</Collapsible.Trigger>
<Collapsible.Content>
- <div class="pl-1.5 grid min-w-0" style="min-height: var(--min-message-height);">
- <div class="min-w-0 border-l border-muted-foreground/20 pl-4 pb-2 my-2">
- {@render children()}
+ <!-- Collapsible.Content renders its children unconditionally and only sets
+ `hidden`, so a closed block would keep re-rendering its whole body on
+ every streamed token. Gate on `open` so collapsed content costs nothing. -->
+ {#if open}
+ <div class="pl-1.5 grid min-w-0" style="min-height: var(--min-message-height);">
+ <div class="min-w-0 border-l border-muted-foreground/20 pl-4 pb-2 my-2">
+ {@render children()}
+ </div>
</div>
- </div>
+ {/if}
</Collapsible.Content>
</Collapsible.Root>
</Collapsible.Trigger>
<Collapsible.Content>
- <div class="p-3 pt-1">
- {@render children()}
- </div>
+ <!-- See CollapsibleContentBlock: bits-ui keeps closed content mounted, which
+ makes a collapsed tool result re-render on every streamed token. -->
+ {#if open}
+ <div class="p-3 pt-1">
+ {@render children()}
+ </div>
+ {/if}
</Collapsible.Content>
</Collapsible.Root>
return null;
});
const liveSvgHtml = $derived(streamingSvgCode !== null ? sanitizeSvg(streamingSvgCode) : '');
+
+ // Derived rather than called inline in the template so it only recomputes when
+ // the block actually changes. Auto-detection is disabled while streaming: it
+ // costs ~38ms a call and re-guesses the language on every chunk.
+ const streamingCodeHtml = $derived(
+ incompleteCodeBlock
+ ? highlightCode(incompleteCodeBlock.code, incompleteCodeBlock.language || 'text', false)
+ : ''
+ );
let previewDialogOpen = $state(false);
let previewCode = $state('');
let previewLanguage = $state('text');
>
<pre class="streaming-code-pre"><code
class="hljs language-{incompleteCodeBlock.language || 'text'}"
- >{@html highlightCode(
- incompleteCodeBlock.code,
- incompleteCodeBlock.language || 'text'
- )}</code
+ >{@html streamingCodeHtml}</code
></pre>
</div>
</div>
/** Regex to capture the content of a $$...\\\\...$$ block (display-formula with line-break) */
export const LATEX_LINEBREAK_REGEXP = /\$\$([\s\S]*?\\\\[\s\S]*?)\$\$/;
+/**
+ * Cheap gate for `preprocessLaTeX`. Every transformation it performs is triggered
+ * by a `$` (inline/display math, currency escaping) or a backslash escape
+ * (`\(`, `\[`, `\ce{`, `\pu{`). Text containing neither is returned untouched, so
+ * this lets the caller skip the whole protect/restore pipeline.
+ */
+export const LATEX_TRIGGER_REGEXP = /[$\\]/;
+
/** map from mchem-regexp to replacement */
export const MHCHEM_PATTERN_MAP: readonly [RegExp, string][] = [
[/(\s)\$\\ce{/g, '$1$\\\\ce{'],
* Updates a message at a specific index in active messages
*/
updateMessageAtIndex(index: number, updates: Partial<DatabaseMessage>): void {
- if (index !== -1 && this.activeMessages[index]) {
- this.activeMessages[index] = { ...this.activeMessages[index], ...updates };
+ const message = index === -1 ? undefined : this.activeMessages[index];
+
+ if (!message) return;
+
+ // Assign field by field rather than replacing the object. Replacing it
+ // changes the array slot, which invalidates every consumer that merely
+ // walks the list - notably ChatMessages.displayMessages, which rebuilds
+ // entries for every message in the conversation. Deep $state proxies make
+ // per-field writes fine-grained, so only readers of the changed field wake.
