From 9b713f142a9e932ec20e1d17f656c438615ccfa6 Mon Sep 17 00:00:00 2001 From: Evan Lucas Date: Mon, 16 Nov 2015 18:50:14 -0600 Subject: [PATCH] module: cache regular expressions None of these regular expressions will change, so there is no need to generate them every time in hot code paths. Provides a small performance improvement in module loading. (5-10%) PR-URL: https://github.com/nodejs/node/pull/3869 Reviewed-By: Colin Ihrig Reviewed-By: James M Snell --- lib/module.js | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/lib/module.js b/lib/module.js index 2f5f6941510ed6..2d660c4b23d1d0 100644 --- a/lib/module.js +++ b/lib/module.js @@ -11,6 +11,9 @@ const path = require('path'); const internalModuleReadFile = process.binding('fs').internalModuleReadFile; const internalModuleStat = process.binding('fs').internalModuleStat; +const splitRe = process.platform === 'win32' ? /[\/\\]/ : /\//; +const isIndexRe = /^index\.\w+?$/; +const shebangRe = /^\#\!.*/; // If obj.hasOwnProperty has been overridden, then calling // obj.hasOwnProperty(prop) will break. @@ -191,7 +194,6 @@ Module._nodeModulePaths = function(from) { // note: this approach *only* works when the path is guaranteed // to be absolute. Doing a fully-edge-case-correct path.split // that works on both Windows and Posix is non-trivial. - var splitRe = process.platform === 'win32' ? /[\/\\]/ : /\//; var paths = []; var parts = from.split(splitRe); @@ -244,7 +246,7 @@ Module._resolveLookupPaths = function(request, parent) { // Is the parent an index module? // We can assume the parent has a valid extension, // as it already has been accepted as a module. - var isIndex = /^index\.\w+?$/.test(path.basename(parent.filename)); + var isIndex = isIndexRe.test(path.basename(parent.filename)); var parentIdPath = isIndex ? parent.id : path.dirname(parent.id); var id = path.resolve(parentIdPath, request); @@ -377,7 +379,7 @@ var resolvedArgv; Module.prototype._compile = function(content, filename) { var self = this; // remove shebang - content = content.replace(/^\#\!.*/, ''); + content = content.replace(shebangRe, ''); function require(path) { return self.require(path);