Merge pull request Expensify#724 from callstack-internal/VickyStash/poc/get-rid-of-macro-micro-tasks

Remove macro/micro tasks during subscriber update

Author: mountiny

lib/Onyx.ts

@@ -260,9 +260,8 @@ function merge<TKey extends OnyxKey>(key: TKey, changes: OnyxMergeInput<TKey>):
                     return Promise.resolve();
                 }
 
-                return OnyxMerge.applyMerge(key, existingValue, validChanges).then(({mergedValue, updatePromise}) => {
+                return OnyxMerge.applyMerge(key, existingValue, validChanges).then(({mergedValue}) => {
                     OnyxUtils.sendActionToDevTools(OnyxUtils.METHOD.MERGE, key, changes, mergedValue);
-                    return updatePromise;
                 });
             } catch (error) {
                 Logger.logAlert(`An error occurred while applying merge for key: ${key}, Error: ${error}`);
@@ -374,16 +373,6 @@ function clear(keysToPreserve: OnyxKey[] = []): Promise<void> {
                     keysToBeClearedFromStorage.push(key);
                 }
 
-                const updatePromises: Array<Promise<void>> = [];
-
-                // Notify the subscribers for each key/value group so they can receive the new values
-                for (const [key, value] of Object.entries(keyValuesToResetIndividually)) {
-                    updatePromises.push(OnyxUtils.scheduleSubscriberUpdate(key, value));
-                }
-                for (const [key, value] of Object.entries(keyValuesToResetAsCollection)) {
-                    updatePromises.push(OnyxUtils.scheduleNotifyCollectionSubscribers(key, value.newValues, value.oldValues));
-                }
-
                 // Exclude RAM-only keys to prevent them from being saved to storage
                 const defaultKeyValuePairs = Object.entries(
                     Object.keys(defaultKeyStates)
@@ -402,7 +391,14 @@ function clear(keysToPreserve: OnyxKey[] = []): Promise<void> {
                     .then(() => Storage.multiSet(defaultKeyValuePairs))
                     .then(() => {
                         DevTools.clearState(keysToPreserve);
-                        return Promise.all(updatePromises);
+
+                        // Notify the subscribers for each key/value group so they can receive the new values
+                        for (const [key, value] of Object.entries(keyValuesToResetIndividually)) {
+                            OnyxUtils.keyChanged(key, value);
+                        }
+                        for (const [key, value] of Object.entries(keyValuesToResetAsCollection)) {
+                            OnyxUtils.keysChanged(key, value.newValues, value.oldValues);
+                        }
                     });
             })
             .then(() => undefined);

lib/OnyxMerge/index.native.ts

@@ -26,21 +26,20 @@ const applyMerge: ApplyMerge = <TKey extends OnyxKey, TValue extends OnyxInput<T
     OnyxUtils.logKeyChanged(OnyxUtils.METHOD.MERGE, key, mergedValue, hasChanged);
 
     // This approach prioritizes fast UI changes without waiting for data to be stored in device storage.
-    const updatePromise = OnyxUtils.broadcastUpdate(key, mergedValue as OnyxValue<TKey>, hasChanged);
+    OnyxUtils.broadcastUpdate(key, mergedValue as OnyxValue<TKey>, hasChanged);
 
     const shouldSkipStorageOperations = !hasChanged || OnyxUtils.isRamOnlyKey(key);
 
     // If the value has not changed, calling Storage.setItem() would be redundant and a waste of performance, so return early instead.
     // If the key is marked as RAM-only, it should not be saved nor updated in the storage.
     if (shouldSkipStorageOperations) {
-        return Promise.resolve({mergedValue, updatePromise});
+        return Promise.resolve({mergedValue});
     }
 
     // For native platforms we use `mergeItem` that will take advantage of JSON_PATCH and JSON_REPLACE SQL operations to
     // merge the object in a performant way.
     return Storage.mergeItem(key, batchedChanges as OnyxValue<TKey>, replaceNullPatches).then(() => ({
         mergedValue,
-        updatePromise,
     }));
 };
 

lib/OnyxMerge/index.ts

@@ -18,20 +18,19 @@ const applyMerge: ApplyMerge = <TKey extends OnyxKey, TValue extends OnyxInput<T
     OnyxUtils.logKeyChanged(OnyxUtils.METHOD.MERGE, key, mergedValue, hasChanged);
 
     // This approach prioritizes fast UI changes without waiting for data to be stored in device storage.
-    const updatePromise = OnyxUtils.broadcastUpdate(key, mergedValue as OnyxValue<TKey>, hasChanged);
+    OnyxUtils.broadcastUpdate(key, mergedValue as OnyxValue<TKey>, hasChanged);
 
     const shouldSkipStorageOperations = !hasChanged || OnyxUtils.isRamOnlyKey(key);
 
     // If the value has not changed, calling Storage.setItem() would be redundant and a waste of performance, so return early instead.
     // If the key is marked as RAM-only, it should not be saved nor updated in the storage.
     if (shouldSkipStorageOperations) {
-        return Promise.resolve({mergedValue, updatePromise});
+        return Promise.resolve({mergedValue});
     }
 
     // For web platforms we use `setItem` since the object was already merged with its changes before.
     return Storage.setItem(key, mergedValue as OnyxValue<TKey>).then(() => ({
         mergedValue,
-        updatePromise,
     }));
 };
 

lib/OnyxMerge/types.ts

@@ -2,7 +2,6 @@ import type {OnyxInput, OnyxKey} from '../types';
 
 type ApplyMergeResult<TValue> = {
     mergedValue: TValue;
-    updatePromise: Promise<void>;
 };
 
 type ApplyMerge = <TKey extends OnyxKey, TValue extends OnyxInput<OnyxKey> | undefined, TChange extends OnyxInput<OnyxKey> | null>(