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diff --git a/src/mongo/db/pipeline/document_source_internal_shard_filter.cpp b/src/mongo/db/pipeline/document_source_internal_shard_filter.cpp
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+/**
+ *    Copyright (C) 2019-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.
+ */
+
+#define MONGO_LOG_DEFAULT_COMPONENT ::mongo::logger::LogComponent::kQuery
+
+#include "mongo/platform/basic.h"
+
+#include "mongo/db/pipeline/document_source_internal_shard_filter.h"
+
+#include "mongo/db/pipeline/document.h"
+#include "mongo/util/log.h"
+
+namespace mongo {
+
+//
+// This DocumentSource is not registered and can only be created as part of expansions for other
+// DocumentSources.
+//
+
+DocumentSourceInternalShardFilter::DocumentSourceInternalShardFilter(
+    const boost::intrusive_ptr<ExpressionContext>& pExpCtx,
+    std::unique_ptr<ShardFilterer> shardFilterer)
+    : DocumentSource(pExpCtx), _shardFilterer(std::move(shardFilterer)) {}
+
+DocumentSource::GetNextResult DocumentSourceInternalShardFilter::getNext() {
+    pExpCtx->checkForInterrupt();
+
+    auto next = pSource->getNext();
+    invariant(_shardFilterer);
+    for (; next.isAdvanced(); next = pSource->getNext()) {
+        BSONMatchableDocument matchable(next.getDocument().toBson());
+        const auto belongsRes = _shardFilterer->documentBelongsToMe(matchable);
+        if (belongsRes == ShardFilterer::DocumentBelongsResult::kBelongs) {
+            return next;
+        }
+
+        if (belongsRes == ShardFilterer::DocumentBelongsResult::kNoShardKey) {
+            warning() << "no shard key found in document " << redact(next.getDocument().toBson())
+                      << " "
+                      << "for shard key pattern " << _shardFilterer->getKeyPattern() << ", "
+                      << "document may have been inserted manually into shard";
+        }
+
+        // For performance reasons, a streaming stage must not keep references to documents across
+        // calls to getNext(). Such stages must retrieve a result from their child and then release
+        // it (or return it) before asking for another result. Failing to do so can result in extra
+        // work, since the Document/Value library must copy data on write when that data has a
+        // refcount above one.
+        next.releaseDocument();
+    }
+    return next;
+}
+
+Pipeline::SourceContainer::iterator DocumentSourceInternalShardFilter::doOptimizeAt(
+    Pipeline::SourceContainer::iterator itr, Pipeline::SourceContainer* container) {
+    invariant(*itr == this);
+
+    if (_shardFilterer->isCollectionSharded()) {
+        return std::next(itr);
+    }
+
+    if (itr == container->begin()) {
+        // Delete this stage from the pipeline if the operation does not require shard versioning.
+        container->erase(itr);
+        return container->begin();
+    }
+
+    auto ret = std::prev(itr);
+    container->erase(itr);
+    return ret;
+}
+
+Value DocumentSourceInternalShardFilter::serialize(
+    boost::optional<ExplainOptions::Verbosity> explain) const {
+    return Value(DOC(getSourceName() << Document()));
+}
+
+}  // namespace mongo