+ const target = message as unknown as Record<string, unknown>;
+
+ for (const [key, value] of Object.entries(updates)) {
+ if (target[key] !== value) {
+ target[key] = value;
+ }
}
}
return code.replace(TRIM_LEADING_PADDING_REGEX, '').replace(TRIM_TRAILING_PADDING_REGEX, '');
}
+function escapeCode(code: string): string {
+ return code.replace(AMPERSAND_REGEX, '&').replace(LT_REGEX, '<').replace(GT_REGEX, '>');
+}
+
/**
* Highlights code using highlight.js
* @param code - The code to highlight
* @param language - The programming language
+ * @param autoDetect - Fall back to `highlightAuto` when `language` is unknown.
+ * Callers rendering a still-streaming block should pass false: auto-detection
+ * costs ~38ms per call and re-guesses on every chunk, so the language (and
+ * therefore the whole highlight) flickers as the block grows.
* @returns HTML string with syntax highlighting
*/
-export function highlightCode(code: string, language: string): string {
+export function highlightCode(code: string, language: string, autoDetect = true): string {
if (!code) return '';
const trimmed = trimCodePadding(code);
if (isSupported) {
return hljs.highlight(trimmed, { language: lang }).value;
- } else {
+ } else if (autoDetect) {
return hljs.highlightAuto(trimmed).value;
+ } else {
+ return escapeCode(trimmed);
}
} catch {
// Fallback to escaped plain text
- return trimmed
- .replace(AMPERSAND_REGEX, '&')
- .replace(LT_REGEX, '<')
- .replace(GT_REGEX, '>');
+ return escapeCode(trimmed);
}
}
CODE_BLOCK_REGEXP,
LATEX_MATH_AND_CODE_PATTERN,
LATEX_LINEBREAK_REGEXP,
+ LATEX_TRIGGER_REGEXP,
MHCHEM_PATTERN_MAP
} from '$lib/constants';
// See also:
// https://github.com/danny-avila/LibreChat/blob/main/client/src/utils/latex.ts
+ // Every step below keys off a `$` or a backslash escape (\[ \] \( \) \ce{ \pu{).
+ // With neither present the protect/restore passes round-trip the input
+ // unchanged, so skip them: the step 2 scan is O(n^2) in line length and costs
+ // ~90ms on a 26KB single-line message that contains no math at all. This
+ // matters during streaming, where the whole message is reprocessed per frame.
+ if (!LATEX_TRIGGER_REGEXP.test(content)) {
+ return content;
+ }
+
// Step 0: Temporarily remove blockquote markers (>) to process LaTeX correctly
// Store the structure so we can restore it later
const blockquoteMarkers: Map<number, string> = new Map();
const latexExpressions: string[] = [];
// Match \S...\[...\] and protect them and insert a line-break.
- content = content.replace(/([\S].*?)\\\[([\s\S]*?)\\\](.*)/g, (match, group1, group2, group3) => {
- // Check if there are characters following the formula (display-formula in a table-cell?)
- if (group1.endsWith('\\')) {
- return match; // Backslash before \[, do nothing.
- }
- const hasSuffix = /\S/.test(group3);
- let optBreak;
-
- if (hasSuffix) {
- latexExpressions.push(`\\(${group2.trim()}\\)`); // Convert into inline.
- optBreak = '';
- } else {
- latexExpressions.push(`\\[${group2}\\]`);
- optBreak = '\n';
- }
+ // Guarded: with no `\[` present this pattern still probes every start offset,
+ // expanding `.*?` to the end of each line before failing - O(n^2) for nothing.
+ if (content.includes('\\[')) {
+ content = content.replace(
+ /([\S].*?)\\\[([\s\S]*?)\\\](.*)/g,
+ (match, group1, group2, group3) => {
+ // Check if there are characters following the formula (display-formula in a table-cell?)
+ if (group1.endsWith('\\')) {
+ return match; // Backslash before \[, do nothing.
