gstack/browse/src/memory-command.ts

116 lines
4.9 KiB
TypeScript

// `$B memory` — diagnostic snapshot of Bun heap + per-tab JS heap +
// Chromium process tree + bounded buffer sizes. Lives in its own file
// because the meta-commands dispatcher imports it lazily — projects
// that never run the diagnostic don't pay the import-graph cost (CDP
// bridge, memory-snapshot types, buffer accessors).
import type { BrowserManager } from './browser-manager';
import { formatBytes, type MemorySnapshot, type MemoryStructureStats } from './memory-snapshot';
import { getModificationHistoryStats } from './cdp-inspector';
import { getSubscriberCount as getActivitySubscriberCount } from './activity';
import { getInspectorSubscriberCount } from './server';
import { consoleBuffer, networkBuffer, dialogBuffer } from './buffers';
import { getCaptureBuffer } from './network-capture';
/**
* Assemble the MemoryStructureStats from the modules that own each buffer.
* Browser-manager doesn't take a hard dep on every buffer-owning module —
* the snapshot caller passes them in.
*/
function collectStructureStats(): MemoryStructureStats {
return {
modificationHistory: getModificationHistoryStats(),
activitySubscribers: getActivitySubscriberCount(),
inspectorSubscribers: getInspectorSubscriberCount(),
consoleBufferLen: consoleBuffer.length,
networkBufferLen: networkBuffer.length,
dialogBufferLen: dialogBuffer.length,
captureBufferBytes: getCaptureBuffer().byteSize,
};
}
/**
* Pretty-print the snapshot for terminal output. JSON mode (--json) goes
* straight through JSON.stringify so the extension footer and any test
* harness can consume it programmatically.
*/
function formatSnapshotText(s: MemorySnapshot): string {
const lines: string[] = [];
lines.push(
`Bun server: RSS: ${formatBytes(s.bunServer.rss)} ` +
`heap: ${formatBytes(s.bunServer.heapUsed)} / ${formatBytes(s.bunServer.heapTotal)} ` +
`external: ${formatBytes(s.bunServer.external)}`,
);
if (s.processes && s.processes.length > 0) {
// Group by type so the user sees "renderer: 12" vs listing 12 separate rows.
const byType: Record<string, number> = {};
for (const p of s.processes) byType[p.type] = (byType[p.type] ?? 0) + 1;
const typeSummary = Object.entries(byType)
.map(([t, n]) => `${t}=${n}`)
.join(' ');
lines.push(`Chromium processes: ${s.processes.length} total (${typeSummary})`);
} else if (s.processes === null) {
lines.push('Chromium processes: (unavailable — see notes)');
} else {
lines.push('Chromium processes: 0');
}
if (s.tabs.length > 0) {
// Sort by JS heap descending; show top 10 plus "...N more" tail.
const sorted = [...s.tabs].sort((a, b) => b.jsHeapUsed - a.jsHeapUsed);
const shown = sorted.slice(0, 10);
lines.push(`Renderers: ${s.tabs.length} tabs (top by JS heap):`);
for (const t of shown) {
const urlShort = t.url.length > 80 ? t.url.slice(0, 77) + '...' : t.url;
lines.push(
` [${formatBytes(t.jsHeapUsed).padStart(8)} JS, ` +
`${String(t.nodes).padStart(6)} nodes, ` +
`${String(t.listeners).padStart(5)} listeners] ` +
`tab #${t.id}${urlShort}`,
);
}
if (sorted.length > shown.length) {
lines.push(` ...and ${sorted.length - shown.length} more`);
}
} else {
lines.push('Renderers: (no tabs tracked)');
}
lines.push('─────────────────────────────────────────────────');
lines.push('In-memory structures (Bun side):');
const m = s.structures.modificationHistory;
lines.push(
` modificationHistory: ${m.current} / ${m.cap} entries` +
(m.evicted > 0 ? ` (${m.evicted} evicted since reset)` : ''),
);
lines.push(` inspectorSubscribers: ${s.structures.inspectorSubscribers}`);
lines.push(` activitySubscribers: ${s.structures.activitySubscribers}`);
lines.push(` consoleBuffer: ${s.structures.consoleBufferLen} entries`);
lines.push(` networkBuffer: ${s.structures.networkBufferLen} entries`);
lines.push(` dialogBuffer: ${s.structures.dialogBufferLen} entries`);
lines.push(` captureBuffer: ${formatBytes(s.structures.captureBufferBytes)}`);
if (s.notes.length > 0) {
lines.push('');
lines.push('Notes:');
for (const n of s.notes) lines.push(` - ${n}`);
}
return lines.join('\n');
}
export async function handleMemoryCommand(args: string[], bm: BrowserManager): Promise<string> {
const jsonMode = args.includes('--json');
const structures = collectStructureStats();
const snapshot = await bm.getMemorySnapshot(structures);
if (jsonMode) return JSON.stringify(snapshot);
return formatSnapshotText(snapshot);
}
/** Entry point used by the /memory HTTP endpoint — same data, always JSON. */
export async function buildMemorySnapshotJson(bm: BrowserManager): Promise<MemorySnapshot> {
const structures = collectStructureStats();
return bm.getMemorySnapshot(structures);
}