SERVER-53150 Specify input/output to hello command

4 files changed, 95 insertions, 79 deletions

diff --git a/src/mongo/rpc/SConscript b/src/mongo/rpc/SConscript
index 957647e5721..257e556da03 100644
--- a/src/mongo/rpc/SConscript
+++ b/src/mongo/rpc/SConscript
@@ -135,6 +135,7 @@ env.Library(
     target='client_metadata',
     source=[
         'metadata/client_metadata.cpp',
+        'metadata/client_metadata.idl',
     ],
     LIBDEPS=[
         '$BUILD_DIR/mongo/base',
diff --git a/src/mongo/rpc/metadata/client_metadata.cpp b/src/mongo/rpc/metadata/client_metadata.cpp
index a4a8767aadc..6ea09b44b02 100644
--- a/src/mongo/rpc/metadata/client_metadata.cpp
+++ b/src/mongo/rpc/metadata/client_metadata.cpp
@@ -84,7 +84,7 @@ const auto getOperationState = OperationContext::declareDecoration<ClientMetadat
 
 }  // namespace
 
-StatusWith<boost::optional<ClientMetadata>> ClientMetadata::parse(const BSONElement& element) {
+StatusWith<boost::optional<ClientMetadata>> ClientMetadata::parse(const BSONElement& element) try {
     if (element.eoo()) {
         return {boost::none};
     }
@@ -93,84 +93,50 @@ StatusWith<boost::optional<ClientMetadata>> ClientMetadata::parse(const BSONElem
         return Status(ErrorCodes::TypeMismatch, "The client metadata document must be a document");
     }
 
-    ClientMetadata clientMetadata;
-    Status s = clientMetadata.parseClientMetadataDocument(element.Obj());
-    if (!s.isOK()) {
-        return s;
-    }
-
-    return {std::move(clientMetadata)};
+    return boost::make_optional(parseFromBSON(element.Obj()));
+} catch (const DBException& ex) {
+    return ex.toStatus();
 }
 
-Status ClientMetadata::parseClientMetadataDocument(const BSONObj& doc) {
+ClientMetadata::ClientMetadata(BSONObj doc) {
     uint32_t maxLength = kMaxMongoDMetadataDocumentByteLength;
     if (isMongos()) {
         maxLength = kMaxMongoSMetadataDocumentByteLength;
     }
 
-    if (static_cast<uint32_t>(doc.objsize()) > maxLength) {
-        return Status(ErrorCodes::ClientMetadataDocumentTooLarge,
-                      str::stream() << "The client metadata document must be less then or equal to "
-                                    << maxLength << "bytes");
-    }
+    uassert(ErrorCodes::ClientMetadataDocumentTooLarge,
+            str::stream() << "The client metadata document must be less then or equal to "
+                          << maxLength << "bytes",
+            static_cast<uint32_t>(doc.objsize()) <= maxLength);
+
+    const auto isobj = [](StringData name, const BSONElement& e) {
+        uassert(ErrorCodes::TypeMismatch,
+                str::stream()
+                    << "The '" << name
+                    << "' field is required to be a BSON document in the client metadata document",
+                e.isABSONObj());
+    };
 
     // Get a copy so that we can take a stable reference to the app name inside
-    BSONObj docOwned = doc.getOwned();
+    _document = doc.getOwned();
 
-    StringData appName;
     bool foundDriver = false;
     bool foundOperatingSystem = false;
-
-    BSONObjIterator i(docOwned);
-    while (i.more()) {
-        BSONElement e = i.next();
-        StringData name = e.fieldNameStringData();
+    for (const auto& e : _document) {
+        auto name = e.fieldNameStringData();
 
         if (name == kApplication) {
             // Application is an optional sub-document, but we require it to be a document if
             // specified.
-            if (!e.isABSONObj()) {
-                return Status(ErrorCodes::TypeMismatch,
-                              str::stream() << "The '" << kApplication
-                                            << "' field is required to be a BSON document in the "
-                                               "client metadata document");
-            }
-
-            auto swAppName = parseApplicationDocument(e.Obj());
-            if (!swAppName.getStatus().isOK()) {
-                return swAppName.getStatus();
-            }
-
-            appName = swAppName.getValue();
-
+            isobj(kApplication, e);
+            _appName = uassertStatusOK(parseApplicationDocument(e.Obj()));
         } else if (name == kDriver) {
-            if (!e.isABSONObj()) {
-                return Status(ErrorCodes::TypeMismatch,
-                              str::stream() << "The '" << kDriver
-                                            << "' field is required to be a "
-                                               "BSON document in the client "
-                                               "metadata document");
-            }
-
-            Status s = validateDriverDocument(e.Obj());
-            if (!s.isOK()) {
-                return s;
-            }
-
+            isobj(kDriver, e);
+            uassertStatusOK(validateDriverDocument(e.Obj()));
             foundDriver = true;
         } else if (name == kOperatingSystem) {
-            if (!e.isABSONObj()) {
-                return Status(ErrorCodes::TypeMismatch,
-                              str::stream() << "The '" << kOperatingSystem
-                                            << "' field is required to be a BSON document in the "
-                                               "client metadata document");
-            }
-
-            Status s = validateOperatingSystemDocument(e.Obj());
-            if (!s.isOK()) {
-                return s;
-            }
-
+            isobj(kOperatingSystem, e);
+            uassertStatusOK(validateOperatingSystemDocument(e.Obj()));
             foundOperatingSystem = true;
         }
 
