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longhaul.cpp/tools/ui/tests/client/agentic-stream.perf.svelte.test.ts
2026-07-29 01:00:10 -05:00

411 lines
13 KiB
TypeScript

// Tier 1 perf harness for the agentic thread.
//
// Drives ChatMessageAgenticContent the way the real streaming pipeline does:
// chat.svelte.ts -> conversations.svelte.ts:184 replaces the message object per
// SSE chunk (`{ ...old, ...updates }`), which changes prop identity and cascades
// through deriveAgenticSections into every tool-call block in the message.
//
// The fixture is parameterized so the *scaling curve* identifies the culprit -
// a single number would not. See tests/client/README-perf.md.
//
// Run: npx vitest --project=client --run tests/client/agentic-stream.perf.svelte.test.ts
import { describe, it } from 'vitest';
import { render } from 'vitest-browser-svelte';
import { tick } from 'svelte';
import AgenticPerfWrapper from './components/AgenticPerfWrapper.svelte';
import ChatMessagesPerfWrapper from './components/ChatMessagesPerfWrapper.svelte';
import { perfState } from './components/agentic-perf-state.svelte';
import { conversationsStore } from '$lib/stores/conversations.svelte';
import type { DatabaseMessage } from '$lib/types';
import { MessageRole } from '$lib/enums';
// --- fixture construction -------------------------------------------------
interface FixtureOpts {
/** Completed tool-call sections preceding the streaming text. */
priorToolCalls: number;
/** Size of each tool result blob. */
toolResultBytes: number;
/** Number of edit_file calls (each a 400x400-line diff). */
editFileEdits: number;
/** Leave an unclosed ``` fence at the end of the streamed content. */
openCodeFence: boolean;
/**
* Emit a blank line every N chunks so the content forms real markdown
* blocks. 0 = one unbroken paragraph, which defeats MarkdownContent's
* stable-block cache entirely (worst case). Typical prose has breaks.
*/
paragraphEvery: number;
}
const DEFAULTS: FixtureOpts = {
priorToolCalls: 0,
toolResultBytes: 1024,
editFileEdits: 0,
openCodeFence: false,
paragraphEvery: 0
};
function blob(bytes: number, seed: string): string {
const line = `${seed} output line with some representative width to it`;
const n = Math.max(1, Math.ceil(bytes / (line.length + 1)));
const out: string[] = [];
for (let i = 0; i < n; i++) out.push(`${line} ${i}`);
return out.join('\n');
}
function diffLines(n: number, seed: string): string {
const out: string[] = [];
for (let i = 0; i < n; i++) out.push(`${seed} line ${i} const value_${i} = compute(${i});`);
return out.join('\n');
}
let msgSeq = 0;
function baseMessage(overrides: Partial<DatabaseMessage>): DatabaseMessage {
return {
id: `m${msgSeq++}`,
convId: 'perf-conv',
type: 'text',
timestamp: 0,
role: MessageRole.ASSISTANT,
content: '',
parent: null,
children: [],
...overrides
} as DatabaseMessage;
}
function buildFixture(opts: FixtureOpts): {
message: DatabaseMessage;
toolMessages: DatabaseMessage[];
} {
const toolCalls: unknown[] = [];
const toolMessages: DatabaseMessage[] = [];
for (let i = 0; i < opts.priorToolCalls; i++) {
const id = `call_${i}`;
toolCalls.push({
id,
type: 'function',
function: {
name: 'exec_shell_command',
arguments: JSON.stringify({ command: `grep -rn "thing_${i}" src/` })
}
});
toolMessages.push(
baseMessage({
role: MessageRole.TOOL,
toolCallId: id,
content: `${blob(opts.toolResultBytes, `t${i}`)}\n[exit code: 0]`
})
);
}
for (let i = 0; i < opts.editFileEdits; i++) {
const id = `edit_${i}`;
toolCalls.push({
id,
type: 'function',
function: {
name: 'edit_file',
arguments: JSON.stringify({
path: `/src/file_${i}.ts`,
edits: [{ old_text: diffLines(400, 'old'), new_text: diffLines(400, 'new') }]
})
}
});
toolMessages.push(
baseMessage({
role: MessageRole.TOOL,
toolCallId: id,
content: JSON.stringify({ result: 'ok', edits_applied: 1 })
})
);
}
const message = baseMessage({
toolCalls: toolCalls.length > 0 ? JSON.stringify(toolCalls) : undefined,
content: ''
});
return { message, toolMessages };
}
// --- the driver -----------------------------------------------------------
interface Sample {
label: string;
tokens: number;
mean: number;
p95: number;
max: number;
/** Sum of the synchronous per-token windows. */
total: number;
/** Wall-clock for the whole run incl. deferred rAF work, then settle. */
wall: number;
}
function nextFrame(): Promise<void> {
return new Promise((resolve) => requestAnimationFrame(() => resolve()));
}
const results: Sample[] = [];
/**
* Replays `tokens` streamed chunks, replacing the message object each time
* exactly as conversations.svelte.ts:184 does, flushing Svelte and forcing
* layout so the measurement includes render + style/layout, not just script.
