eltro/lib/watch/index.mjs

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import fs from 'fs'
import path from 'path'
import util from 'util'
import events from 'events'
import hasNativeRecursive from './has-native-recursive.mjs'
import * as is from './is.mjs'
const EVENT_UPDATE = 'update';
const EVENT_REMOVE = 'remove';
const SKIP_FLAG = Symbol('skip');
function hasDup(arr) {
return arr.some(function(v, i, self) {
return self.indexOf(v) !== i;
});
}
function unique(arr) {
return arr.filter(function(v, i, self) {
return self.indexOf(v) === i;
});
}
// One level flat
function flat1(arr) {
return arr.reduce(function(acc, v) {
return acc.concat(v);
}, []);
}
function assertEncoding(encoding) {
if (encoding && encoding !== 'buffer' && !Buffer.isEncoding(encoding)) {
throw new Error('Unknown encoding: ' + encoding);
}
}
function guard(fn) {
if (is.func(fn)) {
return function(arg, action) {
if (fn(arg, false)) action();
}
}
if (is.regExp(fn)) {
return function(arg, action) {
if (fn.test(arg)) action();
}
}
return function(arg, action) {
action();
}
}
function composeMessage(names) {
return names.map(function(n) {
return is.exists(n)
? [EVENT_UPDATE, n]
: [EVENT_REMOVE, n];
});
}
function getMessages(cache) {
var filtered = unique(cache);
// Saving file from an editor? If so, assuming the
// non-existed files in the cache are temporary files
// generated by an editor and thus be filtered.
var reg = /~$|^\.#|^##$/g;
var hasSpecialChar = cache.some(function(c) {
return reg.test(c);
});
if (hasSpecialChar) {
var dup = hasDup(cache.map(function(c) {
return c.replace(reg, '');
}));
if (dup) {
filtered = filtered.filter(function(m) {
return is.exists(m);
});
}
}
return composeMessage(filtered);
}
function debounce(info, fn) {
var timer, cache = [];
var encoding = info.options.encoding;
var delay = info.options.delay;
if (!is.number(delay)) {
delay = 200;
}
function handle() {
getMessages(cache).forEach(function(msg) {
msg[1] = Buffer.from(msg[1]);
if (encoding !== 'buffer') {
msg[1] = msg[1].toString(encoding);
}
fn.apply(null, msg);
});
timer = null;
cache = [];
}
return function(rawEvt, name) {
cache.push(name);
if (!timer) {
timer = setTimeout(handle, delay);
}
}
}
function createDupsFilter() {
var memo = {};
return function(fn) {
return function(evt, name) {
memo[evt + name] = [evt, name];
setTimeout(function() {
Object.keys(memo).forEach(function(n) {
fn.apply(null, memo[n]);
});
memo = {};
});
}
}
}
function tryWatch(watcher, dir, opts) {
try {
return fs.watch(dir, opts);
} catch (e) {
process.nextTick(function() {
watcher.emit('error', e);
});
}
}
function getSubDirectories(dir, fn, done = function() {}) {
if (is.directory(dir)) {
fs.readdir(dir, function(err, all) {
if (err) {
// don't throw permission errors.
if (/^(EPERM|EACCES)$/.test(err.code)) {
console.warn('Warning: Cannot access %s.', dir);
} else {
throw err;
}
}
else {
all.forEach(function(f) {
var sdir = path.join(dir, f);
if (is.directory(sdir)) fn(sdir);
});
done();
}
});
} else {
done();
}
}
function semaphore(final) {
var counter = 0;
return function start() {
counter++;
return function stop() {
counter--;
if (counter === 0) final();
};
};
}
function nullCounter() {
return function nullStop() {};
}
function shouldNotSkip(filePath, filter) {
// watch it only if the filter is not function
// or not being skipped explicitly.
