1888079 - Don't call getStyleSheetRuleCountAndAtRules when modifying a Rule from the Inspector

Status: RESOLVED FIXED

(DevTools :: Inspector: Rules, task)

Description

[Nicolas Chevobbe [:nchevobbe]]

setStyleSheetText always calls getStyleSheetRuleCountAndAtRules and triggers an at-rules-changed stylesheet update:

https://searchfox.org/mozilla-central/rev/7bbc54b70e348a11f9cd12071ada2cb47c8a14e3/devtools/server/actors/utils/stylesheets-manager.js#425-426,439-440,444,449-454,468-474

/**
 * Update the style sheet in place with new text.
...
 */
async setStyleSheetText(
...
) {
...
  const { atRules, ruleCount } =
    this.getStyleSheetRuleCountAndAtRules(styleSheet);

  if (kind !== UPDATE_PRESERVING_RULES) {
    this.#notifyPropertyChanged(resourceId, "ruleCount", ruleCount);
  }
...
  this.#onStyleSheetUpdated({
    resourceId,
    updateKind: "at-rules-changed",
    updates: {
      resourceUpdates: { atRules },
    },
  });

But when modifying a property from the inspector, the rule count and the at-rules can't be modified, so we could avoid computing those information that can be costly on large stylesheets.

Comment 1

[Nicolas Chevobbe [:nchevobbe]]

Attachment: Bug 1888079 - [devtools] Don't call getStyleSheetRuleCountAndAtRules in setStyleSheetText when it's not needed. r=#devtools-reviewers.

When we modify a rule from the inspector, the number of rules and the at-rules
data can't be impacted, so avoid computing this costly information.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/76f2f82eefe2
[devtools] Don't call getStyleSheetRuleCountAndAtRules in setStyleSheetText when it's not needed. r=devtools-reviewers,ochameau.

Comment 3

[Serban Stanca [:SerbanS]]

https://hg.mozilla.org/mozilla-central/rev/76f2f82eefe2