From 3ece55a2b93a8535164340828ebbce8bc416a9e8 Mon Sep 17 00:00:00 2001
From: Skye <63878374+MierenManz@users.noreply.github.com>
Date: Wed, 10 Jan 2024 11:03:38 +0100
Subject: [PATCH] perf: Optimize Tuple Read & Write (#24)

---
 src/compound/tuple.ts | 41 ++++++++++++++++++++++++++++-------------
 1 file changed, 28 insertions(+), 13 deletions(-)

diff --git a/src/compound/tuple.ts b/src/compound/tuple.ts
index c81b277..f0064cd 100644
--- a/src/compound/tuple.ts
+++ b/src/compound/tuple.ts
@@ -6,31 +6,32 @@ export class Tuple<
   V extends [...unknown[]] = { [I in keyof T]: InnerType<T[I]> },
 > extends UnsizedType<V> {
   #tupleTypes: T;
-
+  #length: number;
   constructor(types: T) {
     super(getBiggestAlignment(types));
     this.#tupleTypes = types;
+    this.#length = types.length;
   }
 
   readPacked(dt: DataView, options: Options = { byteOffset: 0 }): V {
-    if (this.#tupleTypes.length === 0) return [] as unknown as V;
-
-    const result: unknown[] = [];
-    result.length = this.#tupleTypes.length;
+    if (this.#length === 0) return [] as unknown as V;
+    const result: unknown[] = new Array(this.#length);
 
+    const tupleTypes = this.#tupleTypes;
     for (let i = 0; i < result.length; i++) {
-      result[i] = this.#tupleTypes[i].readPacked(dt, options);
+      result[i] = tupleTypes[i].readPacked(dt, options);
     }
 
     return result as V;
   }
 
   read(dt: DataView, options: Options = { byteOffset: 0 }): V {
-    const result: unknown[] = [];
-    result.length = this.#tupleTypes.length;
+    if (this.#length === 0) return [] as unknown as V;
+    const result: unknown[] = new Array(this.#length);
 
+    const tupleTypes = this.#tupleTypes;
     for (let i = 0; i < result.length; i++) {
-      result[i] = this.#tupleTypes[i].read(dt, options);
+      result[i] = tupleTypes[i].read(dt, options);
     }
 
     return result as V;
@@ -41,16 +42,30 @@ export class Tuple<
     dt: DataView,
     options: Options = { byteOffset: 0 },
   ): void {
+    if (value.length !== this.#length) {
+      throw new TypeError(
+        `value V has more entries than expected\nExpected:${this.#length} but got ${value.length}`,
+      );
+    }
     if (value.length === 0) return;
 
-    for (let i = 0; i < this.#tupleTypes.length; i++) {
-      this.#tupleTypes[i].writePacked(value[i], dt, options);
+    const tupleTypes = this.#tupleTypes;
+    for (let i = 0; i < value.length; i++) {
+      tupleTypes[i].writePacked(value[i], dt, options);
     }
   }
 
   write(value: V, dt: DataView, options: Options = { byteOffset: 0 }): void {
-    for (let i = 0; i < this.#tupleTypes.length; i++) {
-      this.#tupleTypes[i].write(value[i], dt, options);
+    if (value.length !== this.#length) {
+      throw new TypeError(
+        `value V has more entries than expected\nExpected:${this.#length} but got ${value.length}`,
+      );
+    }
+    if (value.length === 0) return;
+
+    const tupleTypes = this.#tupleTypes;
+    for (let i = 0; i < value.length; i++) {
+      tupleTypes[i].write(value[i], dt, options);
     }
   }
 }