YeonGyu-Kim
48 lines
1.3 KiB
TypeScript
48 lines
1.3 KiB
TypeScript
import { mkdirSync, rmSync } from "node:fs";
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import { dirname } from "node:path";
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export const SESSION_STATE_LOCK_CONTENDED = Symbol("session-state-lock-contended");
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export type SessionStateLockResult<T> = T | typeof SESSION_STATE_LOCK_CONTENDED;
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const LOCK_RETRY_COUNT = 20;
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const LOCK_RETRY_DELAY_MS = 5;
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const LOCK_SLEEP_VIEW = new Int32Array(new SharedArrayBuffer(4));
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export function withSessionStateLock<T>(cachePath: string, callback: () => T): SessionStateLockResult<T> {
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const lockPath = `${cachePath}.lock`;
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mkdirSync(dirname(cachePath), { recursive: true });
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for (let attempt = 0; attempt < LOCK_RETRY_COUNT; attempt += 1) {
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try {
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mkdirSync(lockPath);
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try {
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return callback();
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} finally {
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rmSync(lockPath, { recursive: true, force: true });
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}
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} catch (error) {
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if (errorCode(error) === "EEXIST") {
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sleepSync(LOCK_RETRY_DELAY_MS);
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continue;
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}
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throw error;
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}
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}
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return SESSION_STATE_LOCK_CONTENDED;
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}
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function errorCode(error: unknown): unknown {
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if (!isRecord(error)) {
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return undefined;
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}
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return Reflect.get(error, "code");
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}
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function isRecord(value: unknown): value is Record<string, unknown> {
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return typeof value === "object" && value !== null && !Array.isArray(value);
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}
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function sleepSync(milliseconds: number): void {
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Atomics.wait(LOCK_SLEEP_VIEW, 0, 0, milliseconds);
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}
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