SERVER-40015 make $sb work sharded

8 files changed, 47 insertions, 2 deletions

diff --git a/src/mongo/db/pipeline/mongo_process_interface.h b/src/mongo/db/pipeline/mongo_process_interface.h
index e96298a9fe3..1e19144b4f5 100644
--- a/src/mongo/db/pipeline/mongo_process_interface.h
+++ b/src/mongo/db/pipeline/mongo_process_interface.h
@@ -243,6 +243,23 @@ public:
         const boost::intrusive_ptr<ExpressionContext>& expCtx, Pipeline* pipeline) = 0;
 
     /**
+     * Accepts a pipeline and returns a new one which will draw input from the underlying
+     * collection _locally_. Trying to run this method on mongos is a programming error. Running
+     * this method on a shard server will only return results which match the pipeline on that
+     * shard.
+
+     * Performs no further optimization of the pipeline. NamespaceNotFound will be
+     * thrown if ExpressionContext has a UUID and that UUID doesn't exist anymore. That should be
+     * the only case where NamespaceNotFound is returned.
+     *
+     * This function takes ownership of the 'pipeline' argument as if it were a unique_ptr.
+     * Changing it to a unique_ptr introduces a circular dependency on certain platforms where the
+     * compiler expects to find an implementation of PipelineDeleter.
+     */
+    virtual std::unique_ptr<Pipeline, PipelineDeleter> attachCursorSourceToPipelineForLocalRead(
+        const boost::intrusive_ptr<ExpressionContext>& expCtx, Pipeline* pipeline) = 0;
+
+    /**
      * Returns a vector of owned BSONObjs, each of which contains details of an in-progress
      * operation or, optionally, an idle connection. If userMode is kIncludeAllUsers, report
      * operations for all authenticated users; otherwise, report only the current user's operations.
diff --git a/src/mongo/db/pipeline/mongos_process_interface.h b/src/mongo/db/pipeline/mongos_process_interface.h
index ae78e9e7f89..16780eb1398 100644
--- a/src/mongo/db/pipeline/mongos_process_interface.h
+++ b/src/mongo/db/pipeline/mongos_process_interface.h
@@ -168,6 +168,12 @@ public:
     std::unique_ptr<Pipeline, PipelineDeleter> attachCursorSourceToPipeline(
         const boost::intrusive_ptr<ExpressionContext>& expCtx, Pipeline* pipeline) final;
 
+    std::unique_ptr<Pipeline, PipelineDeleter> attachCursorSourceToPipelineForLocalRead(
+        const boost::intrusive_ptr<ExpressionContext>& expCtx, Pipeline* pipeline) final {
+        // It is not meaningful to perform a "local read" on mongos.
+        MONGO_UNREACHABLE;
+    }
+
     std::string getShardName(OperationContext* opCtx) const final {
         MONGO_UNREACHABLE;
     }
diff --git a/src/mongo/db/pipeline/process_interface_shardsvr.cpp b/src/mongo/db/pipeline/process_interface_shardsvr.cpp
index a66fe05d25b..ea6b39f8472 100644
--- a/src/mongo/db/pipeline/process_interface_shardsvr.cpp
+++ b/src/mongo/db/pipeline/process_interface_shardsvr.cpp
@@ -197,7 +197,7 @@ unique_ptr<Pipeline, PipelineDeleter> MongoInterfaceShardServer::attachCursorSou
     // this function, to be sure the collection didn't become sharded between the time we checked
     // whether it's sharded and the time we took the lock.
 
-    return MongoInterfaceStandalone::attachCursorSourceToPipeline(expCtx, pipeline.release());
+    return attachCursorSourceToPipelineForLocalRead(expCtx, pipeline.release());
 }
 
 }  // namespace mongo
diff --git a/src/mongo/db/pipeline/process_interface_standalone.cpp b/src/mongo/db/pipeline/process_interface_standalone.cpp
index e0f26909e61..ca12adc1640 100644
--- a/src/mongo/db/pipeline/process_interface_standalone.cpp
+++ b/src/mongo/db/pipeline/process_interface_standalone.cpp
@@ -379,6 +379,12 @@ std::unique_ptr<Pipeline, PipelineDeleter> MongoInterfaceStandalone::makePipelin
 
 unique_ptr<Pipeline, PipelineDeleter> MongoInterfaceStandalone::attachCursorSourceToPipeline(
     const boost::intrusive_ptr<ExpressionContext>& expCtx, Pipeline* ownedPipeline) {
+    return attachCursorSourceToPipelineForLocalRead(expCtx, ownedPipeline);
+}
+
+unique_ptr<Pipeline, PipelineDeleter>
+MongoInterfaceStandalone::attachCursorSourceToPipelineForLocalRead(
+    const boost::intrusive_ptr<ExpressionContext>& expCtx, Pipeline* ownedPipeline) {
     std::unique_ptr<Pipeline, PipelineDeleter> pipeline(ownedPipeline,
                                                         PipelineDeleter(expCtx->opCtx));
 
