Less indirection in SchedulerWithReactIntegration

I originally kept the React PriorityLevel and Scheduler PriorityLevel
types separate in case there was a versioning mismatch between the
two modules. However, it looks like we're going to keep the Scheduler
module private in the short to medium term, and longer term the public
interface will match `postTask`. So I've removed the extra indirection
(the switch statements that convert between the two types).

Author: acdlite

packages/react-reconciler/src/SchedulerWithReactIntegration.new.js

@@ -59,15 +59,12 @@ type SchedulerCallbackOptions = {timeout?: number, ...};
 
 const fakeCallbackNode = {};
 
-// Except for NoPriority, these correspond to Scheduler priorities. We use
-// ascending numbers so we can compare them like numbers. They start at 90 to
-// avoid clashing with Scheduler's priorities.
-export const ImmediatePriority: ReactPriorityLevel = 99;
-export const UserBlockingPriority: ReactPriorityLevel = 98;
-export const NormalPriority: ReactPriorityLevel = 97;
-export const LowPriority: ReactPriorityLevel = 96;
-export const IdlePriority: ReactPriorityLevel = 95;
-// NoPriority is the absence of priority. Also React-only.
+export const ImmediatePriority: ReactPriorityLevel = Scheduler_ImmediatePriority;
+export const UserBlockingPriority: ReactPriorityLevel = Scheduler_UserBlockingPriority;
+export const NormalPriority: ReactPriorityLevel = Scheduler_NormalPriority;
+export const LowPriority: ReactPriorityLevel = Scheduler_LowPriority;
+export const IdlePriority: ReactPriorityLevel = Scheduler_IdlePriority;
+// NoPriority is the absence of priority. React-only.
 export const NoPriority: ReactPriorityLevel = 90;
 
 export const shouldYield = Scheduler_shouldYield;
@@ -78,66 +75,25 @@ export const requestPaint =
 let syncQueue: Array<SchedulerCallback> | null = null;
 let immediateQueueCallbackNode: mixed | null = null;
 let isFlushingSyncQueue: boolean = false;
-const initialTimeMs: number = Scheduler_now();
-
-// If the initial timestamp is reasonably small, use Scheduler's `now` directly.
-// This will be the case for modern browsers that support `performance.now`. In
-// older browsers, Scheduler falls back to `Date.now`, which returns a Unix
-// timestamp. In that case, subtract the module initialization time to simulate
-// the behavior of performance.now and keep our times small enough to fit
-// within 32 bits.
-// TODO: Consider lifting this into Scheduler.
-export const now =
-  initialTimeMs < 10000 ? Scheduler_now : () => Scheduler_now() - initialTimeMs;
 
-export function getCurrentPriorityLevel(): ReactPriorityLevel {
-  switch (Scheduler_getCurrentPriorityLevel()) {
-    case Scheduler_ImmediatePriority:
-      return ImmediatePriority;
-    case Scheduler_UserBlockingPriority:
-      return UserBlockingPriority;
-    case Scheduler_NormalPriority:
-      return NormalPriority;
-    case Scheduler_LowPriority:
-      return LowPriority;
-    case Scheduler_IdlePriority:
-      return IdlePriority;
-    default:
-      invariant(false, 'Unknown priority level.');
-  }
-}
+export const now = Scheduler_now;
 
-function reactPriorityToSchedulerPriority(reactPriorityLevel) {
-  switch (reactPriorityLevel) {
-    case ImmediatePriority:
-      return Scheduler_ImmediatePriority;
-    case UserBlockingPriority:
-      return Scheduler_UserBlockingPriority;
-    case NormalPriority:
-      return Scheduler_NormalPriority;
-    case LowPriority:
-      return Scheduler_LowPriority;
-    case IdlePriority:
-      return Scheduler_IdlePriority;
-    default:
-      invariant(false, 'Unknown priority level.');
-  }
+export function getCurrentPriorityLevel(): ReactPriorityLevel {
+  return Scheduler_getCurrentPriorityLevel();
 }
 
 export function runWithPriority<T>(
-  reactPriorityLevel: ReactPriorityLevel,
+  priorityLevel: ReactPriorityLevel,
   fn: () => T,
 ): T {
-  const priorityLevel = reactPriorityToSchedulerPriority(reactPriorityLevel);
   return Scheduler_runWithPriority(priorityLevel, fn);
 }
 
 export function scheduleCallback(
-  reactPriorityLevel: ReactPriorityLevel,
+  priorityLevel: ReactPriorityLevel,
   callback: SchedulerCallback,
   options: SchedulerCallbackOptions | void | null,
 ) {
-  const priorityLevel = reactPriorityToSchedulerPriority(reactPriorityLevel);
   return Scheduler_scheduleCallback(priorityLevel, callback, options);
 }
 

packages/react-reconciler/src/SchedulerWithReactIntegration.old.js

@@ -59,15 +59,12 @@ type SchedulerCallbackOptions = {timeout?: number, ...};
 
 const fakeCallbackNode = {};
 
