Express_Crud_Example/node_modules/graceful-fs/graceful-fs.js

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2022-01-28 22:33:42 +01:00
var fs = require('fs')
var polyfills = require('./polyfills.js')
var legacy = require('./legacy-streams.js')
var clone = require('./clone.js')
var util = require('util')
/* istanbul ignore next - node 0.x polyfill */
var gracefulQueue
var previousSymbol
/* istanbul ignore else - node 0.x polyfill */
if (typeof Symbol === 'function' && typeof Symbol.for === 'function') {
gracefulQueue = Symbol.for('graceful-fs.queue')
// This is used in testing by future versions
previousSymbol = Symbol.for('graceful-fs.previous')
} else {
gracefulQueue = '___graceful-fs.queue'
previousSymbol = '___graceful-fs.previous'
}
function noop () {}
function publishQueue(context, queue) {
Object.defineProperty(context, gracefulQueue, {
get: function() {
return queue
}
})
}
var debug = noop
if (util.debuglog)
debug = util.debuglog('gfs4')
else if (/\bgfs4\b/i.test(process.env.NODE_DEBUG || ''))
debug = function() {
var m = util.format.apply(util, arguments)
m = 'GFS4: ' + m.split(/\n/).join('\nGFS4: ')
console.error(m)
}
// Once time initialization
if (!fs[gracefulQueue]) {
// This queue can be shared by multiple loaded instances
var queue = global[gracefulQueue] || []
publishQueue(fs, queue)
// Patch fs.close/closeSync to shared queue version, because we need
// to retry() whenever a close happens *anywhere* in the program.
// This is essential when multiple graceful-fs instances are
// in play at the same time.
fs.close = (function (fs$close) {
function close (fd, cb) {
return fs$close.call(fs, fd, function (err) {
// This function uses the graceful-fs shared queue
if (!err) {
resetQueue()
}
if (typeof cb === 'function')
cb.apply(this, arguments)
})
}
Object.defineProperty(close, previousSymbol, {
value: fs$close
})
return close
})(fs.close)
fs.closeSync = (function (fs$closeSync) {
function closeSync (fd) {
// This function uses the graceful-fs shared queue
fs$closeSync.apply(fs, arguments)
resetQueue()
}
Object.defineProperty(closeSync, previousSymbol, {
value: fs$closeSync
})
return closeSync
})(fs.closeSync)
if (/\bgfs4\b/i.test(process.env.NODE_DEBUG || '')) {
process.on('exit', function() {
debug(fs[gracefulQueue])
require('assert').equal(fs[gracefulQueue].length, 0)
})
}
}
if (!global[gracefulQueue]) {
publishQueue(global, fs[gracefulQueue]);
}
module.exports = patch(clone(fs))
if (process.env.TEST_GRACEFUL_FS_GLOBAL_PATCH && !fs.__patched) {
module.exports = patch(fs)
fs.__patched = true;
}
function patch (fs) {
// Everything that references the open() function needs to be in here
polyfills(fs)
fs.gracefulify = patch
fs.createReadStream = createReadStream
fs.createWriteStream = createWriteStream
var fs$readFile = fs.readFile
fs.readFile = readFile
function readFile (path, options, cb) {
if (typeof options === 'function')
cb = options, options = null
return go$readFile(path, options, cb)
function go$readFile (path, options, cb, startTime) {
return fs$readFile(path, options, function (err) {
if (err && (err.code === 'EMFILE' || err.code === 'ENFILE'))
enqueue([go$readFile, [path, options, cb], err, startTime || Date.now(), Date.now()])
else {
if (typeof cb === 'function')
cb.apply(this, arguments)
}
})
}
}
var fs$writeFile = fs.writeFile
fs.writeFile = writeFile
function writeFile (path, data, options, cb) {
if (typeof options === 'function')
cb = options, options = null
return go$writeFile(path, data, options, cb)
function go$writeFile (path, data, options, cb, startTime) {