+ }
+ const hasSuffix = /\S/.test(group3);
+ let optBreak;
+
+ if (hasSuffix) {
+ latexExpressions.push(`\\(${group2.trim()}\\)`); // Convert into inline.
+ optBreak = '';
+ } else {
+ latexExpressions.push(`\\[${group2}\\]`);
+ optBreak = '\n';
+ }
- return `${group1}${optBreak}<<LATEX_${latexExpressions.length - 1}>>${optBreak}${group3}`;
- });
+ return `${group1}${optBreak}<<LATEX_${latexExpressions.length - 1}>>${optBreak}${group3}`;
+ }
+ );
+ }
// Match \(...\), \[...\], $$...$$ and protect them
content = content.replace(
--- /dev/null
+# Agentic thread perf harness
+
+Two tiers, both reusing the existing vitest projects (see `vite.config.ts`).
+
+## Tier 1 - `agentic-stream.perf.svelte.test.ts` (project: `client`, real Chromium)
+
+Mounts `ChatMessageAgenticContent` and replays a stream, replacing the message
+object on each chunk exactly as the real pipeline does:
+
+- `chat.svelte.ts` `updateStreamingUI()` runs per SSE chunk
+- `conversations.svelte.ts` `updateMessageAtIndex` does `{ ...old, ...updates }`
+
+That new object identity is the thing under test: it cascades through
+`deriveAgenticSections` (which returns fresh `AgenticSection` objects) into every
+tool-call block in the message, including completed ones.
+
+```
+npx vitest --project=client --run tests/client/agentic-stream.perf.svelte.test.ts
+```
+
+### Reading the output
+
+- `mean` / `p95` / `max` - the synchronous window per token: prop write,
+ `await tick()`, then a forced `offsetHeight` read so style and layout are
+ included rather than deferred.
+- `sync` - sum of those windows. This is the number to optimize.
+- `wall` - the whole run including work `MarkdownContent` defers into its own
+ `requestAnimationFrame`. It carries a ~16.7ms/token idle floor because the
+ harness yields a frame each iteration, so compare `wall` **across fixtures**,
+ never against `sync`.
+
+### The knobs, and what each one discriminates
+
+The point of the harness is the _scaling curve_, not any single number.
+
+| Knob | Reads on |
+| --------------------------- | ---------------------------------------------------------------------------------------------------- |
+| `priorToolCalls` (0/1/5/20) | the reactive fan-out. Flat => no fan-out. Linear => confirmed. |
+| `toolResultBytes` | whole-blob string scans (`extractSearchResults`, `parseToolResultWithImages`, `classifyToolResult`). |
+| `editFileEdits` | `computeLineDiff`, the O(m\*n) LCS. |
+| `openCodeFence` | `hljs.highlightAuto` on partial code. |
+
+Deliberately no hard assertions: CI timing is noisy and the value here is the
+before/after delta, not a gate.
+
+### Caveat
+
+This measures one message's subtree. In the real app `ChatMessages.svelte`
+rebuilds its whole `displayMessages` list per token, so multiply by the number
+of rendered messages to get the conversation-level cost.
+
+## Tier 2 - `../unit/agentic-hotpath.bench.ts` (project: `unit`, node)
+
+Per-call costs for the pure functions the curve implicates.
+
+```
+npx vitest bench --project=unit --run tests/unit/agentic-hotpath.bench.ts
+```
--- /dev/null
+// 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();
+ });
+});
--- /dev/null
+// Guards the lazy-body behaviour of the shared collapsible wrappers.
+//
+// bits-ui's Collapsible.Content renders its children unconditionally and only
+// sets `hidden`, so before this was gated a collapsed tool result kept its whole
+// body in the DOM and re-rendered it on every streamed token (measured at
+// ~41ms/section/token for a 200KB result). These tests pin the fix: closed means
+// not rendered, and opening still mounts the body.
