parse function: improve memory management (#11370)

Co-authored-by: phryneas <phryneas@users.noreply.github.com>

.api-reports/api-report-react.md

@@ -1432,6 +1432,12 @@ type OperationVariables = Record<string, any>;
 // @public (undocumented)
 export function parser(document: DocumentNode): IDocumentDefinition;
 
+// @public (undocumented)
+export namespace parser {
+    var // (undocumented)
+    resetCache: () => void;
+}
+
 // @public (undocumented)
 type Path = ReadonlyArray<string | number>;
 

.api-reports/api-report-react_parser.md

@@ -34,6 +34,12 @@ export function operationName(type: DocumentType_2): string;
 // @public (undocumented)
 export function parser(document: DocumentNode): IDocumentDefinition;
 
+// @public (undocumented)
+export namespace parser {
+    var // (undocumented)
+    resetCache: () => void;
+}
+
 // @public (undocumented)
 export function verifyDocumentType(document: DocumentNode, type: DocumentType_2): void;
 

.api-reports/api-report.md

@@ -1931,6 +1931,12 @@ export function parseAndCheckHttpResponse(operations: Operation | Operation[]):
 // @public (undocumented)
 export function parser(document: DocumentNode): IDocumentDefinition;
 
+// @public (undocumented)
+export namespace parser {
+    var // (undocumented)
+    resetCache: () => void;
+}
+
 // @public (undocumented)
 export type Path = ReadonlyArray<string | number>;
 

.changeset/cold-llamas-turn.md

@@ -0,0 +1,8 @@
+---
+"@apollo/client": patch
+---
+
+`parse` function: improve memory management
+* use LRU `WeakCache` instead of `Map` to keep a limited number of parsed results
+* cache is initiated lazily, only when needed
+* expose `parse.resetCache()` method

.size-limits.json

@@ -1,4 +1,4 @@
 {
-  "dist/apollo-client.min.cjs": 38603,
+  "dist/apollo-client.min.cjs": 38625,
   "import { ApolloClient, InMemoryCache, HttpLink } from \"dist/index.js\" (production)": 32203
 }

src/react/parser/index.ts

@@ -1,3 +1,4 @@
+import { WeakCache } from "@wry/caches";
 import { invariant } from "../../utilities/globals/index.js";
 
 import type {
@@ -19,7 +20,16 @@ export interface IDocumentDefinition {
   variables: ReadonlyArray<VariableDefinitionNode>;
 }
 
-const cache = new Map();
+let cache:
+  | undefined
+  | WeakCache<
+      DocumentNode,
+      {
+        name: string;
+        type: DocumentType;
+        variables: readonly VariableDefinitionNode[];
+      }
+    >;
 
 export function operationName(type: DocumentType) {
   let name;
@@ -39,6 +49,10 @@ export function operationName(type: DocumentType) {
 
 // This parser is mostly used to safety check incoming documents.
 export function parser(document: DocumentNode): IDocumentDefinition {
+  if (!cache) {
+    cache =
+      new WeakCache(/** TODO: decide on a maximum size (will do all max sizes in a combined separate PR) */);
+  }
   const cached = cache.get(document);
   if (cached) return cached;
 
@@ -131,6 +145,10 @@ export function parser(document: DocumentNode): IDocumentDefinition {
   return payload;
 }
 
+parser.resetCache = () => {
+  cache = undefined;
+};
+
 export function verifyDocumentType(document: DocumentNode, type: DocumentType) {
   const operation = parser(document);
   const requiredOperationName = operationName(type);