langsmith
Version:
Client library to connect to the LangSmith Observability and Evaluation Platform.
104 lines (103 loc) • 3.15 kB
JavaScript
import * as fsUtils from "./fs.js";
const LOCK_POLL_INTERVAL_MS = 10;
const LOCK_STALE_AFTER_MS = 10_000;
const LOCK_METADATA_FILE = "created_at";
function sleep(ms) {
return new Promise((resolve) => setTimeout(resolve, ms));
}
function isEEXIST(err) {
return (typeof err === "object" &&
err !== null &&
err.code === "EEXIST");
}
function lockMetadataLines(lockDir) {
try {
return fsUtils
.readFileSync(fsUtils.path.join(lockDir, LOCK_METADATA_FILE))
.split("\n");
}
catch {
return undefined;
}
}
function lockCreatedAtMs(lockDir) {
const lines = lockMetadataLines(lockDir);
if (lines && lines[0] && lines[0].trim()) {
const parsed = Date.parse(lines[0].trim());
if (!Number.isNaN(parsed)) {
return parsed;
}
}
return fsUtils.statMtimeMs(lockDir);
}
function lockOwner(lockDir) {
const lines = lockMetadataLines(lockDir);
if (lines && lines.length >= 2 && lines[1].trim()) {
return lines[1].trim();
}
return undefined;
}
async function removeStaleLock(lockDir) {
const createdAt = lockCreatedAtMs(lockDir);
if (createdAt === undefined ||
Date.now() - createdAt <= LOCK_STALE_AFTER_MS) {
return false;
}
await fsUtils.rmRecursive(lockDir);
return true;
}
/**
* Acquire an exclusive cross-process lock for refreshing OAuth tokens.
*
* Uses an atomic-`mkdir` directory lock at `<configPath>.oauth.lock.lock` with a
* stale-break heuristic and owner-checked release, mirroring langsmith-go's
* non-POSIX path. `deadline` is a `Date.now()`-based timestamp; acquisition
* rejects once it passes. Callers treat any rejection as "skip refresh, use the
* current token".
*/
export async function acquireOAuthRefreshLock(configPath, deadline) {
const lockDir = `${configPath}.oauth.lock.lock`;
const parent = fsUtils.path.dirname(lockDir);
if (parent) {
await fsUtils.mkdir(parent);
}
const owner = globalThis.crypto.randomUUID();
for (;;) {
try {
await fsUtils.mkdirExclusive(lockDir);
}
catch (err) {
if (!isEEXIST(err)) {
throw err;
}
if (!(await removeStaleLock(lockDir))) {
if (Date.now() >= deadline) {
throw new Error("timed out acquiring OAuth refresh lock");
}
await sleep(Math.min(LOCK_POLL_INTERVAL_MS, Math.max(0, deadline - Date.now())));
}
continue;
}
try {
await fsUtils.writeFileAtomic(fsUtils.path.join(lockDir, LOCK_METADATA_FILE), `${new Date().toISOString()}\n${owner}\n`);
}
catch (err) {
await fsUtils.rmRecursive(lockDir);
throw err;
}
break;
}
return {
async release() {
if (lockOwner(lockDir) === owner) {
await fsUtils.rmRecursive(lockDir);
}
},
};
}
// Exposed for tests only.
export const _internal = {
LOCK_METADATA_FILE,
LOCK_STALE_AFTER_MS,
lockOwner,
};