397777089e
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
108 lines
4.4 KiB
JavaScript
108 lines
4.4 KiB
JavaScript
// tools/parallel-session-lock.mjs
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/**
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* Pure parallel-session lock — router-gate v4 Stream H Task 7.
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*
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* Prevents two Claude sessions on the same workspace from concurrently
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* mutating files. Lock file lives at
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* ~/.claude/runtime/session-lock-<workspaceHash>.json
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* with TTL-based stale recovery (default 5 minutes).
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*
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* I/O is injected (readLock/writeLock/deleteLock) so this module stays pure
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* and unit-testable. The wrapper hook (enforce-parallel-session-lock.mjs)
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* binds real fs implementations.
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*
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* Lock format:
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* { schema_version: 1, session_id, pid, acquired_at: <ms>, ttl_ms }
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*/
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import { createHash } from 'node:crypto';
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export const LOCK_SCHEMA_VERSION = 1;
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export const LOCK_DEFAULT_TTL_MS = 5 * 60 * 1000;
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/** Derive a deterministic 12-char hex workspace hash from a path. */
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export function computeWorkspaceHash(workspacePath) {
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return createHash('md5').update(String(workspacePath || ''), 'utf-8').digest('hex').slice(0, 12);
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}
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function isStale(record, now) {
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if (!record || typeof record !== 'object') return true;
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const ttl = typeof record.ttl_ms === 'number' ? record.ttl_ms : LOCK_DEFAULT_TTL_MS;
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return now - (record.acquired_at || 0) > ttl;
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}
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/**
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* 7.5 (дыра 5): жив ли процесс-держатель. process.kill(pid, 0) не убивает — лишь проверяет
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* существование: ESRCH → мёртв; EPERM → существует (нет прав) → жив; иначе → жив. Невалидный
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* pid → мёртв. Реальная реализация для обёртки; в acquire инъектируется (чистота/тестируемость).
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*/
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export function isProcessAlive(pid) {
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if (typeof pid !== 'number' || !Number.isInteger(pid) || pid <= 0) return false;
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try { process.kill(pid, 0); return true; }
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catch (e) { return e && e.code === 'EPERM'; }
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}
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/**
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* Try to acquire the lock for sessionId. Takes over stale or same-session locks.
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*
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* @param {object} args
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* @param {string} args.sessionId
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* @param {number} args.pid
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* @param {string} args.workspaceHash
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* @param {number} args.now - unix ms
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* @param {function} args.readLock - () => record | null
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* @param {function} args.writeLock - (record) => void
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* @param {number} [args.ttlMs] - override default TTL
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* @returns {{acquired: boolean, holder?: {session_id, pid, acquired_at}}}
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*/
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export function acquire({ sessionId, pid, workspaceHash, now, readLock, writeLock, ttlMs = LOCK_DEFAULT_TTL_MS, isPidAlive }) {
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const existing = readLock();
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// 7.5 (дыра 5): держатель свежего лока, чей процесс МЁРТВ, не должен блокировать на весь TTL.
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// Перехватываем, если isPidAlive предоставлен и holder.pid не жив. Без isPidAlive — старое
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// поведение (backward-compat): перехват только по stale/same-session.
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const holderDead = !!existing && typeof isPidAlive === 'function' && !isPidAlive(existing.pid);
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// Stale OR same-session OR dead-holder → take over.
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if (!existing || isStale(existing, now) || existing.session_id === sessionId || holderDead) {
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const record = {
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schema_version: LOCK_SCHEMA_VERSION,
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session_id: sessionId,
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pid,
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acquired_at: now,
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ttl_ms: ttlMs,
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};
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writeLock(record);
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return { acquired: true, holder: { session_id: sessionId, pid, acquired_at: now } };
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}
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// Fresh lock from another session — blocked.
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return {
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acquired: false,
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holder: { session_id: existing.session_id, pid: existing.pid, acquired_at: existing.acquired_at },
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};
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}
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/**
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* Same-session refresh — bumps acquired_at if we still own the lock.
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* Other-session refresh is a no-op (does not steal).
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*
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* @returns {{refreshed: boolean}}
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*/
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export function refresh({ sessionId, workspaceHash, now, readLock, writeLock, ttlMs = LOCK_DEFAULT_TTL_MS }) {
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const existing = readLock();
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if (!existing || existing.session_id !== sessionId) return { refreshed: false };
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writeLock({
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schema_version: LOCK_SCHEMA_VERSION,
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session_id: sessionId,
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pid: existing.pid,
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acquired_at: now,
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ttl_ms: ttlMs,
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});
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return { refreshed: true };
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}
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/**
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* Release the lock if we own it; no-op otherwise.
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*/
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export function release({ sessionId, workspaceHash, readLock, deleteLock }) {
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const existing = readLock();
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if (existing && existing.session_id === sessionId) deleteLock();
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}
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