name : nodefs-handler.js 'use strict'; const fs = require('fs'); const sysPath = require('path'); const { promisify } = require('util'); const isBinaryPath = require('is-binary-path'); const { isWindows, isLinux, EMPTY_FN, EMPTY_STR, KEY_LISTENERS, KEY_ERR, KEY_RAW, HANDLER_KEYS, EV_CHANGE, EV_ADD, EV_ADD_DIR, EV_ERROR, STR_DATA, STR_END, BRACE_START, STAR } = require('./constants'); const THROTTLE_MODE_WATCH = 'watch'; const open = promisify(fs.open); const stat = promisify(fs.stat); const lstat = promisify(fs.lstat); const close = promisify(fs.close); const fsrealpath = promisify(fs.realpath); const statMethods = { lstat, stat }; // TODO: emit errors properly. Example: EMFILE on Macos. const foreach = (val, fn) => { if (val instanceof Set) { val.forEach(fn); } else { fn(val); } }; const addAndConvert = (main, prop, item) => { let container = main[prop]; if (!(container instanceof Set)) { main[prop] = container = new Set([container]); } container.add(item); }; const clearItem = cont => key => { const set = cont[key]; if (set instanceof Set) { set.clear(); } else { delete cont[key]; } }; const delFromSet = (main, prop, item) => { const container = main[prop]; if (container instanceof Set) { container.delete(item); } else if (container === item) { delete main[prop]; } }; const isEmptySet = (val) => val instanceof Set ? val.size === 0 : !val; /** * @typedef {String} Path */ // fs_watch helpers // object to hold per-process fs_watch instances // (may be shared across chokidar FSWatcher instances) /** * @typedef {Object} FsWatchContainer * @property {Set} listeners * @property {Set} errHandlers * @property {Set} rawEmitters * @property {fs.FSWatcher=} watcher * @property {Boolean=} watcherUnusable */ /** * @type {Map<String,FsWatchContainer>} */ const FsWatchInstances = new Map(); /** * Instantiates the fs_watch interface * @param {String} path to be watched * @param {Object} options to be passed to fs_watch * @param {Function} listener main event handler * @param {Function} errHandler emits info about errors * @param {Function} emitRaw emits raw event data * @returns {fs.FSWatcher} new fsevents instance */ function createFsWatchInstance(path, options, listener, errHandler, emitRaw) { const handleEvent = (rawEvent, evPath) => { listener(path); emitRaw(rawEvent, evPath, {watchedPath: path}); // emit based on events occurring for files from a directory's watcher in // case the file's watcher misses it (and rely on throttling to de-dupe) if (evPath && path !== evPath) { fsWatchBroadcast( sysPath.resolve(path, evPath), KEY_LISTENERS, sysPath.join(path, evPath) ); } }; try { return fs.watch(path, options, handleEvent); } catch (error) { errHandler(error); } } /** * Helper for passing fs_watch event data to a collection of listeners * @param {Path} fullPath absolute path bound to fs_watch instance * @param {String} type listener type * @param {*=} val1 arguments to be passed to listeners * @param {*=} val2 * @param {*=} val3 */ const fsWatchBroadcast = (fullPath, type, val1, val2, val3) => { const cont = FsWatchInstances.get(fullPath); if (!cont) return; foreach(cont[type], (listener) => { listener(val1, val2, val3); }); }; /** * Instantiates the fs_watch interface or binds listeners * to an existing one covering the same file system entry * @param {String} path * @param {String} fullPath absolute path * @param {Object} options to be passed to fs_watch * @param {Object} handlers container for event listener functions */ const setFsWatchListener = (path, fullPath, options, handlers) => { const {listener, errHandler, rawEmitter} = handlers; let cont = FsWatchInstances.get(fullPath); /** @type {fs.FSWatcher=} */ let watcher; if (!options.persistent) { watcher = createFsWatchInstance( path, options, listener, errHandler, rawEmitter ); return watcher.close.bind(watcher); } if (cont) { addAndConvert(cont, KEY_LISTENERS, listener); addAndConvert(cont, KEY_ERR, errHandler); addAndConvert(cont, KEY_RAW, rawEmitter); } else { watcher = createFsWatchInstance( path, options, fsWatchBroadcast.bind(null, fullPath, KEY_LISTENERS), errHandler, // no need to use broadcast here fsWatchBroadcast.bind(null, fullPath, KEY_RAW) ); if (!watcher) return; watcher.on(EV_ERROR, async (error) => { const broadcastErr = fsWatchBroadcast.bind(null, fullPath, KEY_ERR); cont.watcherUnusable = true; // documented since Node 10.4.1 // Workaround for https://github.com/joyent/node/issues/4337 if (isWindows && error.code === 'EPERM') { try { const fd = await open(path, 'r'); await