diff --git a/src/mongo/db/pipeline/process_interface_standalone.h b/src/mongo/db/pipeline/process_interface_standalone.h
index 6d09bd2a28c..d6b15346f97 100644
--- a/src/mongo/db/pipeline/process_interface_standalone.h
+++ b/src/mongo/db/pipeline/process_interface_standalone.h
@@ -101,6 +101,8 @@ public:
         const MakePipelineOptions opts = MakePipelineOptions{}) final;
     std::unique_ptr<Pipeline, PipelineDeleter> attachCursorSourceToPipeline(
         const boost::intrusive_ptr<ExpressionContext>& expCtx, Pipeline* pipeline) override;
+    std::unique_ptr<Pipeline, PipelineDeleter> attachCursorSourceToPipelineForLocalRead(
+        const boost::intrusive_ptr<ExpressionContext>& expCtx, Pipeline* pipeline) override;
     std::string getShardName(OperationContext* opCtx) const final;
     std::pair<std::vector<FieldPath>, bool> collectDocumentKeyFieldsForHostedCollection(
         OperationContext* opCtx, const NamespaceString&, UUID) const override;
diff --git a/src/mongo/db/pipeline/stub_mongo_process_interface.h b/src/mongo/db/pipeline/stub_mongo_process_interface.h
index abbf1555cb0..4647a8e2cb8 100644
--- a/src/mongo/db/pipeline/stub_mongo_process_interface.h
+++ b/src/mongo/db/pipeline/stub_mongo_process_interface.h
@@ -141,6 +141,11 @@ public:
         MONGO_UNREACHABLE;
     }
 
+    std::unique_ptr<Pipeline, PipelineDeleter> attachCursorSourceToPipelineForLocalRead(
+        const boost::intrusive_ptr<ExpressionContext>& expCtx, Pipeline* pipeline) override {
+        MONGO_UNREACHABLE;
+    }
+
     std::vector<BSONObj> getCurrentOps(const boost::intrusive_ptr<ExpressionContext>& expCtx,
                                        CurrentOpConnectionsMode connMode,
                                        CurrentOpSessionsMode sessionMode,
diff --git a/src/mongo/db/pipeline/stub_mongo_process_interface_lookup_single_document.cpp b/src/mongo/db/pipeline/stub_mongo_process_interface_lookup_single_document.cpp
index cb4abf32cb6..a5b877a9e49 100644
--- a/src/mongo/db/pipeline/stub_mongo_process_interface_lookup_single_document.cpp
+++ b/src/mongo/db/pipeline/stub_mongo_process_interface_lookup_single_document.cpp
@@ -56,7 +56,7 @@ StubMongoProcessInterfaceLookupSingleDocument::makePipeline(
 }
 
 std::unique_ptr<Pipeline, PipelineDeleter>
-StubMongoProcessInterfaceLookupSingleDocument::attachCursorSourceToPipeline(
+StubMongoProcessInterfaceLookupSingleDocument::attachCursorSourceToPipelineForLocalRead(
     const boost::intrusive_ptr<ExpressionContext>& expCtx, Pipeline* ownedPipeline) {
     std::unique_ptr<Pipeline, PipelineDeleter> pipeline(ownedPipeline,
                                                         PipelineDeleter(expCtx->opCtx));
@@ -64,6 +64,13 @@ StubMongoProcessInterfaceLookupSingleDocument::attachCursorSourceToPipeline(
     return pipeline;
 }
 
+std::unique_ptr<Pipeline, PipelineDeleter>
+StubMongoProcessInterfaceLookupSingleDocument::attachCursorSourceToPipeline(
+    const boost::intrusive_ptr<ExpressionContext>& expCtx, Pipeline* ownedPipeline) {
+    return attachCursorSourceToPipelineForLocalRead(expCtx, ownedPipeline);
+}
+
+
 boost::optional<Document> StubMongoProcessInterfaceLookupSingleDocument::lookupSingleDocument(
     const boost::intrusive_ptr<ExpressionContext>& expCtx,
     const NamespaceString& nss,
diff --git a/src/mongo/db/pipeline/stub_mongo_process_interface_lookup_single_document.h b/src/mongo/db/pipeline/stub_mongo_process_interface_lookup_single_document.h
index 089d38b2908..4b3bcbaafdc 100644
--- a/src/mongo/db/pipeline/stub_mongo_process_interface_lookup_single_document.h
+++ b/src/mongo/db/pipeline/stub_mongo_process_interface_lookup_single_document.h
@@ -56,6 +56,8 @@ public:
 
     std::unique_ptr<Pipeline, PipelineDeleter> attachCursorSourceToPipeline(
         const boost::intrusive_ptr<ExpressionContext>& expCtx, Pipeline* ownedPipeline) final;
+    std::unique_ptr<Pipeline, PipelineDeleter> attachCursorSourceToPipelineForLocalRead(
+        const boost::intrusive_ptr<ExpressionContext>& expCtx, Pipeline* ownedPipeline) final;
 
     boost::optional<Document> lookupSingleDocument(
         const boost::intrusive_ptr<ExpressionContext>& expCtx,