Blink's Graph Data Structures and Traversals
Blink28613 Loka 2025

Blink's Graph Data Structures and Traversals

The text provides an extensive overview of the graph-structured data structures used within Blink, Chromium's rendering engine, detailing how web content is processed from initial input to final display. The core of the pipeline relies on sequential graph transformations, beginning with the DOM tree (representing the document structure), which is used to build the Layout Tree (representing visual formatting and geometry). Modern Blink transitions this into the Immutable Fragment Tree, which is key for painting and hit-testing. The subsequent stage involves the Paint Artifact, composed of a display list and four parallel Property Trees (Transform, Clip, Effect, and Scroll), which manage visual state hierarchies. Finally, these artifacts inform the construction of the Compositing Layer Tree on both the main and compositor threads, enabling efficient rendering and animation. Throughout all these stages, the document emphasizes various traversal concepts—such as pre-order, post-order, and finding the common ancestor—that are fundamental to Blink's algorithms for layout, style calculation, and drawing.

Jaksot(397)

gpu::SkiaOutputSurfaceImplOnGpu / gpu::CommandBuffer

gpu::SkiaOutputSurfaceImplOnGpu / gpu::CommandBuffer

Bridges Skia’s recorded commands to the GPU command buffer; submits and SwapBuffers to present. (Backend: GL/Vulkan/Metal via GPU process.)

23 Syys 202532min

viz::SkiaRenderer

viz::SkiaRenderer

Renderer that turns quads into Skia operations (recording DDLs / drawing to the output surface).

23 Syys 202552min

viz::Display

viz::Display

The display compositor that walks the aggregated render passes and issues draw commands for the final output.

23 Syys 202538min

cc::LayerTreeHostImpl (Input Handler & Scroll Logic)

cc::LayerTreeHostImpl (Input Handler & Scroll Logic)

Scroll processing and overscroll detection in the compositor. The LayerTreeHostImpl in cc implements the compositor-thread InputHandler that processes gesture scroll updates and flings. It manages the...

23 Syys 202527min

blink::EventHandler (Blink core input handling)

blink::EventHandler (Blink core input handling)

Scroll chain builder and overscroll chaining logic. Blink’s EventHandler is responsible for building the scroll chain (the sequence of nested scrollable ancestors) when the user scrolls an element . I...

23 Syys 202526min

blink::ElasticOverscrollController

blink::ElasticOverscrollController

Overscroll orchestration and animation. This Blink-side controller manages the rubber-banding (elastic stretch and rebound) effect when a scrollable area is overscrolled. It observes gesture scroll ev...

23 Syys 202526min

viz::Surface / SurfaceAggregator

viz::Surface / SurfaceAggregator

Receives frames from one or more surfaces (main page and OOPIFs), aggregates them into a single display frame.

23 Syys 202535min

viz::CompositorFrameSink (client side)

viz::CompositorFrameSink (client side)

The submission interface used by cc to hand the frame to viz.

23 Syys 202531min