Speed up Interface construction:
- Hoist the history accessor property descriptors to module scope and
define them with a single ObjectDefineProperties call, instead of
allocating six closures and four descriptor objects per instance.
- Stop assigning the history options onto the input stream. This avoids
hidden class transitions on the user provided stream and no longer
mutates it observably.
- Only check process.env.TERM for a dumb terminal when the interface is
in terminal mode. Reading process.env goes through the environment
interceptor and is comparatively expensive, and _ttyWrite is never
called when terminal is false.
Signed-off-by: Matteo Collina <hello@matteocollina.com>
PR-URL: https://github.com/nodejs/node/pull/64585
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Rafael Gonzaga <rafael.nunu@hotmail.com>
Reviewed-By: Yagiz Nizipli <yagiz@nizipli.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Gürgün Dayıoğlu <hey@gurgun.day>
Using a direct approach to create the readline async iterator
allowed an iteration over 20 to 58% faster.
**BREAKING CHANGE**: With that change, the async iteterator
obtained from the readline interface doesn't have the
property "stream" any longer. This happened because it's no
longer created through a Readable, instead, the async
iterator is created directly from the events of the readline
interface instance, so, if anyone is using that property,
this change will break their code.
Also, the Readable added a backpressure control that is
fairly compensated by the use of FixedQueue + monitoring
its size. This control wasn't really precise with readline
before, though, because it only pauses the reading of the
original stream, but the lines generated from the last
message received from it was still emitted. For example:
if the readable was paused at 1000 messages but the last one
received generated 10k lines, but no further messages were
emitted again until the queue was lower than the readable
highWaterMark. A similar behavior still happens with the
new implementation, but the highWaterMark used is fixed: 1024,
and the original stream is resumed again only after the queue
is cleared.
Before making that change, I created a package implementing
the same concept used here to validate it. You can find it
[here](https://github.com/Farenheith/faster-readline-iterator)
if this helps anyhow.
PR-URL: https://github.com/nodejs/node/pull/41276
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Matteo Collina