Skip to content

util: improve readability of normalizeEncoding #10439

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
Closed
Show file tree
Hide file tree
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
65 changes: 65 additions & 0 deletions benchmark/util/normalize-encoding.js
Original file line number Diff line number Diff line change
@@ -0,0 +1,65 @@
'use strict';

const common = require('../common.js');
const assert = require('assert');

const groupedInputs = {
group_common: ['undefined', 'utf8', 'utf-8', 'base64', 'binary', 'latin1'],
group_upper: ['UTF-8', 'UTF8', 'UCS2', 'UTF-16LE', 'UTF16LE', 'BASE64'],
group_uncommon: [ 'foo', '1', 'false', 'undefined', '[]'],
group_misc: ['', 'utf16le', 'usc2', 'hex', 'HEX', 'BINARY']
};

const inputs = [
'', 'utf8', 'utf-8', 'UTF-8',
'UTF8', 'Utf8', 'uTf-8', 'utF-8', 'ucs2',
'UCS2', 'utf16le', 'utf-16le', 'UTF-16LE', 'UTF16LE',
'binary', 'BINARY', 'latin1', 'base64', 'BASE64',
'hex', 'HEX', 'foo', '1', 'false', 'undefined', '[]'];

const bench = common.createBenchmark(main, {
input: inputs.concat(Object.keys(groupedInputs)),
n: [1e5]
}, {
flags: '--expose-internals'
});

function getInput(input) {
switch (input) {
case 'group_common':
return groupedInputs.group_common;
case 'group_upper':
return groupedInputs.group_upper;
case 'group_uncommon':
return groupedInputs.group_uncommon;
case 'group_misc':
return groupedInputs.group_misc;
case '1':
return [1];
case 'false':
return [false];
case 'undefined':
return [undefined];
case '[]':
return [[]];
default:
return [input];
}
}

function main(conf) {
const normalizeEncoding = require('internal/util').normalizeEncoding;

const n = conf.n | 0;
const inputs = getInput(conf.input);
var noDead = '';

bench.start();
for (var i = 0; i < n; i += 1) {
for (var j = 0; j < inputs.length; ++j) {
noDead = normalizeEncoding(inputs[j]);
}
}
bench.end(n);
assert.ok(noDead === undefined || noDead.length > 0);
}
14 changes: 10 additions & 4 deletions lib/internal/util.js
Original file line number Diff line number Diff line change
Expand Up @@ -103,10 +103,16 @@ exports.assertCrypto = function(exports) {
};

exports.kIsEncodingSymbol = Symbol('node.isEncoding');

// The loop should only run at most twice, retrying with lowercased enc
// if there is no match in the first pass.
// We use a loop instead of branching to retry with a helper
// function in order to avoid the performance hit.
// Return undefined if there is no match.
exports.normalizeEncoding = function normalizeEncoding(enc) {
if (!enc) return 'utf8';
var low;
for (;;) {
var retried;
while (true) {
switch (enc) {
case 'utf8':
case 'utf-8':
Expand All @@ -124,9 +130,9 @@ exports.normalizeEncoding = function normalizeEncoding(enc) {
case 'hex':
return enc;
default:
if (low) return; // undefined
if (retried) return; // undefined
enc = ('' + enc).toLowerCase();
low = true;
retried = true;
}
}
};
Expand Down