1852908 - Remove mirrored C++ maplike/setlike data structures in Custom Highlight API

Status: ASSIGNED

(Core :: CSS Parsing and Computation, enhancement)

Description

[Jan Jaeschke [:jjaschke]]

Custom Highlight API classes Highlight and HighlightRegistry are exposed to JS as setlike / maplike interfaces. However, the contents of the maplike/setlike are accessed from C++.

Currently the webIDL interface only provides the ability to inject code into Add()/Set(), Delete() and Clear(). This allowed to add a mirrored data structure (nsTArray<T> for setlike, nsTArray<CompactPair<K, V>> for maplike) which is accessible from C++ and allows to iterate the contents.

Even if these mirrored data structures are private members of the classes, it imposes the danger of the C++ data becoming out of sync with the original data. To avoid this in a proper way, begin() and end() iterators should be provided by the webIDL code so that C++ code can iterate on the original data without imposing the risk of the data becoming out of sync.

Comment 1

[Jan Jaeschke [:jjaschke]]

Attachment: Bug 1852908, part 2 - Migrate HighlightRegistry to MaplikeMixin with [DOMBackedStorage], remove mHighlightsOrdered. r=edgar!

Comment 2

[Jan Jaeschke [:jjaschke]]

Attachment: Bug 1852908, part 1 - Migrate Highlight to SetlikeMixin, remove mRanges. r=edgar!

Comment 3

[Jan Jaeschke [:jjaschke]]

Attachment: Bug 1852908, part 2 - Migrate HighlightRegistry to MaplikeMixin with [DOMBackedStorage], remove mHighlightsOrdered. r=edgar!