*/
async function measure(label: string, partial: Partial<FixtureOpts>, tokens = 60) {
const opts = { ...DEFAULTS, ...partial };
const { message, toolMessages } = buildFixture(opts);
perfState.message = message;
perfState.toolMessages = toolMessages;
perfState.isStreaming = true;
// Every wrapper reads the same module state, so a leftover mount from a
// previous fixture would re-render on each mutation and fold its cost into
// this measurement. Tear down explicitly between fixtures.
const { unmount } = render(AgenticPerfWrapper);
await tick();
const CHUNK = 'The quick brown fox jumps over the lazy dog. ';
let accumulated = opts.openCodeFence ? '```notalanguage\n' : '';
const durations: number[] = [];
const wallStart = performance.now();
for (let i = 0; i < tokens; i++) {
accumulated += CHUNK;
if (opts.paragraphEvery > 0 && (i + 1) % opts.paragraphEvery === 0) {
accumulated += '\n\n';
}
const t0 = performance.now();
// Mirrors updateMessageAtIndex: a brand-new object identity per chunk.
perfState.message = { ...perfState.message!, content: accumulated };
await tick();
void document.body.offsetHeight; // force style + layout
durations.push(performance.now() - t0);
// MarkdownContent coalesces its parse into a rAF, so that work lands
// outside the window above. Yield a frame each iteration so it is
// captured in `wall` - the gap between `wall` and `total` is the
// deferred cost.
await nextFrame();
}
// Let any trailing coalesced work drain before stopping the clock.
await nextFrame();
await nextFrame();
const wall = performance.now() - wallStart;
await unmount();
durations.sort((a, b) => a - b);
const total = durations.reduce((a, b) => a + b, 0);
results.push({
label,
tokens,
mean: total / durations.length,
p95: durations[Math.floor(durations.length * 0.95)],
max: durations[durations.length - 1],
total,
wall
});
}
function report() {
const pad = (s: string, n: number) => s.padEnd(n);
const num = (n: number) => n.toFixed(2).padStart(8);
const header = `${pad('fixture', 40)}${pad('tok', 5)}${'mean'.padStart(8)}${'p95'.padStart(8)}${'max'.padStart(8)}${'sync'.padStart(9)}${'wall'.padStart(9)}`;
const lines = [
'',
'=== Tier 1: ms per streamed token (agentic content subtree) ===',
'mean/p95/max = synchronous window per token (script + style + layout).',
'sync = sum of those windows.',
'wall = whole run, incl. work MarkdownContent defers into its own rAF.',
' NOTE: wall carries a ~16.7ms/token idle floor from the harness',
' yielding a frame each iteration (60 tokens => ~1000ms floor).',
' Compare wall ACROSS fixtures / against the baseline row,',
' never against sync.',
'',
header,
'-'.repeat(header.length)
];
for (const r of results) {
lines.push(
`${pad(r.label, 40)}${pad(String(r.tokens), 5)}${num(r.mean)}${num(r.p95)}${num(r.max)}${num(r.total)}${num(r.wall)}`
);
}
lines.push('');
console.log(lines.join('\n'));
}
// --- conversation-level driver --------------------------------------------
// The per-message driver above cannot see the fan-out in ChatMessages: a single
// token mutation invalidates `displayMessages`, which rebuilds a fresh
// toolMessages array for EVERY message in the conversation. Drive the real
// store through the real list component to measure that.
async function measureConversation(
label: string,
priorMessages: number,
tokens = 60,
/**
* Give each prior assistant turn a resolved tool call, so the fixture pays
* `hasAgenticContent`'s JSON.parse and the tool-message grouping walk that a
* real agent thread would - plain prose messages skip both.
