Add design documentation for the layout DOM wrappers#225
Merged
Conversation
mrobinson
added a commit
to mrobinson/servo
that referenced
this pull request
Apr 11, 2026
This change reworks the layout DOM wrappers so that they are simpler and easier to reason about. The main changes here: **Combine layout wrappers into one interface:** - `LayoutNode`/`ThreadSafeLayoutNode` is combined into `LayoutNode`: The idea here is that `LayoutNode` is always thread-safe when used in layout as long as no `unsafe` calls are used. These interfaces only expose what is necessary for layout. - `LayoutElement`/`ThreadSafeLayoutElement` is combined into `LayoutElement`: See above. **Expose two new interfaces to be used *only* with `stylo` and `selectors`:** `DangerousStyleNode` and `DangerousStyleElement`. `stylo` and `selectors` have a different way of ensuring safety that is incompatible with Servo's layout (access all of the DOM tree anywhere, but ensure that writing only happens from a single-thread). These types only implement things like `TElement`, `TNode` and are not intended to be used by layout at all. All traits and implementations are moved to files that are named after the struct or trait inside them, in order to better understand what one is looking at. The main goals here are: - Make it easier to reason about the safe use of the DOM APIs. - Remove the interdependencies between the `stylo` and `selectors` interface implementations and the layout interface. This helps with the first point as well and makes it simpler to know where a method is implemented. - Reduce the amount of code. - Make it possible to eliminate `TrustedNodeAddress` in the future. - Document and bring the method naming up to modern Rust conventions. This is a lot of code changes, but is very well tested by the WPT tests. Unfortunately, it is difficult to make a change like this iteratively. In addition, this new design comes with new documentation at servo/book#225. Signed-off-by: Martin Robinson <mrobinson@fastmail.fm>
mrobinson
force-pushed
the
add-documentation-for-layout-dom
branch
from
8184462 to
eeefa14
Compare
mrobinson
added a commit
to mrobinson/servo
that referenced
this pull request
Apr 11, 2026
This change reworks the layout DOM wrappers so that they are simpler and easier to reason about. The main changes here: **Combine layout wrappers into one interface:** - `LayoutNode`/`ThreadSafeLayoutNode` is combined into `LayoutNode`: The idea here is that `LayoutNode` is always thread-safe when used in layout as long as no `unsafe` calls are used. These interfaces only expose what is necessary for layout. - `LayoutElement`/`ThreadSafeLayoutElement` is combined into `LayoutElement`: See above. **Expose two new interfaces to be used *only* with `stylo` and `selectors`:** `DangerousStyleNode` and `DangerousStyleElement`. `stylo` and `selectors` have a different way of ensuring safety that is incompatible with Servo's layout (access all of the DOM tree anywhere, but ensure that writing only happens from a single-thread). These types only implement things like `TElement`, `TNode` and are not intended to be used by layout at all. All traits and implementations are moved to files that are named after the struct or trait inside them, in order to better understand what one is looking at. The main goals here are: - Make it easier to reason about the safe use of the DOM APIs. - Remove the interdependencies between the `stylo` and `selectors` interface implementations and the layout interface. This helps with the first point as well and makes it simpler to know where a method is implemented. - Reduce the amount of code. - Make it possible to eliminate `TrustedNodeAddress` in the future. - Document and bring the method naming up to modern Rust conventions. This is a lot of code changes, but is very well tested by the WPT tests. Unfortunately, it is difficult to make a change like this iteratively. In addition, this new design comes with new documentation at servo/book#225. Signed-off-by: Martin Robinson <mrobinson@fastmail.fm>
mrobinson
added a commit
to mrobinson/servo
that referenced
this pull request
Apr 11, 2026
This change reworks the layout DOM wrappers so that they are simpler and easier to reason about. The main changes here: **Combine layout wrappers into one interface:** - `LayoutNode`/`ThreadSafeLayoutNode` is combined into `LayoutNode`: The idea here is that `LayoutNode` is always thread-safe when used in layout as long as no `unsafe` calls are used. These interfaces only expose what is necessary for layout. - `LayoutElement`/`ThreadSafeLayoutElement` is combined into `LayoutElement`: See above. **Expose two new interfaces to be used *only* with `stylo` and `selectors`:** `DangerousStyleNode` and `DangerousStyleElement`. `stylo` and `selectors` have a different way of ensuring safety that is incompatible with Servo's layout (access all of the DOM tree anywhere, but ensure that writing only happens from a single-thread). These types only implement things like `TElement`, `TNode` and are not intended to be used by layout at all. All traits and implementations are moved to files that are named after the struct or trait inside them, in order to better understand what one is looking at. The main goals here are: - Make it easier to reason about the safe use of the DOM APIs. - Remove the interdependencies between the `stylo` and `selectors` interface implementations and the layout interface. This helps with the first point as well and makes it simpler to know where a method is implemented. - Reduce the amount of code. - Make it possible to eliminate `TrustedNodeAddress` in the future. - Document and bring the method naming up to modern Rust conventions. This is a lot of code changes, but is very well tested by the WPT tests. Unfortunately, it is difficult to make a change like this iteratively. In addition, this new design comes with new documentation at servo/book#225. Signed-off-by: Martin Robinson <mrobinson@fastmail.fm>
