1 files changed, 103 insertions, 0 deletions
diff --git a/src/mongo/db/pipeline/process_interface/stub_lookup_single_document_process_interface.cpp b/src/mongo/db/pipeline/process_interface/stub_lookup_single_document_process_interface.cpp
new file mode 100644
index 00000000000..cba2a97ffcc
--- /dev/null
+++ b/src/mongo/db/pipeline/process_interface/stub_lookup_single_document_process_interface.cpp
@@ -0,0 +1,103 @@
+/**
+ *    Copyright (C) 2018-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.
+ */
+
+#include "mongo/platform/basic.h"
+
+#include "mongo/db/pipeline/process_interface/stub_lookup_single_document_process_interface.h"
+
+#include "mongo/db/pipeline/document_source.h"
+#include "mongo/db/pipeline/document_source_mock.h"
+#include "mongo/util/assert_util.h"
+
+namespace mongo {
+
+std::unique_ptr<Pipeline, PipelineDeleter> StubLookupSingleDocumentProcessInterface::makePipeline(
+    const std::vector<BSONObj>& rawPipeline,
+    const boost::intrusive_ptr<ExpressionContext>& expCtx,
+    const MakePipelineOptions opts) {
+    auto pipeline = uassertStatusOK(Pipeline::parse(rawPipeline, expCtx));
+
+    if (opts.optimize) {
+        pipeline->optimizePipeline();
+    }
+
+    if (opts.attachCursorSource) {
+        pipeline =
+            attachCursorSourceToPipeline(expCtx, pipeline.release(), opts.allowTargetingShards);
+    }
+
+    return pipeline;
+}
+
+std::unique_ptr<Pipeline, PipelineDeleter>
+StubLookupSingleDocumentProcessInterface::attachCursorSourceToPipelineForLocalRead(
+    const boost::intrusive_ptr<ExpressionContext>& expCtx, Pipeline* ownedPipeline) {
+    std::unique_ptr<Pipeline, PipelineDeleter> pipeline(ownedPipeline,
+                                                        PipelineDeleter(expCtx->opCtx));
+    pipeline->addInitialSource(DocumentSourceMock::createForTest(_mockResults));
+    return pipeline;
+}
+
+std::unique_ptr<Pipeline, PipelineDeleter>
+StubLookupSingleDocumentProcessInterface::attachCursorSourceToPipeline(
+    const boost::intrusive_ptr<ExpressionContext>& expCtx,
+    Pipeline* ownedPipeline,
+    bool allowTargetingShards) {
+    return attachCursorSourceToPipelineForLocalRead(expCtx, ownedPipeline);
+}
+
+boost::optional<Document> StubLookupSingleDocumentProcessInterface::lookupSingleDocument(
+    const boost::intrusive_ptr<ExpressionContext>& expCtx,
+    const NamespaceString& nss,
+    UUID collectionUUID,
+    const Document& documentKey,
+    boost::optional<BSONObj> readConcern,
+    bool allowSpeculativeMajorityRead) {
+    // The namespace 'nss' may be different than the namespace on the ExpressionContext in the
+    // case of a change stream on a whole database so we need to make a copy of the
+    // ExpressionContext with the new namespace.
+    auto foreignExpCtx = expCtx->copyWith(nss, collectionUUID, boost::none);
+    std::unique_ptr<Pipeline, PipelineDeleter> pipeline;
+    try {
+        pipeline = makePipeline({BSON("$match" << documentKey)}, foreignExpCtx);
+    } catch (ExceptionFor<ErrorCodes::NamespaceNotFound>&) {
+        return boost::none;
+    }
+
+    auto lookedUpDocument = pipeline->getNext();
+    if (auto next = pipeline->getNext()) {
+        uasserted(ErrorCodes::TooManyMatchingDocuments,
+                  str::stream() << "found more than one document matching "
+                                << documentKey.toString() << " [" << lookedUpDocument->toString()
+                                << ", " << next->toString() << "]");
+    }
+    return lookedUpDocument;
+}
+
+}  // namespace mongo