perf: speed bounded projections and correct click timing

autoresearch.sh

@@ -0,0 +1,69 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+repo_root="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+cd "$repo_root"
+
+if [[ "$(node -p 'process.versions.node.split(".")[0]')" != "24" ]]; then
+  echo "autoresearch requires Node 24; found $(node --version)" >&2
+  exit 1
+fi
+for command_name in pnpm tee timeout; do
+  if ! command -v "$command_name" >/dev/null 2>&1; then
+    echo "missing required command: $command_name" >&2
+    exit 1
+  fi
+done
+if [[ ! -d node_modules ]]; then
+  echo "dependencies are missing; run pnpm install --frozen-lockfile before autoresearch" >&2
+  exit 1
+fi
+
+entry_count="${T4_PERF_ENTRY_COUNT:-10000}"
+event_count="${T4_PERF_EVENT_COUNT:-100000}"
+repetitions="${T4_PERF_REPETITIONS:-7}"
+warmups="${T4_PERF_WARMUPS:-1}"
+timeout_seconds="${T4_AUTORESEARCH_TIMEOUT_SECONDS:-120}"
+run_id="$(date -u +%Y%m%dT%H%M%SZ)-$$"
+output_dir="test-results/perf/autoresearch/$run_id"
+mkdir -p "$output_dir"
+log_path="$output_dir/run.log"
+
+runner=()
+cpu_affinity="unbound"
+if command -v taskset >/dev/null 2>&1; then
+  requested_cpu="${T4_AUTORESEARCH_CPU:-}"
+  if [[ -z "$requested_cpu" ]]; then
+    allowed_affinity="$(taskset -pc "$$" 2>/dev/null || true)"
+    allowed_affinity="${allowed_affinity##*: }"
+    first_affinity_range="${allowed_affinity%%,*}"
+    requested_cpu="${first_affinity_range%%-*}"
+  fi
+  if [[ -n "$requested_cpu" ]] && taskset -c "$requested_cpu" true 2>/dev/null; then
+    cpu_affinity="$requested_cpu"
+    runner=(taskset -c "$cpu_affinity")
+  elif [[ -n "${T4_AUTORESEARCH_CPU:-}" ]]; then
+    echo "T4_AUTORESEARCH_CPU is outside this process's allowed CPU set" >&2
+    exit 1
+  fi
+fi
+
+export CI=1
+export NODE_OPTIONS="${NODE_OPTIONS:+$NODE_OPTIONS }--expose-gc"
+export T4_PERF_ENTRY_COUNT="$entry_count"
+export T4_PERF_EVENT_COUNT="$event_count"
+export T4_PERF_REPETITIONS="$repetitions"
+export T4_PERF_WARMUPS="$warmups"
+export T4_PERF_MACHINE_LABEL="${T4_PERF_MACHINE_LABEL:-linux-vps-x64}"
+export T4_PERF_OUTPUT_DIR="$output_dir"
+export T4_AUTORESEARCH_TIMEOUT_SECONDS_RESOLVED="$timeout_seconds"
+export T4_AUTORESEARCH_CPU_AFFINITY_RESOLVED="$cpu_affinity"
+
+{
+  "${runner[@]}" timeout "$timeout_seconds" pnpm exec vp test run packages/client/test/projection.test.ts
+  "${runner[@]}" timeout "$timeout_seconds" pnpm exec vp test run scripts/perf/core.test.ts
+  node scripts/perf/autoresearch-report.mjs "$output_dir/latest-core.json"
+  printf 'ASI timeout_seconds=%s\n' "$timeout_seconds"
+  printf 'ASI cpu_affinity=%s\n' "$cpu_affinity"
+  printf 'ASI log=%s\n' "$log_path"
+} 2>&1 | tee "$log_path"

docs/PERFORMANCE.md

@@ -29,6 +29,14 @@ settle before replacing the warm copy. The tail paint sample is taken after the
 that copy and two more browser animation frames have elapsed. These numbers show where a slowdown
 occurs; they are not a claim about a physical display's pixel response time.
 
