Merge pull request #576 from callstack-internal/perf/use-startswith-only

perf: avoid re-calculating collection key length and use key.startsWith
Expensify · Aug 7, 2024 · 9605e91 · 9605e91
2 parents 190d8d1 + eee10ec
commit 9605e91
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Showing 3 changed files with 14 additions and 6 deletions.
diff --git a/lib/Onyx.ts b/lib/Onyx.ts
@@ -645,6 +645,7 @@ function updateSnapshots(data: OnyxUpdate[]) {
     const promises: Array<() => Promise<void>> = [];
 
     const snapshotCollection = OnyxUtils.getCachedCollection(snapshotCollectionKey);
+    const snapshotCollectionKeyLength = snapshotCollectionKey.length;
 
     Object.entries(snapshotCollection).forEach(([snapshotKey, snapshotValue]) => {
         // Snapshots may not be present in cache. We don't know how to update them so we skip.
@@ -656,7 +657,7 @@ function updateSnapshots(data: OnyxUpdate[]) {
 
         data.forEach(({key, value}) => {
             // snapshots are normal keys so we want to skip update if they are written to Onyx
-            if (OnyxUtils.isCollectionMemberKey(snapshotCollectionKey, key)) {
+            if (OnyxUtils.isCollectionMemberKey(snapshotCollectionKey, key, snapshotCollectionKeyLength)) {
                 return;
             }
 

diff --git a/lib/OnyxUtils.ts b/lib/OnyxUtils.ts
@@ -396,8 +396,8 @@ function isCollectionKey(key: OnyxKey): key is CollectionKeyBase {
     return onyxCollectionKeySet.has(key);
 }
 
-function isCollectionMemberKey<TCollectionKey extends CollectionKeyBase>(collectionKey: TCollectionKey, key: string): key is `${TCollectionKey}${string}` {
-    return Str.startsWith(key, collectionKey) && key.length > collectionKey.length;
+function isCollectionMemberKey<TCollectionKey extends CollectionKeyBase>(collectionKey: TCollectionKey, key: string, collectionKeyLength: number): key is `${TCollectionKey}${string}` {
+    return key.startsWith(collectionKey) && key.length > collectionKeyLength;
 }
 
 /**
@@ -556,12 +556,14 @@ function getCachedCollection<TKey extends CollectionKeyBase>(collectionKey: TKey
     const allKeys = collectionMemberKeys || cache.getAllKeys();
     const collection: OnyxCollection<KeyValueMapping[TKey]> = {};
 
+    const collectionKeyLength = collectionKey.length;
+
     // forEach exists on both Set and Array
     allKeys.forEach((key) => {
         // If we don't have collectionMemberKeys array then we have to check whether a key is a collection member key.
         // Because in that case the keys will be coming from `cache.getAllKeys()` and we need to filter out the keys that
         // are not part of the collection.
-        if (!collectionMemberKeys && !isCollectionMemberKey(collectionKey, key)) {
+        if (!collectionMemberKeys && !isCollectionMemberKey(collectionKey, key, collectionKeyLength)) {
             return;
         }
 
@@ -597,6 +599,7 @@ function keysChanged<TKey extends CollectionKeyBase>(
     // individual collection key member for the collection that is being updated. It is important to note that the collection parameter cane be a PARTIAL collection
     // and does not represent all of the combined keys and values for a collection key. It is just the "new" data that was merged in via mergeCollection().
     const stateMappingKeys = Object.keys(callbackToStateMapping);
+    const collectionKeyLength = collectionKey.length;
     for (let i = 0; i < stateMappingKeys.length; i++) {
         const subscriber = callbackToStateMapping[stateMappingKeys[i]];
         if (!subscriber) {
@@ -616,7 +619,7 @@ function keysChanged<TKey extends CollectionKeyBase>(
         /**
          * e.g. Onyx.connect({key: `${ONYXKEYS.COLLECTION.REPORT}{reportID}`, callback: ...});
          */
-        const isSubscribedToCollectionMemberKey = isCollectionMemberKey(collectionKey, subscriber.key);
+        const isSubscribedToCollectionMemberKey = isCollectionMemberKey(collectionKey, subscriber.key, collectionKeyLength);
 
         // Regular Onyx.connect() subscriber found.
         if (typeof subscriber.callback === 'function') {

diff --git a/lib/useOnyx.ts b/lib/useOnyx.ts
@@ -109,7 +109,11 @@ function useOnyx<TKey extends OnyxKey, TReturnValue = OnyxValue<TKey>>(key: TKey
             const previousCollectionKey = OnyxUtils.splitCollectionMemberKey(previousKey)[0];
             const collectionKey = OnyxUtils.splitCollectionMemberKey(key)[0];
 
-            if (OnyxUtils.isCollectionMemberKey(previousCollectionKey, previousKey) && OnyxUtils.isCollectionMemberKey(collectionKey, key) && previousCollectionKey === collectionKey) {
+            if (
+                OnyxUtils.isCollectionMemberKey(previousCollectionKey, previousKey, previousCollectionKey.length) &&
+                OnyxUtils.isCollectionMemberKey(collectionKey, key, collectionKey.length) &&
+                previousCollectionKey === collectionKey
+            ) {
                 return;
             }
         } catch (e) {