Merge pull request #670 from sveltejs/transition-perf

improve transition performance

src/parse/utils/hash.ts

@@ -3,6 +3,6 @@ export default function hash(str: string): number {
 	let hash = 5381;
 	let i = str.length;
 
-	while (i--) hash = (hash * 33) ^ str.charCodeAt(i);
+	while (i--) hash = ((hash << 5) - hash) ^ str.charCodeAt(i);
 	return hash >>> 0;
 }

src/shared/transitions.js

@@ -4,37 +4,31 @@ export function linear(t) {
 	return t;
 }
 
-export function generateKeyframes(
+export function generateRule(
 	a,
 	b,
 	delta,
 	duration,
 	ease,
-	fn,
+	fn
-	node,
-	style
 ) {
-	var id = '__svelte' + ~~(Math.random() * 1e9); // TODO make this more robust
+	var keyframes = '{\n';
-	var keyframes = '@keyframes ' + id + '{\n';
 
 	for (var p = 0; p <= 1; p += 16.666 / duration) {
 		var t = a + delta * ease(p);
 		keyframes += p * 100 + '%{' + fn(t) + '}\n';
 	}
 
-	keyframes += '100% {' + fn(b) + '}\n}';
+	return keyframes + '100% {' + fn(b) + '}\n}';
-	style.textContent += keyframes;
+}
 
-	document.head.appendChild(style);
+// https://github.com/darkskyapp/string-hash/blob/master/index.js
+export function hash(str) {
+	var hash = 5381;
+	var i = str.length;
 
-	node.style.animation = (node.style.animation || '')
+	while (i--) hash = ((hash << 5) - hash) ^ str.charCodeAt(i);
-		.split(',')
+	return hash >>> 0;
-		.filter(function(anim) {
-			// when introing, discard old animations if there are any
-			return anim && (delta < 0 || !/__svelte/.test(anim));
-		})
-		.concat(id + ' ' + duration + 'ms linear 1 forwards')
-		.join(', ');
 }
 
 export function wrapTransition(node, fn, params, intro, outgroup) {
@@ -43,9 +37,10 @@ export function wrapTransition(node, fn, params, intro, outgroup) {
 	var ease = obj.easing || linear;
 	var cssText;
 
-	// TODO share <style> tag between all transitions?
+	if (obj.css && !transitionManager.stylesheet) {
-	if (obj.css) {
 		var style = document.createElement('style');
+		document.head.appendChild(style);
+		transitionManager.stylesheet = style.sheet;
 	}
 
 	if (intro) {
@@ -89,16 +84,26 @@ export function wrapTransition(node, fn, params, intro, outgroup) {
 
 			if (obj.css) {
 				if (obj.delay) node.style.cssText = cssText;
-				generateKeyframes(
+
+				program.rule = generateRule(
 					program.a,
 					program.b,
 					program.delta,
 					program.duration,
 					ease,
-					obj.css,
+					obj.css
-					node,
-					style
 				);
+
+				transitionManager.addRule(program.rule, program.name = '__svelte_' + hash(program.rule));
+
+				node.style.animation = (node.style.animation || '')
+					.split(', ')
+					.filter(function(anim) {
+						// when introing, discard old animations if there are any
+						return anim && (program.delta < 0 || !/__svelte/.test(anim));
+					})
+					.concat(program.name + ' ' + duration + 'ms linear 1 forwards')
+					.join(', ');
 			}
 
 			this.program = program;
@@ -113,16 +118,17 @@ export function wrapTransition(node, fn, params, intro, outgroup) {
 			if (obj.tick) obj.tick(this.t);
 		},
 		done: function() {
-			this.t = this.program.b;
+			var program = this.program;
+			this.t = program.b;
 			if (obj.tick) obj.tick(this.t);
-			if (obj.css) document.head.removeChild(style);
+			if (obj.css) transitionManager.deleteRule(node, program.name);
-			this.program.callback();
+			program.callback();
-			this.program = null;
+			program = null;
 			this.running = !!this.pending;
 		},
 		abort: function() {
 			if (obj.tick) obj.tick(1);
-			if (obj.css) document.head.removeChild(style);
+			if (obj.css) transitionManager.deleteRule(node, this.program.name);
 			this.program = this.pending = null;
 			this.running = false;
 		}
@@ -133,6 +139,8 @@ export var transitionManager = {
 	running: false,
 	transitions: [],
 	bound: null,
+	stylesheet: null,
+	activeRules: {},
 
 	add: function(transition) {
 		this.transitions.push(transition);
@@ -143,6 +151,13 @@ export var transitionManager = {
 		}
 	},
 
+	addRule: function(rule, name) {
+		if (!this.activeRules[name]) {
+			this.activeRules[name] = true;
+			this.stylesheet.insertRule('@keyframes ' + name + ' ' + rule, this.stylesheet.cssRules.length);
+		}
+	},
+
 	next: function() {
 		this.running = false;
 