+
+import { describe, it, expect } from 'vitest';
+import { render } from 'vitest-browser-svelte';
+import { tick } from 'svelte';
+import CollapsibleLazyBodyHarness from './components/CollapsibleLazyBodyHarness.svelte';
+
+const MARKER = 'collapsible-body-marker';
+
+describe('collapsible wrappers render their body lazily', () => {
+ for (const variant of ['content', 'terminal'] as const) {
+ it(`${variant}: body is absent while closed and present once open`, async () => {
+ const screen = render(CollapsibleLazyBodyHarness, { variant, open: false });
+ await tick();
+
+ expect(document.body.textContent).not.toContain(MARKER);
+
+ await screen.rerender({ variant, open: true });
+ await tick();
+
+ expect(document.body.textContent).toContain(MARKER);
+
+ // And it unmounts again on close, so a collapsed block stops costing
+ // anything during streaming.
+ await screen.rerender({ variant, open: false });
+ await tick();
+
+ expect(document.body.textContent).not.toContain(MARKER);
+ });
+ }
+});
--- /dev/null
+<script lang="ts">
+ import * as Tooltip from '$lib/components/ui/tooltip';
+ import ChatMessageAgenticContent from '$lib/components/app/chat/ChatMessages/ChatMessageAgenticContent.svelte';
+ import { perfState } from './agentic-perf-state.svelte';
+</script>
+
+<Tooltip.Provider>
+ {#if perfState.message}
+ <ChatMessageAgenticContent
+ message={perfState.message}
+ toolMessages={perfState.toolMessages}
+ isStreaming={perfState.isStreaming}
+ isLastAssistantMessage
+ />
+ {/if}
+</Tooltip.Provider>
--- /dev/null
+<script lang="ts">
+ // Mounts the real ChatMessages list against the real conversations store, so
+ // the harness exercises `displayMessages` (which rebuilds every message's
+ // toolMessages array) rather than a single message subtree.
+ import * as Tooltip from '$lib/components/ui/tooltip';
+ import ChatMessages from '$lib/components/app/chat/ChatMessages/ChatMessages.svelte';
+ import { conversationsStore } from '$lib/stores/conversations.svelte';
+</script>
+
+<Tooltip.Provider>
+ <ChatMessages messages={conversationsStore.activeMessages} />
+</Tooltip.Provider>
--- /dev/null
+<script lang="ts">
+ import CollapsibleContentBlock from '$lib/components/app/content/CollapsibleContentBlock.svelte';
+ import CollapsibleTerminalBlock from '$lib/components/app/content/CollapsibleTerminalBlock.svelte';
+
+ interface Props {
+ variant: 'content' | 'terminal';
+ open: boolean;
+ }
+
+ let { variant, open }: Props = $props();
+</script>
+
+{#if variant === 'content'}
+ <CollapsibleContentBlock {open} title="Block">
+ <span>collapsible-body-marker</span>
+ </CollapsibleContentBlock>
+{:else}
+ <CollapsibleTerminalBlock {open} title="Block">
+ <span>collapsible-body-marker</span>
+ </CollapsibleTerminalBlock>
+{/if}
--- /dev/null
+// Shared reactive fixture state for the Tier 1 perf harness.
+//
+// The wrapper component reads this module directly rather than taking props,
+// so the driver can mutate it without depending on how the test renderer
+// forwards props.
+
+import type { DatabaseMessage } from '$lib/types';
+
+export const perfState = $state<{
+ message: DatabaseMessage | null;
+ toolMessages: DatabaseMessage[];
+ isStreaming: boolean;
+}>({
+ message: null,
+ toolMessages: [],
+ isStreaming: true
+});
--- /dev/null
+// Pins the contract that makes streaming cheap: updateMessageAtIndex mutates the
+// existing message object instead of replacing it.
+//
+// Replacing it (`{ ...old, ...updates }`) changes the array slot, which
+// invalidates every consumer that merely walks the list - ChatMessages'
+// `displayMessages` rebuilds entries for EVERY message in the conversation. That
+// made per-token cost scale with conversation length (1.26ms at 1 prior message
+// -> 3.07ms at 40). Mutating in place keeps it flat.
