Skip to content

Navigation Menu

Sign in
Appearance settings

Search code, repositories, users, issues, pull requests...

Provide feedback

We read every piece of feedback, and take your input very seriously.

Saved searches

Use saved searches to filter your results more quickly

Appearance settings

Commit d0bf09d

Browse filesBrowse files
mscdexMyles Borins
authored andcommitted
util: improve format() performance further
Replacing the regexp and replace function with a loop improves performance by ~60-200%. PR-URL: #5360 Reviewed-By: James M Snell <jasnell@gmail.com>
1 parent 72fb281 commit d0bf09d
Copy full SHA for d0bf09d

File tree

Expand file treeCollapse file tree

1 file changed

+49
-24
lines changed
Open diff view settings
Filter options
Expand file treeCollapse file tree

1 file changed

+49
-24
lines changed
Open diff view settings
Collapse file

‎lib/util.js‎

Copy file name to clipboardExpand all lines: lib/util.js
+49-24Lines changed: 49 additions & 24 deletions
Original file line numberDiff line numberDiff line change
@@ -17,7 +17,6 @@ function tryStringify(arg) {
1717
}
1818
}
1919

20-
const formatRegExp = /%[sdj%]/g;
2120
exports.format = function(f) {
2221
if (typeof f !== 'string') {
2322
const objects = new Array(arguments.length);
@@ -27,30 +26,56 @@ exports.format = function(f) {
2726
return objects.join(' ');
2827
}
2928

30-
if (arguments.length === 1) return f;
31-
32-
const len = arguments.length;
33-
const args = new Array(len);
34-
var i;
35-
for (i = 0; i < len; i++) {
36-
args[i] = arguments[i];
37-
}
38-
39-
i = 1;
40-
var str = f.replace(formatRegExp, function(x) {
41-
if (x === '%%') return '%';
42-
if (i >= len) return x;
43-
switch (x) {
44-
case '%s': return String(args[i++]);
45-
case '%d': return Number(args[i++]);
46-
case '%j': return tryStringify(args[i++]);
47-
// falls through
48-
default:
49-
return x;
29+
var argLen = arguments.length;
30+
31+
if (argLen === 1) return f;
32+
33+
var str = '';
34+
var a = 1;
35+
var lastPos = 0;
36+
for (var i = 0; i < f.length;) {
37+
if (f.charCodeAt(i) === 37/*'%'*/ && i + 1 < f.length) {
38+
switch (f.charCodeAt(i + 1)) {
39+
case 100: // 'd'
40+
if (a >= argLen)
41+
break;
42+
if (lastPos < i)
43+
str += f.slice(lastPos, i);
44+
str += Number(arguments[a++]);
45+
lastPos = i = i + 2;
46+
continue;
47+
case 106: // 'j'
48+
if (a >= argLen)
49+
break;
50+
if (lastPos < i)
51+
str += f.slice(lastPos, i);
52+
str += tryStringify(arguments[a++]);
53+
lastPos = i = i + 2;
54+
continue;
55+
case 115: // 's'
56+
if (a >= argLen)
57+
break;
58+
if (lastPos < i)
59+
str += f.slice(lastPos, i);
60+
str += String(arguments[a++]);
61+
lastPos = i = i + 2;
62+
continue;
63+
case 37: // '%'
64+
if (lastPos < i)
65+
str += f.slice(lastPos, i);
66+
str += '%';
67+
lastPos = i = i + 2;
68+
continue;
69+
}
5070
}
51-
});
52-
while (i < len) {
53-
const x = args[i++];
71+
++i;
72+
}
73+
if (lastPos === 0)
74+
str = f;
75+
else if (lastPos < f.length)
76+
str += f.slice(lastPos);
77+
while (a < argLen) {
78+
const x = arguments[a++];
5479
if (x === null || (typeof x !== 'object' && typeof x !== 'symbol')) {
5580
str += ' ' + x;
5681
} else {

0 commit comments

Comments
0 (0)
Morty Proxy This is a proxified and sanitized view of the page, visit original site.