close(fd); broadcastErr(error); } catch (err) {} } else { broadcastErr(error); } }); cont = { listeners: listener, errHandlers: errHandler, rawEmitters: rawEmitter, watcher }; FsWatchInstances.set(fullPath, cont); } // const index = cont.listeners.indexOf(listener); // removes this instance's listeners and closes the underlying fs_watch // instance if there are no more listeners left return () => { delFromSet(cont, KEY_LISTENERS, listener); delFromSet(cont, KEY_ERR, errHandler); delFromSet(cont, KEY_RAW, rawEmitter); if (isEmptySet(cont.listeners)) { // Check to protect against issue gh-730. // if (cont.watcherUnusable) { cont.watcher.close(); // } FsWatchInstances.delete(fullPath); HANDLER_KEYS.forEach(clearItem(cont)); cont.watcher = undefined; Object.freeze(cont); } }; }; // fs_watchFile helpers // object to hold per-process fs_watchFile instances // (may be shared across chokidar FSWatcher instances) const FsWatchFileInstances = new Map(); /** * Instantiates the fs_watchFile interface or binds listeners * to an existing one covering the same file system entry * @param {String} path to be watched * @param {String} fullPath absolute path * @param {Object} options options to be passed to fs_watchFile * @param {Object} handlers container for event listener functions * @returns {Function} closer */ const setFsWatchFileListener = (path, fullPath, options, handlers) => { const {listener, rawEmitter} = handlers; let cont = FsWatchFileInstances.get(fullPath); /* eslint-disable no-unused-vars, prefer-destructuring */ let listeners = new Set(); let rawEmitters = new Set(); const copts = cont && cont.options; if (copts && (copts.persistent < options.persistent || copts.interval > options.interval)) { // "Upgrade" the watcher to persistence or a quicker interval. // This creates some unlikely edge case issues if the user mixes // settings in a very weird way, but solving for those cases // doesn't seem worthwhile for the added complexity. listeners = cont.listeners; rawEmitters = cont.rawEmitters; fs.unwatchFile(fullPath); cont = undefined; } /* eslint-enable no-unused-vars, prefer-destructuring */ if (cont) { addAndConvert(cont, KEY_LISTENERS, listener); addAndConvert(cont, KEY_RAW, rawEmitter); } else { // TODO // listeners.add(listener); // rawEmitters.add(rawEmitter); cont = { listeners: listener, rawEmitters: rawEmitter, options, watcher: fs.watchFile(fullPath, options, (curr, prev) => { foreach(cont.rawEmitters, (rawEmitter) => { rawEmitter(EV_CHANGE, fullPath, {curr, prev}); }); const currmtime = curr.mtimeMs; if (curr.size !== prev.size || currmtime > prev.mtimeMs || currmtime === 0) { foreach(cont.listeners, (listener) => listener(path, curr)); } }) }; FsWatchFileInstances.set(fullPath, cont); } // const index = cont.listeners.indexOf(listener); // Removes this instance's listeners and closes the underlying fs_watchFile // instance if there are no more listeners left. return () => { delFromSet(cont, KEY_LISTENERS, listener); delFromSet(cont, KEY_RAW, rawEmitter); if (isEmptySet(cont.listeners)) { FsWatchFileInstances.delete(fullPath); fs.unwatchFile(fullPath); cont.options = cont.watcher = undefined; Object.freeze(cont); } }; }; /** * @mixin */ class NodeFsHandler { /** * @param {import("../index").FSWatcher} fsW */ constructor(fsW) { this.fsw = fsW; this._boundHandleError = (error) => fsW._handleError(error); } /** * Watch file for changes with fs_watchFile or fs_watch. * @param {String} path to file or dir * @param {Function} listener on fs change * @returns {Function} closer for the watcher instance */ _watchWithNodeFs(path, listener) { const opts = this.fsw.options; const directory = sysPath.dirname(path); const basename = sysPath.basename(path); const parent = this.fsw._getWatchedDir(directory); parent.add(basename); const absolutePath = sysPath.resolve(path); const options = {persistent: opts.persistent}; if (!listener) listener = EMPTY_FN; let closer; if (opts.usePolling) { options.interval = opts.enableBinaryInterval && isBinaryPath(basename) ? opts.binaryInterval : opts.interval; closer = setFsWatchFileListener(path, absolutePath, options, { listener, rawEmitter: this.fsw._emitRaw }); } else { closer = setFsWatchListener(path, absolutePath, options, { listener, errHandler: this._boundHandleError, rawEmitter: this.fsw._emitRaw }); } return closer; } /** * Watch a file and emit add event if warranted. * @param {Path} file Path * @param {fs.Stats} stats result of fs_stat * @param {Boolean} initialAdd was the file added at