+
+import { describe, it, expect } from 'vitest';
+import { conversationsStore } from '$lib/stores/conversations.svelte';
+import type { DatabaseMessage } from '$lib/types';
+import { MessageRole } from '$lib/enums';
+
+function makeMessage(id: string): DatabaseMessage {
+ return {
+ id,
+ convId: 'c1',
+ type: 'text',
+ timestamp: 0,
+ role: MessageRole.ASSISTANT,
+ content: '',
+ parent: null,
+ children: []
+ } as DatabaseMessage;
+}
+
+describe('conversationsStore.updateMessageAtIndex', () => {
+ it('mutates in place, preserving object identity', () => {
+ conversationsStore.activeMessages = [makeMessage('a'), makeMessage('b')];
+ const before = conversationsStore.activeMessages[1];
+
+ conversationsStore.updateMessageAtIndex(1, { content: 'hello' });
+
+ expect(conversationsStore.activeMessages[1].content).toBe('hello');
+ expect(conversationsStore.activeMessages[1]).toBe(before);
+
+ conversationsStore.activeMessages = [];
+ });
+
+ it('leaves other messages and unrelated fields untouched', () => {
+ conversationsStore.activeMessages = [makeMessage('a'), makeMessage('b')];
+ const untouched = conversationsStore.activeMessages[0];
+
+ conversationsStore.updateMessageAtIndex(1, { content: 'x', model: 'm1' });
+
+ expect(conversationsStore.activeMessages[0]).toBe(untouched);
+ expect(conversationsStore.activeMessages[0].content).toBe('');
+ expect(conversationsStore.activeMessages[1].model).toBe('m1');
+ expect(conversationsStore.activeMessages[1].id).toBe('b');
+
+ conversationsStore.activeMessages = [];
+ });
+
+ it('is a no-op for an index of -1 or out of range', () => {
+ conversationsStore.activeMessages = [makeMessage('a')];
+
+ expect(() => conversationsStore.updateMessageAtIndex(-1, { content: 'x' })).not.toThrow();
+ expect(() => conversationsStore.updateMessageAtIndex(9, { content: 'x' })).not.toThrow();
+ expect(conversationsStore.activeMessages[0].content).toBe('');
+
+ conversationsStore.activeMessages = [];
+ });
+});
--- /dev/null
+// Microbenchmarks for the functions on the agentic-thread streaming hot path.
+//
+// Every function here is invoked from a `$derived` that is invalidated on each
+// streamed token, for every tool-call section in the message. These numbers give
+// the per-call cost; multiply by (tokens x sections) for the real damage.
+//
+// Run: npx vitest bench --project=unit tests/unit/agentic-hotpath.bench.ts
+
+import { bench, describe } from 'vitest';
+
+import { remark } from 'remark';
+import remarkBreaks from 'remark-breaks';
+import remarkGfm from 'remark-gfm';
+import remarkMath from 'remark-math';
+import remarkRehype from 'remark-rehype';
+import rehypeKatex from 'rehype-katex';
+import rehypeHighlight from 'rehype-highlight';
+import rehypeStringify from 'rehype-stringify';
+import { all as lowlightAll } from 'lowlight';
+
+import { computeLineDiff } from '$lib/utils/compute-line-diff';
+import { extractSearchResults, extractSearchQuery } from '$lib/utils/search-results';
+import { parsePartialJsonArgs } from '$lib/utils/parse-partial-json-args';
+import { highlightCode, detectIncompleteCodeBlock } from '$lib/utils/code';
+import { classifyToolResult, parseToolResultWithImages } from '$lib/utils/agentic';
+import { preprocessLaTeX } from '$lib/utils/latex-protection';
+
+// --- fixtures -------------------------------------------------------------
+
+function lines(n: number, seed: string): string {
+ const out: string[] = [];
+ for (let i = 0; i < n; i++) out.push(`${seed} line ${i} const value_${i} = compute(${i});`);
+ return out.join('\n');
+}
+
+const SHELL_OUTPUT_1KB = lines(12, 'out');
+const SHELL_OUTPUT_200KB = lines(2600, 'out');
+const SHELL_OUTPUT_2MB = lines(26000, 'out');
+
+// Realistic exec_shell_command result: the exit-code marker is the final line,
+// which is what the un-anchored EXIT_CODE regex has to scan the whole blob for.
