This is a preparation for publishing to crates.io. Changes include:
- Add `servo-` prefixes to avoid name collisions on crates.io
- Use `-` instead of `_` in package names.
- Rename the crates to their original names in Cargo.toml,
to keep the diff minimal
- Rename `media` to `servo-media-thread` to avoid name collision with
`servo-media` (originally from the media repository).
This is an outcome of the previous discussion at [#general > Switch
remaining git dependencies to
crates.io](https://servo.zulipchat.com/#narrow/channel/263398-general/topic/Switch.20remaining.20git.20dependencies.20to.20crates.2Eio/with/576336288)
Testing: This should be mostly covered by our CI, but some amount of
breakage is to be expected, since some package names could still be
referenced from scripts which are not tested or run in CI. [mach try
run](https://github.com/jschwe/servo/actions/runs/22502945949)
---------
Signed-off-by: Jonathan Schwender <schwenderjonathan@gmail.com>
Remove embedder defined `ScrollEvent` and merge the payload of it to the
`SetScrollStates` message which tell the `ScriptThread` to update the
scroll state.
In the past, `ScrollEvent` is defined as a embedder's `InputEvent` and
being used only to forward the external scroll node id for a node that
is considered scrolled. This make us sends an additional message to
constellation and additionally, `ScrollEvent` went through lengthy
pipelines as it was deemed as an embedder input event, albeit being a
synthetic input fired by `WebviewRenderer`.
Subsequently, we could introduce a flag to detect whether the scrolling
is still ongoing or not (like whether it is still flinging) for
`scrollend` event.
Testing: No WPT changes
---------
Signed-off-by: Jo Steven Novaryo <steven.novaryo@gmail.com>
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Co-authored-by: Martin Robinson <mrobinson@igalia.com>
this patch adds a Servo::set_accessibility_active() method that
embedders can use to tell Servo to start building and sending
accessibility trees to the platform, as long as the pref is enabled
(#42333). doing so sets a global flag in the constellation, which is
then propagated to the layout of all existing and future pipelines.
Testing: none yet, no functional change
Fixes: part of #4344
---------
Signed-off-by: delan azabani <dazabani@igalia.com>
Signed-off-by: Alice Boxhall <alice@igalia.com>
Co-authored-by: Alice Boxhall <alice@igalia.com>
The patch adds the following functionality to the per-WebView
`UserContentManager` API.
- Removing a `UserScript` at that was previously added.
- Adding a new `UserStyleSheet` representing a user-origin style sheet.
allow removing user script
- Removing a previously added `UserStyleSheet`.
There might be scope for some improvements in the API:
- `UserScript` and `UserStyleSheet` have different ways of representing
the source location - a `PathBuf` and `Url` respectively. This is due to
how those values are used by the underlying evaluation APIs in script
and stylo. More investigation is needed here and could be addressed in
future patches.
Testing: New unit tests are added for the user stylesheet APIs. Existing
tests have been updated to test the removal of user scripts.
Continuing the implementation of `VisualViewport`, the resizing of
`PinchZoom` should be notified to `ScriptThread` to update the
`VisualViewport` interface and to fire the appropriate JS event. Top
level `Window`/`Pipeline` would have a `VisualViewport` interface that
mirrors the `PinchZoom` viewport, while nested `Window` would have a
default value that represent layout viewport of the relevant iframe. The
`VisualViewport` of an iframe is updated after each reflow that
calculate the rectangle of the iframe.
The updates of DOM's `VisualViewport` occurs immediately (instead of
waiting for the event loop like the viewport) but integrates with the
event loop for the JS events. This behavior would helps with the fact
that `VisualViewport` needs to be updated both when it is scrolled or
resized.
Testing: Existing WPTs and new unit test.
Part of: https://github.com/servo/servo/issues/41341
---------
Signed-off-by: Jo Steven Novaryo <steven.novaryo@gmail.com>
We populate the required field for all relevant entrypoints
and set it to `document.base_url` when the url is `about:blank`
or `about:srcdoc`. In all other cases, it uses
`document.about_base_url`.
Testing: WPT
Fixes#41836
---------
Signed-off-by: Tim van der Lippe <tvanderlippe@gmail.com>
This change finishes the big rename associated with the old
`compositing` crates. Long ago, these crates managed a compositor, like
you might find in a traditional web engine. These days, compositing is
done in WebRender so the name has stopped making much sense. Various
structs inside the crates have already been renamed and this is the
final big change necessary for the rename
Testing: This is just a rename so existing tests should cover it.
