import path from 'path'
import fs from 'fs'
import events from 'events'
import chokidar from 'chokidar'
import get from 'lodash-es/get.js'
import ispint from './ispint.mjs'
import isbol from './isbol.mjs'
import cint from './cint.mjs'
import fsIsFolder from './fsIsFolder.mjs'
/**
* 後端nodejs基於chokidar提供偵測資料夾內檔案變更或出現或消失事件
*
* 因使用chokidar，變更至少要3秒才能監測，不適用於頻繁觸發事件之工作
*
* Unit Test: {@link https://github.com/yuda-lyu/wsemi/blob/master/test/fsWatchFolder.test.mjs Github}
* @memberOf wsemi
* @param {String} fd 輸入偵測資料夾路徑字串
* @param {Object} [opt={}] 輸入設定物件，預設{}
* @param {Boolean} [opt.polling=false] 輸入是否使用輪循布林值，代表chokidar的usePolling，預設為false
* @param {Integer} [opt.timeInterval=100] 輸入當polling為true時偵測檔案變更間隔時間整數，代表chokidar開啟polling時的interval，單位為毫秒ms，預設為100
* @param {Integer} [opt.timeBinaryInterval=300] 輸入當polling為true時偵測二進位檔案變更間隔時間整數，代表chokidar開啟polling時的binaryInterval，單位為毫秒ms，預設為300
* @returns {Object} 回傳事件物件，包含on、clear函數，on可進行監聽change事件，clear為停止全部監聽，不須輸入
* @example
* need test in nodejs.
*
* import getFileName from './src/getFileName.mjs'
* import fsDeleteFile from './src/fsDeleteFile.mjs'
* import fsRenameFile from './src/fsRenameFile.mjs'
* import fsCreateFolder from './src/fsCreateFolder.mjs'
* import fsDeleteFolder from './src/fsDeleteFolder.mjs'
* import fsRenameFolder from './src/fsRenameFolder.mjs'
* import fsWatchFolder from './src/fsWatchFolder.mjs'
*
* let test = async () => {
* return new Promise((resolve, reject) => {
* let ms = []
*
* let fp = './_test_fsWatchFolder'
*
* fsDeleteFolder(fp)
*
* let ev = fsWatchFolder(fp)
* ev.on('change', (msg) => {
* console.log(msg.type, getFileName(msg.fp))
* ms.push({ type: msg.type, fp: getFileName(msg.fp) })
* })
*
* setTimeout(() => {
* fsCreateFolder(fp)
* }, 1)
*
* setTimeout(() => {
* fs.writeFileSync(`${fp}/abc.txt`, 'abc', 'utf8')
* }, 3000)
*
* setTimeout(() => {
* fsRenameFile(`${fp}/abc.txt`, `${fp}/abc.txt` + '.tmp')
* }, 6000)
*
* setTimeout(() => {
* fsRenameFile(`${fp}/abc.txt` + '.tmp', `${fp}/abc.txt`)
* }, 9000)
*
* setTimeout(() => {
* fs.writeFileSync(`${fp}/abc.txt`, 'def', 'utf8')
* }, 12000)
*
* setTimeout(() => {
* fsCreateFolder(`${fp}/test-fd`)
* }, 15000)
*
* setTimeout(() => {
* fsRenameFolder(`${fp}/test-fd`, `${fp}/test-fd` + '-tmp')
* }, 18000)
*
* setTimeout(() => {
* fsRenameFolder(`${fp}/test-fd` + '-tmp', `${fp}/test-fd`)
* }, 21000)
*
* setTimeout(() => {
* fsDeleteFile(`${fp}/abc.txt`)
* }, 24000)
*
* setTimeout(() => {
* fsDeleteFolder(`${fp}/test-fd`)
* }, 27000)
*
* setTimeout(() => {
* fsDeleteFolder(fp)
* }, 30000)
*
* setTimeout(() => {
* ev.clear()
* console.log('ms', ms)
* resolve(ms)
* }, 33000)
*
* })
* }
* test()
* .catch(() => {})
* // addDir _test_fsWatchFolder
* // add abc.txt
* // unlink abc.txt
* // add abc.txt.tmp
* // unlink abc.txt.tmp
* // add abc.txt
* // change abc.txt
