1877249 - Can we save some memory by making JS_Stringify use Latin1 by default?

Status: RESOLVED WONTFIX

(Core :: JavaScript Engine, enhancement, P1)

Description

[Nicolas B. Pierron [:nbp]]

JS_Stringify is used while writting JSON files for the SessionWritter, which has some latency and potentially some memory consumption issues.
Today JS_Stringify enforces that all strings are encoded with 2 bytes.

We should double check if we can reduce the amount of memory allocated and copied simply letting the StringBuffer promote the buffer to char16_t when this becomes needed.

Comment 1

[Nicolas B. Pierron [:nbp]]

Removing the line which forces to allocation a char16_t buffer does not seems to improve any benchmarks:
https://treeherder.mozilla.org/perfherder/compare?originalProject=try&originalRevision=7229778a48e4e7bcd2383643c43300af9069ff4b&newProject=try&newRevision=fe0eafe90081007e2eccb165fe71f57647a6e3e2&page=1&framework=13