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
These changes introduce a new OriginSnapshot type, which is an immutable
version of MutableOrigin (ie. an origin that includes an optional domain
modifier). This is now propagated as part of LoadData's origin, allowing
us to perform the same-origin-domain check for javascript: URLs as
needed.
Testing: Newly-passing tests.
Signed-off-by: Josh Matthews <josh@joshmatthews.net>
This changes routed_promise to use the GenericCallback functionality.
This mostly effected WebGPU but also Clipboard and Memory Reporting.
We also added a GenericCallback::new_blocking() functionality which
produces a callback and a channel
which then can be blocked on. This was used a couple of times in the
code.
Signed-off-by: Narfinger <Narfinger@users.noreply.github.com>
Testing: This should not change functionality.
---------
Signed-off-by: Narfinger <Narfinger@users.noreply.github.com>
Changed most #[allow]s to #[expect]s, mainly for
clippy::too_many_arguments
Removed unfulfilled expectations
This is my first opensource contribution, so please let me know if
anything should
be done differently.
Testing: Refactor
Part of: #40838
---------
Signed-off-by: Tim van der Lippe <tvanderlippe@gmail.com>
Signed-off-by: TimurBora <timurborisov5561@gmail.com>
Co-authored-by: Tim van der Lippe <TimvdLippe@users.noreply.github.com>
Instead of the creation URL of the containing global,
it should instead use the URL of the current worker.
Despite the referrer specification stating that we
should use the creation URL, instead browsers use
the current URL. A new WPT test is added to cover that
which we currently fail because of incorrect
serialization of query parameters of a URL. But the
actual redirect and all work now.
Signed-off-by: Tim van der Lippe <tvanderlippe@gmail.com>
This change moves the `UserContentManager` abstraction from the
`ServoBuilder` to `WebViewBuilder` so that embedders can inject content
for each `WebView` independently. It also adds basic support for runtime
mutations to the `UserContentManager` API. Only adding new scripts is
currently supported, but future changes will add support for both other
mutations such as removal of scripts and addition & removal of
stylesheets. Future changes could also optimize the way mutations are
propagated to `ScriptThread`s by sending just the "delta" rather than
the whole `UserContents` structure for each mutation.
The `UserContentManager` now becomes just a convenient handle for the
embedders to invoke the mutation API while the actual management of the
manager's content is handled by the Constellation. The mutations are
relayed to the constellation via messages. The change also separates the
serialized version containg the user contents into a new `UserContent`
structure so that the API cannot be misused.
Testing: New unit tests have been added for the different scenarios
involving UserContentManager.
---------
Signed-off-by: Mukilan Thiyagarajan <mukilan@igalia.com>
This PR adds an initial `site_data` API to `SiteDataManager`, allowing
embedders to obtain a unified list of sites that have associated site
data.
The implementation introduces supporting infrastructure across storage
and
`SiteDataManager` layers, including a small helper for obtaining
WebStorage
origins and initial support for filtering by storage type. At this
stage,
sites correspond directly to origins, future work will extend this to
higher
level grouping (e.g. domain or eTLD+1).
Testing: Added a new integration test covering site data behavior across
localStorage and sessionStorage.
---------
Signed-off-by: Jan Varga <jvarga@igalia.com>
This PR removes the unused `EmbedderToConstellationMessage::ClearCache`
variant.
Clearing the network cache is now expected to be handled through
upcoming `SiteDataManager`, with direct communication to the resource
threads,
rather than via the constellation.
Testing: Unit tests continue to pass
Signed-off-by: Jan Varga <jvarga@igalia.com>
For a long time, the "Compositor" hasn't done any compositing. This is
handled by WebRender. In addition the "Compositor" does many other
tasks. This change renames `IOCompositor` to `Paint`.
`Paint` is Servo's paint subsystem and contains multiple `Painter`s.
This change does not rename the crate; that will be done in a
followup change.
Testing: This just renames types and updates comments, so no new tests
are necessary.
---------
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Switch the devtools part to GenericCallback and GenericSender.
To keep the diff small the names where not changes as a Sender almost
fills the same requirement as a callback.
