[Darwin] MTRDevice cache make use of controller storage for persistent cache (project-chip#31952)

* [Darwin] MTRDevice cache make use of controller storage for persistent cache

---------

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

Author: jtung-apple

src/darwin/Framework/CHIP/MTRBaseDevice.h

@@ -549,7 +549,7 @@ MTR_AVAILABLE(ios(16.1), macos(13.0), watchos(9.1), tvos(16.1))
  * wildcards).
  */
 MTR_AVAILABLE(ios(16.4), macos(13.3), watchos(9.4), tvos(16.4))
-@interface MTRClusterPath : NSObject <NSCopying>
+@interface MTRClusterPath : NSObject <NSCopying, NSSecureCoding>
 
 @property (nonatomic, readonly, copy) NSNumber * endpoint;
 @property (nonatomic, readonly, copy) NSNumber * cluster;
@@ -565,7 +565,7 @@ MTR_AVAILABLE(ios(16.4), macos(13.3), watchos(9.4), tvos(16.4))
  * wildcards).
  */
 MTR_AVAILABLE(ios(16.1), macos(13.0), watchos(9.1), tvos(16.1))
-@interface MTRAttributePath : MTRClusterPath
+@interface MTRAttributePath : MTRClusterPath <NSSecureCoding>
 
 @property (nonatomic, readonly, copy) NSNumber * attribute;
 

src/darwin/Framework/CHIP/MTRBaseDevice.mm

@@ -2425,6 +2425,42 @@ - (id)copyWithZone:(NSZone *)zone
     return [MTRClusterPath clusterPathWithEndpointID:_endpoint clusterID:_cluster];
 }
 
+static NSString * const sEndpointKey = @"endpointKey";
+static NSString * const sClusterKey = @"clusterKey";
+
++ (BOOL)supportsSecureCoding
+{
+    return YES;
+}
+
+- (nullable instancetype)initWithCoder:(NSCoder *)decoder
+{
+    self = [super init];
+    if (self == nil) {
+        return nil;
+    }
+
+    _endpoint = [decoder decodeObjectOfClass:[NSNumber class] forKey:sEndpointKey];
+    if (_endpoint && ![_endpoint isKindOfClass:[NSNumber class]]) {
+        MTR_LOG_ERROR("MTRClusterPath decoded %@ for endpoint, not NSNumber.", _endpoint);
+        return nil;
+    }
+
+    _cluster = [decoder decodeObjectOfClass:[NSNumber class] forKey:sClusterKey];
+    if (_cluster && ![_cluster isKindOfClass:[NSNumber class]]) {
+        MTR_LOG_ERROR("MTRClusterPath decoded %@ for cluster, not NSNumber.", _cluster);
+        return nil;
+    }
+
+    return self;
+}
+
+- (void)encodeWithCoder:(NSCoder *)coder
+{
+    [coder encodeObject:_endpoint forKey:sEndpointKey];
+    [coder encodeObject:_cluster forKey:sClusterKey];
+}
+
 @end
 
 @implementation MTRAttributePath
@@ -2482,6 +2518,35 @@ - (ConcreteAttributePath)_asConcretePath
     return ConcreteAttributePath([self.endpoint unsignedShortValue], static_cast<ClusterId>([self.cluster unsignedLongValue]),
         static_cast<AttributeId>([self.attribute unsignedLongValue]));
 }
+
+static NSString * const sAttributeKey = @"attributeKey";
+
++ (BOOL)supportsSecureCoding
+{
+    return YES;
+}
+
+- (nullable instancetype)initWithCoder:(NSCoder *)decoder
+{
+    self = [super initWithCoder:decoder];
+    if (self == nil) {
+        return nil;
+    }
+
+    _attribute = [decoder decodeObjectOfClass:[NSNumber class] forKey:sAttributeKey];
+    if (_attribute && ![_attribute isKindOfClass:[NSNumber class]]) {
+        MTR_LOG_ERROR("MTRAttributePath decoded %@ for attribute, not NSNumber.", _attribute);
+        return nil;
+    }
+
+    return self;
+}
+
+- (void)encodeWithCoder:(NSCoder *)coder
+{
+    [coder encodeObject:_attribute forKey:sAttributeKey];
+}
+
 @end
 