*/
agentic = false
) {
const history: DatabaseMessage[] = [];
for (let i = 0; i < priorMessages; i++) {
const isAssistant = i % 2 !== 0;
if (isAssistant && agentic) {
const id = `prior_call_${i}`;
history.push(
baseMessage({
role: MessageRole.ASSISTANT,
content: `Message ${i}`,
toolCalls: JSON.stringify([
{
id,
type: 'function',
function: {
name: 'exec_shell_command',
arguments: JSON.stringify({ command: `grep -rn "thing_${i}" src/` })
}
}
])
})
);
history.push(
baseMessage({
role: MessageRole.TOOL,
toolCallId: id,
content: `${blob(1024, `r${i}`)}\n[exit code: 0]`
})
);
continue;
}
history.push(
baseMessage({
role: isAssistant ? MessageRole.ASSISTANT : MessageRole.USER,
content: `Message ${i}: ${blob(512, `m${i}`)}`
})
);
}
const streaming = baseMessage({ role: MessageRole.ASSISTANT, content: '' });
history.push(streaming);
conversationsStore.activeMessages = history;
const { unmount } = render(ChatMessagesPerfWrapper);
await tick();
const idx = conversationsStore.findMessageIndex(streaming.id);
const CHUNK = 'The quick brown fox jumps over the lazy dog. ';
let accumulated = '';
const durations: number[] = [];
const wallStart = performance.now();
for (let i = 0; i < tokens; i++) {
accumulated += CHUNK;
const t0 = performance.now();
// The real path: chat.svelte.ts -> conversations.svelte.ts.
conversationsStore.updateMessageAtIndex(idx, { content: accumulated });
await tick();
void document.body.offsetHeight;
durations.push(performance.now() - t0);
await nextFrame();
}
await nextFrame();
await nextFrame();
const wall = performance.now() - wallStart;
await unmount();
conversationsStore.activeMessages = [];
durations.sort((a, b) => a - b);
const total = durations.reduce((a, b) => a + b, 0);
results.push({
label,
tokens,
mean: total / durations.length,
p95: durations[Math.floor(durations.length * 0.95)],
max: durations[durations.length - 1],
total,
wall
});
}
// --- the matrix -----------------------------------------------------------
// Sequential, in one test, so the table prints together and the samples do not
// interleave with other suites competing for the main thread.
describe('agentic streaming perf', () => {
it('scales', { timeout: 600_000 }, async () => {
// Baseline: plain text streaming, nothing agentic.
await measure('baseline: no tool calls', {});
// Knob: priorToolCalls. Flat => no fan-out. Linear => fan-out confirmed.
await measure('priorToolCalls=1 (1KB results)', { priorToolCalls: 1 });
await measure('priorToolCalls=5 (1KB results)', { priorToolCalls: 5 });
await measure('priorToolCalls=20 (1KB results)', { priorToolCalls: 20 });
// Knob: toolResultBytes, at fixed section count.
await measure('5 calls x 200KB results', {
priorToolCalls: 5,
toolResultBytes: 200 * 1024
});
// Knob: editFileEdits (computeLineDiff, 400x400 LCS).
await measure('3 edit_file calls (400x400 diff)', { editFileEdits: 3 });
// Knob: openCodeFence (hljs highlightAuto on partial code).
await measure('open code fence, unknown language', { openCodeFence: true });
// Conversation level: does streaming one message cost more as the
// conversation grows? Flat => no fan-out. Linear => confirmed.
await measureConversation('convo: 1 prior message', 1);
await measureConversation('convo: 10 prior messages', 10);
await measureConversation('convo: 40 prior messages', 40);
// Same, but each prior assistant turn carries a resolved tool call.
await measureConversation('convo: 10 prior, agentic', 10, 60, true);
await measureConversation('convo: 40 prior, agentic', 40, 60, true);
// Message length: MarkdownContent re-parses the whole accumulated string
// each frame, so per-token cost should climb as the response grows.
// A rising mean across these three rows means O(n^2) over the stream.
// One unbroken paragraph: worst case, stable-block cache never applies.
await measure('len 60tok 1-para (worst case)', {}, 60);
await measure('len 250tok 1-para (worst case)', {}, 250);
await measure('len 600tok 1-para (worst case)', {}, 600);
// Same lengths, broken into paragraphs every 8 chunks: the typical shape,
// where only the trailing paragraph should be unstable.
await measure('len 60tok paras (typical)', { paragraphEvery: 8 }, 60);
await measure('len 250tok paras (typical)', { paragraphEvery: 8 }, 250);
await measure('len 600tok paras (typical)', { paragraphEvery: 8 }, 600);
report();
});
});