Testing: As this is mostly type changes, the compilation is the test but
also devtools seem to work fine with these changes. ./mach try run is
here: https://github.com/Narfinger/servo/actions/runs/19931697694
---------
Signed-off-by: Narfinger <Narfinger@users.noreply.github.com>
Changed some allow to expects and removed the unfulfilled expectations.
Testing: Refactor
Part of: #40383
Signed-off-by: anonmiraj <nabilmalek48@gmail.com>
Currently starting a script `EventLoop` depends on sending data about
the initial `Pipeline`. This change breaks this dependency. The goal
here is to:
1. Allow `ScriptThread`s to be shared between `WebView`s. This will
allow more flexiblity with the way that `ScriptThread`s are created,
which should allow us to perserve system resources by allowing them
to be shared between `WebView`s. With this change, we can do away
with the `InitialPipelineState` entirely, which was gather
information necessary for both a new `EventLoop` and a new
`Pipeline`. We no longer have to do many clones when reusing an
existing even loop.
1. Simplify the way that `EventLoop`s and `Pipeline`s are spawned. Now
`Pipeline`s are spawned in the same way no matter what.
Now the general order of operations when starting a pipeline is:
1. Get or create an event loop for the pipeline:
- If the event loop needs to be spawn, spawned it in a new thread or
process.
2. Send the spawn pipeline message to the event loop (kept alive via an
`Rc`.
Testing: This should not change behavior in a way that is observable, so
should
be covered by existing tests.
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
`ScriptThread`s start with an initial `Pipeline`, but that `Pipeline`
should not be used for any `ScriptThread` global data as a
`ScriptThread` can have any number of `Pipeline`s that come and go.
There's no architectural reason why a `ScriptThread` should be
associated with only a single `WebView`.
This change makes it so that the `ScriptThread` no longer uses the
`PipelineId` and the `WebViewId` of the initial `Pipeline` to initialize
itself. Instead a `ScriptEventLoopId` is used to uniquely identify every
`ScriptThread` in both the `ScriptThread` and the `Constellation`.
The remaining use was for crash reporting. Now when a crash happens, it
launches the sad tab in all `WebView`s that depeneded on that
`ScriptThread`.
This is a change which should allow simplifying the way that
`EventLoop`s/`ScriptThread`s are started in the `Constellation`, which
will be handled in a followup.
Testing: This shouldn't change behavior except in the case where a
`ScriptThread` is used in more than a single `WebView`, which should
work
properly now. I tested this change manually by running servoshell in
multiprocess mode while causing a panic to happen due to a null pointer
dereference. The sad tab appeared after this change, so things seem to
work
properly still. Testing crashes is tricky with the way we test servo
now.
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
The `scripts_traits` crate was the only crate depending on `strum` with
the
`derive` feature. This accidentally allowed other crates to import strum
macros via `strum::` without declaring their own dependency on
`strum_macros`,
causing compilation issues when running `./mach test-unit -p net`.
This PR makes the imports consistent across the code base by:
- replacing all `strum_macro::` imports with `strum::` imports
- removing strum_macro dependencies
- adding derive feature to the strum workspace
Testing: Unit tests continue to pass
Signed-off-by: Jan Varga <jvarga@igalia.com>
Add context menu options for images, links, and editable text areas. In
addition add the ability to show menu options that are disabled. This
also improves the visual style of the context menu in egui as part of
supporting disabled options.
Testing: This has been manually tested, but we could we should be able
to
easily add unit tests when enriching the API with information about the
active element under context menus.
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Co-authored-by: Rakhi Sharma <atbrakhi@igalia.com>
This change makes it so that the `HTMLCanvasElement` is responsible for
managing the `ImageKey` for associated `RenderingContext`s. Only
canvases display their contents into WebRender directly, so this makes
it so that keys are not generated for `OffscreenCanvas`.
The main goal here is that `ImageKey`s are always associated with a
particular `WebView`, which isn't possible in the various canvas
backends yet. This is important because each `WebView` may soon have a
different WebRender instance entirely with its own set of `ImageKey`s.
This also allows for clearing `ImageKey`s when canvases are disconnected
from the DOM in a future change. One tricky thing here is placeholder
canvases, which are meant to be driven from workers.
It seems that the implementation isn't correct for these at the moment
as they need to be updated to the specification. Instead, what is
happening is that any existing context / image is completely lost when
converting to an `OffscreenCanvas`.
Testing: This shouldn't change observable behavior, so is covered by
existing tests.
