Skip to content

Commit

Permalink
module: cache regular expressions
Browse files Browse the repository at this point in the history
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: #3869
Reviewed-By: Colin Ihrig <[email protected]>
Reviewed-By: James M Snell <[email protected]>
  • Loading branch information
evanlucas authored and Fishrock123 committed Nov 17, 2015
1 parent df1fdba commit 5c54fa0
Showing 1 changed file with 5 additions and 3 deletions.
8 changes: 5 additions & 3 deletions lib/module.js
Original file line number Diff line number Diff line change
Expand Up @@ -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.
Expand Down Expand Up @@ -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);

Expand Down Expand Up @@ -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);

Expand Down Expand Up @@ -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);
Expand Down

0 comments on commit 5c54fa0

Please sign in to comment.