54 lines
1.3 KiB
TypeScript
54 lines
1.3 KiB
TypeScript
// Copyright 2024 Signal Messenger, LLC
|
|
// SPDX-License-Identifier: AGPL-3.0-only
|
|
|
|
import { type FileHandle, open } from 'node:fs/promises';
|
|
import { Buffer } from 'node:buffer';
|
|
import { InputStream } from '@signalapp/libsignal-client/dist/io';
|
|
|
|
export class FileStream extends InputStream {
|
|
private file: FileHandle | undefined;
|
|
private position = 0;
|
|
private buffer = Buffer.alloc(16 * 1024);
|
|
private initPromise: Promise<unknown> | undefined;
|
|
|
|
constructor(private readonly filePath: string) {
|
|
super();
|
|
}
|
|
|
|
public async close(): Promise<void> {
|
|
await this.initPromise;
|
|
await this.file?.close();
|
|
}
|
|
|
|
async read(amount: number): Promise<Buffer> {
|
|
const file = await this.lazyOpen();
|
|
if (this.buffer.length < amount) {
|
|
this.buffer = Buffer.alloc(amount);
|
|
}
|
|
const { bytesRead } = await file.read(
|
|
this.buffer,
|
|
0,
|
|
amount,
|
|
this.position
|
|
);
|
|
this.position += bytesRead;
|
|
return this.buffer.slice(0, bytesRead);
|
|
}
|
|
|
|
async skip(amount: number): Promise<void> {
|
|
this.position += amount;
|
|
}
|
|
|
|
private async lazyOpen(): Promise<FileHandle> {
|
|
await this.initPromise;
|
|
|
|
if (this.file) {
|
|
return this.file;
|
|
}
|
|
|
|
const filePromise = open(this.filePath);
|
|
this.initPromise = filePromise;
|
|
this.file = await filePromise;
|
|
return this.file;
|
|
}
|
|
}
|