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