From 83e9cc5d5d405c9cbd20176c0bc636bb782178a6 Mon Sep 17 00:00:00 2001
From: Robin Munn <rmunn@pobox.com>
Date: Sun, 5 Dec 2021 11:36:42 +0700
Subject: [PATCH] Remove queue implementation for dirty components

Found a way to make it work without changing the dirty components array
into a queue structure, reducing bundle size.
---
 src/runtime/internal/scheduler.ts | 11 ++++++----
 src/runtime/internal/utils.ts     | 34 -------------------------------
 2 files changed, 7 insertions(+), 38 deletions(-)

diff --git a/src/runtime/internal/scheduler.ts b/src/runtime/internal/scheduler.ts
index d275920295..73bd5e8395 100644
--- a/src/runtime/internal/scheduler.ts
+++ b/src/runtime/internal/scheduler.ts
@@ -1,7 +1,7 @@
-import { run_all, Queue } from './utils';
+import { run_all } from './utils';
 import { get_current_component, set_current_component } from './lifecycle';
 
-export const dirty_components = new Queue<any>();
+export const dirty_components = [];
 export const intros = { enabled: false };
 
 export const binding_callbacks = [];
@@ -32,6 +32,7 @@ export function add_flush_callback(fn) {
 }
 
 const seen_callbacks = new Set();
+let flushidx = 0;  // Do *not* move this inside the flush() function
 export function flush() {
 
 	let current_component = null;
@@ -44,14 +45,16 @@ export function flush() {
 	do {
 		// first, call beforeUpdate functions
 		// and update components
-		while (dirty_components.length) {
-			const component = dirty_components.shift();
+		while (flushidx < dirty_components.length) {
+			const component = dirty_components[flushidx];
+			flushidx++;
 			set_current_component(component);
 			update(component.$$);
 		}
 		set_current_component(null);
 
 		dirty_components.length = 0;
+		flushidx = 0;
 
 		while (binding_callbacks.length) binding_callbacks.pop()();
 
diff --git a/src/runtime/internal/utils.ts b/src/runtime/internal/utils.ts
index 582870ec32..8868e38ee2 100644
--- a/src/runtime/internal/utils.ts
+++ b/src/runtime/internal/utils.ts
@@ -58,40 +58,6 @@ export function is_empty(obj) {
 	return Object.keys(obj).length === 0;
 }
 
-export class Queue<T> {
-	forward: T[];
-	reverse: T[];
-
-	constructor() {
-		this.forward = [];
-		this.reverse = [];
-	}
-	push(value: T) {
-		return this.forward.push(value);
-	}
-	shift() {
-		if (this.reverse.length === 0) {
-			while (this.forward.length) {
-				this.reverse.push(this.forward.pop());
-			}
-		}
-		return this.reverse.pop();
-	}
-	get length() {
-		return this.forward.length + this.reverse.length;
-	}
-	set length(len: number) {
-		if (len === 0) {
-			this.forward.length = 0;
-			this.reverse.length = 0;
-		} else {
-			while (this.length > len) {
-				this.shift();
-			}
-		}
-	}
-}
-
 export function validate_store(store, name) {
 	if (store != null && typeof store.subscribe !== 'function') {
 		throw new Error(`'${name}' is not a store with a 'subscribe' method`);