return fs$writeFile(path, data, options, function (err) {
if (err && (err.code === 'EMFILE' || err.code === 'ENFILE'))
enqueue([go$writeFile, [path, data, options, cb], err, startTime || Date.now(), Date.now()])
else {
if (typeof cb === 'function')
cb.apply(this, arguments)
}
})
}
}
var fs$appendFile = fs.appendFile
if (fs$appendFile)
fs.appendFile = appendFile
function appendFile (path, data, options, cb) {
if (typeof options === 'function')
cb = options, options = null
return go$appendFile(path, data, options, cb)
function go$appendFile (path, data, options, cb, startTime) {
return fs$appendFile(path, data, options, function (err) {
if (err && (err.code === 'EMFILE' || err.code === 'ENFILE'))
enqueue([go$appendFile, [path, data, options, cb], err, startTime || Date.now(), Date.now()])
else {
if (typeof cb === 'function')
cb.apply(this, arguments)
}
})
}
}
var fs$copyFile = fs.copyFile
if (fs$copyFile)
fs.copyFile = copyFile
function copyFile (src, dest, flags, cb) {
if (typeof flags === 'function') {
cb = flags
flags = 0
}
return go$copyFile(src, dest, flags, cb)
function go$copyFile (src, dest, flags, cb, startTime) {
return fs$copyFile(src, dest, flags, function (err) {
if (err && (err.code === 'EMFILE' || err.code === 'ENFILE'))
enqueue([go$copyFile, [src, dest, flags, cb], err, startTime || Date.now(), Date.now()])
else {
if (typeof cb === 'function')
cb.apply(this, arguments)
}
})
}
}
var fs$readdir = fs.readdir
fs.readdir = readdir
function readdir (path, options, cb) {
if (typeof options === 'function')
cb = options, options = null
return go$readdir(path, options, cb)
function go$readdir (path, options, cb, startTime) {
return fs$readdir(path, options, function (err, files) {
if (err && (err.code === 'EMFILE' || err.code === 'ENFILE'))
enqueue([go$readdir, [path, options, cb], err, startTime || Date.now(), Date.now()])
else {
if (files && files.sort)
files.sort()
if (typeof cb === 'function')
cb.call(this, err, files)
}
})
}
}
if (process.version.substr(0, 4) === 'v0.8') {
var legStreams = legacy(fs)
ReadStream = legStreams.ReadStream
WriteStream = legStreams.WriteStream
}
var fs$ReadStream = fs.ReadStream
if (fs$ReadStream) {
ReadStream.prototype = Object.create(fs$ReadStream.prototype)
ReadStream.prototype.open = ReadStream$open
}
var fs$WriteStream = fs.WriteStream
if (fs$WriteStream) {
WriteStream.prototype = Object.create(fs$WriteStream.prototype)
WriteStream.prototype.open = WriteStream$open
}
Object.defineProperty(fs, 'ReadStream', {
get: function () {
return ReadStream
},
set: function (val) {
ReadStream = val
},
enumerable: true,
configurable: true
})
Object.defineProperty(fs, 'WriteStream', {
get: function () {
return WriteStream
},
set: function (val) {
WriteStream = val
},
enumerable: true,
configurable: true
})
// legacy names
var FileReadStream = ReadStream
Object.defineProperty(fs, 'FileReadStream', {
get: function () {
return FileReadStream
},
set: function (val) {
FileReadStream = val
},
enumerable: true,
configurable: true
})
var FileWriteStream = WriteStream
Object.defineProperty(fs, 'FileWriteStream', {
get: function () {
return FileWriteStream
},
set: function (val) {
FileWriteStream = val
},
enumerable: true,
configurable: true
})
function ReadStream (path, options) {
if (this instanceof ReadStream)
return fs$ReadStream.apply(this, arguments), this
else
return ReadStream.apply(Object.create(ReadStream.prototype), arguments)
}
function ReadStream$open () {
var that = this
open(that.path, that.flags, that.mode, function (err, fd) {
if (err) {
if (that.autoClose)
that.destroy()
that.emit('error', err)
} else {