mrobinson
added a commit
to mrobinson/servo
that referenced
this pull request
Apr 11, 2026
This change reworks the layout DOM wrappers so that they are simpler and easier to reason about. The main changes here: **Combine layout wrappers into one interface:** - `LayoutNode`/`ThreadSafeLayoutNode` is combined into `LayoutNode`: The idea here is that `LayoutNode` is always thread-safe when used in layout as long as no `unsafe` calls are used. These interfaces only expose what is necessary for layout. - `LayoutElement`/`ThreadSafeLayoutElement` is combined into `LayoutElement`: See above. **Expose two new interfaces to be used *only* with `stylo` and `selectors`:** `DangerousStyleNode` and `DangerousStyleElement`. `stylo` and `selectors` have a different way of ensuring safety that is incompatible with Servo's layout (access all of the DOM tree anywhere, but ensure that writing only happens from a single-thread). These types only implement things like `TElement`, `TNode` and are not intended to be used by layout at all. All traits and implementations are moved to files that are named after the struct or trait inside them, in order to better understand what one is looking at. The main goals here are: - Make it easier to reason about the safe use of the DOM APIs. - Remove the interdependencies between the `stylo` and `selectors` interface implementations and the layout interface. This helps with the first point as well and makes it simpler to know where a method is implemented. - Reduce the amount of code. - Make it possible to eliminate `TrustedNodeAddress` in the future. - Document and bring the method naming up to modern Rust conventions. This is a lot of code changes, but is very well tested by the WPT tests. Unfortunately, it is difficult to make a change like this iteratively. In addition, this new design comes with new documentation at servo/book#225. Signed-off-by: Martin Robinson <mrobinson@fastmail.fm>
mrobinson
force-pushed
the
add-documentation-for-layout-dom
branch
from
eeefa14 to
1255d48
Compare
mrobinson
added a commit
to mrobinson/servo
that referenced
this pull request
Apr 11, 2026
This change reworks the layout DOM wrappers so that they are simpler and easier to reason about. The main changes here: **Combine layout wrappers into one interface:** - `LayoutNode`/`ThreadSafeLayoutNode` is combined into `LayoutNode`: The idea here is that `LayoutNode` is always thread-safe when used in layout as long as no `unsafe` calls are used. These interfaces only expose what is necessary for layout. - `LayoutElement`/`ThreadSafeLayoutElement` is combined into `LayoutElement`: See above. **Expose two new interfaces to be used *only* with `stylo` and `selectors`:** `DangerousStyleNode` and `DangerousStyleElement`. `stylo` and `selectors` have a different way of ensuring safety that is incompatible with Servo's layout (access all of the DOM tree anywhere, but ensure that writing only happens from a single-thread). These types only implement things like `TElement`, `TNode` and are not intended to be used by layout at all. All traits and implementations are moved to files that are named after the struct or trait inside them, in order to better understand what one is looking at. The main goals here are: - Make it easier to reason about the safe use of the DOM APIs. - Remove the interdependencies between the `stylo` and `selectors` interface implementations and the layout interface. This helps with the first point as well and makes it simpler to know where a method is implemented. - Reduce the amount of code. - Make it possible to eliminate `TrustedNodeAddress` in the future. - Document and bring the method naming up to modern Rust conventions. This is a lot of code changes, but is very well tested by the WPT tests. Unfortunately, it is difficult to make a change like this iteratively. In addition, this new design comes with new documentation at servo/book#225. Signed-off-by: Martin Robinson <mrobinson@fastmail.fm>
mrobinson
added a commit
to mrobinson/servo
that referenced
this pull request
Apr 11, 2026