return !is.func(filter) || filter(filePath, SKIP_FLAG) !== SKIP_FLAG;
}
var deprecationWarning = util.deprecate(
function() {},
'(node-watch) First param in callback function\
is replaced with event name since 0.5.0, use\
`(evt, filename) => {}` if you want to get the filename'
);
function Watcher() {
events.EventEmitter.call(this);
this.watchers = {};
this._isReady = false;
this._isClosed = false;
}
util.inherits(Watcher, events.EventEmitter);
Watcher.prototype.expose = function() {
var expose = {};
var self = this;
var methods = [
'on', 'emit', 'once',
'close', 'isClosed',
'listeners', 'setMaxListeners', 'getMaxListeners',
'getWatchedPaths'
];
methods.forEach(function(name) {
expose[name] = function() {
return self[name].apply(self, arguments);
}
});
expose.options = self.options
return expose;
}
Watcher.prototype.isClosed = function() {
return this._isClosed;
}
Watcher.prototype.close = function(fullPath) {
var self = this;
if (fullPath) {
var watcher = this.watchers[fullPath];
if (watcher && watcher.close) {
watcher.close();
delete self.watchers[fullPath];
}
getSubDirectories(fullPath, function(fpath) {
self.close(fpath);
});
}
else {
Object.keys(self.watchers).forEach(function(fpath) {
var watcher = self.watchers[fpath];
if (watcher && watcher.close) {
watcher.close();
}
});
this.watchers = {};
}
// Do not close the Watcher unless all child watchers are closed.
// https://github.com/yuanchuan/node-watch/issues/75
if (is.emptyObject(self.watchers)) {
// should emit once
if (!this._isClosed) {
this._isClosed = true;
process.nextTick(emitClose, this);
}
}
}
Watcher.prototype.getWatchedPaths = function(fn) {
if (is.func(fn)) {
var self = this;
if (self._isReady) {
fn(Object.keys(self.watchers));
} else {
self.on('ready', function() {
fn(Object.keys(self.watchers));
});
}
}
}
function emitReady(self) {
if (!self._isReady) {
self._isReady = true;
// do not call emit for 'ready' until after watch() has returned,
// so that consumer can call on().
process.nextTick(function () {
self.emit('ready');
});
}
}
function emitClose(self) {
self.emit('close');
}
Watcher.prototype.add = function(watcher, info) {
var self = this;
info = info || { fpath: '' };
var watcherPath = path.resolve(info.fpath);
this.watchers[watcherPath] = watcher;
// Internal callback for handling fs.FSWatcher 'change' events
var internalOnChange = function(rawEvt, rawName) {
if (self.isClosed()) {
return;
}
// normalise lack of name and convert to full path
var name = rawName;
if (is.nil(name)) {
name = '';
}
name = path.join(info.fpath, name);
if (info.options.recursive) {
hasNativeRecursive(function(has) {
if (!has) {
var fullPath = path.resolve(name);
// remove watcher on removal
if (!is.exists(name)) {
self.close(fullPath);
}
// watch new created directory
else {
var shouldWatch = is.directory(name)
&& !self.watchers[fullPath]
&& shouldNotSkip(name, info.options.filter);
if (shouldWatch) {
self.watchDirectory(name, info.options);
}
}
}
});
}
handlePublicEvents(rawEvt, name);
};
// Debounced based on the 'delay' option
var handlePublicEvents = debounce(info, function (evt, name) {
// watch single file
if (info.compareName) {
if (info.compareName(name)) {
self.emit('change', evt, name);
}
}
// watch directory
else {
var filterGuard = guard(info.options.filter);
filterGuard(name, function() {
if (self.flag) self.flag = '';
else self.emit('change', evt, name);
});
}
});
watcher.on('error', function(err) {
if (self.isClosed()) {
return;
}
if (is.windows() && err.code === 'EPERM') {
watcher.emit('change', EVENT_REMOVE, info.fpath && '');
self.flag = 'windows-error';
self.close(watcherPath);
} else {
self.emit('error', err);
}
});
watcher.on('change', internalOnChange);
}
Watcher.prototype.watchFile = function(file, options, fn) {
var parent = path.join(file, '../');
var opts = Object.assign({}, options, {
// no filter for single file
filter: null,
encoding: 'utf8'
});
// no need to watch recursively
delete opts.recursive;
var watcher = tryWatch(this, parent, opts);
if (!watcher) {
return;
}
this.add(watcher, {
type: 'file',
fpath: parent,
options: Object.assign({}, opts, {
encoding: options.encoding
}),
compareName: function(n) {
return is.samePath(n, file);
}
});
if (is.func(fn)) {
if (fn.length === 1) deprecationWarning();
this.on('change', fn);
}
}
Watcher.prototype.updateDelay = function(delay) {
console.log()
}
Watcher.prototype.watchDirectory = function(dir, options, fn, counter = nullCounter) {
var self = this;
var done = counter();
hasNativeRecursive(function(has) {
// always specify recursive
options.recursive = !!options.recursive;
// using utf8 internally
var opts = Object.assign({}, options, {
encoding: 'utf8'
});
if (!has) {
delete opts.recursive;
}
// check if it's closed before calling watch.
