heap-snapshot-toolkit/index.d.ts

Tools for parsing Chromium heap snapshot (`*.heapsnapshot`) files and doing useful things with them

import {ReadStream} from 'node:fs'
import {
    HeapSnapshotLoader,
    HeapSnapshotModel,
    JSHeapSnapshot,
    SecondaryInitManager
} from './thirdparty/devtools-frontend/index.js'

export type JSHeapSnapshotDiff = {[name: string]: any}

/**
 * Parse a UTF-8 ReadStream or ReadableStream into a JSHeapSnapshot object.
 * @param readStream - ReadableStream | ReadStream
 */
export declare function parse (readStream: ReadableStream | ReadStream): Promise<JSHeapSnapshot>

/**
 * Diff two JSHeapSnapshots.
 * @param startSnapshot - JSHeapSnapshot
 * @param endSnapshot - JSHeapSnapshot
 */
export declare function diff(startSnapshot: JSHeapSnapshot, endSnapshot: JSHeapSnapshot): Promise<JSHeapSnapshotDiff>

export type DiffItemStart = {
    type: 'start',
    result: JSHeapSnapshot
}

export type DiffItemEnd = {
    type: 'end',
    result: JSHeapSnapshot
}

export type DiffItemDiff = {
    type: 'diff',
    result: JSHeapSnapshotDiff
}

/**
 * Diff two JSHeapsnapshots from two ReadStreams/ReadableStreams. Same as `diff()` but more memory-efficient
 * since both snapshots are not read into memory at once.
 * @param startStream
 * @param endStream
 */
export declare function diffFromStreams(startStream: any, endStream: any): AsyncGenerator<{
    type: string;
    result: DiffItemStart | DiffItemEnd | DiffItemDiff;
}, void, unknown>;

/**
 * All heap snapshot-related DevTools APIs in case you need them for something.
 */
export declare const DevToolsAPI: {
    HeapSnapshotLoader: HeapSnapshotLoader,
    HeapSnapshotModel: typeof HeapSnapshotModel,
    SecondaryInitManager: SecondaryInitManager
}