This change reworks the layout DOM wrappers so that they are simpler and easier to reason about. The main changes here: **Combine layout wrappers into one interface:** - `LayoutNode`/`ThreadSafeLayoutNode` is combined into `LayoutNode`: The idea here is that `LayoutNode` is always thread-safe when used in layout as long as no `unsafe` calls are used. These interfaces only expose what is necessary for layout. - `LayoutElement`/`ThreadSafeLayoutElement` is combined into `LayoutElement`: See above. **Expose two new interfaces to be used *only* with `stylo` and `selectors`:** `DangerousStyleNode` and `DangerousStyleElement`. `stylo` and `selectors` have a different way of ensuring safety that is incompatible with Servo's layout (access all of the DOM tree anywhere, but ensure that writing only happens from a single-thread). These types only implement things like `TElement`, `TNode` and are not intended to be used by layout at all. All traits and implementations are moved to files that are named after the struct or trait inside them, in order to better understand what one is looking at. The main goals here are: - Make it easier to reason about the safe use of the DOM APIs. - Remove the interdependencies between the `stylo` and `selectors` interface implementations and the layout interface. This helps with the first point as well and makes it simpler to know where a method is implemented. - Reduce the amount of code. - Make it possible to eliminate `TrustedNodeAddress` in the future. - Document and bring the method naming up to modern Rust conventions. This is a lot of code changes, but is very well tested by the WPT tests. Unfortunately, it is difficult to make a change like this iteratively. In addition, this new design comes with new documentation at servo/book#225. Signed-off-by: Martin Robinson <mrobinson@fastmail.fm>
mrobinson
added a commit
to mrobinson/servo
that referenced
this pull request
Apr 12, 2026
This change reworks the layout DOM wrappers so that they are simpler and easier to reason about. The main changes here: **Combine layout wrappers into one interface:** - `LayoutNode`/`ThreadSafeLayoutNode` is combined into `LayoutNode`: The idea here is that `LayoutNode` is always thread-safe when used in layout as long as no `unsafe` calls are used. These interfaces only expose what is necessary for layout. - `LayoutElement`/`ThreadSafeLayoutElement` is combined into `LayoutElement`: See above. **Expose two new interfaces to be used *only* with `stylo` and `selectors`:** `DangerousStyleNode` and `DangerousStyleElement`. `stylo` and `selectors` have a different way of ensuring safety that is incompatible with Servo's layout (access all of the DOM tree anywhere, but ensure that writing only happens from a single-thread). These types only implement things like `TElement`, `TNode` and are not intended to be used by layout at all. All traits and implementations are moved to files that are named after the struct or trait inside them, in order to better understand what one is looking at. The main goals here are: - Make it easier to reason about the safe use of the DOM APIs. - Remove the interdependencies between the `stylo` and `selectors` interface implementations and the layout interface. This helps with the first point as well and makes it simpler to know where a method is implemented. - Reduce the amount of code. - Make it possible to eliminate `TrustedNodeAddress` in the future. - Document and bring the method naming up to modern Rust conventions. This is a lot of code changes, but is very well tested by the WPT tests. Unfortunately, it is difficult to make a change like this iteratively. In addition, this new design comes with new documentation at servo/book#225. Signed-off-by: Martin Robinson <mrobinson@fastmail.fm>
github-merge-queue Bot
pushed a commit
to servo/servo
that referenced
this pull request
Apr 12, 2026
This change reworks the layout DOM wrappers so that they are simpler and easier to reason about. The main changes here: **Combine layout wrappers into one interface:** - `LayoutNode`/`ThreadSafeLayoutNode` is combined into `LayoutNode`: The idea here is that `LayoutNode` is always thread-safe when used in layout as long as no `unsafe` calls are used. These interfaces only expose what is necessary for layout. - `LayoutElement`/`ThreadSafeLayoutElement` is combined into `LayoutElement`: See above. **Expose two new interfaces to be used *only* with `stylo` and `selectors`:** `DangerousStyleNode` and `DangerousStyleElement`. `stylo` and `selectors` have a different way of ensuring safety that is incompatible with Servo's layout (access all of the DOM tree anywhere, but ensure that writing only happens from a single-thread). These types only implement things like `TElement`, `TNode` and are not intended to be used by layout at all. All traits and implementations are moved to files that are named after the struct or trait inside them, in order to better understand what one is looking at. The main goals here are: - Make it easier to reason about the safe use of the DOM APIs. - Remove the interdependencies between the `stylo` and `selectors` interface implementations and the layout interface. This helps with the first point as well and makes it simpler to know where a method is implemented. - Reduce the amount of code. - Make it possible to eliminate `TrustedNodeAddress` in the future. - Document and bring the method naming up to modern Rust conventions. This is a lot of code changes, but is very well tested by the WPT tests. Unfortunately, it is difficult to make a change like this iteratively. In addition, this new design comes with new documentation at servo/book#225. Testing: This should not change behavior so should be covered by existing WPT tests. Signed-off-by: Martin Robinson <mrobinson@fastmail.fm>
mrobinson
force-pushed
the
add-documentation-for-layout-dom
branch
from
1255d48 to
a728d7e
Compare
Member
Author
|
This is ready for review now. |
Signed-off-by: Martin Robinson <mrobinson@fastmail.fm>
mrobinson
force-pushed
the
add-documentation-for-layout-dom
branch
from
a728d7e to
2f8d14e
Compare
jdm
approved these changes
Apr 15, 2026
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
This depends on #224.