-// Except for NoPriority, these correspond to Scheduler priorities. We use
-// ascending numbers so we can compare them like numbers. They start at 90 to
-// avoid clashing with Scheduler's priorities.
-export const ImmediatePriority: ReactPriorityLevel = 99;
-export const UserBlockingPriority: ReactPriorityLevel = 98;
-export const NormalPriority: ReactPriorityLevel = 97;
-export const LowPriority: ReactPriorityLevel = 96;
-export const IdlePriority: ReactPriorityLevel = 95;
-// NoPriority is the absence of priority. Also React-only.
+export const ImmediatePriority: ReactPriorityLevel = Scheduler_ImmediatePriority;
+export const UserBlockingPriority: ReactPriorityLevel = Scheduler_UserBlockingPriority;
+export const NormalPriority: ReactPriorityLevel = Scheduler_NormalPriority;
+export const LowPriority: ReactPriorityLevel = Scheduler_LowPriority;
+export const IdlePriority: ReactPriorityLevel = Scheduler_IdlePriority;
+// NoPriority is the absence of priority. React-only.
 export const NoPriority: ReactPriorityLevel = 90;
 
 export const shouldYield = Scheduler_shouldYield;
@@ -78,66 +75,25 @@ export const requestPaint =
 let syncQueue: Array<SchedulerCallback> | null = null;
 let immediateQueueCallbackNode: mixed | null = null;
 let isFlushingSyncQueue: boolean = false;
-const initialTimeMs: number = Scheduler_now();
-
-// If the initial timestamp is reasonably small, use Scheduler's `now` directly.
-// This will be the case for modern browsers that support `performance.now`. In
-// older browsers, Scheduler falls back to `Date.now`, which returns a Unix
-// timestamp. In that case, subtract the module initialization time to simulate
-// the behavior of performance.now and keep our times small enough to fit
-// within 32 bits.
-// TODO: Consider lifting this into Scheduler.
-export const now =
-  initialTimeMs < 10000 ? Scheduler_now : () => Scheduler_now() - initialTimeMs;
 
-export function getCurrentPriorityLevel(): ReactPriorityLevel {
-  switch (Scheduler_getCurrentPriorityLevel()) {
-    case Scheduler_ImmediatePriority:
-      return ImmediatePriority;
-    case Scheduler_UserBlockingPriority:
-      return UserBlockingPriority;
-    case Scheduler_NormalPriority:
-      return NormalPriority;
-    case Scheduler_LowPriority:
-      return LowPriority;
-    case Scheduler_IdlePriority:
-      return IdlePriority;
-    default:
-      invariant(false, 'Unknown priority level.');
-  }
-}
+export const now = Scheduler_now;
 
-function reactPriorityToSchedulerPriority(reactPriorityLevel) {
-  switch (reactPriorityLevel) {
-    case ImmediatePriority:
-      return Scheduler_ImmediatePriority;
-    case UserBlockingPriority:
-      return Scheduler_UserBlockingPriority;
-    case NormalPriority:
-      return Scheduler_NormalPriority;
-    case LowPriority:
-      return Scheduler_LowPriority;
-    case IdlePriority:
-      return Scheduler_IdlePriority;
-    default:
-      invariant(false, 'Unknown priority level.');
-  }
+export function getCurrentPriorityLevel(): ReactPriorityLevel {
+  return Scheduler_getCurrentPriorityLevel();
 }
 
 export function runWithPriority<T>(
-  reactPriorityLevel: ReactPriorityLevel,
+  priorityLevel: ReactPriorityLevel,
   fn: () => T,
 ): T {
-  const priorityLevel = reactPriorityToSchedulerPriority(reactPriorityLevel);
   return Scheduler_runWithPriority(priorityLevel, fn);
 }
 
 export function scheduleCallback(
-  reactPriorityLevel: ReactPriorityLevel,
+  priorityLevel: ReactPriorityLevel,
   callback: SchedulerCallback,
   options: SchedulerCallbackOptions | void | null,
 ) {
-  const priorityLevel = reactPriorityToSchedulerPriority(reactPriorityLevel);
   return Scheduler_scheduleCallback(priorityLevel, callback, options);
 }