perf(sessions): avoid redundant clone on skipCache loads

root · root · commit e05be9ffd09a · 2026-04-03T23:49:17.000Z
diff --git a/src/config/sessions.test.ts b/src/config/sessions.test.ts
@@ -761,4 +761,31 @@ describe("sessions", () => {
     expect(store[mainSessionKey]?.providerOverride).toBe("anthropic");
     expect(store[mainSessionKey]?.thinkingLevel).toBe("high");
   });
+
+  it("loadSessionStore skipCache returns a fresh mutable store without tainting cached reads", async () => {
+    const mainSessionKey = "agent:main:main";
+    const { storePath } = await createSessionStoreFixture({
+      prefix: "loadSessionStore-skip-cache-fresh",
+      entries: {
+        [mainSessionKey]: {
+          sessionId: "sess-1",
+          updatedAt: 123,
+          thinkingLevel: "low",
+        },
+      },
+    });
+
+    const fresh = loadSessionStore(storePath, { skipCache: true });
+    expect(fresh[mainSessionKey]?.thinkingLevel).toBe("low");
+
+    fresh[mainSessionKey] = {
+      ...fresh[mainSessionKey],
+      thinkingLevel: "high",
+    };
+
+    expect(loadSessionStore(storePath)[mainSessionKey]?.thinkingLevel).toBe("low");
+    expect(loadSessionStore(storePath, { skipCache: true })[mainSessionKey]?.thinkingLevel).toBe(
+      "low",
+    );
+  });
 });
diff --git a/src/config/sessions/store-load.ts b/src/config/sessions/store-load.ts
@@ -129,5 +129,12 @@ export function loadSessionStore(
     });
   }
 
+  // `skipCache` callers already forced a fresh disk load, so there is no shared
+  // cached object to protect here. Returning the parsed store directly avoids an
+  // extra full-store clone on hot read-modify-write paths.
+  if (opts.skipCache) {
+    return store;
+  }
+
   return structuredClone(store);
 }

Original file line number	Diff line number	Diff line change
`@@ -129,5 +129,12 @@ export function loadSessionStore(`
`129`	`129`	`});`
`130`	`130`	`}`
`131`	`131`
	`132`	+ // `skipCache` callers already forced a fresh disk load, so there is no shared
	`133`	`+ // cached object to protect here. Returning the parsed store directly avoids an`
	`134`	`+ // extra full-store clone on hot read-modify-write paths.`
	`135`	`+ if (opts.skipCache) {`
	`136`	`+ return store;`
	`137`	`+ }`
	`138`	`+`
`132`	`139`	`return structuredClone(store);`
`133`	`140`	`}`