+Session-click phases have two boundaries. Metrics named `browser.session-dom-click-to-*` start at
+the actual DOM click received by the application and are the primary product-performance signal.
+The older `browser.session-click-to-*` metrics start immediately before Playwright asks Chromium to
+click, so they also include Playwright's actionability checks, pointer movement, and input delivery.
+The separate `browser.playwright-session-click-command-to-dom-click` metric makes that
+automation-only time visible. Do not attribute it to application rendering or use it alone to judge
+a product optimization.
+
 `ui.mount-bounded-10k` stops after the original mount assertions, before the paint-only wait and
 phase-file write. `ui.playwright-scenario-instrumented` records the full instrumented test duration
 under a new name so paint instrumentation cannot silently change an existing comparison boundary.

e2e/remote-app.spec.ts

@@ -545,6 +545,11 @@ test("@soak mounts the bounded tail of a 10k history on a phone viewport", async
       };
       requestAnimationFrame(inspect);
     });
+    await rail.locator('[data-session-row="host-history/session-history"]').evaluate((element) => {
+      element.addEventListener("click", () => {
+        Object.assign(window, { __t4SessionDomClickAt: performance.now() });
+      }, { capture: true, once: true });
+    });
     const sessionClickStartedAt = await page.evaluate(() => performance.now());
     await rail.locator('[data-session-row="host-history/session-history"]').click();
 
@@ -587,6 +592,10 @@ test("@soak mounts the bounded tail of a 10k history on a phone viewport", async
     ) {
       throw new Error("browser paint observer returned incomplete phases");
     }
+    const sessionDomClickAt = await page.evaluate(() => (
+      window as typeof window & { __t4SessionDomClickAt?: number }
+    ).__t4SessionDomClickAt);
+    if (sessionDomClickAt === undefined) throw new Error("session DOM click timestamp was not captured");
     const phaseOutput = process.env.T4_PERF_PHASE_OUTPUT;
     if (phaseOutput !== undefined) {
       await writeFile(
@@ -595,6 +604,11 @@ test("@soak mounts the bounded tail of a 10k history on a phone viewport", async
           mountDuration,
           navigationDomContentLoaded: navigationTiming.domContentLoaded,
           connectedAfterDomContentLoaded: connectedAt - navigationTiming.domContentLoaded,
+          sessionClickCommandToDomClick: sessionDomClickAt - sessionClickStartedAt,
+          sessionDomClickToTranscriptVisible: phases.transcriptVisibleAt - sessionDomClickAt,
+          sessionDomClickToTailAligned: phases.tailAlignedAt - sessionDomClickAt,
+          sessionDomClickToRealListVisible: phases.realListVisibleAt - sessionDomClickAt,
+          sessionDomClickToTailPainted: phases.tailPaintedAt - sessionDomClickAt,
           sessionClickToTranscriptVisible: phases.transcriptVisibleAt - sessionClickStartedAt,
           sessionClickToTailAligned: phases.tailAlignedAt - sessionClickStartedAt,
           tailAlignedToRealListVisible: phases.realListVisibleAt - phases.tailAlignedAt,

packages/client/src/projection.ts

@@ -591,6 +591,15 @@ function touch(
   options: Required<ProjectionOptions>,
 ): ProjectionSnapshot {
   const existing = snapshot.sessions.get(sessionKey);
+  if (
+    existing !== undefined &&
+    snapshot.lru.at(-1) === sessionKey &&
+    snapshot.lru.length <= options.maxWarmSessions &&
+    snapshot.activeSessionKey !== undefined &&
+    snapshot.lru.includes(snapshot.activeSessionKey)
+  ) {
+    return snapshot;
+  }
   const lru = [...snapshot.lru.filter((item) => item !== sessionKey), sessionKey];
   let sessions = snapshot.sessions;
   if (existing === undefined)
@@ -619,15 +628,19 @@ function withSession(
   sessionKey: string,
   update: (session: SessionProjection) => SessionProjection,
   options: Required<ProjectionOptions>,
+  arrivalOrdinal?: number,
 ): ProjectionSnapshot {
   const warmed = touch(snapshot, sessionKey, options);
   const current = warmed.sessions.get(sessionKey)!;
   const updated = update(current);
-  if (updated === current) return warmed;
-  return Object.freeze({
-    ...warmed,
-    sessions: mapWith(warmed.sessions, sessionKey, Object.freeze(updated)),
-  });
+  if (updated === current) {
+    if (arrivalOrdinal === undefined || warmed.arrivalOrdinal === arrivalOrdinal) return warmed;
+    return Object.freeze({ ...warmed, arrivalOrdinal });
+  }
+  const sessions = mapWith(warmed.sessions, sessionKey, Object.freeze(updated));
+  return arrivalOrdinal === undefined
+    ? Object.freeze({ ...warmed, sessions })
+    : Object.freeze({ ...warmed, sessions, arrivalOrdinal });
 }
 function updateRoot(
   snapshot: ProjectionSnapshot,
@@ -1103,10 +1116,9 @@ function applyProjectionInput(
           });
         },
         config,
+        frame.type === "event" ? eventArrivalOrdinal : undefined,
       );
-      return frame.type === "event"
-        ? Object.freeze({ ...next, arrivalOrdinal: eventArrivalOrdinal })
-        : next;
+      return next;
     }
     case "gap": {
       const sessionKey = key(String(frame.hostId), String(frame.sessionId));

