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diff --git a/src/mongo/db/pipeline/document_source_query_stats.h b/src/mongo/db/pipeline/document_source_query_stats.h
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+/**
+ *    Copyright (C) 2022-present MongoDB, Inc.
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the Server Side Public License, version 1,
+ *    as published by MongoDB, Inc.
+ *
+ *    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
+ *    Server Side Public License for more details.
+ *
+ *    You should have received a copy of the Server Side Public License
+ *    along with this program. If not, see
+ *    <http://www.mongodb.com/licensing/server-side-public-license>.
+ *
+ *    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 Server Side 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"
+#include "mongo/db/pipeline/lite_parsed_document_source.h"
+#include "mongo/db/query/query_stats.h"
+#include "mongo/util/producer_consumer_queue.h"
+
+namespace mongo {
+
+using namespace query_stats;
+
+class DocumentSourceQueryStats final : public DocumentSource {
+public:
+    static constexpr StringData kStageName = "$queryStats"_sd;
+
+    class LiteParsed final : public LiteParsedDocumentSource {
+    public:
+        static std::unique_ptr<LiteParsed> parse(const NamespaceString& nss,
+                                                 const BSONElement& spec);
+
+        LiteParsed(std::string parseTimeName, bool applyHmacToIdentifiers, std::string hmacKey)
+            : LiteParsedDocumentSource(std::move(parseTimeName)),
+              _applyHmacToIdentifiers(applyHmacToIdentifiers),
+              _hmacKey(hmacKey) {}
+
+        stdx::unordered_set<NamespaceString> getInvolvedNamespaces() const override {
+            return stdx::unordered_set<NamespaceString>();
+        }
+
+        PrivilegeVector requiredPrivileges(bool isMongos,
+                                           bool bypassDocumentValidation) const override {
+            return {Privilege(ResourcePattern::forClusterResource(), ActionType::queryStatsRead)};
+            ;
+        }
+
+        bool allowedToPassthroughFromMongos() const final {
+            // $queryStats must be run locally on a mongod.
+            return false;
+        }
+
+        bool isInitialSource() const final {
+            return true;
+        }
+
+        void assertSupportsMultiDocumentTransaction() const {
+            transactionNotSupported(kStageName);
+        }
+
+        bool _applyHmacToIdentifiers;
+
+        std::string _hmacKey;
+    };
+
+    static boost::intrusive_ptr<DocumentSource> createFromBson(
+        BSONElement elem, const boost::intrusive_ptr<ExpressionContext>& pExpCtx);
+
+    virtual ~DocumentSourceQueryStats() = default;
+
+    StageConstraints constraints(
+        Pipeline::SplitState = Pipeline::SplitState::kUnsplit) const override {
+        StageConstraints constraints{StreamType::kStreaming,
+                                     PositionRequirement::kFirst,
+                                     HostTypeRequirement::kLocalOnly,
+                                     DiskUseRequirement::kNoDiskUse,
+                                     FacetRequirement::kNotAllowed,
+                                     TransactionRequirement::kNotAllowed,
+                                     LookupRequirement::kNotAllowed,
+                                     UnionRequirement::kNotAllowed};
+
+        constraints.requiresInputDocSource = false;
+        constraints.isIndependentOfAnyCollection = true;
+        return constraints;
+    }
+
+    boost::optional<DistributedPlanLogic> distributedPlanLogic() final {
+        return boost::none;
+    }
+
+    const char* getSourceName() const override {
+        return kStageName.rawData();
+    }
+
+    Value serialize(SerializationOptions opts = SerializationOptions()) const final override;
+
+    void addVariableRefs(std::set<Variables::Id>* refs) const final {}
+
+private:
+    DocumentSourceQueryStats(const boost::intrusive_ptr<ExpressionContext>& expCtx,
+                             bool applyHmacToIdentifiers = false,
+                             std::string hmacKey = {})
+        : DocumentSource(kStageName, expCtx),
+          _applyHmacToIdentifiers(applyHmacToIdentifiers),
+          _hmacKey(hmacKey) {}
+
+    GetNextResult doGetNext() final;
+
+    /**
+     * The current partition materialized as a set of Document instances. We pop from the queue and
+     * return DocumentSource results.
+     */
+    std::deque<Document> _materializedPartition;
+
+    /**
+     * Iterator over all queryStats partitions. This is incremented when we exhaust the current
+     * _materializedPartition.
+     */
+    QueryStatsStore::PartitionId _currentPartition = -1;
+
+    // When true, apply hmac to field names from returned query shapes.
+    bool _applyHmacToIdentifiers;
+
+    /**
+     * Key used for SHA-256 HMAC application on field names.
+     */
+    std::string _hmacKey;
+};
+
+}  // namespace mongo