+const SHELL_2MB_WITH_EXIT = `${SHELL_OUTPUT_2MB}\n[exit code: 0]`;
+
+const EDIT_OLD_400 = lines(400, 'old');
+const EDIT_NEW_400 = lines(400, 'new');
+const EDIT_OLD_50 = lines(50, 'old');
+const EDIT_NEW_50 = lines(50, 'new');
+
+const WRITE_FILE_ARGS = JSON.stringify({
+ path: '/src/lib/thing.ts',
+ content: lines(1500, 'src')
+});
+
+const MARKDOWN_50KB = Array.from(
+ { length: 400 },
+ (_, i) =>
+ `## Section ${i}\n\nSome **bold** prose with a [link](https://example.com) and \`inline\` code.\n\n- bullet one\n- bullet two\n\n\`\`\`ts\nconst x${i} = ${i};\n\`\`\`\n`
+).join('\n');
+
+const CODE_BLOCK_5KB = lines(60, 'code');
+
+// --- A: computeLineDiff (O(m*n) LCS, allocates a full matrix) --------------
+
+describe('computeLineDiff', () => {
+ bench('50 x 50 lines', () => {
+ computeLineDiff(EDIT_OLD_50, EDIT_NEW_50);
+ });
+
+ bench('400 x 400 lines', () => {
+ computeLineDiff(EDIT_OLD_400, EDIT_NEW_400);
+ });
+});
+
+// --- B: the unified processor, rebuilt per call ---------------------------
+// Mirrors MarkdownContent.svelte:144-176. The local rehype/remark plugins are
+// omitted (they pull in browser-only modules); rehypeHighlight + lowlightAll is
+// the dominant term, so this is a lower bound on the real cost.
+
+function buildProcessor() {
+ // eslint-disable-next-line @typescript-eslint/no-explicit-any
+ let proc: any = remark().use(remarkGfm);
+ proc = proc.use(remarkMath).use(remarkBreaks).use(remarkRehype).use(rehypeKatex);
+ return proc.use(rehypeHighlight, { languages: lowlightAll }).use(rehypeStringify, {
+ allowDangerousHtml: true
+ });
+}
+
+describe('markdown processor', () => {
+ bench('build processor (per processMarkdown call, x2)', () => {
+ buildProcessor();
+ });
+
+ const prebuilt = buildProcessor();
+
+ bench('parse 50KB markdown with a prebuilt processor', () => {
+ prebuilt.parse(MARKDOWN_50KB);
+ });
+});
+
+// Isolates the O(n^2) term measured in Tier 1: processMarkdown re-parses the
+// WHOLE accumulated string every frame, while only the last block can have
+// changed. If parse() dominates at these sizes, incremental parsing (re-parsing
+// only the tail after the last stable block) is the fix; if not, the cost is
+// downstream in transform/stringify/DOM.
+describe('markdown parse scaling (whole-string reparse per frame)', () => {
+ const proc = buildProcessor();
+ const prose = (kb: number) =>
+ Array.from(
+ { length: Math.ceil((kb * 1024) / 64) },
+ (_, i) => `The quick brown fox jumps over the lazy dog. Sentence ${i}.`
+ ).join(' ');
+
+ const MD_3KB = prose(3);
+ const MD_11KB = prose(11);
+ const MD_26KB = prose(26);
+
+ bench('parse 3KB', () => {
+ proc.parse(MD_3KB);
+ });
+
+ bench('parse 11KB', () => {
+ proc.parse(MD_11KB);
+ });
+
+ bench('parse 26KB', () => {
+ proc.parse(MD_26KB);
+ });
+
+ bench('parse only a 200-char tail (proposed incremental)', () => {
+ proc.parse(MD_26KB.slice(-200));
+ });
+});
+
+// processMarkdown runs these over the WHOLE accumulated string every frame too,
+// before parse() even starts. Measure them before assuming parse is the target.
