Improve performance greatly (#337)

benchmark.js

@@ -3,22 +3,48 @@
 const chalk = require('.');
 
 suite('chalk', () => {
-	set('iterations', 100000);
+	set('iterations', 1000000);
 
-	bench('single style', () => {
+	const chalkRed = chalk.red;
+	const chalkBgRed = chalk.bgRed;
+	const chalkBlueBgRed = chalk.blue.bgRed;
+	const chalkBlueBgRedBold = chalk.blue.bgRed.bold;
+
+	const blueStyledString = 'the fox jumps' + chalk.blue('over the lazy dog') + '!';
+
+	bench('1 style', () => {
 		chalk.red('the fox jumps over the lazy dog');
 	});
 
-	bench('several styles', () => {
+	bench('2 styles', () => {
+		chalk.blue.bgRed('the fox jumps over the lazy dog');
+	});
+
+	bench('3 styles', () => {
 		chalk.blue.bgRed.bold('the fox jumps over the lazy dog');
 	});
 
-	const cached = chalk.blue.bgRed.bold;
-	bench('cached styles', () => {
-		cached('the fox jumps over the lazy dog');
+	bench('cached: 1 style', () => {
+		chalkRed('the fox jumps over the lazy dog');
+	});
+
+	bench('cached: 2 styles', () => {
+		chalkBlueBgRed('the fox jumps over the lazy dog');
+	});
+
+	bench('cached: 3 styles', () => {
+		chalkBlueBgRedBold('the fox jumps over the lazy dog');
+	});
+
+	bench('cached: 1 style with newline', () => {
+		chalkRed('the fox jumps\nover the lazy dog');
+	});
+
+	bench('cached: 1 style nested intersecting', () => {
+		chalkRed(blueStyledString);
 	});
 
-	bench('nested styles', () => {
-		chalk.red('the fox jumps', chalk.underline.bgBlue('over the lazy dog') + '!');
+	bench('cached: 1 style nested non-intersecting', () => {
+		chalkBgRed(blueStyledString);
 	});
 });

examples/screenshot.js

@@ -1,6 +1,6 @@
 'use strict';
-const chalk = require('..');
 const styles = require('ansi-styles');
+const chalk = require('..');
 
 // Generates screenshot
 for (const key of Object.keys(styles)) {

index.js

@@ -1,9 +1,13 @@
 'use strict';
-const escapeStringRegexp = require('escape-string-regexp');
 const ansiStyles = require('ansi-styles');
 const {stdout: stdoutColor} = require('supports-color');
 const template = require('./templates.js');
 
+const {
+	stringReplaceAll,
+	stringEncaseCRLFWithFirstIndex
+} = require('./lib/util');
+
 // `supportsColor.level` → `ansiStyles.color[name]` mapping
 const levelMapping = [
 	'ansi',
@@ -57,22 +61,23 @@ function Chalk(options) {
 }
 
 for (const [styleName, style] of Object.entries(ansiStyles)) {
-	style.closeRe = new RegExp(escapeStringRegexp(style.close), 'g');
-
 	styles[styleName] = {
 		get() {
-			return createBuilder(this, [...(this._styles || []), style], this._isEmpty);
+			const builder = createBuilder(this, createStyler(style.open, style.close, this._styler), this._isEmpty);
+			Object.defineProperty(this, styleName, {value: builder});
+			return builder;
 		}
 	};
 }
 
 styles.visible = {
 	get() {
-		return createBuilder(this, this._styles || [], true);
+		const builder = createBuilder(this, this._styler, true);
+		Object.defineProperty(this, 'visible', {value: builder});
+		return builder;
 	}
 };
 