if (self._isClosed) {
done();
return self.close();
}
var watcher = tryWatch(self, dir, opts);
if (!watcher) {
done();
return;
}
self.add(watcher, {
type: 'dir',
fpath: dir,
options: options
});
if (is.func(fn)) {
if (fn.length === 1) deprecationWarning();
self.on('change', fn);
}
if (options.recursive && !has) {
getSubDirectories(dir, function(d) {
if (shouldNotSkip(d, options.filter)) {
self.watchDirectory(d, options, null, counter);
}
}, counter());
}
done();
});
}
function composeWatcher(watchers) {
var watcher = new Watcher();
var filterDups = createDupsFilter();
var counter = watchers.length;
watchers.forEach(function(w) {
w.on('change', filterDups(function(evt, name) {
watcher.emit('change', evt, name);
}));
w.on('error', function(err) {
watcher.emit('error', err);
});
w.on('ready', function() {
if (!(--counter)) {
emitReady(watcher);
}
});
});
watcher.close = function() {
watchers.forEach(function(w) {
w.close();
});
process.nextTick(emitClose, watcher);
}
watcher.getWatchedPaths = function(fn) {
if (is.func(fn)) {
var promises = watchers.map(function(w) {
return new Promise(function(resolve) {
w.getWatchedPaths(resolve);
});
});
Promise.all(promises).then(function(result) {
var ret = unique(flat1(result));
fn(ret);
});
}
}
return watcher.expose();
}
export default function watch(fpath, options, fn) {
var watcher = new Watcher();
if (is.buffer(fpath)) {
fpath = fpath.toString();
}
if (!is.array(fpath) && !is.exists(fpath)) {
process.nextTick(function() {
watcher.emit('error',
new Error(fpath + ' does not exist.')
);
});
}
if (is.string(options)) {
throw new Error(`Invalid option, encoding as string is no longer supported. Use { encoding: "${options}" } instead.`)
}
if (is.func(options)) {
fn = options;
options = {};
}
if (arguments.length < 2) {
options = {};
}
if (options.encoding) {
assertEncoding(options.encoding);
} else {
options.encoding = 'utf8';
}
if (is.array(fpath)) {
if (fpath.length === 1) {
return watch(fpath[0], options, fn);
}
var filterDups = createDupsFilter();
return composeWatcher(unique(fpath).map(function(f) {
var w = watch(f, options);
if (is.func(fn)) {
w.on('change', filterDups(fn));
}
return w;
}));
}
if (is.file(fpath)) {
watcher.watchFile(fpath, options, fn);
emitReady(watcher);
}
else if (is.directory(fpath)) {
var counter = semaphore(function () {
emitReady(watcher);
});
watcher.watchDirectory(fpath, options, fn, counter);
}
return watcher.expose();
}