SERVER-78160 Create new QuerySolutionNode for $search

Author: pdan101

src/mongo/db/query/classic_stage_builder.cpp

@@ -455,7 +455,8 @@ std::unique_ptr<PlanStage> ClassicStageBuilder::build(const QuerySolutionNode* r
         case STAGE_SPOOL:
         case STAGE_SENTINEL:
         case STAGE_COLUMN_SCAN:
-        case STAGE_UPDATE: {
+        case STAGE_UPDATE:
+        case STAGE_SEARCH: {
             LOGV2_WARNING(4615604, "Can't build exec tree for node", "node"_attr = *root);
         }
     }

src/mongo/db/query/query_solution.cpp

@@ -1812,4 +1812,15 @@ void SentinelNode::appendToString(str::stream* ss, int indent) const {
     addIndent(ss, indent);
     *ss << "SENTINEL\n";
 }
+
+std::unique_ptr<QuerySolutionNode> SearchNode::clone() const {
+    return std::make_unique<SearchNode>(isSearchMeta);
+}
+
+void SearchNode::appendToString(str::stream* ss, int indent) const {
+    addIndent(ss, indent);
+    *ss << "SEARCH\n";
+    addIndent(ss, indent + 1);
+    *ss << "isSearchMeta = " << isSearchMeta << '\n';
+}
 }  // namespace mongo

src/mongo/db/query/query_solution.h

@@ -1660,7 +1660,6 @@ struct EqLookupNode : public QuerySolutionNode {
 };
 
 struct SentinelNode : public QuerySolutionNode {
-
     SentinelNode() {}
 
     virtual StageType getType() const {
@@ -1686,4 +1685,37 @@ struct SentinelNode : public QuerySolutionNode {
 
     std::unique_ptr<QuerySolutionNode> clone() const final;
 };
+
+struct SearchNode : public QuerySolutionNode {
+    explicit SearchNode(bool isSearchMeta) : isSearchMeta(isSearchMeta) {}
+
+    StageType getType() const override {
+        return STAGE_SEARCH;
+    }
+
+    void appendToString(str::stream* ss, int indent) const override;
+
+    bool fetched() const {
+        return true;
+    }
+
+    FieldAvailability getFieldAvailability(const std::string& field) const {
+        return FieldAvailability::kFullyProvided;
+    }
+
+    bool sortedByDiskLoc() const override {
+        return false;
+    }
+
+    const ProvidedSortSet& providedSorts() const final {
+        return kEmptySet;
+    }
+
+    std::unique_ptr<QuerySolutionNode> clone() const final;
+
+    /**
+     * True for $searchMeta, False for $search query.
+     */
+    bool isSearchMeta;
+};
 }  // namespace mongo

src/mongo/db/query/stage_types.cpp

@@ -67,6 +67,7 @@ StringData stageTypeToString(StageType stageType) {
         {STAGE_RECORD_STORE_FAST_COUNT, "RECORD_STORE_FAST_COUNT"_sd},
         {STAGE_RETURN_KEY, "RETURN_KEY"_sd},
         {STAGE_SAMPLE_FROM_TIMESERIES_BUCKET, "SAMPLE_FROM_TIMESERIES_BUCKET"_sd},
+        {STAGE_SEARCH, "SEARCH"_sd},
         {STAGE_SHARDING_FILTER, "SHARDING_FILTER"_sd},
         {STAGE_SKIP, "SKIP"_sd},
         {STAGE_SORT_DEFAULT, "SORT"_sd},

src/mongo/db/query/stage_types.h

@@ -138,6 +138,7 @@ enum StageType {
     // Stages for DocumentSources.
     STAGE_GROUP,
     STAGE_EQ_LOOKUP,
+    STAGE_SEARCH,
     STAGE_SENTINEL,
 };