gstack/browse/src/memory-snapshot.ts

74 lines
2.4 KiB
TypeScript

// Shared types for the $B memory diagnostic command and the /memory
// endpoint. Lives in its own module so server.ts, read-commands.ts, and
// the extension footer poll can import without taking a circular dep on
// browser-manager.ts.
//
// Background: the gbrowser-OOM investigation (160 GB Activity Monitor
// reading on a friend's machine) needed a diagnostic that could land
// before the next incident — measurement comes first, fixes come after.
// $B memory is that diagnostic.
/** Counts/bytes for the bounded in-memory structures on the Bun side. */
export interface MemoryStructureStats {
modificationHistory: { current: number; cap: number; evicted: number };
activitySubscribers: number;
inspectorSubscribers: number;
consoleBufferLen: number;
networkBufferLen: number;
dialogBufferLen: number;
captureBufferBytes: number;
}
/** Per-tab JS heap snapshot (CDP Performance.getMetrics). */
export interface MemoryTabSnapshot {
id: number;
url: string;
title: string;
jsHeapUsed: number;
jsHeapTotal: number;
documents: number;
nodes: number;
listeners: number;
}
/** Chromium process metadata via CDP SystemInfo.getProcessInfo. */
export interface MemoryProcess {
/** Chromium-internal process id (not OS PID). */
id: number;
/** 'browser' | 'renderer' | 'gpu' | 'utility' | 'extension' | ... */
type: string;
/** CPU time accumulated since process start (seconds). */
cpuTime: number;
}
export interface MemorySnapshot {
bunServer: {
rss: number;
heapUsed: number;
heapTotal: number;
external: number;
};
tabs: MemoryTabSnapshot[];
/**
* Chromium process tree. `null` when no browser handle is available
* (server in connection mode, or browser not yet launched).
*
* Per-process RSS is NOT included: SystemInfo.getProcessInfo returns
* id+type+cpuTime but Chromium does not expose RSS via CDP. The
* `notes[]` field tells the caller why — see the follow-up TODO
* "native/GPU memory breakdown" for the deferred fix.
*/
processes: MemoryProcess[] | null;
structures: MemoryStructureStats;
capturedAt: number;
notes: string[];
}
/** Format bytes as a short human string ("1.4 GB", "312 MB", "84 KB"). */
export function formatBytes(n: number): string {
if (n < 1024) return `${n} B`;
if (n < 1024 * 1024) return `${(n / 1024).toFixed(1)} KB`;
if (n < 1024 * 1024 * 1024) return `${(n / 1024 / 1024).toFixed(1)} MB`;
return `${(n / 1024 / 1024 / 1024).toFixed(2)} GB`;
}