SERVER-62016 support tagged write concerns

2 files changed, 22 insertions, 13 deletions

diff --git a/src/mongo/idl/basic_types.h b/src/mongo/idl/basic_types.h
index 42619522f3b..a725e9a8c87 100644
--- a/src/mongo/idl/basic_types.h
+++ b/src/mongo/idl/basic_types.h
@@ -29,6 +29,7 @@
 
 #pragma once
 
+#include "mongo/util/assert_util.h"
 #include <boost/optional.hpp>
 
 #include "mongo/base/string_data.h"
@@ -191,21 +192,32 @@ public:
             return WriteConcernW{wEl.safeNumberLong()};
         } else if (wEl.type() == BSONType::String) {
             return WriteConcernW{wEl.str()};
+        } else if (wEl.type() == BSONType::Object) {
+            auto tags = wEl.Obj().getOwned();
+            auto valid =
+                std::all_of(tags.begin(), tags.end(), [](BSONElement e) { return e.isNumber(); });
+            uassert(ErrorCodes::FailedToParse,
+                    "tags must be a single level document with only number values",
+                    valid);
+
+            return WriteConcernW{std::move(tags)};
         } else if (wEl.eoo() || wEl.type() == BSONType::jstNULL ||
                    wEl.type() == BSONType::Undefined) {
             return WriteConcernW{};
         }
-        uasserted(ErrorCodes::FailedToParse, "w has to be a number or string");
+        uasserted(ErrorCodes::FailedToParse, "w has to be a number, string, or object");
     }
 
     void serializeWriteConcernW(StringData fieldName, BSONObjBuilder* builder) const {
         if (auto stringVal = stdx::get_if<std::string>(&_w)) {
             builder->append(fieldName, *stringVal);
-            return;
+        } else if (auto objVal = stdx::get_if<BSONObj>(&_w)) {
+            builder->append(fieldName, *objVal);
+        } else {
+            auto intVal = stdx::get_if<std::int64_t>(&_w);
+            invariant(intVal);
+            builder->appendNumber(fieldName, static_cast<long long>(*intVal));
         }
-        auto intVal = stdx::get_if<std::int64_t>(&_w);
-        invariant(intVal);
-        builder->appendNumber(fieldName, static_cast<long long>(*intVal));
     }
 
     WriteConcernW() : _w{1}, _usedDefaultConstructedW1{true} {};
@@ -214,14 +226,16 @@ public:
         return _usedDefaultConstructedW1;
     }
 
-    stdx::variant<std::string, std::int64_t> getValue() const {
+    stdx::variant<std::string, std::int64_t, BSONObj> getValue() const {
         return _w;
     }
 
 private:
     WriteConcernW(std::int64_t w) : _w{w}, _usedDefaultConstructedW1{false} {};
     WriteConcernW(std::string&& w) : _w(std::move(w)), _usedDefaultConstructedW1{false} {};
-    stdx::variant<std::string, std::int64_t> _w;
+    WriteConcernW(BSONObj&& tags) : _w(std::move(tags)), _usedDefaultConstructedW1{false} {};
+
+    stdx::variant<std::string, std::int64_t, BSONObj> _w;
     bool _usedDefaultConstructedW1;
 };
 
diff --git a/src/mongo/idl/basic_types.idl b/src/mongo/idl/basic_types.idl
index ae3041063cd..03cf00ba413 100644
--- a/src/mongo/idl/basic_types.idl
+++ b/src/mongo/idl/basic_types.idl
@@ -242,12 +242,7 @@ types:
         deserializer: mongo::IDLAnyTypeOwned::parseFromBSON
 
     writeConcernW:
-        bson_serialization_type:
-                                 - string
-                                 - int
-                                 - decimal
-                                 - double
-                                 - long
+        bson_serialization_type: any
         description: >-
             A string or integer representing the 'w' option in a document specifying write concern.
             See https://docs.mongodb.com/manual/reference/write-concern/"