Apply suggestions from code review

Co-authored-by: Boris Zbarsky <bzbarsky@apple.com>

src/app/clusters/scenes/ExtensionFieldSets.h

@@ -27,7 +27,7 @@ static constexpr uint8_t kInvalidPosition         = 0xff;
 static constexpr uint8_t kMaxClustersPerScene     = CHIP_CONFIG_SCENES_MAX_CLUSTERS_PER_SCENE;
 static constexpr uint8_t kMaxFieldBytesPerCluster = CHIP_CONFIG_SCENES_MAX_EXTENSION_FIELDSET_SIZE_PER_CLUSTER;
 
-/// @brief class meant serialize all extension ßfield sets of a scene so it can be stored and retrieved from flash memory.
+/// @brief A way to serialize and deserialize all cluster attribute data for a scene.
 class ExtensionFieldSets
 {
 public:

src/app/clusters/scenes/ExtensionFieldSetsImpl.cpp

@@ -99,7 +99,7 @@ CHIP_ERROR ExtensionFieldSetsImpl::InsertFieldSet(const ExtensionFieldSet & fiel
         }
     }
 
-    // if found, replace at found position, otherwise at insert first free position, otherwise return error
+    // if found, replace at found position, otherwise insert at first free position, otherwise return error
     if (firstEmptyPosition < kMaxClusterPerScenes)
     {
         mEFS[firstEmptyPosition] = fieldSet;

src/app/clusters/scenes/ExtensionFieldSetsImpl.h

@@ -81,7 +81,7 @@ struct ExtensionFieldSet
         ReturnErrorOnFailure(
             writer.StartContainer(TLV::ContextTag(TagEFS::kIndividualContainer), TLV::kTLVType_Structure, container));
 
-        ReturnErrorOnFailure(writer.Put(TLV::ContextTag(TagEFS::kClusterID), static_cast<uint32_t>(mID)));
+        ReturnErrorOnFailure(writer.Put(TLV::ContextTag(TagEFS::kClusterID), mID));
         ReturnErrorOnFailure(writer.PutBytes(TLV::ContextTag(TagEFS::kClusterFieldSetData), mBytesBuffer, mUsedBytes));
 
         return writer.EndContainer(container);
@@ -113,12 +113,12 @@ struct ExtensionFieldSet
         mUsedBytes = 0;
     }
 
-    bool IsEmpty() const { return (this->mUsedBytes == 0); }
+    bool IsEmpty() const { return (mUsedBytes == 0); }
 
     bool operator==(const ExtensionFieldSet & other) const
     {
-        return (this->mID == other.mID && this->mUsedBytes == other.mUsedBytes &&
-                !memcmp(this->mBytesBuffer, other.mBytesBuffer, this->mUsedBytes));
+        return (mID == other.mID && mUsedBytes == other.mUsedBytes &&
+                !memcmp(mBytesBuffer, other.mBytesBuffer, mUsedBytes));
     }
 };
 
@@ -164,7 +164,7 @@ class ExtensionFieldSetsImpl : public ExtensionFieldSets
     }
 
 protected:
-    ExtensionFieldSet mEFS[kMaxClusterPerScenes];
+    ExtensionFieldSet mFieldSets[kMaxClusterPerScenes];
     uint8_t mFieldSetsCount = 0;
 };
 } // namespace scenes

src/app/clusters/scenes/SceneTable.h

@@ -36,18 +36,25 @@ typedef uint32_t SceneTransitionTime;
 constexpr GroupId kGlobalGroupSceneId       = 0x0000;
 constexpr SceneIndex kUndefinedSceneIndex   = 0xff;
 constexpr SceneId kUndefinedSceneId         = 0xff;
-static constexpr uint8_t kMaxScenePerFabric = CHIP_CONFIG_SCENES_MAX_PER_FABRIC;
+static constexpr uint8_t kMaxScenesPerFabric = CHIP_CONFIG_SCENES_MAX_PER_FABRIC;
+
 static constexpr size_t kIteratorsMax       = CHIP_CONFIG_MAX_SCENES_CONCURRENT_ITERATORS;
-static constexpr size_t kSceneNameMax       = CHIP_CONFIG_SCENES_CLUSTER_MAXIMUM_NAME_LENGTH;
+static constexpr size_t kSceneNameMaxLength = CHIP_CONFIG_SCENES_CLUSTER_MAXIMUM_NAME_LENGTH;
+
 