packages/client/src/transcript-retention.ts

@@ -46,25 +46,29 @@ const SECRET_KEY = /token|secret|password|credential|authorization|cookie|privat
 
 /** Exact byte totals for immutable values created by this module. */
 const retainedJsonByteCache = new WeakMap<object, number>();
-
-const IMPORTANT_KEYS = [
-  "type",
-  "images",
-  "role",
-  "text",
-  "reasoning",
-  "tool",
-  "title",
-  "args",
-  "result",
-  "details",
-  "customType",
-  "customDetails",
-  "output",
-  "stdout",
-  "stderr",
-  "content",
-] as const;
+const UTF8_ENCODER = new TextEncoder();
+
+const IMPORTANT_KEY_PRIORITY: Readonly<Record<string, number>> = Object.freeze(
+  Object.assign(Object.create(null) as Record<string, number>, {
+    type: 0,
+    images: 1,
+    role: 2,
+    text: 3,
+    reasoning: 4,
+    tool: 5,
+    title: 6,
+    args: 7,
+    result: 8,
+    details: 9,
+    customType: 10,
+    customDetails: 11,
+    output: 12,
+    stdout: 13,
+    stderr: 14,
+    content: 15,
+  }),
+);
+const IMPORTANT_KEY_COUNT = Math.max(...Object.values(IMPORTANT_KEY_PRIORITY)) + 1;
 
 interface SanitizedNode {
   readonly value: unknown;
@@ -97,14 +101,53 @@ export type RetainedTranscriptEvent = Extract<
   { kind: "snapshot" | "entry" | "event" | "agent.transcript" | "gap" }
 >;
 
+function jsonStringBytes(value: string): number {
+  let bytes = 2;
+  for (let index = 0; index < value.length; index += 1) {
+    const code = value.charCodeAt(index);
+    if (
+      code === 0x22 ||
+      code === 0x5c ||
+      code === 0x08 ||
+      code === 0x09 ||
+      code === 0x0a ||
+      code === 0x0c ||
+      code === 0x0d
+    ) {
+      bytes += 2;
+    } else if (code < 0x20) {
+      bytes += 6;
+    } else if (code < 0x80) {
+      bytes += 1;
+    } else if (code < 0x800) {
+      bytes += 2;
+    } else if (code >= 0xd800 && code <= 0xdbff) {
+      const next = value.charCodeAt(index + 1);
+      if (next >= 0xdc00 && next <= 0xdfff) {
+        bytes += 4;
+        index += 1;
+      } else {
+        bytes += 6;
+      }
+    } else {
+      bytes += code >= 0xdc00 && code <= 0xdfff ? 6 : 3;
+    }
+  }
+  return bytes;
+}
+
 export function retainedJsonBytes(value: unknown): number {
-  if (value !== null && (typeof value === "object" || typeof value === "function")) {
+  if (typeof value === "string") return jsonStringBytes(value);
+  if (typeof value === "number") return Number.isFinite(value) ? String(value).length : 4;
+  if (typeof value === "boolean") return value ? 4 : 5;
+  if (value === null) return 4;
+  if (typeof value === "object" || typeof value === "function") {
     const cached = retainedJsonByteCache.get(value);
     if (cached !== undefined) return cached;
   }
   const serialized = JSON.stringify(value);
   if (serialized === undefined) return 0;
-  return new TextEncoder().encode(serialized).byteLength;
+  return UTF8_ENCODER.encode(serialized).byteLength;
 }
 
 function rememberRetainedJsonBytes<T>(value: T, bytes: number): T {
@@ -131,9 +174,8 @@ function boundedInteger(value: number | undefined, fallback: number, ceiling: nu
  */
 export function retainedText(value: string, maxJsonBytes: number): string {
   const budget = Math.max(2, Math.floor(maxJsonBytes));
-  if (retainedJsonBytes(value) <= budget && retainedJsonBytes(value) <= MAX_RETAINED_VALUE_STRING_BYTES + 2) {
-    return value;
-  }
+  const valueBytes = retainedJsonBytes(value);
+  if (valueBytes <= budget && valueBytes <= MAX_RETAINED_VALUE_STRING_BYTES + 2) return value;
 