Fixes: This is part of #40261.
---------
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Signed-off-by: Mukilan Thiyagarajan <mukilan@igalia.com>
Co-authored-by: Mukilan Thiyagarajan <mukilan@igalia.com>
Steps for calculating LCP:
1. When the pref for `largest_contentful_paint_enabled` is enabled,
`LargestContentfulPaintCandidateCollector` is created once per
LayoutThread using `viewport_size`.
2. While building the `display_list`, it send the pre-calculated
`clip_rect` and `bounds` to `LCPCollector` along with `transform` and
`LCPCandidateType` for `visual_rect` calculation for `LCPCandidates`.
3. After `visual_rect` calculation, update the `lcp_candidate` based on
`area` of `visual_rect` and send it to `compositor`.
4. Then among `lcp_candidates`, we find out the
`largest_contentful_paint` and send it to `paint_metric`
5. In addition to above `LCP` also uses `PaintMetricState` to save
console from spamming with duplicate entries.
This PR includes following commits better segregation of code
1. Add `LargestContentfulPaintCandidate` struct
2. Add `LargestContentfulPaintCandidateCollector`
6. Collect the `LargestContentfulPaintCandidates`when feature is
enabled.
7. Send the `LargestContentfulPaintCandidates` to compositor
8. Add `LargestContentfulPaintCalculator`
9. Calculates the `LargestContentfulPaint`
10. Send `LCP` to `PaintMetrics`
11. Disable `LCP` feature on user interaction
Elements considered for LCP in this PR:
- Image element
- An element with background image
Reference: https://github.com/servo/servo/pull/38041
Testing: Tested using
[perf-analysis-tools](https://github.com/servo/perf-analysis-tools) See
attached screenshot.
Fixes: None
Perfetto
<img width="2566" height="1151" alt="Screenshot from 2025-10-16
11-37-41"
src="https://github.com/user-attachments/assets/96e4f933-b39c-4ac7-833c-46dcc0c1671e"
/>
Console Output of Metric
<img width="1784" height="282" alt="Screenshot from 2025-10-16 11-33-16"
src="https://github.com/user-attachments/assets/441746a5-92ae-47c6-9022-f49114f23a2d"
/>
---------
Signed-off-by: Shubham Gupta <shubham.gupta@chromium.org>
Co-authored-by: boluochoufeng <1355990831@qq.com>
This splits `Snapshot` into two structs:
- `Snapshot`: A non-serializable owned image buffer that might contain
either shared memory or a `Vec<u8>`. When mutated the shared memory
version is converted into a `Vec<u8>` avoiding a copy of the data
until absolutely necessary.
- `SharedSnapshot`: A serialzable version of `Snapshot` that contains
only shared memory and is suitable for sending across IPC channels.
This version is cheaply convertible from and to owned `Snapshot`s as
long as the source is also a shared memory `Snapshot`.
In addition, it does copyless conversions of `RasterImage` into
`Snapshot`s (including for frame offsets in animated images). Finally,
there are a few minor changes to try harder not to have to do a
`transform()` operation.
Testing: This should not change observable behavior, so is covered by
existing
tests. It should come with a mild performance improvement and open up
the
opportunity for others.
Fixes: #36594.
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Workers now call `run_a_classic_worker_script`, also scripts gets
unminified.
Testing: no new tests passes are expected
---------
Signed-off-by: Gae24 <96017547+Gae24@users.noreply.github.com>
It would be useful for the Constellation is ever going to store data
per-WebView for the purposes of making cleanup and resource management
easier. If that's ever going to happen the `WebView` needs to be passed
with all messages that need it. This change makes it so that messages to
the Constellation that require a Pipeline also carry a WebViewId. This
eliminates one way in which message handling might go wrong.
This avoids making the Constelaltion look up the `WebViewId` for many
messages
that it receives.
Testing: This should not change observable behavior, so should be
covered by existing tests.
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
The renderer needs needs to know when touch events processing has
finished in the DOM in order to properly handle them. This was
previously done using the `CompositorMsg::TouchEventProcessed` message.
This message is now redudant with the general-purpose
`EmbedderMsg::InputEventHandled` message.
This change removes the former message and instead, has the
`TouchHandler` keep a `HashMap` of pending touch events which is uses to
finish their processing when they come back from script. The goal here
is reduce the number of messages sent and to keep the complexity of
touch handling more centered in the `TouchHandler`.