+describe('other whole-string passes per frame', () => {
+ const prose = (kb: number) =>
+ Array.from(
+ { length: Math.ceil((kb * 1024) / 64) },
+ (_, i) => `The quick brown fox jumps over the lazy dog. Sentence ${i}.`
+ ).join(' ');
+
+ const MD_3KB = prose(3);
+ const MD_11KB = prose(11);
+ const MD_26KB = prose(26);
+ const MD_26KB_LATEX = `${MD_26KB} and some math $x^2 + y^2 = z^2$ inline.`;
+
+ bench('preprocessLaTeX 3KB (no latex present)', () => {
+ preprocessLaTeX(MD_3KB);
+ });
+
+ bench('preprocessLaTeX 11KB (no latex present)', () => {
+ preprocessLaTeX(MD_11KB);
+ });
+
+ bench('preprocessLaTeX 26KB (no latex present)', () => {
+ preprocessLaTeX(MD_26KB);
+ });
+
+ bench('preprocessLaTeX 26KB (latex present)', () => {
+ preprocessLaTeX(MD_26KB_LATEX);
+ });
+
+ bench('detectIncompleteCodeBlock 26KB', () => {
+ detectIncompleteCodeBlock(MD_26KB);
+ });
+});
+
+// --- C: extractSearchResults, run for EVERY tool of every type ------------
+
+describe('extractSearchResults (only .length > 0 is consumed)', () => {
+ bench('1KB non-search tool result', () => {
+ extractSearchResults(SHELL_OUTPUT_1KB);
+ });
+
+ bench('200KB non-search tool result', () => {
+ extractSearchResults(SHELL_OUTPUT_200KB);
+ });
+
+ bench('2MB non-search tool result', () => {
+ extractSearchResults(SHELL_OUTPUT_2MB);
+ });
+});
+
+describe('extractSearchQuery', () => {
+ bench('write_file args (throws on the JSON.parse path)', () => {
+ extractSearchQuery(WRITE_FILE_ARGS);
+ });
+});
+
+// --- E: the un-anchored exit-code regex -----------------------------------
+// Reproduced inline so the bench is independent of the current call site.
+
+const EXIT_CODE_TAIL = /\[exit code: (-?\d+)\]\s*$/;
+
+describe('exit-code regex', () => {
+ bench('whole 2MB blob (current behaviour)', () => {
+ SHELL_2MB_WITH_EXIT.match(EXIT_CODE_TAIL);
+ });
+
+ bench('last 64 chars only (proposed)', () => {
+ SHELL_2MB_WITH_EXIT.slice(-64).match(EXIT_CODE_TAIL);
+ });
+});
+
+// --- per-line result parsers ----------------------------------------------
+
+describe('parseToolResultWithImages', () => {
+ bench('1KB', () => {
+ parseToolResultWithImages(SHELL_OUTPUT_1KB, []);
+ });
+
+ bench('200KB', () => {
+ parseToolResultWithImages(SHELL_OUTPUT_200KB, []);
+ });
+
+ bench('2MB', () => {
+ parseToolResultWithImages(SHELL_OUTPUT_2MB, []);
+ });
+});
+
+describe('classifyToolResult', () => {
+ bench('200KB plain text (falls through to looksLikeMarkdown)', () => {
+ classifyToolResult(SHELL_OUTPUT_200KB);
+ });
+});
+
+describe('parsePartialJsonArgs', () => {
+ bench('write_file args, ~60KB (char-by-char scan)', () => {
+ parsePartialJsonArgs(WRITE_FILE_ARGS);
+ });
+});
+
+// --- F / I: highlight.js ---------------------------------------------------
+
+describe('highlightCode', () => {
+ bench('short bash command (title row, per token)', () => {
+ highlightCode('grep -rn "foo" src/ | head -50', 'bash');
+ });
+
+ bench('5KB known language', () => {
+ highlightCode(CODE_BLOCK_5KB, 'typescript');
