53 lines
1.3 KiB
TypeScript
53 lines
1.3 KiB
TypeScript
import { randomUUID } from "node:crypto";
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import fs from "node:fs/promises";
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import path from "node:path";
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export async function readJsonFile<T>(filePath: string): Promise<T | null> {
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try {
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const raw = await fs.readFile(filePath, "utf8");
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return JSON.parse(raw) as T;
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} catch {
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return null;
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}
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}
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export async function writeJsonAtomic(
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filePath: string,
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value: unknown,
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options?: { mode?: number },
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) {
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const mode = options?.mode ?? 0o600;
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const dir = path.dirname(filePath);
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await fs.mkdir(dir, { recursive: true });
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const tmp = `${filePath}.${randomUUID()}.tmp`;
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await fs.writeFile(tmp, JSON.stringify(value, null, 2), "utf8");
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try {
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await fs.chmod(tmp, mode);
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} catch {
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// best-effort; ignore on platforms without chmod
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}
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await fs.rename(tmp, filePath);
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try {
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await fs.chmod(filePath, mode);
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} catch {
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// best-effort; ignore on platforms without chmod
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}
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}
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export function createAsyncLock() {
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let lock: Promise<void> = Promise.resolve();
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return async function withLock<T>(fn: () => Promise<T>): Promise<T> {
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const prev = lock;
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let release: (() => void) | undefined;
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lock = new Promise<void>((resolve) => {
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release = resolve;
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});
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await prev;
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try {
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return await fn();
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} finally {
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release?.();
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}
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};
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}
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