From b4ec4ce365fab94069f120afdc499df041b08216 Mon Sep 17 00:00:00 2001
From: Abtin Keshavarzian <abtink@google.com>
Date: Mon, 3 Jun 2024 18:25:54 -0700
Subject: [PATCH] [mle] add `ConnectivityTlv::IsSingleton()` (#10329)

This is used to simplify `Mle::HandleParentResponse()`.
---
 src/core/thread/mle.cpp      | 6 +++---
 src/core/thread/mle_tlvs.hpp | 9 +++++++++
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/src/core/thread/mle.cpp b/src/core/thread/mle.cpp
index 9be918d8a..0a0c7fa03 100644
--- a/src/core/thread/mle.cpp
+++ b/src/core/thread/mle.cpp
@@ -3224,7 +3224,7 @@ void Mle::HandleParentResponse(RxInfo &aRxInfo)
         case kBetterPartition:
             VerifyOrExit(!isPartitionIdSame);
 
-            VerifyOrExit(MleRouter::ComparePartitions(connectivityTlv.GetActiveRouters() <= 1, leaderData,
+            VerifyOrExit(MleRouter::ComparePartitions(connectivityTlv.IsSingleton(), leaderData,
                                                       Get<MleRouter>().IsSingleton(), mLeaderData) > 0);
             break;
         }
@@ -3243,7 +3243,7 @@ void Mle::HandleParentResponse(RxInfo &aRxInfo)
 #if OPENTHREAD_FTD
         if (IsFullThreadDevice())
         {
-            compare = MleRouter::ComparePartitions(connectivityTlv.GetActiveRouters() <= 1, leaderData,
+            compare = MleRouter::ComparePartitions(connectivityTlv.IsSingleton(), leaderData,
                                                    mParentCandidate.mIsSingleton, mParentCandidate.mLeaderData);
         }
 
@@ -3305,7 +3305,7 @@ void Mle::HandleParentResponse(RxInfo &aRxInfo)
     mParentCandidate.mSedBufferSize    = connectivityTlv.GetSedBufferSize();
     mParentCandidate.mSedDatagramCount = connectivityTlv.GetSedDatagramCount();
     mParentCandidate.mLeaderData       = leaderData;
-    mParentCandidate.mIsSingleton      = connectivityTlv.GetActiveRouters() <= 1;
+    mParentCandidate.mIsSingleton      = connectivityTlv.IsSingleton();
     mParentCandidate.mLinkMargin       = linkMargin;
 
 exit:
diff --git a/src/core/thread/mle_tlvs.hpp b/src/core/thread/mle_tlvs.hpp
index 68f62a49f..023bac0ee 100644
--- a/src/core/thread/mle_tlvs.hpp
+++ b/src/core/thread/mle_tlvs.hpp
@@ -851,6 +851,15 @@ public:
      */
     uint8_t GetActiveRouters(void) const { return mActiveRouters; }
 
+    /**
+     * Indicates whether or not the partition is a singleton based on Active Routers value.
+     *
+     * @retval TRUE   The partition is a singleton.
+     * @retval FALSE  The partition is not a singleton.
+     *
+     */
+    bool IsSingleton(void) const { return (mActiveRouters <= 1); }
+
     /**
      * Sets the Active Routers value.
      *