From 18f929587bad5469f4783a0444f97c786c05ac25 Mon Sep 17 00:00:00 2001
From: Shu Ding <g@shud.in>
Date: Tue, 28 Dec 2021 01:19:27 +0100
Subject: [PATCH] merge mutation states (#1748)

---
 src/use-swr.ts               | 9 ++-------
 src/utils/broadcast-state.ts | 2 +-
 src/utils/cache.ts           | 4 ++--
 src/utils/global-state.ts    | 3 +--
 src/utils/mutate.ts          | 4 ++--
 5 files changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/use-swr.ts b/src/use-swr.ts
index a4c4421a1..52e09bc3a 100644
--- a/src/use-swr.ts
+++ b/src/use-swr.ts
@@ -49,13 +49,8 @@ export const useSWRHandler = <Data = any, Error = any>(
     refreshWhenOffline
   } = config
 
-  const [
-    EVENT_REVALIDATORS,
-    STATE_UPDATERS,
-    MUTATION_TS,
-    MUTATION_END_TS,
-    CONCURRENT_REQUESTS
-  ] = SWRGlobalState.get(cache) as GlobalState
+  const [EVENT_REVALIDATORS, STATE_UPDATERS, MUTATION, CONCURRENT_REQUESTS] =
+    SWRGlobalState.get(cache) as GlobalState
 
   // `key` is the identifier of the SWR `data` state, `keyErr` and
   // `keyValidating` are identifiers of `error` and `isValidating`,
diff --git a/src/utils/broadcast-state.ts b/src/utils/broadcast-state.ts
index 939cca939..9725995ef 100644
--- a/src/utils/broadcast-state.ts
+++ b/src/utils/broadcast-state.ts
@@ -11,7 +11,7 @@ export const broadcastState: Broadcaster = (
   revalidate,
   broadcast = true
 ) => {
-  const [EVENT_REVALIDATORS, STATE_UPDATERS, , , CONCURRENT_REQUESTS] =
+  const [EVENT_REVALIDATORS, STATE_UPDATERS, , CONCURRENT_REQUESTS] =
     SWRGlobalState.get(cache) as GlobalState
   const revalidators = EVENT_REVALIDATORS[key]
   const updaters = STATE_UPDATERS[key]
diff --git a/src/utils/cache.ts b/src/utils/cache.ts
index 04d10fbc2..7ff30f4a8 100644
--- a/src/utils/cache.ts
+++ b/src/utils/cache.ts
@@ -48,7 +48,7 @@ export const initCache = <Data = any>(
     let unmount = noop
 
     // Update the state if it's new, or the provider has been extended.
-    SWRGlobalState.set(provider, [EVENT_REVALIDATORS, {}, {}, {}, {}, mutate])
+    SWRGlobalState.set(provider, [EVENT_REVALIDATORS, {}, {}, {}, mutate])
 
     // This is a new provider, we need to initialize it and setup DOM events
     // listeners for `focus` and `reconnect` actions.
@@ -96,5 +96,5 @@ export const initCache = <Data = any>(
     return [provider, mutate, unmount]
   }
 
-  return [provider, (SWRGlobalState.get(provider) as GlobalState)[5]]
+  return [provider, (SWRGlobalState.get(provider) as GlobalState)[4]]
 }
diff --git a/src/utils/global-state.ts b/src/utils/global-state.ts
index a57d4d42d..2116cce99 100644
--- a/src/utils/global-state.ts
+++ b/src/utils/global-state.ts
@@ -8,8 +8,7 @@ import {
 export type GlobalState = [
   Record<string, RevalidateCallback[]>, // EVENT_REVALIDATORS
   Record<string, StateUpdateCallback[]>, // STATE_UPDATERS
-  Record<string, number>, // MUTATION_TS
-  Record<string, number>, // MUTATION_END_TS
+  Record<string, [number, number]>, // MUTATION: [ts, end_ts]
   Record<string, [any, number]>, // CONCURRENT_REQUESTS: [data, ts]
   ScopedMutator // Mutator
 ]
diff --git a/src/utils/mutate.ts b/src/utils/mutate.ts
index 74be9e8ee..fa62069fa 100644
--- a/src/utils/mutate.ts
+++ b/src/utils/mutate.ts
@@ -50,8 +50,8 @@ export const internalMutate = async <Data>(
   let error: unknown
 
   // Update global timestamps.
-  const beforeMutationTs = (MUTATION_TS[key] = getTimestamp())
-  MUTATION_END_TS[key] = 0
+  const beforeMutationTs = getTimestamp()
+  MUTATION[key] = [beforeMutationTs, 0]
   const hasOptimisticData = !isUndefined(optimisticData)
   const rollbackData = cache.get(key)