watch instantiation? * @returns {Function} closer for the watcher instance */ _handleFile(file, stats, initialAdd) { if (this.fsw.closed) { return; } const dirname = sysPath.dirname(file); const basename = sysPath.basename(file); const parent = this.fsw._getWatchedDir(dirname); // stats is always present let prevStats = stats; // if the file is already being watched, do nothing if (parent.has(basename)) return; const listener = async (path, newStats) => { if (!this.fsw._throttle(THROTTLE_MODE_WATCH, file, 5)) return; if (!newStats || newStats.mtimeMs === 0) { try { const newStats = await stat(file); if (this.fsw.closed) return; // Check that change event was not fired because of changed only accessTime. const at = newStats.atimeMs; const mt = newStats.mtimeMs; if (!at || at <= mt || mt !== prevStats.mtimeMs) { this.fsw._emit(EV_CHANGE, file, newStats); } if (isLinux && prevStats.ino !== newStats.ino) { this.fsw._closeFile(path) prevStats = newStats; this.fsw._addPathCloser(path, this._watchWithNodeFs(file, listener)); } else { prevStats = newStats; } } catch (error) { // Fix issues where mtime is null but file is still present this.fsw._remove(dirname, basename); } // add is about to be emitted if file not already tracked in parent } else if (parent.has(basename)) { // Check that change event was not fired because of changed only accessTime. const at = newStats.atimeMs; const mt = newStats.mtimeMs; if (!at || at <= mt || mt !== prevStats.mtimeMs) { this.fsw._emit(EV_CHANGE, file, newStats); } prevStats = newStats; } } // kick off the watcher const closer = this._watchWithNodeFs(file, listener); // emit an add event if we're supposed to if (!(initialAdd && this.fsw.options.ignoreInitial) && this.fsw._isntIgnored(file)) { if (!this.fsw._throttle(EV_ADD, file, 0)) return; this.fsw._emit(EV_ADD, file, stats); } return closer; } /** * Handle symlinks encountered while reading a dir. * @param {Object} entry returned by readdirp * @param {String} directory path of dir being read * @param {String} path of this item * @param {String} item basename of this item * @returns {Promise<Boolean>} true if no more processing is needed for this entry. */ async _handleSymlink(entry, directory, path, item) { if (this.fsw.closed) { return; } const full = entry.fullPath; const dir = this.fsw._getWatchedDir(directory); if (!this.fsw.options.followSymlinks) { // watch symlink directly (don't follow) and detect changes this.fsw._incrReadyCount(); let linkPath; try { linkPath = await fsrealpath(path); } catch (e) { this.fsw._emitReady(); return true; } if (this.fsw.closed) return; if (dir.has(item)) { if (this.fsw._symlinkPaths.get(full) !== linkPath) { this.fsw._symlinkPaths.set(full, linkPath); this.fsw._emit(EV_CHANGE, path, entry.stats); } } else { dir.add(item); this.fsw._symlinkPaths.set(full, linkPath); this.fsw._emit(EV_ADD, path, entry.stats); } this.fsw._emitReady(); return true; } // don't follow the same symlink more than once if (this.fsw._symlinkPaths.has(full)) { return true; } this.fsw._symlinkPaths.set(full, true); } _handleRead(directory, initialAdd, wh, target, dir, depth, throttler) { // Normalize the directory name on Windows directory = sysPath.join(directory, EMPTY_STR); if (!wh.hasGlob) { throttler = this.fsw._throttle('readdir', directory, 1000); if (!throttler) return; } const previous = this.fsw._getWatchedDir(wh.path); const current = new Set(); let stream = this.fsw._readdirp(directory, { fileFilter: entry => wh.filterPath(entry), directoryFilter: entry => wh.filterDir(entry), depth: 0 }).on(STR_DATA, async (entry) => { if (this.fsw.closed) { stream = undefined; return; } const item = entry.path; let path = sysPath.join(directory, item); current.add(item); if (entry.stats.isSymbolicLink() && await this._handleSymlink(entry, directory, path, item)) { return; } if (this.fsw.closed) { stream = undefined; return; } // Files that present in current directory snapshot // but absent in previous are added to watch list and // emit `add` event. if (item === target || !target && !previous.has(item)) { this.fsw._incrReadyCount(); // ensure relativeness of path is preserved in case of watcher reuse path = sysPath.join(dir, sysPath.relative(dir, path)); this._addToNodeFs(path, initialAdd, wh, depth + 1); } }).on(EV_ERROR, this._boundHandleError); return new Promise(resolve => stream.once(STR_END, () => { if (this.fsw.closed) { stream = undefined; return; } const wasThrottled = throttler ? throttler.clear() : false; resolve(); // Files that absent in current directory snapshot // but present in previous emit `remove` event // and are removed from @watched[directory]. previous.getChildren().filter((item) => { return item !