that.fd = fd
that.emit('open', fd)
that.read()
}
})
}
function WriteStream (path, options) {
if (this instanceof WriteStream)
return fs$WriteStream.apply(this, arguments), this
else
return WriteStream.apply(Object.create(WriteStream.prototype), arguments)
}
function WriteStream$open () {
var that = this
open(that.path, that.flags, that.mode, function (err, fd) {
if (err) {
that.destroy()
that.emit('error', err)
} else {
that.fd = fd
that.emit('open', fd)
}
})
}
function createReadStream (path, options) {
return new fs.ReadStream(path, options)
}
function createWriteStream (path, options) {
return new fs.WriteStream(path, options)
}
var fs$open = fs.open
fs.open = open
function open (path, flags, mode, cb) {
if (typeof mode === 'function')
cb = mode, mode = null
return go$open(path, flags, mode, cb)
function go$open (path, flags, mode, cb, startTime) {
return fs$open(path, flags, mode, function (err, fd) {
if (err && (err.code === 'EMFILE' || err.code === 'ENFILE'))
enqueue([go$open, [path, flags, mode, cb], err, startTime || Date.now(), Date.now()])
else {
if (typeof cb === 'function')
cb.apply(this, arguments)
}
})
}
}
return fs
}
function enqueue (elem) {
debug('ENQUEUE', elem[0].name, elem[1])
fs[gracefulQueue].push(elem)
retry()
}
// keep track of the timeout between retry() calls
var retryTimer
// reset the startTime and lastTime to now
// this resets the start of the 60 second overall timeout as well as the
// delay between attempts so that we'll retry these jobs sooner
function resetQueue () {
var now = Date.now()
for (var i = 0; i < fs[gracefulQueue].length; ++i) {
// entries that are only a length of 2 are from an older version, don't
// bother modifying those since they'll be retried anyway.
if (fs[gracefulQueue][i].length > 2) {
fs[gracefulQueue][i][3] = now // startTime
fs[gracefulQueue][i][4] = now // lastTime
}
}
// call retry to make sure we're actively processing the queue
retry()
}
function retry () {
// clear the timer and remove it to help prevent unintended concurrency
clearTimeout(retryTimer)
retryTimer = undefined
if (fs[gracefulQueue].length === 0)
return
var elem = fs[gracefulQueue].shift()
var fn = elem[0]
var args = elem[1]
// these items may be unset if they were added by an older graceful-fs
var err = elem[2]
var startTime = elem[3]
var lastTime = elem[4]
// if we don't have a startTime we have no way of knowing if we've waited
// long enough, so go ahead and retry this item now
if (startTime === undefined) {
debug('RETRY', fn.name, args)
fn.apply(null, args)
} else if (Date.now() - startTime >= 60000) {
// it's been more than 60 seconds total, bail now
debug('TIMEOUT', fn.name, args)
var cb = args.pop()
if (typeof cb === 'function')
cb.call(null, err)
} else {
// the amount of time between the last attempt and right now
var sinceAttempt = Date.now() - lastTime
// the amount of time between when we first tried, and when we last tried
// rounded up to at least 1
var sinceStart = Math.max(lastTime - startTime, 1)
// backoff. wait longer than the total time we've been retrying, but only
// up to a maximum of 100ms
var desiredDelay = Math.min(sinceStart * 1.2, 100)
// it's been long enough since the last retry, do it again
if (sinceAttempt >= desiredDelay) {
debug('RETRY', fn.name, args)
fn.apply(null, args.concat([startTime]))
} else {
// if we can't do this job yet, push it to the end of the queue
// and let the next iteration check again
fs[gracefulQueue].push(elem)
}
}
// schedule our next run if one isn't already scheduled
if (retryTimer === undefined) {
retryTimer = setTimeout(retry, 0)
}
}