Core Data: Share parsed blocks cache between resolver and editor hook

packages/core-data/src/hooks/use-entity-block-editor.js

@@ -11,9 +11,9 @@ import { parse, __unstableSerializeAndClean } from '@wordpress/blocks';
 import { STORE_NAME } from '../name';
 import useEntityId from './use-entity-id';
 import { updateFootnotesFromMeta } from '../footnotes';
+import { parsedBlocksCache, getCacheKey } from '../parsed-blocks-cache';
 
 const EMPTY_ARRAY = [];
-const parsedBlocksCache = new Map();
 
 /**
  * Hook that returns block content getters and setters for
@@ -69,7 +69,7 @@ export default function useEntityBlockEditor( kind, name, { id: _id } = {} ) {
 
 		// Cache parsed blocks by entity identity. Store the content
 		// alongside the blocks so we can validate it hasn't changed.
-		const cacheKey = `${ kind }:${ name }:${ id }`;
+		const cacheKey = getCacheKey( kind, name, id );
 		const cached = parsedBlocksCache.get( cacheKey );
 		let _blocks;
 

packages/core-data/src/parsed-blocks-cache.js

@@ -0,0 +1,12 @@
+/**
+ * Shared cache of blocks parsed from an entity's `content` string, keyed by
+ * `kind:name:id`. Populated both eagerly by the `getEntityRecord` resolver
+ * (when the sync manager parses content for transient edits) and lazily by
+ * `useEntityBlockEditor`. The stored `content` string acts as a validator so
+ * stale entries are discarded when the underlying record changes.
+ */
+export const parsedBlocksCache = new Map();
+
+export function getCacheKey( kind, name, id ) {
+	return `${ kind }:${ name }:${ id }`;
+}

packages/core-data/src/resolvers.js

@@ -28,6 +28,7 @@ import {
 } from './utils';
 import { fetchBlockPatterns } from './fetch';
 import { restoreSelection, getSelectionHistory } from './utils/crdt-selection';
+import { parsedBlocksCache, getCacheKey } from './parsed-blocks-cache';
 
 /**
  * Requests authors from the REST API.
@@ -180,6 +181,18 @@ export const getEntityRecord =
 							transientConfig.read( recordWithTransients );
 					} );
 
+				// Share the parsed blocks with `useEntityBlockEditor` so the
+				// editor doesn't re-parse the same `content` string.
+				if (
+					recordWithTransients.blocks &&
+					typeof recordWithTransients.content?.raw === 'string'
+				) {
+					parsedBlocksCache.set( getCacheKey( kind, name, key ), {
+						content: recordWithTransients.content.raw,
+						blocks: recordWithTransients.blocks,
+					} );
+				}
+
 				// Load the entity record for syncing. Do not await promise.
 				void getSyncManager()?.load(
 					entityConfig.syncConfig,