Testing: This should not change observable behavior, so is covered by
existing tests.
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
in #39709, we introduced a single “form control” or “embedder control”
delegate that requests the embedder’s input for <select> and
<input type="color"> elements.
this patch partially merges <input type="file"> elements into that
new system, and renames “form controls” to “embedder controls” for
consistency.
internally we continue to use a separate code path where the embedder
directly communicates with the file manager thread. subsequent work will
make the messages asynchronous via the constellation and script thread,
like other embedder controls.
Testing: this is currently tricky to write an automated test for; we
expect to write a WebDriver test for this once we make the communication
asynchronous
---------
Signed-off-by: delan azabani <dazabani@igalia.com>
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Co-authored-by: Martin Robinson <mrobinson@igalia.com>
Servo currently has three ways of notifying the embedder that input
events have been processed.
1. `WebViewDelegate::notify_keyboard_event`: This is used to implement
overridable keybindings in servoshell. It notifies the embedder when
a keyboard event has been processed, but not "handled" by the engine.
2. WebDriver's command message senders and receivers, this is used to
let WebDriver wait until events have been handled to continue with
script execution.
3. Touch event processing notifications: This is used to serialize touch
event processing.
This change unifies the first two things with a new
`WebViewDelegate::notify_input_event_handled` API. This API informs the
embedder (via a generated id) that an input event has finished
processing and what the result of the processing was.
This allows embedders to do other things with events once they have been
processed. For example, embedders might want to chain unconsumed events
up to parent widgets or to add support for overridable keybindings.
As part of this the `canceled` flag in script's `Event` data structure
is turned into a `bitflags` mirror of the new API type to describe the
result of event handling.
Testing: This shouldn't change observable behavior and is thus covered
by existing tests.
The new API is consumed by servoshell, which uses it for tests.
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Before responses to `FormControl` requests were handled synchronous in
script (ie they would block the page). This change makes it so that they
are handled asynchronously, with their responses filtering back through
the Constellation. This should fix many WPT tests when run with
WebDriver.
Testing: There are some WebDriver-based test for this, but they do
not quite pass yet. More investigation is required, but this is
necessary to get them to pass.
Fixes: #39652Fixes: #37013
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Co-authored-by: Delan Azabani <dazabani@igalia.com>
This change makes it so that `<iframe>` sanboxing is equivalent to the
one used for Content Security Policy, which is how the specification is
written. In addition, these sandboxing flags are passed through to
`<iframe>` `Document`s via `LoadData` and stored as
`Document::creation_sandboxing_flag_set`. The flags are used to
calculate the final `Document::active_sandboxing_flag_set` when loading
a `Document`.
This change makes it so that `<iframe>`s actually behave in a sandboxed
way, the same way that `Document`s with CSP configurations do. For
instance, now scripts and popups are blocked by default in `<iframe>`s
with the
`sandbox` attribute.
Testing: This causes many WPT tests to start to pass or to move from
ERROR to TIMEOUT or failing later. Some tests start to fail:
-
`/html/semantics/embedded-content/the-canvas-element/canvas-descendants-focusability-005.html`:
This test uses a combination of `<iframe allow>` and Canvas fallback
content, which we do not support.
-
`/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_navigate_other_frame_popup.sub.html`:
This test is now failing because the iframe is sanboxed but in the
ScriptThread now due to `allow-same-origin`. More implementation is
needed to add support for the "one permitted sandbox navigator concept."
Fixes: This is part of #31973.
---------
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Co-authored-by: Oriol Brufau <obrufau@igalia.com>
This change adds a new API to the `WebView` for capturing screenshots.
This makes it possible to:
- use the reftest waiting infrastructure via the API
easily.
- take more than a single screenshot in one Servo run.
- take screenshots, but still paint the `WebView` normally prior
to the moment that the screenshot is ready, instead of preventing
all non-screenshot-ready paints while taking a screenshot.
In addition, the previous infrastructure, the `wait_for_stable_image`
option is removed completely.
Testing: This change is tested by the passing of the WPT tests,
as they commonly use the screenshot feature.
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Co-authored-by: Delan Azabani <dazabani@igalia.com>
Add the prefix of "WebStorage" instead of "Storage" for all webstorage
spec related things. For example, a `struct` called `StorageManager`:
this could refer to either webstorage's thread manager or to the backend
for [the storage manager
interface](https://storage.spec.whatwg.org/#storagemanager). webstorage
is the full name of the spec, so I chose to keep that in the names of
files/structs to prevent confusion when storage manager is implemented.
