(s), but you are not obligated to do so. If you do not
+ * wish to do so, delete this exception statement from your version. If you
+ * delete this exception statement from all source files in the program,
+ * then also delete it in the license file.
+ */
+
+#pragma once
+
+#include "mongo/db/pipeline/document_source.h"
+
+namespace mongo {
+
+/**
+ * Provides a document source interface to retrieve collection-level statistics for a given
+ * collection.
+ */
+class DocumentSourceCollStats : public DocumentSourceNeedsMongod {
+public:
+    class LiteParsed final : public LiteParsedDocumentSource {
+    public:
+        static std::unique_ptr<LiteParsed> parse(const AggregationRequest& request,
+                                                 const BSONElement& spec) {
+            return stdx::make_unique<LiteParsed>();
+        }
+
+        bool isCollStats() const final {
+            return true;
+        }
+
+        stdx::unordered_set<NamespaceString> getInvolvedNamespaces() const final {
+            return stdx::unordered_set<NamespaceString>();
+        }
+    };
+
+    DocumentSourceCollStats(const boost::intrusive_ptr<ExpressionContext>& pExpCtx)
+        : DocumentSourceNeedsMongod(pExpCtx) {}
+
+    GetNextResult getNext() final;
+
+    const char* getSourceName() const final;
+
+    bool isValidInitialSource() const final;
+
+    Value serialize(bool explain = false) const;
+
+    static boost::intrusive_ptr<DocumentSource> createFromBson(
+        BSONElement elem, const boost::intrusive_ptr<ExpressionContext>& pExpCtx);
+
+private:
+    // The raw object given to $collStats containing user specified options.
+    BSONObj _collStatsSpec;
+    bool _finished = false;
+};
+
+}  // namespace mongo