-/// @brief Abstract class allowing different Endpoints interactions with the ExtensionFieldSets added to and retrieved from the
-/// scene Table. The Scene Handler's are meant as interface between various clusters and the Scene table. The expected behaviour of
-/// the table with the handler is: Once a scene command involving extension field set is received, the Scene Table will go through
-/// the list of handlers to either retrieve, populate or apply Extension field sets. Each handler is meant to retrieve an extension
-/// field set for a single cluster however it is also possible to use a single generic handler that handles all of them.
+/// @brief SceneHandlers are meant as interface between various clusters and the Scene table. 
+/// When a scene command involving extension field sets is received, the Scene Table will go through
+/// the list of handlers to either retrieve, populate or apply those extension field sets.
+///
+/// Generally, for each specific <endpoint, cluster> pair there should be one and only one handler
+/// registered with the scene table that claims to handle that pair.
 ///
-/// @note If more than one handler is implemented for a specific <endpoint, cluster> pair, ONLY THE FIRST HANDLER FOR THAT SPECIFIC
-/// PAIR will get called on executing extension field sets related ations on the scene table.
+/// A SceneHandler can handle a single <endpoint, cluster> pair, or many such pairs.
+///
+/// @note If more than one handler claims to handl a specific <endpoint, cluster> pair, only one of 
+/// those handlers will get called when executing actions related to extension field sets on the scene
+/// table.  It is not defined which handler will be selected.
+
 class SceneHandler : public IntrusiveListNodeBase<>
 {
 public:
@@ -58,8 +65,10 @@ class SceneHandler : public IntrusiveListNodeBase<>
     /// supported clusters
     /// @param endpoint target endpoint
     /// @param clusterBuffer Buffer to hold the supported cluster IDs, cannot hold more than
-    /// CHIP_CONFIG_SCENES_MAX_CLUSTERS_PER_SCENES, the function shall use the reduce_size() method in the event it is supporting
-    /// less than CHIP_CONFIG_SCENES_MAX_CLUSTERS_PER_SCENES clusters
+    /// CHIP_CONFIG_SCENES_MAX_CLUSTERS_PER_SCENE. The function shall use the reduce_size() method in the event it is supporting
+
+    /// less than CHIP_CONFIG_SCENES_MAX_CLUSTERS_PER_SCENE clusters.
+
     virtual void GetSupportedClusters(EndpointId endpoint, Span<ClusterId> & clusterBuffer) = 0;
 
     /// @brief Returns whether or not a cluster for scenes is supported on an endpoint
@@ -69,7 +78,8 @@ class SceneHandler : public IntrusiveListNodeBase<>
     /// @return true if supported, false if not supported
     virtual bool SupportsCluster(EndpointId endpoint, ClusterId cluster) = 0;
 
-    /// @brief From command AddScene, allows handler to filter through clusters in command to serialize only the supported ones.
+    /// @brief Called when handling AddScene.  Allows the handler to filter through the clusters in the command to serialize only the supported ones.
+
     /// @param endpoint[in] Endpoint ID
     /// @param extensionFieldSet[in] ExtensionFieldSets provided by the AddScene Command, pre initialized
     /// @param cluster[out]  Cluster in the Extension field set, filled by the function
@@ -79,10 +89,10 @@ class SceneHandler : public IntrusiveListNodeBase<>
                                     const app::Clusters::Scenes::Structs::ExtensionFieldSet::DecodableType & extensionFieldSet,
                                     ClusterId & cluster, MutableByteSpan & serialisedBytes) = 0;
 
-    /// @brief From command StoreScene, retrieves ExtensionField from currently active values, it is the function's responsibility
-    /// to
+    /// @brief Called when handling StoreScene, and only if the handler supports the given endpoint and cluster.
+    ///
+    /// The implementation must write the actual scene data to store to serializedBytes as described below.
 
-    /// place the serialized data in serializedBytes as described below.
 
