* Store list of contexts on the fiber
Currently, context can only be read by a special type of component,
ContextConsumer. We want to add support to all fibers, including
classes and functional components.
Each fiber may read from one or more contexts. To enable quick, mono-
morphic access of this list, we'll store them on a fiber property.
* Context.unstable_read
unstable_read can be called anywhere within the render phase. That
includes the render method, getDerivedStateFromProps, constructors,
functional components, and context consumer render props.
If it's called outside the render phase, an error is thrown.
* Remove vestigial context cursor
Wasn't being used.
* Split fiber.expirationTime into two separate fields
Currently, the `expirationTime` field represents the pending work of
both the fiber itself — including new props, state, and context — and of
any updates in that fiber's subtree.
This commit adds a second field called `childExpirationTime`. Now
`expirationTime` only represents the pending work of the fiber itself.
The subtree's pending work is represented by `childExpirationTime`.
The biggest advantage is it requires fewer checks to bailout on already
finished work. For most types of work, if the `expirationTime` does not
match the render expiration time, we can bailout immediately without
any further checks. This won't work for fibers that have
`shouldComponentUpdate` semantics (class components), for which we still
need to check for props and state changes explicitly.
* Performance nits
Optimize `readContext` for most common case
* Use %s in the console calls
* Add shared/warningWithStack
* Convert some warning callsites to warningWithStack
* Use warningInStack in shared utilities and remove unnecessary checks
* Replace more warning() calls with warningWithStack()
* Fixes after rebase + use warningWithStack in react
* Make warning have stack by default; warningWithoutStack opts out
* Forbid builds that may not use internals
* Revert newly added stacks
I changed my mind and want to keep this PR without functional changes. So we won't "fix" any warnings that are already missing stacks. We'll do it in follow-ups instead.
* Fix silly find/replace mistake
* Reorder imports
* Add protection against warning argument count mismatches
* Address review
* Use global state for `hasForceUpdate` instead of persisting to queue
Fixes a bug where `hasForceUpdate` was not reset on commit.
Ideally we'd use a tuple and return `hasForceUpdate` from
`processUpdateQueue`.
* Remove underscore and add comment
* Remove temporary variables
* Decouple update queue from Fiber type
The update queue is in need of a refactor. Recent bugfixes (#12528) have
exposed some flaws in how it's modeled. Upcoming features like Suspense
and [redacted] also rely on the update queue in ways that weren't
anticipated in the original design.
Major changes:
- Instead of boolean flags for `isReplace` and `isForceUpdate`, updates
have a `tag` field (like Fiber). This lowers the cost for adding new
types of updates.
- Render phase updates are special cased. Updates scheduled during
the render phase are dropped if the work-in-progress does not commit.
This is used for `getDerivedStateFrom{Props,Catch}`.
- `callbackList` has been replaced with a generic effect list. Aside
from callbacks, this is also used for `componentDidCatch`.
* Remove first class UpdateQueue types and use closures instead
I tried to avoid this at first, since we avoid it everywhere else in the Fiber
codebase, but since updates are not in a hot path, the trade off with file size
seems worth it.
* Store captured errors on a separate part of the update queue
This way they can be reused independently of updates like
getDerivedStateFromProps. This will be important for resuming.
* Revert back to storing hasForceUpdate on the update queue
Instead of using the effect tag. Ideally, this would be part of the
return type of processUpdateQueue.
* Rename UpdateQueue effect type back to Callback
I don't love this name either, but it's less confusing than UpdateQueue
I suppose. Conceptually, this is usually a callback: setState callbacks,
componentDidCatch. The only case that feels a bit weird is Timeouts,
which use this effect to attach a promise listener. I guess that kinda
fits, too.
* Call getDerivedStateFromProps every render, even if props did not change
Rather than enqueue a new setState updater for every props change, we
can skip the update queue entirely and merge the result into state at
the end. This makes more sense, since "receiving props" is not an event
that should be observed. It's still a bit weird, since eventually we do
persist the derived state (in other words, it accumulates).
* Store captured effects on separate list from "own" effects (callbacks)
For resuming, we need the ability to discard the "own" effects while
reusing the captured effects.
* Optimize for class components
Change `process` and `callback` to match the expected payload types
for class components. I had intended for the update queue to be reusable
for both class components and a future React API, but we'll likely have
to fork anyway.
* Only double-invoke render phase lifecycles functions in DEV
* Use global state to track currently processing queue in DEV
Andrew ClarkandGitHub
Dan AbramovandGitHub