-ansiStyles.color.closeRe = new RegExp(escapeStringRegexp(ansiStyles.color.close), 'g');
 for (const model of Object.keys(ansiStyles.color.ansi)) {
 	if (skipModels.has(model)) {
 		continue;
@@ -82,19 +87,13 @@ for (const model of Object.keys(ansiStyles.color.ansi)) {
 		get() {
 			const {level} = this;
 			return function (...arguments_) {
-				const open = ansiStyles.color[levelMapping[level]][model](...arguments_);
-				const codes = {
-					open,
-					close: ansiStyles.color.close,
-					closeRe: ansiStyles.color.closeRe
-				};
-				return createBuilder(this, [...(this._styles || []), codes], this._isEmpty);
+				const styler = createStyler(ansiStyles.color[levelMapping[level]][model](...arguments_), ansiStyles.color.close, this._styler);
+				return createBuilder(this, styler, this._isEmpty);
 			};
 		}
 	};
 }
 
-ansiStyles.bgColor.closeRe = new RegExp(escapeStringRegexp(ansiStyles.bgColor.close), 'g');
 for (const model of Object.keys(ansiStyles.bgColor.ansi)) {
 	if (skipModels.has(model)) {
 		continue;
@@ -105,72 +104,106 @@ for (const model of Object.keys(ansiStyles.bgColor.ansi)) {
 		get() {
 			const {level} = this;
 			return function (...arguments_) {
-				const open = ansiStyles.bgColor[levelMapping[level]][model](...arguments_);
-				const codes = {
-					open,
-					close: ansiStyles.bgColor.close,
-					closeRe: ansiStyles.bgColor.closeRe
-				};
-				return createBuilder(this, [...(this._styles || []), codes], this._isEmpty);
+				const styler = createStyler(ansiStyles.bgColor[levelMapping[level]][model](...arguments_), ansiStyles.bgColor.close, this._styler);
+				return createBuilder(this, styler, this._isEmpty);
 			};
 		}
 	};
 }
 
-const proto = Object.defineProperties(() => {}, styles);
-
-const createBuilder = (self, _styles, _isEmpty) => {
-	const builder = (...arguments_) => applyStyle(builder, ...arguments_);
-	builder._styles = _styles;
-	builder._isEmpty = _isEmpty;
-
-	Object.defineProperty(builder, 'level', {
+const proto = Object.defineProperties(() => {}, {
+	...styles,
+	level: {
 		enumerable: true,
 		get() {
-			return self.level;
+			return this._generator.level;
 		},
 		set(level) {
-			self.level = level;
+			this._generator.level = level;
 		}
-	});
-
-	Object.defineProperty(builder, 'enabled', {
+	},
+	enabled: {
 		enumerable: true,
 		get() {
-			return self.enabled;
+			return this._generator.enabled;
 		},
 		set(enabled) {
-			self.enabled = enabled;
+			this._generator.enabled = enabled;
 		}
-	});
+	}
+});
+
+const createStyler = (open, close, parent) => {
+	let openAll;
+	let closeAll;
+	if (parent === undefined) {
+		openAll = open;
+		closeAll = close;
+	} else {
+		openAll = parent.openAll + open;
+		closeAll = close + parent.closeAll;
+	}
+
+	return {
+		open,
+		close,
+		openAll,
+		closeAll,
+		parent
+	};
+};
+
+const createBuilder = (self, _styler, _isEmpty) => {
+	const builder = (...arguments_) => {
+		// Single argument is hot path, implicit coercion is faster than anything
+		// eslint-disable-next-line no-implicit-coercion
+		return applyStyle(builder, (arguments_.length === 1) ? ('' + arguments_[0]) : arguments_.join(' '));
+	};
 
 	// `__proto__` is used because we must return a function, but there is
 	// no way to create a function with a different prototype
 	builder.__proto__ = proto; // eslint-disable-line no-proto
 
+	builder._generator = self;
+	builder._styler = _styler;
+	builder._isEmpty = _isEmpty;
+
 	return builder;
 };
 
-const applyStyle = (self, ...arguments_) => {
-	let string = arguments_.join(' ');
-
+const applyStyle = (self, string) => {
 	if (!self.enabled || self.level <= 0 || !string) {
 		return self._isEmpty ? '' : string;
 	}
 