     /// @param endpoint[in] Target Endpoint
     /// @param cluster[in] Target Cluster
@@ -92,7 +102,8 @@ class SceneHandler : public IntrusiveListNodeBase<>
     /// @return CHIP_NO_ERROR if successful, CHIP_ERROR value otherwise
     virtual CHIP_ERROR SerializeSave(EndpointId endpoint, ClusterId cluster, MutableByteSpan & serializedBytes) = 0;
 
-    /// @brief From stored scene (e.g. ViewScene), deserialize ExtensionFieldSet into a cluster object
+    /// @brief Deserialize an ExtensionFieldSet into a cluster object (e.g. when handling ViewScene).
+
     /// @param endpoint[in] Endpoint ID
     /// @param cluster[in] Cluster ID to save
     /// @param serializedBytes[in] ExtensionFieldSet stored in NVM
@@ -103,7 +114,8 @@ class SceneHandler : public IntrusiveListNodeBase<>
 
                                    app::Clusters::Scenes::Structs::ExtensionFieldSet::Type & extensionFieldSet) = 0;
 
-    /// @brief From stored scene (e.g RecallScene), applies EFS values to cluster at transition time
+    /// @brief Restore a stored scene for the given cluster instance, over timeMs milliseconds (e.g. when handling RecallScene)
+
     /// @param endpoint[in] Endpoint ID
     /// @param cluster[in] Cluster ID
     /// @param serializedBytes[in] ExtensionFieldSet stored in NVM
@@ -141,7 +153,8 @@ class SceneTable
 
         bool operator==(const SceneStorageId & other)
         {
-            return (this->mEndpointId == other.mEndpointId && this->mGroupId == other.mGroupId && this->mSceneId == other.mSceneId);
+            return (mEndpointId == other.mEndpointId && mGroupId == other.mGroupId && mSceneId == other.mSceneId);
+
         }
     };
 
@@ -162,17 +175,20 @@ class SceneTable
 
         SceneData(const CharSpan & sceneName = CharSpan(), SceneTransitionTime time = 0) : mSceneTransitionTimeMs(time)
         {
-            this->SetName(sceneName);
+            SetName(sceneName);
+
         }
         SceneData(EFStype fields, const CharSpan & sceneName = CharSpan(), SceneTransitionTime time = 0) :
             mSceneTransitionTimeMs(time)
         {
-            this->SetName(sceneName);
+            SetName(sceneName);
+
             mExtensionFieldSets = fields;
         }
         SceneData(const SceneData & other) : mSceneTransitionTimeMs(other.mSceneTransitionTimeMs)
         {
-            this->SetName(CharSpan(other.mName, other.mNameLength));
+            SetName(CharSpan(other.mName, other.mNameLength));
+
             mExtensionFieldSets = other.mExtensionFieldSets;
         }
         ~SceneData(){};
@@ -194,7 +210,8 @@ class SceneTable
 
         void Clear()
         {
-            this->SetName(CharSpan());
+            SetName(CharSpan());
+
             mSceneTransitionTimeMs = 0;
             mExtensionFieldSets.Clear();
         }
@@ -229,13 +246,15 @@ class SceneTable
 
         bool operator==(const SceneTableEntry & other)
         {
-            return (this->mStorageId == other.mStorageId && this->mStorageData == other.mStorageData);
+            return (mStorageId == other.mStorageId && mStorageData == other.mStorageData);
+
         }
 
         void operator=(const SceneTableEntry & other)
         {
-            this->mStorageId   = other.mStorageId;
-            this->mStorageData = other.mStorageData;
+            mStorageId   = other.mStorageId;
+            mStorageData = other.mStorageData;
+
         }
     };
 
@@ -275,12 +294,11 @@ class SceneTable
     virtual SceneEntryIterator * IterateSceneEntries(FabricIndex fabric_index) = 0;
 
     // Handlers
-    virtual bool HandlerListEmpty() { return (mNumHandlers == 0); }
-    virtual uint8_t GetHandlerNum() { return this->mNumHandlers; }
+    virtual bool HandlerListEmpty() { return mHandlerList.Empty(); }
+
 
     // SceneHandler * mHandlers[kMaxSceneHandlers] = { nullptr };
     IntrusiveList<SceneHandler> mHandlerList;
-    uint8_t mNumHandlers = 0;
 };
 
