Make the copy from a pointer logic cleaner

Author: andy31415

src/app/AttributeEncodeState.h

@@ -21,14 +21,38 @@
 namespace chip {
 namespace app {
 
-/**
- * Maintains the internal state of list encoding
- */
+/// Maintains the internal state of list encoding
+///
+/// List encoding is generally assumed incremental and chunkable (i.e.
+/// partial encoding is ok.). For this purpose the class maintains two
+/// pieces of data:
+///   - AllowPartialData tracks if partial encoding is acceptable in the
+///     current encoding state (to be used for atomic/non-atomic list item writes)
+///   - CurrentEncodingListIndex representing the list index that is next
+///     to be encoded in the output. kInvalidListIndex means that a new list
+///     encoding has been started.
 class AttributeEncodeState
 {
 public:
     AttributeEncodeState() = default;
 
+    /// Allows the encode state to be initialized from an OPTIONAL
+    /// other encoding state
+    ///
+    /// if other is nullptr, this is the same as the default initializer.
+    AttributeEncodeState(AttributeEncodeState * other)
+    {
+        if (other != nullptr)
+        {
+            *this = *other;
+        }
+        else
+        {
+            mCurrentEncodingListIndex = kInvalidListIndex;
+            mAllowPartialData         = false;
+        }
+    }
+
     bool AllowPartialData() const { return mAllowPartialData; }
     ListIndex CurrentEncodingListIndex() const { return mCurrentEncodingListIndex; }
 

src/app/AttributeValueEncoder.h

@@ -17,8 +17,8 @@
 #pragma once
 
 #include <access/SubjectDescriptor.h>
-#include <app/AttributeReportBuilder.h>
 #include <app/AttributeEncodeState.h>
+#include <app/AttributeReportBuilder.h>
 #include <app/ConcreteAttributePath.h>
 #include <app/MessageDef/AttributeReportIBs.h>
 #include <app/data-model/FabricScoped.h>
@@ -141,7 +141,7 @@ class AttributeValueEncoder
         if (err == CHIP_NO_ERROR)
         {
             // The Encode procedure finished without any error, clear the state.
-            mEncodeState = AttributeEncodeState();
+            mEncodeState.Reset();
         }
         return err;
     }

src/app/BUILD.gn

@@ -277,8 +277,8 @@ source_set("events") {
 
 static_library("attribute-access") {
   sources = [
-    "AttributeAccessInterfaceCache.h",
     "AttributeAccessInterface.h",
+    "AttributeAccessInterfaceCache.h",
     "AttributeAccessInterfaceRegistry.cpp",
     "AttributeAccessInterfaceRegistry.h",
     "AttributeEncodeState.h",

src/app/util/ember-compatibility-functions.cpp

@@ -430,12 +430,7 @@ CHIP_ERROR ReadViaAccessInterface(SubjectDescriptor subjectDescriptor, bool aIsF
                                   AttributeEncodeState * aEncoderState, AttributeAccessInterface * aAccessInterface,
                                   bool * aTriedEncode)
 {
-    AttributeEncodeState state;
-    if (aEncoderState != nullptr)
-    {
-        state = *aEncoderState;
-    }
-
+    AttributeEncodeState state(aEncoderState);
     DataVersion version = 0;
     ReturnErrorOnFailure(ReadClusterDataVersion(aPath, version));
     AttributeValueEncoder valueEncoder(aAttributeReports, subjectDescriptor, aPath, version, aIsFabricFiltered, state);

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

@@ -350,11 +350,7 @@ CHIP_ERROR ReadSingleMockClusterData(FabricIndex aAccessingFabricIndex, const Co
     // Attribute 4 acts as a large attribute to trigger chunking.
     if (aPath.mAttributeId == MockAttributeId(4))
     {
-        AttributeEncodeState state;
-        if (apEncoderState != nullptr)
-        {
-            state = *apEncoderState;
-        }
+        AttributeEncodeState state(apEncoderState);
         Access::SubjectDescriptor subject;
         subject.fabricIndex = aAccessingFabricIndex;
 

src/controller/tests/data_model/TestRead.cpp

@@ -109,11 +109,7 @@ CHIP_ERROR ReadSingleClusterData(const Access::SubjectDescriptor & aSubjectDescr
             // Use an incorrect attribute id for some of the responses.
             path.mAttributeId =
                 static_cast<AttributeId>(path.mAttributeId + (i / 2) + (responseDirective == kSendManyDataResponsesWrongPath));
-            AttributeEncodeState state;
-            if (apEncoderState != nullptr)
-            {
-                state = *apEncoderState;
-            }
+            AttributeEncodeState state(apEncoderState);
             AttributeValueEncoder valueEncoder(aAttributeReports, aSubjectDescriptor, path, kDataVersion, aIsFabricFiltered, state);
             ReturnErrorOnFailure(valueEncoder.Encode(true));
         }
@@ -126,11 +122,7 @@ CHIP_ERROR ReadSingleClusterData(const Access::SubjectDescriptor & aSubjectDescr
         if (aPath.mClusterId == app::Clusters::UnitTesting::Id &&
             aPath.mAttributeId == app::Clusters::UnitTesting::Attributes::ListFabricScoped::Id)
         {
-            AttributeEncodeState state;
-            if (apEncoderState != nullptr)
-            {
-                state = *apEncoderState;
-            }
+            AttributeEncodeState state(apEncoderState);
             AttributeValueEncoder valueEncoder(aAttributeReports, aSubjectDescriptor, aPath, kDataVersion, aIsFabricFiltered,
                                                state);
 
@@ -146,11 +138,7 @@ CHIP_ERROR ReadSingleClusterData(const Access::SubjectDescriptor & aSubjectDescr
         if (aPath.mClusterId == app::Clusters::UnitTesting::Id &&
             aPath.mAttributeId == app::Clusters::UnitTesting::Attributes::Int16u::Id)
         {
-            AttributeEncodeState state;
-            if (apEncoderState != nullptr)
-            {
-                state = *apEncoderState;
-            }
+            AttributeEncodeState state(apEncoderState);
             AttributeValueEncoder valueEncoder(aAttributeReports, aSubjectDescriptor, aPath, kDataVersion, aIsFabricFiltered,
                                                state);
 
@@ -182,11 +170,7 @@ CHIP_ERROR ReadSingleClusterData(const Access::SubjectDescriptor & aSubjectDescr
         if (aPath.mClusterId == app::Clusters::IcdManagement::Id &&
             aPath.mAttributeId == app::Clusters::IcdManagement::Attributes::OperatingMode::Id)
         {
-            AttributeEncodeState state;
-            if (apEncoderState != nullptr)
-            {
-                state = *apEncoderState;
-            }
+            AttributeEncodeState state(apEncoderState);
             AttributeValueEncoder valueEncoder(aAttributeReports, aSubjectDescriptor, aPath, kDataVersion, aIsFabricFiltered,
                                                state);