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authorpack <pack@packgekko.xyz>2026-08-09 10:37:07 +0000
committerpack <pack@packgekko.xyz>2026-08-09 10:37:07 +0000
commit55a4f1fc869e41aca748c63d3018f0448b1606e0 (patch)
treed132d1d01772b6d53faee3e63c534dea5706b78a /node_modules/tar/dist/esm/path-reservations.js
downloadcrud-55a4f1fc869e41aca748c63d3018f0448b1606e0.tar.gz
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+// A path exclusive reservation system
+// reserve([list, of, paths], fn)
+// When the fn is first in line for all its paths, it
+// is called with a cb that clears the reservation.
+//
+// Used by async unpack to avoid clobbering paths in use,
+// while still allowing maximal safe parallelization.
+import { join } from 'node:path';
+import { normalizeUnicode } from './normalize-unicode.js';
+import { stripTrailingSlashes } from './strip-trailing-slashes.js';
+const platform = process.env.TESTING_TAR_FAKE_PLATFORM || process.platform;
+const isWindows = platform === 'win32';
+// return a set of parent dirs for a given path
+// '/a/b/c/d' -> ['/', '/a', '/a/b', '/a/b/c', '/a/b/c/d']
+const getDirs = (path) => {
+ const dirs = path
+ .split('/')
+ .slice(0, -1)
+ .reduce((set, path) => {
+ const s = set.at(-1);
+ if (s !== undefined) {
+ path = join(s, path);
+ }
+ set.push(path || '/');
+ return set;
+ }, []);
+ return dirs;
+};
+export class PathReservations {
+ // path => [function or Set]
+ // A Set object means a directory reservation
+ // A fn is a direct reservation on that path
+ #queues = new Map();
+ // fn => {paths:[path,...], dirs:[path, ...]}
+ #reservations = new Map();
+ // functions currently running
+ #running = new Set();
+ reserve(paths, fn) {
+ paths =
+ isWindows ?
+ ['win32 parallelization disabled']
+ : paths.map(p => {
+ // don't need normPath, because we skip this entirely for windows
+ return stripTrailingSlashes(join(normalizeUnicode(p)));
+ });
+ const dirs = new Set(paths.map(path => getDirs(path)).reduce((a, b) => a.concat(b)));
+ this.#reservations.set(fn, { dirs, paths });
+ for (const p of paths) {
+ const q = this.#queues.get(p);
+ if (!q) {
+ this.#queues.set(p, [fn]);
+ }
+ else {
+ q.push(fn);
+ }
+ }
+ for (const dir of dirs) {
+ const q = this.#queues.get(dir);
+ if (!q) {
+ this.#queues.set(dir, [new Set([fn])]);
+ }
+ else {
+ const l = q.at(-1);
+ if (l instanceof Set) {
+ l.add(fn);
+ }
+ else {
+ q.push(new Set([fn]));
+ }
+ }
+ }
+ return this.#run(fn);
+ }
+ // return the queues for each path the function cares about
+ // fn => {paths, dirs}
+ #getQueues(fn) {
+ const res = this.#reservations.get(fn);
+ /* c8 ignore start */
+ if (!res) {
+ throw new Error('function does not have any path reservations');
+ }
+ /* c8 ignore stop */
+ return {
+ paths: res.paths.map((path) => this.#queues.get(path)),
+ dirs: [...res.dirs].map(path => this.#queues.get(path)),
+ };
+ }
+ // check if fn is first in line for all its paths, and is
+ // included in the first set for all its dir queues
+ check(fn) {
+ const { paths, dirs } = this.#getQueues(fn);
+ return (paths.every(q => q && q[0] === fn) &&
+ dirs.every(q => q && q[0] instanceof Set && q[0].has(fn)));
+ }
+ // run the function if it's first in line and not already running
+ #run(fn) {
+ if (this.#running.has(fn) || !this.check(fn)) {
+ return false;
+ }
+ this.#running.add(fn);
+ fn(() => this.#clear(fn));
+ return true;
+ }
+ #clear(fn) {
+ if (!this.#running.has(fn)) {
+ return false;
+ }
+ const res = this.#reservations.get(fn);
+ /* c8 ignore start */
+ if (!res) {
+ throw new Error('invalid reservation');
+ }
+ /* c8 ignore stop */
+ const { paths, dirs } = res;
+ const next = new Set();
+ for (const path of paths) {
+ const q = this.#queues.get(path);
+ /* c8 ignore start */
+ if (!q || q?.[0] !== fn) {
+ continue;
+ }
+ /* c8 ignore stop */
+ const q0 = q[1];
+ if (!q0) {
+ this.#queues.delete(path);
+ continue;
+ }
+ q.shift();
+ if (typeof q0 === 'function') {
+ next.add(q0);
+ }
+ else {
+ for (const f of q0) {
+ next.add(f);
+ }
+ }
+ }
+ for (const dir of dirs) {
+ const q = this.#queues.get(dir);
+ const q0 = q?.[0];
+ /* c8 ignore next - type safety only */
+ if (!q || !(q0 instanceof Set))
+ continue;
+ if (q0.size === 1 && q.length === 1) {
+ this.#queues.delete(dir);
+ continue;
+ }
+ else if (q0.size === 1) {
+ q.shift();
+ // next one must be a function,
+ // or else the Set would've been reused
+ const n = q[0];
+ if (typeof n === 'function') {
+ next.add(n);
+ }
+ }
+ else {
+ q0.delete(fn);
+ }
+ }
+ this.#running.delete(fn);
+ next.forEach(fn => this.#run(fn));
+ return true;
+ }
+}
+//# sourceMappingURL=path-reservations.js.map \ No newline at end of file