+ });
+
+ bench('5KB unknown language -> highlightAuto', () => {
+ highlightCode(CODE_BLOCK_5KB, 'not-a-language');
+ });
+});
const framed = highlightCode('\nfunction foo() {}\n', 'javascript');
expect(framed).toBe(trimmed);
});
+
+ it('auto-detects an unknown language by default', () => {
+ const html = highlightCode('const answer = 42;', 'not-a-language');
+ expect(html).toContain('hljs-');
+ });
+
+ it('escapes instead of auto-detecting when autoDetect is false', () => {
+ const html = highlightCode('const answer = 42;', 'not-a-language', false);
+ expect(html).not.toContain('hljs-');
+ expect(html).toBe('const answer = 42;');
+ });
+
+ it('still highlights a known language when autoDetect is false', () => {
+ const html = highlightCode('const answer = 42;', 'javascript', false);
+ expect(html).toContain('hljs-');
+ });
+
+ it('escapes html metacharacters when falling back to plain text', () => {
+ const html = highlightCode('<script>a && b</script>', 'not-a-language', false);
+ expect(html).toBe('<script>a && b</script>');
+ });
});
expect(output).toBe('Regular text with $x^2$.\n\n> Quote with $y^2$.\n\nMore text with $z^2$.');
});
});
+
+// The fast path skips the whole protect/restore pipeline when the content has
+// neither `$` nor a backslash. These pin the assumption it relies on: such
+// content is returned byte-for-byte unchanged, and anything carrying a trigger
+// character still goes through the full pipeline.
+describe('preprocessLaTeX fast path', () => {
+ const untouched = [
+ ['plain prose', 'The quick brown fox jumps over the lazy dog.'],
+ ['headings and lists', '# Title\n\n- one\n- two\n\n## Sub\n\n1. first\n2. second'],
+ ['fenced code without escapes', '```ts\nconst x = 1;\n```'],
+ ['inline code and emphasis', 'Use `npm run build` with **bold** and _italic_.'],
+ ['blockquotes', '> quoted line\n> another line'],
+ ['tables', '| a | b |\n| --- | --- |\n| 1 | 2 |'],
+ ['brackets and parens without escapes', 'array[0] and call(arg) and [link](/url)'],
+ ['multi-paragraph prose', 'First para.\n\nSecond para.\n\nThird para.']
+ ];
+
+ for (const [label, input] of untouched) {
+ test(`returns ${label} unchanged`, () => {
+ expect(preprocessLaTeX(input)).toBe(input);
+ });
+ }
+
+ test('still processes content once a trigger character is present', () => {
+ expect(preprocessLaTeX('inline \\(x^2\\) here')).toBe('inline $x^2$ here');
+ expect(preprocessLaTeX('Price: $5')).toBe('Price: \\$5');
+ });
+
+ test('fast path result matches the full pipeline for trigger-free content', () => {
+ // Appending a trigger char forces the slow path; stripping it back off
+ // must agree with what the fast path returned for the same prefix.
+ const body = 'Plain paragraph with no math.\n\nAnother paragraph here.';
+ const viaFastPath = preprocessLaTeX(body);
+ const viaFullPipeline = preprocessLaTeX(`${body}\n\n\\(z\\)`);
+
+ expect(viaFullPipeline.startsWith(viaFastPath)).toBe(true);
+ });
+});
overview / pkg / ggml / sources / llama.cpp / commitdiff