* // addDir test-fd
* // unlinkDir test-fd
* // addDir test-fd-tmp
* // unlinkDir test-fd-tmp
* // addDir test-fd
* // unlink abc.txt
* // unlinkDir test-fd
* // unlinkDir _test_fsWatchFolder
* // ms [
* // { type: 'addDir', fp: '_test_fsWatchFolder' },
* // { type: 'add', fp: 'abc.txt' },
* // { type: 'unlink', fp: 'abc.txt' },
* // { type: 'add', fp: 'abc.txt.tmp' },
* // { type: 'unlink', fp: 'abc.txt.tmp' },
* // { type: 'add', fp: 'abc.txt' },
* // { type: 'change', fp: 'abc.txt' },
* // { type: 'addDir', fp: 'test-fd' },
* // { type: 'unlinkDir', fp: 'test-fd' },
* // { type: 'addDir', fp: 'test-fd-tmp' },
* // { type: 'unlinkDir', fp: 'test-fd-tmp' },
* // { type: 'addDir', fp: 'test-fd' },
* // { type: 'unlink', fp: 'abc.txt' },
* // { type: 'unlinkDir', fp: 'test-fd' },
* // { type: 'unlinkDir', fp: '_test_fsWatchFolder' }
* // ]
*
*/
function fsWatchFolder(fd, opt = {}) {
//polling
let polling = get(opt, 'polling')
if (!isbol(polling)) {
polling = false
}
//timeInterval
let timeInterval = get(opt, 'timeInterval')
if (!ispint(timeInterval)) {
timeInterval = 100
}
timeInterval = cint(timeInterval)
//timeBinaryInterval
let timeBinaryInterval = get(opt, 'timeBinaryInterval')
if (!ispint(timeBinaryInterval)) {
timeBinaryInterval = 300
}
timeBinaryInterval = cint(timeBinaryInterval)
//ev
let ev = new events.EventEmitter()
//fpSpe
let fpSpe = fd
//timer
let watcher = null
let t = setInterval(() => {
//check
if (watcher !== null) {
//check, 若watcher已成功監聽fd, 但更名fd時會無法觸發
if (!fsIsFolder(fpSpe)) {
//因監聽觸發狀態不能unWatch, 故要延遲呼叫
//stats
let stats = fs.fstatSync
//emit
ev.emit('change', {
type: 'unlinkDir',
fp: path.resolve(fpSpe),
stats,
})
setTimeout(() => {
unWatch()
}, 1)
}
return
}
//check
if (!fsIsFolder(fpSpe)) {
return
}
//watcher
watcher = chokidar.watch(fpSpe, {
// persistent: true,
// ignoreInitial: false,
usePolling: polling,
interval: timeInterval,
binaryInterval: timeBinaryInterval,
awaitWriteFinish: true, //須比較多延遲偵測檔案是否變更完成, 但對於連鎖驅動比較保險
// depth: undefined,
})
//on
watcher
.on('all', (type, fp, stats) => {
// console.log(type, fp, stats)
//type=add,unlink,change,addDir,unlinkDir
//注意當unlinkDir原本監聽的fd後, 就不會再觸發變更事件, 故外層用timer重新偵測
//fp
fp = path.resolve(fp)
//emit
ev.emit('change', { type, fp, stats })
//check
if (type === 'unlinkDir' && path.resolve(fpSpe) === fp) {
//因監聽觸發狀態不能unWatch, 故要延遲呼叫
setTimeout(() => {
unWatch()
}, 1)
}
})
}, timeInterval)
//unWatch
let unWatch = () => {
// console.log('call unWatch')
if (watcher === null) {
return
}
try {
watcher.unwatch(fpSpe)
}
catch (err) {
console.log(err)
}
watcher.close()
// .then(() => {})
.catch((err) => {
console.log(err)
})
.finally(() => {
watcher = null
// console.log('watcher=null')
})
}
//clear
let clear = () => {
unWatch()
clearInterval(t)
}
//save
ev.clear = clear
return ev
}
export default fsWatchFolder