Enable persistent storage on Darwin in Server.h. (#14342)

There were two remaining issues in the Darwin KVS impl that needed
to be fixed to get this to pass:

1) The errors returned did not match the API documentation, which
   caused some consumers to fail.  The most important problem here was
   returning CHIP_ERROR_KEY_NOT_FOUND instead of
   CHIP_ERROR_PERSISTED_STORAGE_VALUE_NOT_FOUND from _Get, but I went
   ahead and aligned the other error cases (not initialized, buffer
   passed to _Get too small, deleting unknown key, failures to save to
   persistent storage) with the API documentation.

2) In _Put, if the item already existed the change of "value" was not
   being picked up by the NSManagedObject machinery, so updating the
   value of an already-existing key did not work.  The fix for this is
   to use @dynamic instead of @synthesize for the properties of
   KeyValueItem (shamelessly copy/pasting from the documentation at
   https://developer.apple.com/library/archive/documentation/Cocoa/Conceptual/CoreData/LifeofaManagedObject.html),
   which I _think_ causes the getter/setter to be provided by the
   NSMnagedObject bits, which then know about the set we perform and
   know to update the data store.

Fixes #12174

src/app/server/BUILD.gn

@@ -31,13 +31,6 @@ config("server_config") {
   if (chip_enable_group_messaging_tests) {
     defines += [ "CHIP_ENABLE_GROUP_MESSAGING_TESTS" ]
   }
-
-  if (current_os == "mac" || current_os == "ios") {
-    # Using Non persistent storage delegate since
-    # persistence is also disable in Unit test for linux and MacOS
-    # Issue #12174 for Darwin
-    defines += [ "CHIP_USE_NON_PERSISTENT_STORAGE_DELEGATE" ]
-  }
 }
 
 static_library("server") {

src/app/server/Server.h

@@ -28,7 +28,6 @@
 #include <inet/InetConfig.h>
 #include <lib/core/CHIPConfig.h>
 #include <lib/support/SafeInt.h>
-#include <lib/support/TestPersistentStorageDelegate.h>
 #include <messaging/ExchangeMgr.h>
 #include <platform/KeyValueStoreManager.h>
 #include <protocols/secure_channel/CASEServer.h>
@@ -190,13 +189,7 @@ class Server
 
     // Both PersistentStorageDelegate, and GroupDataProvider should be injected by the applications
     // See: https://github.com/project-chip/connectedhomeip/issues/12276
-    // Currently, the GroupDataProvider cannot use KeyValueStoreMgr() due to
-    // (https://github.com/project-chip/connectedhomeip/issues/12174)
-#ifdef CHIP_USE_NON_PERSISTENT_STORAGE_DELEGATE
-    TestPersistentStorageDelegate mDeviceStorage;
-#else
     DeviceStorageDelegate mDeviceStorage;
-#endif
     Credentials::GroupDataProviderImpl mGroupsProvider;
     app::DefaultAttributePersistenceProvider mAttributePersister;
     GroupDataProviderListener mListener;

src/platform/Darwin/KeyValueStoreManagerImpl.mm

@@ -43,16 +43,14 @@ @interface KeyValueItem : NSManagedObject
 
 @implementation KeyValueItem
 
-@synthesize key;
-@synthesize value;
+@dynamic key;
+@dynamic value;
 
-- (instancetype)initWithContext:(nonnull NSManagedObjectContext *)context
-                            key:(nonnull NSString *)key_
-                          value:(nonnull NSData *)value_
+- (instancetype)initWithContext:(nonnull NSManagedObjectContext *)context key:(nonnull NSString *)key value:(nonnull NSData *)value
 {
     if (self = [super initWithContext:context]) {
-        key = key_;
-        value = value_;
+        self.key = key;
+        self.value = value;
     }
     return self;
 }
@@ -209,10 +207,11 @@ - (instancetype)initWithContext:(nonnull NSManagedObjectContext *)context
         {
             ReturnErrorCodeIf(key == nullptr, CHIP_ERROR_INVALID_ARGUMENT);
             ReturnErrorCodeIf(offset != 0, CHIP_ERROR_INVALID_ARGUMENT);
+            ReturnErrorCodeIf(gContext == nullptr, CHIP_ERROR_WELL_UNINITIALIZED);
 