   const available = Math.max(0, Math.min(value.length, MAX_RETAINED_VALUE_STRING_BYTES));
   let low = 0;
@@ -156,19 +198,26 @@ export function retainedText(value: string, maxJsonBytes: number): string {
 }
 
 function orderedEntries(value: Record<string, unknown>): Array<[string, unknown]> {
-  const priority = new Map<string, number>(IMPORTANT_KEYS.map((key, index) => [key, index]));
-  return Object.entries(value).sort(([left], [right]) => {
-    const leftPriority = priority.get(left) ?? IMPORTANT_KEYS.length;
-    const rightPriority = priority.get(right) ?? IMPORTANT_KEYS.length;
-    return leftPriority - rightPriority;
-  });
+  const entries = Object.entries(value);
+  for (let index = 1; index < entries.length; index += 1) {
+    const previous = IMPORTANT_KEY_PRIORITY[entries[index - 1]![0]] ?? IMPORTANT_KEY_COUNT;
+    const current = IMPORTANT_KEY_PRIORITY[entries[index]![0]] ?? IMPORTANT_KEY_COUNT;
+    if (previous <= current) continue;
+    entries.sort(([left], [right]) => {
+      const leftPriority = IMPORTANT_KEY_PRIORITY[left] ?? IMPORTANT_KEY_COUNT;
+      const rightPriority = IMPORTANT_KEY_PRIORITY[right] ?? IMPORTANT_KEY_COUNT;
+      return leftPriority - rightPriority;
+    });
+    break;
+  }
+  return entries;
 }
 
 function sanitizeNode(
   value: unknown,
   budget: number,
   depth: number,
-  ancestors: ReadonlySet<object>,
+  ancestors: Set<object>,
   imageBlock = false,
 ): SanitizedNode | undefined {
   if (budget < 1 || value === undefined) return undefined;
@@ -190,19 +239,19 @@ function sanitizeNode(
     return undefined;
   }
 
-  const nextAncestors = new Set(ancestors);
-  nextAncestors.add(value);
+  ancestors.add(value);
   if (Array.isArray(value)) {
     let bytes = 2;
     const output: unknown[] = [];
     for (const item of value.slice(0, MAX_RETAINED_VALUE_ARRAY_ITEMS)) {
       const separator = output.length === 0 ? 0 : 1;
-      const child = sanitizeNode(item, budget - bytes - separator, depth + 1, nextAncestors);
+      const child = sanitizeNode(item, budget - bytes - separator, depth + 1, ancestors);
       if (child === undefined) continue;
       output.push(child.value);
       bytes += separator + child.bytes;
       if (bytes >= budget) break;
     }
+    ancestors.delete(value);
     return bytes <= budget ? { value: Object.freeze(output), bytes } : undefined;
   }
 
@@ -231,7 +280,7 @@ function sanitizeNode(
       item,
       budget - bytes - fixedBytes,
       depth + 1,
-      nextAncestors,
+      ancestors,
       sourceIsImageBlock,
     );
     if (child === undefined) continue;
@@ -240,6 +289,7 @@ function sanitizeNode(
     bytes += fixedBytes + child.bytes;
     if (bytes >= budget) break;
   }
+  ancestors.delete(value);
   return bytes <= budget ? { value: Object.freeze(output), bytes } : undefined;
 }
 
@@ -378,7 +428,8 @@ export function appendRetainedValue<T>(
     retainedCount -= 1;
   }
 
-  const candidates = [...values.slice(firstPriorIndex), value];
+  const candidates = values.slice(firstPriorIndex) as T[];
+  candidates.push(value);
   bytes += retainedArrayItemBytes(value) + (retainedCount === 0 ? 0 : 1);
   retainedCount += 1;
 
@@ -390,7 +441,9 @@ export function appendRetainedValue<T>(
     firstRetainedIndex += 1;
   }
 
-  const retained = Object.freeze(candidates.slice(firstRetainedIndex));
+  const retained = Object.freeze(
+    firstRetainedIndex === 0 ? candidates : candidates.slice(firstRetainedIndex),
+  );
   return rememberRetainedJsonBytes(retained, bytes);
 }