 } // namespace scenes

src/app/clusters/scenes/SceneTableImpl.cpp

@@ -167,7 +167,7 @@ struct FabricSceneData : public PersistentData<kPersistentFabricBufferMax>
         TLV::TLVType container;
         ReturnErrorOnFailure(writer.StartContainer(TLV::AnonymousTag(), TLV::kTLVType_Structure, container));
 
-        ReturnErrorOnFailure(writer.Put(TLV::ContextTag(TagSceneImpl::kSceneCount), (scene_count)));
+        ReturnErrorOnFailure(writer.Put(TLV::ContextTag(TagSceneImpl::kSceneCount), scene_count));
         // Storing the scene map
         for (uint8_t i = 0; i < kMaxScenePerFabric; i++)
         {
@@ -387,7 +387,7 @@ void DefaultSceneTableImpl::RegisterHandler(SceneHandler * handler)
 void DefaultSceneTableImpl::UnregisterHandler(SceneHandler * handler)
 {
     // Verify list is populated and handler is not null
-    VerifyOrReturn(!this->HandlerListEmpty() && !(handler == nullptr));
+    VerifyOrReturn(!HandlerListEmpty() && !(handler == nullptr));
     mHandlerList.Remove(handler);
     mNumHandlers--;
 }
@@ -398,7 +398,7 @@ void DefaultSceneTableImpl::UnregisterAllHandlers()
     {
         IntrusiveList<SceneHandler>::Iterator foo = mHandlerList.begin();
         SceneHandler * handle                     = &(*foo);
-        mHandlerList.Remove((handle));
+        mHandlerList.Remove(handle);
         mNumHandlers--;
     }
 }
@@ -409,7 +409,7 @@ void DefaultSceneTableImpl::UnregisterAllHandlers()
 CHIP_ERROR DefaultSceneTableImpl::SceneSaveEFS(SceneTableEntry & scene)
 {
 
-    if (!this->HandlerListEmpty())
+    if (!HandlerListEmpty())
     {
         uint8_t clusterCount = 0;
         clusterId cArray[kMaxClusterPerScenes];
@@ -422,10 +422,9 @@ CHIP_ERROR DefaultSceneTableImpl::SceneSaveEFS(SceneTableEntry & scene)
             MutableByteSpan EFSSpan = MutableByteSpan(EFS.mBytesBuffer, kMaxFieldBytesPerCluster);
             EFS.mID                 = cluster;
 
-            IntrusiveList<SceneHandler>::Iterator iter = mHandlerList.begin();
-            while (iter != mHandlerList.end())
+            for (auto & handler : mHandlerList)
             {
-                if (iter->SupportsCluster(scene.mStorageId.mEndpointId, cluster))
+                if (handler.SupportsCluster(scene.mStorageId.mEndpointId, cluster))
                 {
                     ReturnErrorOnFailure(iter->SerializeSave(scene.mStorageId.mEndpointId, EFS.mID, EFSSpan));
                     EFS.mUsedBytes = static_cast<uint8_t>(EFSSpan.size());
@@ -495,7 +494,7 @@ CHIP_ERROR DefaultSceneTableImpl::RemoveFabric(FabricIndex fabric_index)
     return fabric.Delete(mStorage);
 }
 
-/// @brief wrapper function around emberAfGetClustersFromEndpoint to allow testing, shimed in test configuration because
+/// @brief wrapper function around emberAfGetClustersFromEndpoint to allow testing, shimmed in test configuration because
 /// emberAfGetClusterFromEndpoint relies on <app/util/attribute-storage.h>, which relies on zap generated files
 uint8_t DefaultSceneTableImpl::GetClustersFromEndpoint(EndpointId endpoint, ClusterId * clusterList, uint8_t listLen)
 {

src/app/util/mock/attribute-storage.cpp

@@ -188,7 +188,7 @@ chip::Optional<chip::ClusterId> emberAfGetNthClusterId(chip::EndpointId endpoint
 // for the given endpoint and client/server polarity
 uint8_t emberAfGetClustersFromEndpoint(EndpointId endpoint, ClusterId * clusterList, uint8_t listLen, bool server)
 {
-    uint8_t cluster_Count = emberAfClusterCount(endpoint, server);
+    uint8_t cluster_count = emberAfClusterCount(endpoint, server);
     uint8_t i;
 
     if (cluster_Count > listLen)