# Summary TextEncoder.encodeInto() adds encoding JavaScript strings into UTF-8 into caller-provided byte buffers. This is a performance optimization for JavaScript/Wasm interop that allows the encoder output to be written directly into Wasm memory without extra copies.
# Details TextEncoder.encode() returns a DOM implementation-created buffer. This involves coping internally in the implementation (in principle, this copy could be optimized away with internal-only API changes) and then yet another copy from the returned buffer into Wasm memory (optimizing away this copy needs a Web-visible change anyway). TextEncoder.encodeInto() avoids both copies. https://bugzilla.mozilla.org/show_bug.cgi?id=1449849 combined with TextEncoder.encodeInto() is expected to avoid yet more copying. The expectation is that passing strings from JS to Wasm is / is going to be common enough to be worthwhile to optimize. # Bug https://bugzilla.mozilla.org/show_bug.cgi?id=1514664 # Link to standard https://github.com/whatwg/encoding/pull/166 # Platform coverage All # Estimated or target release 67 # Preference behind which this will be implemented Not planning to have a pref for this. # Is this feature enabled by default in sandboxed iframes? Yes. # DevTools bug No need for new DevTools integration. # Do other browser engines implement this No, but Chrome developers have been active in the spec discussion. # web-platform-tests https://github.com/web-platform-tests/wpt/pull/14505 # Is this feature restricted to secure contexts? No. This is a new method on an interface that predates restricting features to secure contexts. -- Henri Sivonen hsivo...@mozilla.com _______________________________________________ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
