perf(boot): load isogit on session open and span boot to mount

Author: TheGreatAxios

src/index.ts

@@ -13,6 +13,7 @@ import {
 } from "./config/settings.js";
 import { flushFileLogSinkSync, installFileLogSink } from "./logging/sink.js";
 import { flushPerfToOtel } from "./perf/index.js";
+import { startBootSpans } from "./perf/boot-spans.js";
 import { createTelemetry, telemetryDisabledByEnv } from "./telemetry/index.js";
 import { getTelemetry, setTelemetry } from "./telemetry/singleton.js";
 import {
@@ -36,6 +37,7 @@ export async function mainWithRunners(
   argv: readonly string[],
   runners: Runners,
 ): Promise<number> {
+  startBootSpans();
   // Must run first: @intx/log installs a console sink on import, and
   // loadConfig can log (e.g. healed settings). This replaces that default so
   // nothing — including vendored loggers — reaches the terminal the TUI owns.

src/perf/boot-spans.test.ts

@@ -0,0 +1,50 @@
+import { EventEmitter } from "node:events";
+import { expect, test } from "bun:test";
+
+import { main } from "../index.js";
+import { clear, snapshot } from "./index.js";
+import { endBootSpans, startBootSpans } from "./boot-spans.js";
+import { createHarness } from "../tui/harness.js";
+import { mountRunnerHost } from "../tui/runner/host.js";
+
+test("boot starts boot and first-paint spans before config exits", async () => {
+  clear();
+  endBootSpans();
+  await expect(main(["--help"])).rejects.toThrow();
+  const open = snapshot().filter((span) => span.endNs === undefined);
+  expect(open.some((span) => span.name === "boot")).toBe(true);
+  expect(open.some((span) => span.name === "first-paint")).toBe(true);
+  endBootSpans();
+  clear();
+});
+
+test("mount ends the boot and first-paint spans", async () => {
+  clear();
+  endBootSpans();
+  startBootSpans();
+  const harness = await createHarness({ width: 80, height: 24 });
+  const host = await mountRunnerHost({
+    title: "test",
+    eventEmitter: new EventEmitter(),
+    send: () => undefined,
+    interrupt: () => undefined,
+    deliver: () => undefined,
+    providers: {},
+    onModelSelect: () => undefined,
+    commands: [],
+    onCommand: () => undefined,
+    chrome: () => ({ agents: [] }),
+    subscribeChrome: () => () => undefined,
+    subAgentSessions: () => [],
+    createRenderer: async () => harness.renderer,
+  });
+  try {
+    const done = snapshot().filter((span) => span.endNs !== undefined);
+    expect(done.some((span) => span.name === "boot")).toBe(true);
+    expect(done.some((span) => span.name === "first-paint")).toBe(true);
+  } finally {
+    host.dispose();
+    harness.destroy();
+    clear();
+  }
+});

src/perf/boot-spans.ts

@@ -0,0 +1,26 @@
+import { end, start } from "./index.js";
+
+/**
+ * Brackets process boot through first paint. Config I/O sits inside the
+ * spans; schema work that used to run at import stays outside them until a
+ * value is actually read.
+ */
+let bootId: string | undefined;
+let firstPaintId: string | undefined;
+
+export function startBootSpans(): void {
+  if (bootId !== undefined) return;
+  bootId = start("boot");
+  firstPaintId = start("first-paint");
+}
+
+export function endBootSpans(): void {
+  if (bootId !== undefined) {
+    end(bootId);
+    bootId = undefined;
+  }
+  if (firstPaintId !== undefined) {
+    end(firstPaintId);
+    firstPaintId = undefined;
+  }
+}

src/perf/index.ts

@@ -52,6 +52,8 @@ export const SPAN_NAMES = [
   "adapter.request_build",
   "adapter.first_byte",
   "adapter.transport",
+  "boot",
+  "first-paint",
 ] as const;
 
 export type SpanName = (typeof SPAN_NAMES)[number];

src/session/isogit-boot.test.ts

@@ -0,0 +1,33 @@
+import { mkdtemp, rm } from "node:fs/promises";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { expect, mock, test } from "bun:test";
+
+let nodeEvaluated = false;
+
+mock.module("@intx/storage-isogit/node", () => {
+  nodeEvaluated = true;
+  return {
+    createIsogitStore: async () => {
+      throw new Error("session open reached isogit");
+    },
+  };
+});
+
+test("importing the session store does not construct isogit storage", async () => {
+  await import("./optimized-context-store.js");
+  expect(nodeEvaluated).toBe(false);
+});
+
+test("opening a session constructs isogit storage", async () => {
+  const { createSessionStores } = await import("./optimized-context-store.js");
+  const dir = await mkdtemp(join(tmpdir(), "isogit-boot-"));
+  try {
+    await expect(createSessionStores(dir)).rejects.toThrow(
+      "session open reached isogit",
+    );
+    expect(nodeEvaluated).toBe(true);
+  } finally {
+    await rm(dir, { recursive: true, force: true });
+  }
+});

src/session/isogit-node.ts

@@ -0,0 +1,17 @@
+/**
+ * The node isogit entry builds its runtime and storage at module scope.
+ * Keep that off the import path until a session is actually opened.
+ */
+
+export type IsogitNodeModule = typeof import("@intx/storage-isogit/node");
+
+let loading: Promise<IsogitNodeModule> | undefined;
+
+export function isogitNodeLoadStarted(): boolean {
+  return loading !== undefined;
+}
+
+export function loadIsogitNode(): Promise<IsogitNodeModule> {
+  loading ??= import("@intx/storage-isogit/node");
+  return loading;
+}

src/session/optimized-context-store.ts

@@ -2,10 +2,8 @@ import fs from "node:fs";
 import path from "node:path";
 import { type } from "arktype";
 import git from "isomorphic-git";
-import {
-  createIsogitStore,
-  type CommitSigner,
-} from "@intx/storage-isogit/node";
+import type { CommitSigner } from "@intx/storage-isogit/node";
+import { loadIsogitNode } from "./isogit-node.js";
 import {
   ContentBlock,
   ConnectorThreadState,
@@ -1478,6 +1476,7 @@ export async function createSessionStores(
   opts?: SessionStoreOptions,
 ): Promise<SessionStores> {
   const signer = opts?.signer ?? (await loadOrCreateCommitSigner(dir));
+  const { createIsogitStore } = await loadIsogitNode();
   const base = await createIsogitStore(dir, signer);
   const pendingBlobFilepaths = new Set<string>();
   const pendingSegmentPaths = new Set<string>();

src/tui/runner/host.ts

@@ -61,6 +61,7 @@ import type { QueueKind } from "../delivery-queue.js";
 import type { ShellOutputFeed } from "../../session/shell-output-feed.js";
 import { openModelPickerOverlay } from "../overlays.js";
 import type { ReconnectScope } from "../connect-scope.js";
+import { endBootSpans } from "../../perf/boot-spans.js";
 import {
   reconnectRecoveryItemId,
   reconnectRecoveryItemLabel,
@@ -387,6 +388,7 @@ export async function mountRunnerHost(
       ? { telemetryNotice: deps.telemetryNotice }
       : {}),
   });
+  endBootSpans();
 
   const pushChrome = (): void => {
     host.setChrome(chromeFromSession(deps.chrome()));