@@ -170,6 +185,19 @@ export var transitionManager = {
 
 		if (this.running) {
 			requestAnimationFrame(this.bound || (this.bound = this.next.bind(this)));
+		} else if (this.stylesheet) {
+			var i = this.stylesheet.cssRules.length;
+			while (i--) this.stylesheet.deleteRule(i);
+			this.activeRules = {};
 		}
+	},
+
+	deleteRule: function(node, name) {
+		node.style.animation = node.style.animation
+			.split(', ')
+			.filter(function(anim) {
+				return anim.slice(0, name.length) !== name;
+			})
+			.join(', ');
 	}
 };

test/css/samples/basic/expected.css

@@ -1,4 +1,4 @@
 
-	div[svelte-281576708], [svelte-281576708] div {
+	div[svelte-2278551596], [svelte-2278551596] div {
 		color: red;
 	}

test/css/samples/cascade-false-global-keyframes/_config.js

@@ -0,0 +1,3 @@
+export default {
+	cascade: false
+};

test/css/samples/cascade-false-global-keyframes/expected.css

@@ -4,10 +4,10 @@
 		100% { color: blue; }
 	}
 
-	[svelte-2486527405].animated, [svelte-2486527405] .animated {
+	.animated[svelte-90785995] {
 		animation: why 2s;
 	}
 
-	[svelte-2486527405].also-animated, [svelte-2486527405] .also-animated {
+	.also-animated[svelte-90785995] {
 		animation: not-defined-here 2s;
 	}

test/css/samples/cascade-false-keyframes/_config.js

@@ -0,0 +1,3 @@
+export default {
+	cascade: false
+};

test/css/samples/cascade-false-keyframes/expected.css

@@ -1,13 +1,13 @@
 
-	@keyframes svelte-776829126-why {
+	@keyframes svelte-1647166666-why {
 		0% { color: red; }
 		100% { color: blue; }
 	}
 
-	[svelte-776829126].animated, [svelte-776829126] .animated {
+	.animated[svelte-1647166666] {
-		animation: svelte-776829126-why 2s;
+		animation: svelte-1647166666-why 2s;
 	}
 
-	[svelte-776829126].also-animated, [svelte-776829126] .also-animated {
+	.also-animated[svelte-1647166666] {
 		animation: not-defined-here 2s;
 	}

test/css/samples/cascade-false-pseudo-element/expected.css

@@ -1,12 +1,12 @@
 
-	span[svelte-583610229]::after {
+	span[svelte-2146001331]::after {
 		content: 'i am a pseudo-element';
 	}
 
-	span[svelte-583610229]:first-child {
+	span[svelte-2146001331]:first-child {
 		color: red;
 	}
 
-	span[svelte-583610229]:last-child::after {
+	span[svelte-2146001331]:last-child::after {
 		color: blue;
 	}

test/css/samples/cascade-false/expected.css

@@ -1,12 +1,12 @@
 
-	div[svelte-4161687011] {
+	div[svelte-781920915] {
 		color: red;
 	}
 
-	div.foo[svelte-4161687011] {
+	div.foo[svelte-781920915] {
 		color: blue;
 	}
 
-	.foo[svelte-4161687011] {
+	.foo[svelte-781920915] {
 		font-weight: bold;
 	}

test/css/samples/keyframes/expected.css

@@ -1,9 +1,9 @@
 
-	@keyframes svelte-4112859982-why {
+	@keyframes svelte-2931302006-why {
 		0% { color: red; }
 		100% { color: blue; }
 	}
 
-	[svelte-4112859982].animated, [svelte-4112859982] .animated {
+	[svelte-2931302006].animated, [svelte-2931302006] .animated {
-		animation: svelte-4112859982-why 2s;
+		animation: svelte-2931302006-why 2s;
 	}

test/css/samples/media-query/expected.css

@@ -1,6 +1,6 @@
 
 	@media (min-width: 400px) {
-		[svelte-2352010302].large-screen, [svelte-2352010302] .large-screen {
+		[svelte-411199634].large-screen, [svelte-411199634] .large-screen {
 			display: block;
 		}
 	}

test/js/samples/collapses-text-around-comments/expected-bundle.js

@@ -145,8 +145,8 @@ var template = (function () {
 
 function add_css () {
 	var style = createElement( 'style' );
-	style.id = "svelte-3842350206-style";
+	style.id = "svelte-3590263702-style";
-	style.textContent = "\n\tp[svelte-3842350206], [svelte-3842350206] p {\n\t\tcolor: red;\n\t}\n";
+	style.textContent = "\n\tp[svelte-3590263702], [svelte-3590263702] p {\n\t\tcolor: red;\n\t}\n";
 	appendNode( style, document.head );
 }
 
