SERVER-18384 commented on use of -1 for primary index in replication metadata

2 files changed, 12 insertions, 1 deletions

diff --git a/src/mongo/rpc/metadata/repl_set_metadata.cpp b/src/mongo/rpc/metadata/repl_set_metadata.cpp
index 66780b50633..8ea6f2fa867 100644
--- a/src/mongo/rpc/metadata/repl_set_metadata.cpp
+++ b/src/mongo/rpc/metadata/repl_set_metadata.cpp
@@ -51,6 +51,10 @@ const char kTermFieldName[] = "term";
 
 }  // unnamed namespace
 
+#ifndef _MSC_EXTENSIONS
+const int ReplSetMetadata::kNoPrimary;
+#endif  // _MSC_EXTENSIONS
+
 ReplSetMetadata::ReplSetMetadata(long long term,
                                  OpTime committedOpTime,
                                  OpTime visibleOpTime,
diff --git a/src/mongo/rpc/metadata/repl_set_metadata.h b/src/mongo/rpc/metadata/repl_set_metadata.h
index 97d7b4b8da3..722f3befe3e 100644
--- a/src/mongo/rpc/metadata/repl_set_metadata.h
+++ b/src/mongo/rpc/metadata/repl_set_metadata.h
@@ -44,6 +44,12 @@ extern const char kReplSetMetadataFieldName[];
  */
 class ReplSetMetadata {
 public:
+    /**
+     * Default primary index. Also used to indicate in metadata that there is no
+     * primary.
+     */
+    static const int kNoPrimary = -1;
+
     ReplSetMetadata() = default;
     ReplSetMetadata(long long term,
                     repl::OpTime committedOpTime,
@@ -87,6 +93,7 @@ public:
 
     /**
      * Returns the index of the current primary from the perspective of the sender.
+     * Returns kNoPrimary if there is no primary.
      */
     long long getPrimaryIndex() const {
         return _currentPrimaryIndex;
@@ -104,7 +111,7 @@ private:
     repl::OpTime _lastOpVisible = repl::OpTime(Timestamp(0, 0), repl::OpTime::kUninitializedTerm);
     long long _currentTerm = -1;
     long long _configVersion = -1;
-    int _currentPrimaryIndex = -1;
+    int _currentPrimaryIndex = kNoPrimary;
 };
 
 }  // namespace rpc