 @implementation MTRAttributePath (Deprecated)

src/darwin/Framework/CHIP/MTRDevice.mm

@@ -1503,15 +1503,20 @@ - (NSArray *)_getAttributesToReportWithReportedValues:(NSArray<NSDictionary<NSSt
 
     NSMutableArray * attributesToReport = [NSMutableArray array];
     NSMutableArray * attributePathsToReport = [NSMutableArray array];
-    for (NSDictionary<NSString *, id> * attributeReponseValue in reportedAttributeValues) {
-        MTRAttributePath * attributePath = attributeReponseValue[MTRAttributePathKey];
-        NSDictionary * attributeDataValue = attributeReponseValue[MTRDataKey];
-        NSError * attributeError = attributeReponseValue[MTRErrorKey];
+    BOOL dataStoreExists = _deviceController.controllerDataStore != nil;
+    NSMutableArray * attributesToPersist;
+    if (dataStoreExists) {
+        attributesToPersist = [NSMutableArray array];
+    }
+    for (NSDictionary<NSString *, id> * attributeResponseValue in reportedAttributeValues) {
+        MTRAttributePath * attributePath = attributeResponseValue[MTRAttributePathKey];
+        NSDictionary * attributeDataValue = attributeResponseValue[MTRDataKey];
+        NSError * attributeError = attributeResponseValue[MTRErrorKey];
         NSDictionary * previousValue;
 
         // sanity check either data value or error must exist
         if (!attributeDataValue && !attributeError) {
-            MTR_LOG_INFO("%@ report %@ no data value or error: %@", self, attributePath, attributeReponseValue);
+            MTR_LOG_INFO("%@ report %@ no data value or error: %@", self, attributePath, attributeResponseValue);
             continue;
         }
 
@@ -1532,6 +1537,12 @@ - (NSArray *)_getAttributesToReportWithReportedValues:(NSArray<NSDictionary<NSSt
             previousValue = _readCache[attributePath];
             _readCache[attributePath] = nil;
         } else {
+            BOOL readCacheValueChanged = ![self _attributeDataValue:attributeDataValue isEqualToDataValue:_readCache[attributePath]];
+            // Check if attribute needs to be persisted - compare only to read cache and disregard expected values
+            if (dataStoreExists && readCacheValueChanged) {
+                [attributesToPersist addObject:attributeResponseValue];
+            }
+
             // if expected values exists, purge and update read cache
             NSArray * expectedValue = _expectedValueCache[attributePath];
             if (expectedValue) {
@@ -1542,7 +1553,7 @@ - (NSArray *)_getAttributesToReportWithReportedValues:(NSArray<NSDictionary<NSSt
                 }
                 _expectedValueCache[attributePath] = nil;
                 _readCache[attributePath] = attributeDataValue;
-            } else if (![self _attributeDataValue:attributeDataValue isEqualToDataValue:_readCache[attributePath]]) {
+            } else if (readCacheValueChanged) {
                 // otherwise compare and update read cache
                 previousValue = _readCache[attributePath];
                 _readCache[attributePath] = attributeDataValue;
@@ -1580,21 +1591,40 @@ - (NSArray *)_getAttributesToReportWithReportedValues:(NSArray<NSDictionary<NSSt
 
         if (shouldReportAttribute) {
             if (previousValue) {
-                NSMutableDictionary * mutableAttributeReponseValue = attributeReponseValue.mutableCopy;
-                mutableAttributeReponseValue[MTRPreviousDataKey] = previousValue;
-                [attributesToReport addObject:mutableAttributeReponseValue];
+                NSMutableDictionary * mutableAttributeResponseValue = attributeResponseValue.mutableCopy;
+                mutableAttributeResponseValue[MTRPreviousDataKey] = previousValue;
+                [attributesToReport addObject:mutableAttributeResponseValue];
             } else {
-                [attributesToReport addObject:attributeReponseValue];
+                [attributesToReport addObject:attributeResponseValue];
             }
             [attributePathsToReport addObject:attributePath];
         }
     }
 
