'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;