== directory && !current.has(item) && // in case of intersecting globs; // a path may have been filtered out of this readdir, but // shouldn't be removed because it matches a different glob (!wh.hasGlob || wh.filterPath({ fullPath: sysPath.resolve(directory, item) })); }).forEach((item) => { this.fsw._remove(directory, item); }); stream = undefined; // one more time for any missed in case changes came in extremely quickly if (wasThrottled) this._handleRead(directory, false, wh, target, dir, depth, throttler); }) ); } /** * Read directory to add / remove files from `@watched` list and re-read it on change. * @param {String} dir fs path * @param {fs.Stats} stats * @param {Boolean} initialAdd * @param {Number} depth relative to user-supplied path * @param {String} target child path targeted for watch * @param {Object} wh Common watch helpers for this path * @param {String} realpath * @returns {Promise<Function>} closer for the watcher instance. */ async _handleDir(dir, stats, initialAdd, depth, target, wh, realpath) { const parentDir = this.fsw._getWatchedDir(sysPath.dirname(dir)); const tracked = parentDir.has(sysPath.basename(dir)); if (!(initialAdd && this.fsw.options.ignoreInitial) && !target && !tracked) { if (!wh.hasGlob || wh.globFilter(dir)) this.fsw._emit(EV_ADD_DIR, dir, stats); } // ensure dir is tracked (harmless if redundant) parentDir.add(sysPath.basename(dir)); this.fsw._getWatchedDir(dir); let throttler; let closer; const oDepth = this.fsw.options.depth; if ((oDepth == null || depth <= oDepth) && !this.fsw._symlinkPaths.has(realpath)) { if (!target) { await this._handleRead(dir, initialAdd, wh, target, dir, depth, throttler); if (this.fsw.closed) return; } closer = this._watchWithNodeFs(dir, (dirPath, stats) => { // if current directory is removed, do nothing if (stats && stats.mtimeMs === 0) return; this._handleRead(dirPath, false, wh, target, dir, depth, throttler); }); } return closer; } /** * Handle added file, directory, or glob pattern. * Delegates call to _handleFile / _handleDir after checks. * @param {String} path to file or ir * @param {Boolean} initialAdd was the file added at watch instantiation? * @param {Object} priorWh depth relative to user-supplied path * @param {Number} depth Child path actually targeted for watch * @param {String=} target Child path actually targeted for watch * @returns {Promise} */ async _addToNodeFs(path, initialAdd, priorWh, depth, target) { const ready = this.fsw._emitReady; if (this.fsw._isIgnored(path) || this.fsw.closed) { ready(); return false; } const wh = this.fsw._getWatchHelpers(path, depth); if (!wh.hasGlob && priorWh) { wh.hasGlob = priorWh.hasGlob; wh.globFilter = priorWh.globFilter; wh.filterPath = entry => priorWh.filterPath(entry); wh.filterDir = entry => priorWh.filterDir(entry); } // evaluate what is at the path we're being asked to watch try { const stats = await statMethods[wh.statMethod](wh.watchPath); if (this.fsw.closed) return; if (this.fsw._isIgnored(wh.watchPath, stats)) { ready(); return false; } const follow = this.fsw.options.followSymlinks && !path.includes(STAR) && !path.includes(BRACE_START); let closer; if (stats.isDirectory()) { const absPath = sysPath.resolve(path); const targetPath = follow ? await fsrealpath(path) : path; if (this.fsw.closed) return; closer = await this._handleDir(wh.watchPath, stats, initialAdd, depth, target, wh, targetPath); if (this.fsw.closed) return; // preserve this symlink's target path if (absPath !== targetPath && targetPath !== undefined) { this.fsw._symlinkPaths.set(absPath, targetPath); } } else if (stats.isSymbolicLink()) { const targetPath = follow ? await fsrealpath(path) : path; if (this.fsw.closed) return; const parent = sysPath.dirname(wh.watchPath); this.fsw._getWatchedDir(parent).add(wh.watchPath); this.fsw._emit(EV_ADD, wh.watchPath, stats); closer = await this._handleDir(parent, stats, initialAdd, depth, path, wh, targetPath); if (this.fsw.closed) return; // preserve this symlink's target path if (targetPath !== undefined) { this.fsw._symlinkPaths.set(sysPath.resolve(path), targetPath); } } else { closer = this._handleFile(wh.watchPath, stats, initialAdd); } ready(); this.fsw._addPathCloser(path, closer); return false; } catch (error) { if (this.fsw._handleError(error)) { ready(); return path; } } } } module.exports = NodeFsHandler;