@@ -161,7 +161,7 @@ function create_main_fragment ( state, component ) {
 		},
 
 		hydrate: function ( nodes ) {
-			setAttribute( p, 'svelte-3842350206', '' );
+			setAttribute( p, 'svelte-3590263702', '' );
 		},
 
 		mount: function ( target, anchor ) {
@@ -198,7 +198,7 @@ function SvelteComponent ( options ) {
 	this._yield = options._yield;
 
 	this._torndown = false;
-	if ( !document.getElementById( "svelte-3842350206-style" ) ) add_css();
+	if ( !document.getElementById( "svelte-3590263702-style" ) ) add_css();
 
 	this._fragment = create_main_fragment( this._state, this );
 

test/js/samples/collapses-text-around-comments/expected.js

@@ -10,8 +10,8 @@ var template = (function () {
 
 function add_css () {
 	var style = createElement( 'style' );
-	style.id = "svelte-3842350206-style";
+	style.id = "svelte-3590263702-style";
-	style.textContent = "\n\tp[svelte-3842350206], [svelte-3842350206] p {\n\t\tcolor: red;\n\t}\n";
+	style.textContent = "\n\tp[svelte-3590263702], [svelte-3590263702] p {\n\t\tcolor: red;\n\t}\n";
 	appendNode( style, document.head );
 }
 
@@ -26,7 +26,7 @@ function create_main_fragment ( state, component ) {
 		},
 
 		hydrate: function ( nodes ) {
-			setAttribute( p, 'svelte-3842350206', '' );
+			setAttribute( p, 'svelte-3590263702', '' );
 		},
 
 		mount: function ( target, anchor ) {
@@ -63,7 +63,7 @@ function SvelteComponent ( options ) {
 	this._yield = options._yield;
 
 	this._torndown = false;
-	if ( !document.getElementById( "svelte-3842350206-style" ) ) add_css();
+	if ( !document.getElementById( "svelte-3590263702-style" ) ) add_css();
 
 	this._fragment = create_main_fragment( this._state, this );
 

test/server-side-rendering/samples/styles-nested/_actual.css

@@ -1,14 +1,14 @@
 
-	div[svelte-4188175681], [svelte-4188175681] div {
+	div[svelte-1408461649], [svelte-1408461649] div {
 		color: red;
 	}
 
 
-	div[svelte-146600313], [svelte-146600313] div {
+	div[svelte-54999591], [svelte-54999591] div {
 		color: green;
 	}
 
 
-	div[svelte-1506185237], [svelte-1506185237] div {
+	div[svelte-2385185803], [svelte-2385185803] div {
 		color: blue;
 	}

test/server-side-rendering/samples/styles-nested/_actual.html

@@ -1,5 +1,5 @@
-<div svelte-4188175681>red</div>
+<div svelte-1408461649>red</div>
-<div svelte-146600313>green: foo</div>
+<div svelte-54999591>green: foo</div>
-<div svelte-1506185237>blue: foo</div>
+<div svelte-2385185803>blue: foo</div>
-<div svelte-146600313>green: bar</div>
+<div svelte-54999591>green: bar</div>
-<div svelte-1506185237>blue: bar</div>
+<div svelte-2385185803>blue: bar</div>

test/server-side-rendering/samples/styles-nested/_expected.css

@@ -1,11 +1,14 @@
-div[svelte-4188175681], [svelte-4188175681] div {
+
+	div[svelte-1408461649], [svelte-1408461649] div {
 		color: red;
 	}
 
-div[svelte-146600313], [svelte-146600313] div {
+
+	div[svelte-54999591], [svelte-54999591] div {
 		color: green;
 	}
 
-div[svelte-1506185237], [svelte-1506185237] div {
+
+	div[svelte-2385185803], [svelte-2385185803] div {
 		color: blue;
 	}

test/server-side-rendering/samples/styles-nested/_expected.html

@@ -1,5 +1,5 @@
-<div svelte-4188175681>red</div>
+<div svelte-1408461649>red</div>
-<div svelte-146600313>green: foo</div>
+<div svelte-54999591>green: foo</div>
-<div svelte-1506185237>blue: foo</div>
+<div svelte-2385185803>blue: foo</div>
-<div svelte-146600313>green: bar</div>
+<div svelte-54999591>green: bar</div>
-<div svelte-1506185237>blue: bar</div>
+<div svelte-2385185803>blue: bar</div>

test/server-side-rendering/samples/styles/_actual.css

@@ -1,4 +1,4 @@
 
-	div[svelte-281576708], [svelte-281576708] div {
+	div[svelte-2278551596], [svelte-2278551596] div {
 		color: red;
 	}

test/server-side-rendering/samples/styles/_actual.html

@@ -1 +1 @@
-<div svelte-281576708>red</div>
+<div svelte-2278551596>red</div>

test/server-side-rendering/samples/styles/_expected.css

@@ -1,3 +1,4 @@
-div[svelte-281576708], [svelte-281576708] div {
+
+	div[svelte-2278551596], [svelte-2278551596] div {
 		color: red;
 	}

test/server-side-rendering/samples/styles/_expected.html

@@ -1 +1 @@
-<div svelte-281576708>red</div>
+<div svelte-2278551596>red</div>