Signed-off-by: Ashwin Naren <arihant2math@gmail.com>
When an `<iframe>` cannot scroll because the size of the frame is
greater than or
equal to the size of page contents, chain up the keyboard scroll
operation to the parent frame.
Testing: A new Servo-only WPT tests is added, though needs to be
manually
run with `--product servodriver`.
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Co-authored-by: Delan Azabani <dazabani@igalia.com>
Additionally also improve the warning message if the routed receiver
disconnects and exit the thread.
If the routed receiver disconnects, we can't receive any canvas messages
anymore, and any control messages can't remedy that, so we might as well
exit.
Testing: Channel changes are covered by existing tests. Exiting the
canvas thread if the routed thread disconnects is not tested, and needs
reviewer attention.
Part of https://github.com/servo/servo/issues/38912
Signed-off-by: Jonathan Schwender <schwenderjonathan@gmail.com>
This should be the final PR for the Hash Function series that is
trivial.
Of note: I decided to transform `HashMapTracedValues<Atom,..>` to use
FxBuildHasher. This is likely not going to improve performance as Atom's
already have a unique u32 that is used as the Hash but it safes a few
bytes for the RandomState that is normally in the HashMap.
Signed-off-by: Narfinger <Narfinger@users.noreply.github.com>
Testing: Hash function changes should not change functionality, we
slightly decrease the size and unit tests still work.
Signed-off-by: Narfinger <Narfinger@users.noreply.github.com>
FxHash is faster than FnvHash and SipHash for simple types up to at
least 64 bytes. The cryptographic guarantees are not needed for any
types changed here because they are simple ids.
This changes the types in script and net crates.
In a future PR we will change the remaining Fnv to be also Fx unless
there is a reason to keep them as Fnv.
Testing: Should not change functionality but unit test and wpt will find
it.
Signed-off-by: Narfinger <Narfinger@users.noreply.github.com>
FNV is faster for hashing less than 16 bytes of data and the
cryptographic properties of the default HashMap are not needed for the
various ids.
Testing: This does not change functionality.
Signed-off-by: Narfinger <Narfinger@users.noreply.github.com>
This PR **removes** `ScriptToConstellationMessage::ForwardToEmbedder`,
and replaces it with an explicit `ScriptToEmbedderChannel`. This new
channel is based on `GenericCallback` and in single-process mode will
directly send the message the to the embedder and wake it. In
multi-process mode, the message is routed via the ROUTER, since waking
is only possible from the same process currently. This means in
multi-process mode there are likely no direct perf benefits, since we
still need to hop the message over the ROUTER (instead of over the
constellation).
In single-process mode we can directly send the message to the embedder,
which should provide a noticable latency improvement in all cases where
script is blocked waiting on the embedder to reply.
This does not change the way the embedder receives messages - the
receiving end is unchanged.
## How was sending messages to the embedder working before?
1. Script wraps it's message to the embedder in
`ScriptToConstellationMessage::ForwardToEmbedder` and sends it to
constellation.
2. The [constellation event loop] receives the message in
[handle_request]
3. If deserialization fails, [an error is logged and the message is
ignored]
4. Since our message came from script, it is handle in
[handle_request_from_script]
5. The message is logged with trace log level
6. If the pipeline is closed, [a warning is logged and the message
ignored]
7. The wrapped `EmbedderMsg` [is forwarded to the embedder]. Sending the
message also invokes `wake()` on the embedder eventloop waker.
[constellation event loop]:
2e1b2e7260/components/constellation/constellation.rs (L755)
[handle request]:
2e1b2e7260/components/constellation/constellation.rs (L1182)
[an error is logged and the message is ignored]:
2e1b2e7260/components/constellation/constellation.rs (L1252)
[handle_request_from_script]:
https://github.com/servo/servo/blob/main/components/constellation/constellation.rs#L1590
[a warning is logged and the message ignored]:
2e1b2e7260/components/constellation/constellation.rs (L1599)
[is forwarded to the embedder]:
2e1b2e7260/components/constellation/constellation.rs (L1701)
Testing: Communication between Script and Embedder is extensive, so this
should be covered by existing tests.
Signed-off-by: Jonathan Schwender <schwenderjonathan@gmail.com>
