Skip to content

Perf: cache iconv decoder #2391

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.

Sign up for GitHub

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

Merged
merged 3 commits into from
Jan 23, 2024
Merged

Perf: cache iconv decoder #2391

Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
93c1fac
Cache with Map.
sandinmyjoints Jan 22, 2024
5f4ed84
Cache with lru-cache.
sandinmyjoints Jan 22, 2024
15eec77
Require default explicitly.
sandinmyjoints Jan 23, 2024
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
27 changes: 24 additions & 3 deletions lib/parsers/string.js
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,21 +1,42 @@
'use strict';

const Iconv = require('iconv-lite');
const LRU = require('lru-cache').default;

exports.decode = function(buffer, encoding, start, end, options) {
const decoderCache = new LRU({
max: 500,
});

exports.decode = function (buffer, encoding, start, end, options) {
if (Buffer.isEncoding(encoding)) {
return buffer.toString(encoding, start, end);
}

const decoder = Iconv.getDecoder(encoding, options || {});
// Optimize for common case: encoding="short_string", options=undefined.
Copy link
Contributor Author

@sandinmyjoints sandinmyjoints Jan 22, 2024 •
edited
Loading

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I figure encoding is probably constant for most users. For my use case, it's always "cesu8" (for utf8mb3).

let decoder;
if (!options) {
decoder = decoderCache.get(encoding);
if (!decoder) {
decoder = Iconv.getDecoder(encoding);
decoderCache.set(encoding, decoder);
}
} else {
const decoderArgs = { encoding, options };
const decoderKey = JSON.stringify(decoderArgs);
decoder = decoderCache.get(decoderKey);
if (!decoder) {
decoder = Iconv.getDecoder(decoderArgs.encoding, decoderArgs.options);
decoderCache.set(decoderKey, decoder);
}
}

const res = decoder.write(buffer.slice(start, end));
const trail = decoder.end();

return trail ? res + trail : res;
};

exports.encode = function(string, encoding, options) {
exports.encode = function (string, encoding, options) {
if (Buffer.isEncoding(encoding)) {
return Buffer.from(string, encoding);
}
Expand Down