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Andreas Kling 66263f142b LibWeb: Add StyleScope to keep style caches per Document/ShadowRoot
Before this change, we've been maintaining various StyleComputer caches
at the document level.

This made sense for old-school documents without shadow trees, since
all the style information was document-wide anyway. However, documents
with many shadow trees ended up suffering since any time you mutated
a style sheet inside a shadow tree, *all* style caches for the entire
document would get invalidated.

This was particularly expensive on Reddit, which has tons of shadow
trees with their own style elements. Every time we'd create one of their
custom elements, we'd invalidate the document-level "rule cache" and
have to rebuild it, taking about ~60ms each time (ouch).

This commit introduces a new object called StyleScope.

Every Document and ShadowRoot has its own StyleScope. Rule caches etc
are moved from StyleComputer to StyleScope.

Rule cache invalidation now happens at StyleScope level. As an example,
rule cache rebuilds now take ~1ms on Reddit instead of ~60ms.

This is largely a mechanical change, moving things around, but there's
one key detail to be aware of: due to the :host selector, which works
across the shadow DOM boundary and reaches from inside a shadow tree out
into the light tree, there are various places where we have to check
both the shadow tree's StyleScope *and* the document-level StyleScope
in order to get all rules that may apply.
2025-11-14 22:05:33 +01:00
.devcontainer Everywhere: Remove AudioCodecPlugin and Qt Multimedia 2025-10-27 17:28:49 -07:00
.github CI: Bump JamesIves/github-pages-deploy-action from 4.7.3 to 4.7.4 2025-11-11 00:28:42 +01:00
AK AK: Ignore -Wfree-nonheap-object on RefCounted::unref 2025-11-13 13:52:07 +01:00
Base/res LibWebView+UI: Remove some now-superfluous debug menu items 2025-11-12 09:06:21 -05:00
Documentation Everywhere: Remove AudioCodecPlugin and Qt Multimedia 2025-10-27 17:28:49 -07:00
Libraries LibWeb: Add StyleScope to keep style caches per Document/ShadowRoot 2025-11-14 22:05:33 +01:00
Meta Meta: Validate proper formatting for FIXMEs and AD-HOCs 2025-11-13 15:56:04 +01:00
Services RequestServer: Add a time parameter to the clear cache endpoint 2025-11-12 09:06:21 -05:00
Tests LibWeb: Account for box-sizing in max-content contribution [GFC] 2025-11-14 16:24:30 +01:00
Toolchain Meta: Add SPDX license identifier to ladybird.py and BuildVcpkg.py 2025-05-29 16:24:17 -04:00
UI LibWebView+UI: Remove some now-superfluous debug menu items 2025-11-12 09:06:21 -05:00
Utilities LibJS: Have JS::Lexer take a JS::SourceCode as input 2025-11-09 12:14:03 +01:00
.clang-format Meta: Enforce newlines around namespaces 2025-05-14 02:01:59 -06:00
.clang-tidy Meta: Disable clang-tidy's const correctness checks 2025-07-08 11:04:15 -04:00
.clangd Meta: Change the default build directories to exclude "ladybird" prefix 2024-11-06 10:38:57 -07:00
.editorconfig Meta: Add .editorconfig 2022-09-10 17:32:55 +01:00
.gitattributes LibGfx: Remove support for the various "portable" image formats 2024-06-17 21:57:35 +02:00
.gitignore CMake: Add a flatpak build for org.ladybird.Ladybird 2025-07-08 11:45:32 -06:00
.gn Meta: Automatically generate a compilation database for clangd 2023-11-14 14:29:35 -05:00
.mailmap Meta: Update my e-mail address everywhere 2024-10-04 13:19:50 +02:00
.pre-commit-config.yaml Meta: Replace deprecated pre-commit stage name 2024-10-18 09:40:59 +02:00
.prettierignore LibJS: Remove using-declaration.js from .prettierignore 2025-10-09 15:49:49 -04:00
.prettierrc Meta: Increase the line length enforced by prettier to 120 2025-10-31 19:55:50 -04:00
.swift-format Meta: Add swift-format configuration 2024-07-30 18:38:02 -06:00
.swift-version Meta: Update swift version to 2025-06-22 2025-07-09 16:26:49 -06:00
.ycm_extra_conf.py Meta: Sort all python imports 2025-06-09 11:25:14 -04:00
CMakeLists.txt LibWebView: Enable in Windows CI 2025-08-23 16:04:36 -06:00
CMakePresets.json CI: Add All_Debug CI job 2025-10-27 08:46:02 -04:00
CODE_OF_CONDUCT.md Meta: Add code of conduct (from the Ruby community) 2024-10-02 09:49:52 +02:00
CONTRIBUTING.md Meta: Add Gregory Bertilson to maintainer list :^) 2025-08-21 14:20:45 +02:00
ISSUES.md Everywhere: Document use of ladybird.py over ladybird.sh 2025-05-29 16:24:17 -04:00
LICENSE Meta: Update license year 2025-02-10 11:40:57 +00:00
pyproject.toml Meta: Use "extend-select" to enable non-default python linters 2025-06-09 17:49:35 -04:00
README.md Libraries: Remove LibArchive 2024-11-25 13:37:45 +01:00
SECURITY.md Documentation: Make updates to align better with new issue template 2024-10-31 09:18:08 +01:00
vcpkg-configuration.json Meta: Add overlay port for vulkan-loader 2024-07-07 15:56:59 +02:00
vcpkg.json Everywhere: Remove AudioCodecPlugin and Qt Multimedia 2025-10-27 17:28:49 -07:00

Ladybird

Ladybird is a truly independent web browser, using a novel engine based on web standards.

Important

Ladybird is in a pre-alpha state, and only suitable for use by developers

Features

We aim to build a complete, usable browser for the modern web.

Ladybird uses a multi-process architecture with a main UI process, several WebContent renderer processes, an ImageDecoder process, and a RequestServer process.

Image decoding and network connections are done out of process to be more robust against malicious content. Each tab has its own renderer process, which is sandboxed from the rest of the system.

At the moment, many core library support components are inherited from SerenityOS:

  • LibWeb: Web rendering engine
  • LibJS: JavaScript engine
  • LibWasm: WebAssembly implementation
  • LibCrypto/LibTLS: Cryptography primitives and Transport Layer Security
  • LibHTTP: HTTP/1.1 client
  • LibGfx: 2D Graphics Library, Image Decoding and Rendering
  • LibUnicode: Unicode and locale support
  • LibMedia: Audio and video playback
  • LibCore: Event loop, OS abstraction layer
  • LibIPC: Inter-process communication

How do I build and run this?

See build instructions for information on how to build Ladybird.

Ladybird runs on Linux, macOS, Windows (with WSL2), and many other *Nixes.

How do I read the documentation?

Code-related documentation can be found in the documentation folder.

Get in touch and participate!

Join our Discord server to participate in development discussion.

Please read Getting started contributing if you plan to contribute to Ladybird for the first time.

Before opening an issue, please see the issue policy and the detailed issue-reporting guidelines.

The full contribution guidelines can be found in CONTRIBUTING.md.

License

Ladybird is licensed under a 2-clause BSD license.