@@ -178,23 +144,16 @@ Status ClientMetadata::parseClientMetadataDocument(const BSONObj& doc) {
     }
 
     // Driver is a required sub document.
-    if (!foundDriver) {
-        return Status(ErrorCodes::ClientMetadataMissingField,
-                      str::stream() << "Missing required sub-document '" << kDriver
-                                    << "' in the client metadata document");
-    }
+    uassert(ErrorCodes::ClientMetadataMissingField,
+            str::stream() << "Missing required sub-document '" << kDriver
+                          << "' in the client metadata document",
+            foundDriver);
 
     // OS is a required sub document.
-    if (!foundOperatingSystem) {
-        return Status(ErrorCodes::ClientMetadataMissingField,
-                      str::stream() << "Missing required sub-document '" << kOperatingSystem
-                                    << "' in the client metadata document");
-    }
-
-    _document = std::move(docOwned);
-    _appName = std::move(appName);
-
-    return Status::OK();
+    uassert(ErrorCodes::ClientMetadataMissingField,
+            str::stream() << "Missing required sub-document '" << kOperatingSystem
+                          << "' in the client metadata document",
+            foundOperatingSystem);
 }
 
 StatusWith<StringData> ClientMetadata::parseApplicationDocument(const BSONObj& doc) {
diff --git a/src/mongo/rpc/metadata/client_metadata.h b/src/mongo/rpc/metadata/client_metadata.h
index cc3d870a4f0..309eb5668e0 100644
--- a/src/mongo/rpc/metadata/client_metadata.h
+++ b/src/mongo/rpc/metadata/client_metadata.h
@@ -80,10 +80,16 @@ constexpr auto kMetadataDocumentName = "client"_sd;
  * See Driver Specification: "MongoDB Handshake" for more information.
  */
 class ClientMetadata {
-    ClientMetadata(const ClientMetadata&) = delete;
-    ClientMetadata& operator=(const ClientMetadata&) = delete;
-
 public:
+    explicit ClientMetadata(BSONObj obj);
+
+    ClientMetadata(const ClientMetadata& src) : ClientMetadata(src._document) {}
+    ClientMetadata& operator=(const ClientMetadata& src) {
+        ClientMetadata copy(src._document);
+        *this = std::move(copy);
+        return *this;
+    }
+
     ClientMetadata(ClientMetadata&&) = default;
     ClientMetadata& operator=(ClientMetadata&&) = default;
 
@@ -145,6 +151,13 @@ public:
     static StatusWith<boost::optional<ClientMetadata>> parse(const BSONElement& element);
 
     /**
+     * Wrapper for BSONObj constructor used by IDL parsers.
+     */
+    static ClientMetadata parseFromBSON(BSONObj obj) {
+        return ClientMetadata(obj);
+    }
+
+    /**
      * Create a new client metadata document with os information from the ProcessInfo class.
      *
      * This method outputs the "client" field, and client metadata sub-document in the
@@ -311,7 +324,6 @@ public:
 private:
     ClientMetadata() = default;
 
-    Status parseClientMetadataDocument(const BSONObj& doc);
     static Status validateDriverDocument(const BSONObj& doc);
     static Status validateOperatingSystemDocument(const BSONObj& doc);
     static StatusWith<StringData> parseApplicationDocument(const BSONObj& doc);
diff --git a/src/mongo/rpc/metadata/client_metadata.idl b/src/mongo/rpc/metadata/client_metadata.idl
new file mode 100644
index 00000000000..d1726153d98
--- /dev/null
+++ b/src/mongo/rpc/metadata/client_metadata.idl
@@ -0,0 +1,44 @@
+# Copyright (C) 2021-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.
+#
+
+global:
+    cpp_namespace: "mongo"
+    cpp_includes:
+        - "mongo/rpc/metadata/client_metadata.h"
+
+imports:
+    - "mongo/idl/basic_types.idl"
+
+types:
+    ClientMetadata:
+        description: "Client metadata document"
+        bson_serialization_type: object
+        cpp_type: ClientMetadata
+        serializer: "mongo::ClientMetadata::getDocument"
+        deserializer: "mongo::ClientMetadata::parseFromBSON"
+