-	for (const code of self._styles.slice().reverse()) {
-		// Replace any instances already present with a re-opening code
-		// otherwise only the part of the string until said closing code
-		// will be colored, and the rest will simply be 'plain'.
-		string = code.open + string.replace(code.closeRe, code.open) + code.close;
+	let styler = self._styler;
+
+	if (styler === undefined) {
+		return string;
+	}
+
+	const {openAll, closeAll} = styler;
+	if (string.indexOf('\u001B') !== -1) {
+		while (styler !== undefined) {
+			// Replace any instances already present with a re-opening code
+			// otherwise only the part of the string until said closing code
+			// will be colored, and the rest will simply be 'plain'.
+			string = stringReplaceAll(string, styler.close, styler.open);
+
+			styler = styler.parent;
+		}
+	}
 
-		// Close the styling before a linebreak and reopen
-		// after next line to fix a bleed issue on macOS
-		// https://github.com/chalk/chalk/pull/92
-		string = string.replace(/\r?\n/g, `${code.close}$&${code.open}`);
+	// We can move both next actions out of loop, because remaining actions in loop won't have any/visible effect on parts we add here
+	// Close the styling before a linebreak and reopen
+	// after next line to fix a bleed issue on macOS
+	// https://github.com/chalk/chalk/pull/92
+	const lfIndex = string.indexOf('\n');
+	if (lfIndex !== -1) {
+		string = stringEncaseCRLFWithFirstIndex(string, closeAll, openAll, lfIndex);
 	}
 
-	return string;
+	return openAll + string + closeAll;
 };
 
 const chalkTag = (chalk, ...strings) => {

lib/util.js

@@ -0,0 +1,37 @@
+const stringReplaceAll = (string, substring, replacer) => {
+	let index = string.indexOf(substring);
+	if (index === -1) {
+		return string;
+	}
+
+	const subLen = substring.length;
+	let end = 0;
+	let res = '';
+	do {
+		res += string.substr(end, index - end) + replacer;
+		end = index + subLen;
+		index = string.indexOf(substring, end);
+	} while (index !== -1);
+
+	res += string.substr(end);
+	return res;
+};
+
+const stringEncaseCRLFWithFirstIndex = (string, prefix, postfix, index) => {
+	let end = 0;
+	let res = '';
+	do {
+		const gotCR = string[index - 1] === '\r';
+		res += string.substr(end, (gotCR ? index - 1 : index) - end) + prefix + (gotCR ? '\r\n' : '\n') + postfix;
+		end = index + 1;
+		index = string.indexOf('\n', end);
+	} while (index !== -1);
+
+	res += string.substr(end);
+	return res;
+};
+
+module.exports = {
+	stringReplaceAll,
+	stringEncaseCRLFWithFirstIndex
+};

package.json

@@ -41,7 +41,6 @@
 	],
 	"dependencies": {
 		"ansi-styles": "^3.2.1",
-		"escape-string-regexp": "^1.0.5",
 		"supports-color": "^6.1.0"
 	},
 	"devDependencies": {

test/chalk.js

@@ -82,6 +82,10 @@ test('line breaks should open and close colors', t => {
 	t.is(chalk.grey('hello\nworld'), '\u001B[90mhello\u001B[39m\n\u001B[90mworld\u001B[39m');
 });
 
+test('line breaks should open and close colors with CRLF', t => {
+	t.is(chalk.grey('hello\r\nworld'), '\u001B[90mhello\u001B[39m\r\n\u001B[90mworld\u001B[39m');
+});
+
 test('properly convert RGB to 16 colors on basic color terminals', t => {
 	t.is(new chalk.Instance({level: 1}).hex('#FF0000')('hello'), '\u001B[91mhello\u001B[39m');
 	t.is(new chalk.Instance({level: 1}).bgHex('#FF0000')('hello'), '\u001B[101mhello\u001B[49m');