     MTR_LOG_INFO("%@ report from reported values %@", self, attributePathsToReport);
 
+    if (dataStoreExists && attributesToPersist.count) {
+        [_deviceController.controllerDataStore storeAttributeValues:attributesToPersist forNodeID:_nodeID];
+    }
+
     return attributesToReport;
 }
 
+- (void)setAttributeValues:(NSArray<NSDictionary *> *)attributeValues reportChanges:(BOOL)reportChanges
+{
+    if (reportChanges) {
+        [self _handleAttributeReport:attributeValues];
+    } else {
+        os_unfair_lock_lock(&self->_lock);
+        for (NSDictionary * responseValue in attributeValues) {
+            MTRAttributePath * path = responseValue[MTRAttributePathKey];
+            NSDictionary * dataValue = responseValue[MTRDataKey];
+            _readCache[path] = dataValue;
+        }
+        os_unfair_lock_unlock(&self->_lock);
+    }
+}
+
 // If value is non-nil, associate with expectedValueID
 // If value is nil, remove only if expectedValueID matches
 // previousValue is an out parameter
@@ -1662,9 +1692,9 @@ - (NSArray *)_getAttributesToReportWithNewExpectedValues:(NSArray<NSDictionary<N
 
     NSMutableArray * attributesToReport = [NSMutableArray array];
     NSMutableArray * attributePathsToReport = [NSMutableArray array];
-    for (NSDictionary<NSString *, id> * attributeReponseValue in expectedAttributeValues) {
-        MTRAttributePath * attributePath = attributeReponseValue[MTRAttributePathKey];
-        NSDictionary * attributeDataValue = attributeReponseValue[MTRDataKey];
+    for (NSDictionary<NSString *, id> * attributeResponseValue in expectedAttributeValues) {
+        MTRAttributePath * attributePath = attributeResponseValue[MTRAttributePathKey];
+        NSDictionary * attributeDataValue = attributeResponseValue[MTRDataKey];
 
         BOOL shouldReportValue = NO;
         NSDictionary<NSString *, id> * attributeValueToReport;

src/darwin/Framework/CHIP/MTRDeviceController.mm

@@ -864,6 +864,12 @@ - (MTRDevice *)deviceForNodeID:(NSNumber *)nodeID
         if ([self isRunning]) {
             _nodeIDToDeviceMap[nodeID] = deviceToReturn;
         }
+
+        // Load persisted attributes if they exist.
+        NSArray * attributesFromCache = [_controllerDataStore getStoredAttributesForNodeID:nodeID];
+        if (attributesFromCache) {
+            [deviceToReturn setAttributeValues:attributesFromCache reportChanges:NO];
+        }
     }
     os_unfair_lock_unlock(&_deviceMapLock);
 

src/darwin/Framework/CHIP/MTRDeviceControllerDataStore.h

@@ -63,6 +63,14 @@ NS_ASSUME_NONNULL_BEGIN
 - (CHIP_ERROR)storeLastLocallyUsedNOC:(MTRCertificateTLVBytes)noc;
 - (MTRCertificateTLVBytes _Nullable)fetchLastLocallyUsedNOC;
 
+/**
+ * Storage for MTRDevice attribute read cache. This is local-only storage as an optimization. New controller devices using MTRDevice API can prime their own local cache from devices directly.
+ */
+- (nullable NSArray<NSDictionary *> *)getStoredAttributesForNodeID:(NSNumber *)nodeID;
+- (void)storeAttributeValues:(NSArray<NSDictionary *> *)dataValues forNodeID:(NSNumber *)nodeID;
+- (void)clearStoredAttributesForNodeID:(NSNumber *)nodeID;
+- (void)clearAllStoredAttributes;
+
 @end
 
 NS_ASSUME_NONNULL_END