             KeyValueItem * item = FindItemForKey([[NSString alloc] initWithUTF8String:key], nil, true);
             if (!item) {
-                return CHIP_ERROR_KEY_NOT_FOUND;
+                return CHIP_ERROR_PERSISTED_STORAGE_VALUE_NOT_FOUND;
             }
 
             if (read_bytes_size != nullptr) {
@@ -221,6 +220,17 @@ - (instancetype)initWithContext:(nonnull NSManagedObjectContext *)context
 
             if (value != nullptr) {
                 memcpy(value, item.value.bytes, std::min<size_t>((item.value.length), value_size));
+#if CHIP_CONFIG_DARWIN_STORAGE_VERBOSE_LOGGING
+                fprintf(stderr, "GETTING VALUE FOR: '%s': ", key);
+                for (size_t i = 0; i < std::min<size_t>((item.value.length), value_size); ++i) {
+                    fprintf(stderr, "%02x ", static_cast<uint8_t *>(value)[i]);
+                }
+                fprintf(stderr, "\n");
+#endif
+            }
+
+            if (item.value.length > value_size) {
+                return CHIP_ERROR_BUFFER_TOO_SMALL;
             }
 
             return CHIP_NO_ERROR;
@@ -229,10 +239,11 @@ - (instancetype)initWithContext:(nonnull NSManagedObjectContext *)context
         CHIP_ERROR KeyValueStoreManagerImpl::_Delete(const char * key)
         {
             ReturnErrorCodeIf(key == nullptr, CHIP_ERROR_INVALID_ARGUMENT);
+            ReturnErrorCodeIf(gContext == nullptr, CHIP_ERROR_WELL_UNINITIALIZED);
 
             KeyValueItem * item = FindItemForKey([[NSString alloc] initWithUTF8String:key], nil);
             if (!item) {
-                return CHIP_NO_ERROR;
+                return CHIP_ERROR_PERSISTED_STORAGE_VALUE_NOT_FOUND;
             }
 
             __block BOOL success = NO;
@@ -244,7 +255,7 @@ - (instancetype)initWithContext:(nonnull NSManagedObjectContext *)context
 
             if (!success) {
                 ChipLogError(DeviceLayer, "Error saving context: %s", error.localizedDescription.UTF8String);
-                return CHIP_ERROR_INTERNAL;
+                return CHIP_ERROR_PERSISTED_STORAGE_FAILED;
             }
 
             return CHIP_NO_ERROR;
@@ -253,6 +264,7 @@ - (instancetype)initWithContext:(nonnull NSManagedObjectContext *)context
         CHIP_ERROR KeyValueStoreManagerImpl::_Put(const char * key, const void * value, size_t value_size)
         {
             ReturnErrorCodeIf(key == nullptr, CHIP_ERROR_INVALID_ARGUMENT);
+            ReturnErrorCodeIf(gContext == nullptr, CHIP_ERROR_WELL_UNINITIALIZED);
 
             NSData * data = [[NSData alloc] initWithBytes:value length:value_size];
 
@@ -274,9 +286,17 @@ - (instancetype)initWithContext:(nonnull NSManagedObjectContext *)context
 
             if (!success) {
                 ChipLogError(DeviceLayer, "Error saving context: %s", error.localizedDescription.UTF8String);
-                return CHIP_ERROR_INTERNAL;
+                return CHIP_ERROR_PERSISTED_STORAGE_FAILED;
             }
 
+#if CHIP_CONFIG_DARWIN_STORAGE_VERBOSE_LOGGING
+            fprintf(stderr, "PUT VALUE FOR: '%s': ", key);
+            for (size_t i = 0; i < value_size; ++i) {
+                fprintf(stderr, "%02x ", static_cast<const uint8_t *>(value)[i]);
+            }
+            fprintf(stderr, "\n");
+#endif
+
             return CHIP_NO_ERROR;
         }