Files
openchamber/packages/ui/src/components/chat/lib/messageDisplayNormalization.ts
T
bashrusakh 59ecd86b4b perf: isolate chat streaming renders and reduce sidebar render cost (#1672)
Reworks the chat and session-sidebar render paths to cut render cascades, memory
  churn, and UI jank on large sessions and big session trees. Behavior is preserved;
  the changes are about *when* and *how much* the UI re-renders.

  ## Chat streaming
  - Freeze the streaming message's parts in the bulk turn projection during streaming,
    and re-inject live parts only in an isolated tail leaf, so a ~60/sec delta stream
    no longer re-runs the whole-session projection or re-renders unrelated rows.
    session with referential reuse of unchanged turns.
  - Memoize message rows with field-aware comparators instead of reference equality.
  - Replace the manual child-session polling in the task tool with the live SSE
    stream + a one-shot load, removing a fetch/settle state machine.

  ## History loading & scroll
  - Load an initial page fast, then prepend one older page in the background so the
    scroll container has headroom and "load older on scroll-up" fires before the user
    hits the absolute top.
  - Compensate scroll synchronously (in a layout effect, before paint) for prepends —
    including background prepends that don't originate from a user scroll — so the
    viewport stays stable instead of judder-correcting on the next frame.

  ## Markdown rendering
  - Render markdown synchronously *styled* on first paint (paragraphs, lists, code
    cards, tables, inline code) instead of raw escaped text; the async pass then only
    upgrades syntax-highlight colors. Eliminates the flash of full-width raw text.
  - Load KaTeX CSS eagerly with the main bundle instead of inside the lazy markdown
    chunk, avoiding a late stylesheet injection on first render.

  ## Sidebar
  - Hoist per-row recursive tree walks out of row comparators into per-group
    precomputed sets/keys; batch live-session lookups into a single map; add a
    group-level memo boundary.
  - Isolate rename drafts so per-keystroke typing doesn't repaint the row tree.

  ## Sync layer
  - Add a staleness guard so a slow message fetch can't repopulate a session the user
    navigated away from.
  - Throw on fetch failure for authoritative loaders so a transient blip can't read as
    an empty server response.

  ## Cleanup
  - Remove dead code (unused hooks, params, duplicated inline types) surfaced while
    reworking the above.

  ## Known issue
  - A rare, purely cosmetic first-paint width flash can still appear on large sessions;
    it has no behavioral or data impact and is tracked for a follow-up runtime trace.
2026-06-18 00:43:16 +03:00

80 lines
2.6 KiB
TypeScript

import type { Part } from '@opencode-ai/sdk/v2';
import { filterSyntheticParts } from '@/lib/messages/synthetic';
import { normalizeParts } from '../message/partUtils';
import type { ChatMessageEntry } from './turns/types';
export const hasCompactionPart = (message: ChatMessageEntry): boolean => {
return message.parts.some((part) => {
const type = (part as { type?: unknown } | null | undefined)?.type;
return type === 'compaction';
});
};
const normalizeCompactionCommandMessage = (message: ChatMessageEntry): ChatMessageEntry => {
if (!hasCompactionPart(message)) {
return message;
}
let changedParts = false;
const nextParts = message.parts.map((part) => {
const type = (part as { type?: unknown } | null | undefined)?.type;
if (type !== 'compaction') {
return part;
}
changedParts = true;
return { type: 'text', text: '/compact' } as Part;
});
const info = message.info as unknown as { clientRole?: string | null | undefined };
const needsClientRole = info.clientRole !== 'user';
if (!changedParts && !needsClientRole) {
return message;
}
return {
...message,
info: needsClientRole
? ({
...(message.info as unknown as Record<string, unknown>),
clientRole: 'user',
} as unknown as typeof message.info)
: message.info,
parts: changedParts ? nextParts : message.parts,
};
};
const normalizeMessageParts = (message: ChatMessageEntry): ChatMessageEntry => {
const parts = normalizeParts(message.parts);
if (parts.length === message.parts.length) {
return message;
}
return {
...message,
parts,
};
};
const normalizedMessageBySource = new WeakMap<ChatMessageEntry, ChatMessageEntry>();
export const getNormalizedMessageForDisplay = (message: ChatMessageEntry): ChatMessageEntry => {
const cached = normalizedMessageBySource.get(message);
if (cached) {
return cached;
}
const normalizedPartMessage = normalizeMessageParts(message);
const normalizedCompactionMessage = normalizeCompactionCommandMessage(normalizedPartMessage);
const filteredParts = filterSyntheticParts(normalizedCompactionMessage.parts);
const normalized = filteredParts === normalizedCompactionMessage.parts
? normalizedCompactionMessage
: {
...normalizedCompactionMessage,
parts: filteredParts,
};
normalizedMessageBySource.set(message, normalized);
return normalized;
};