fix(diagnosis): bound repeated profile display text before serialization

Signed-off-by: huangruiteng <huangrt01@163.com>

Author: huangruiteng

examples/personal-workspace-browser/performance-diagnosis.mjs

@@ -43,6 +43,11 @@ export const performanceDiagnosisScenario = {
       await input.setInputFiles({ name: "broken.json", mimeType: "application/json", buffer: Buffer.from('{"profiles":[]}') });
       await panel.getByRole("alert").waitFor();
       if (await panel.getByRole("table").count()) throw new Error("Failed capture retained the previous success");
+      const amplified = { ...capture, shared: { frames: [{ name: "x".repeat(8192) }] },
+        profiles: Array.from({ length: 65 }, () => ({ type: "sampled", name: "thread", unit: "milliseconds", startValue: 0, endValue: 1, samples: [[0]], weights: [1] })) };
+      await input.setInputFiles({ name: "many-threads.json", mimeType: "application/json", buffer: Buffer.from(JSON.stringify(amplified)) });
+      await panel.getByRole("alert").filter({ hasText: "summary text exceeds" }).waitFor();
+      if (await panel.getByRole("table").count()) throw new Error("Rejected summary was silently truncated");
       await input.setInputFiles({ name: "too-large.json", mimeType: "application/json", buffer: Buffer.alloc(16 * 1024 * 1024 + 1, 32) });
       await panel.getByRole("alert").filter({ hasText: "文件超过 16 MiB" }).waitFor();
       const clear = panel.getByRole("button", { name: "清除 / 取消", exact: true });

loopx/capabilities/performance_diagnosis/README.md

@@ -78,7 +78,9 @@ an empty successful diagnosis. Speedscope sampled/evented and V8 CPU time units
 are normalized to milliseconds. Threads/profiles stay separate, recursion is
 counted once per stack observation, and self and inclusive hotspots are distinct.
 Do not sum inclusive rows or thread weights to infer elapsed time.
-Input files are limited to 16 MiB; shorten captures beyond that limit. Larger
+Input files are limited to 16 MiB; shorten captures beyond that limit. Repeated
+profile names and hotspot labels share a 1 Mi-character display-text budget;
+oversized summaries are rejected explicitly, never silently truncated. Larger
 recordings reuse Effect's private local snapshot transport without raising the
 ordinary 2 MiB message limit or returning the raw profile in the summary.
 

loopx/capabilities/performance_diagnosis/README.zh-CN.md

@@ -48,7 +48,8 @@ Memray/V8 heap 用工具自己的 allocation reporter。其余工具是后续诊
 统一时间单位，分别返回 self/inclusive 热点。线程和 profile 保持独立，递归
 不会让同一个栈样本重复计时。不要把 inclusive 行相加，也不要把线程权重当作
 进程执行时长。
-输入限 16 MiB，超出时缩短采集；较大的录制复用 Effect 的私有本地快照传输，
+输入限 16 MiB，超出时缩短采集；重复展示的 profile 名称与热点标签共用 1 Mi 字符
+上限，超出时明确拒绝，不静默截断。较大的录制复用 Effect 的私有本地快照传输，
 不会提高普通命令的 2 MiB 传输上限，也不会把原始 profile 返回到展示结果。
 
 ## 验证结论

loopx/control_plane/capabilities/performance_profile.ts

@@ -33,7 +33,15 @@ export function summarizePerformanceProfile(input: unknown) {
   const raw = object(request.profile, "profile");
   const top = number(request.top ?? 15, "top");
   if (!Number.isInteger(top) || top < 1 || top > 50) throw new Error("top must be an integer from 1 to 50");
+  // Shared frames may appear in many profiles and both rankings. Bound their
+  // repeated display text before serializing or posting the complete summary.
+  let displayedCharacters = 0;
+  const reserveText = (value: string) => {
+    displayedCharacters += value.length;
+    if (displayedCharacters > 1_048_576) throw new Error("profile summary text exceeds 1 Mi characters; select fewer profiles or a smaller top count");
+  };
   const summarize = (name: string, frames: Frame[], unit: string, build: (add: (stack: number[], weight: number) => void) => void) => {
+    reserveText(name);
     const scale = ({nanoseconds: 1e-6, microseconds: 1e-3, milliseconds: 1, seconds: 1000} as Record<string, number>)[unit];
     if (scale === undefined) throw new Error(`unsupported time unit: ${unit}`);
     if (!frames.length || frames.length > 100_000) throw new Error("profile requires 1..100000 frames");
@@ -53,8 +61,10 @@ export function summarizePerformanceProfile(input: unknown) {
     if (!observationsCount || !weightTotal) throw new Error("profile contains no positive-duration observations");
     if (!Number.isFinite(weightTotal)) throw new Error("profile time overflows finite milliseconds");
     const rows = (kind: "self" | "inclusive") => observations.filter(row => row[kind] > 0)
-      .sort((a, b) => b[kind] - a[kind]).slice(0, top).map(row => ({...row.frame,
-        self_ms: row.self, inclusive_ms: row.inclusive}));
+      .sort((a, b) => b[kind] - a[kind]).slice(0, top).map(row => {
+        reserveText(row.frame.name); reserveText(row.frame.file ?? "");
+        return {...row.frame, self_ms: row.self, inclusive_ms: row.inclusive};
+      });
     return {name, observations: observationsCount, observed_weight_ms: weightTotal,
       stack_weight_ms: stackWeight, self_hotspots: rows("self"), inclusive_hotspots: rows("inclusive")};
   };

tests/control_plane_ts/performance_diagnosis.test.ts

@@ -63,6 +63,17 @@ test("evented profiles integrate stack intervals rather than counting opens", ()
   assert.equal(main.inclusive_hotspots[0]!.inclusive_ms, 6);
 });
 
+test("shared long names cannot multiply a small capture into an unbounded summary", () => {
+  const name = "x".repeat(8192);
+  const profile = {$schema: sampled().$schema, shared: {frames: [{name}]},
+    profiles: Array.from({length: 65}, () => ({type: "sampled", name: "thread",
+      unit: "milliseconds", startValue: 0, endValue: 1, samples: [[0]], weights: [1]}))};
+  assert.ok(JSON.stringify(profile).length < 20_000);
+  assert.throws(() => inspect({profile}), /summary text exceeds/);
+  profile.profiles.length = 1;
+  assert.equal(inspect({profile}).profiles[0]!.self_hotspots[0]!.name, name);
+});
+
 test("event ordering, balanced exits and temporal units remain required", () => {
   const profile = {$schema: sampled().$schema, shared: sampled().shared,
     profiles: [{type: "evented", unit: "milliseconds", startValue: 0, endValue: 8,