1488336 - sourceeditor setAutocompletionText could be faster

Status: RESOLVED FIXED

(DevTools :: Shared Components, enhancement, P1)

Description

[Nicolas Chevobbe [:nchevobbe]]

In setAutocompletionText [1] , we do 2 things: 
- clear any previous autocompletion mark that might exist
- then, if the text provided isn't falsy, add a new autocompletion mark

Each operation seems to trigger 2 reflows (so 4 reflows for setting the text), which can be quite an issue if the reflows are slow (e.g. the console panel lately).

We can probably make this better by grouping clearing marks and adding the new one in a codemirror operation [2].


[1] https://searchfox.org/mozilla-central/rev/c3fef66a5b211ea8038c1c132706d02db408093a/devtools/client/sourceeditor/editor.js#1296-1310

[2] https://codemirror.net/doc/manual.html#operation

Comment 1

[Nicolas Chevobbe [:nchevobbe]]

Attachment: Bug 1488336 - Group clear mark and markText for completion text; r=bgrins.

This way, codeMirror does not trigger so many reflows and
makes setAutocompletionText faster.
An unwanted side-effect was that it made closing the console
a lot slower. Looking at the closing code of the JsTerm, we
do call setAutocompletionText("") in the end, which we don't
really need since we destroy the editor shortly after. Removing
this call keeps closing time the same as before.

Comment 2

[Nicolas Chevobbe [:nchevobbe]]

Here's how typing in JsTerm performs with this patch: https://treeherder.mozilla.org/perf.html#/comparesubtest?originalProject=try&originalRevision=7f70127d7b1f10a8ce0bb074590f606beb52a30f&newProject=try&newRevision=f5b7a21562a4690a851a5cd33f58c199e099bb5e&originalSignature=d0aa31b4a8617d5bda9bc8c5ca7bfa9a77c38c7c&newSignature=d0aa31b4a8617d5bda9bc8c5ca7bfa9a77c38c7c&showOnlyImportant=1&framework=12

That's a solid ~30% improvement. For such a small patch this is quite nice :)

Here's a TRY push to make sure we don't break anything (looks good so far): https://treeherder.mozilla.org/#/jobs?repo=try&revision=6111fe91aff6ab87e9002489f1c1203acd37601a

Comment 3

[Brian Grinstead [:bgrins]]

Comment on attachment 9006157 [details]
Bug 1488336 - Group clear mark and markText for completion text; r=bgrins.

Brian Grinstead [:bgrins] has approved the revision.

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/3edd9e52dbfe
Group clear mark and markText for completion text; r=bgrins.

Comment 5

[Dorel Luca [:dluca]]

https://hg.mozilla.org/mozilla-central/rev/3edd9e52dbfe