setup-python/node_modules/walker/lib/walker.js
Danny McCormick 39c08a0eaa Initial pass
2019-06-26 21:12:00 -04:00

112 lines
2.8 KiB
JavaScript

module.exports = Walker
var path = require('path')
, fs = require('fs')
, util = require('util')
, EventEmitter = require('events').EventEmitter
, makeError = require('makeerror')
/**
* To walk a directory. It's complicated (but it's async, so it must be fast).
*
* @param root {String} the directory to start with
*/
function Walker(root) {
if (!(this instanceof Walker)) return new Walker(root)
EventEmitter.call(this)
this._pending = 0
this._filterDir = function() { return true }
this.go(root)
}
util.inherits(Walker, EventEmitter)
/**
* Errors of this type are thrown when the type of a file could not be
* determined.
*/
var UnknownFileTypeError = Walker.UnknownFileTypeError = makeError(
'UnknownFileTypeError',
'The type of this file could not be determined.'
)
/**
* Setup a function to filter out directory entries.
*
* @param fn {Function} a function that will be given a directory name, which
* if returns true will include the directory and it's children
*/
Walker.prototype.filterDir = function(fn) {
this._filterDir = fn
return this
}
/**
* Process a file or directory.
*/
Walker.prototype.go = function(entry) {
var that = this
this._pending++
fs.lstat(entry, function(er, stat) {
if (er) {
that.emit('error', er, entry, stat)
that.doneOne()
return
}
if (stat.isDirectory()) {
if (!that._filterDir(entry, stat)) {
that.doneOne()
} else {
fs.readdir(entry, function(er, files) {
if (er) {
that.emit('error', er, entry, stat)
that.doneOne()
return
}
that.emit('entry', entry, stat)
that.emit('dir', entry, stat)
files.forEach(function(part) {
that.go(path.join(entry, part))
})
that.doneOne()
})
}
} else if (stat.isSymbolicLink()) {
that.emit('entry', entry, stat)
that.emit('symlink', entry, stat)
that.doneOne()
} else if (stat.isBlockDevice()) {
that.emit('entry', entry, stat)
that.emit('blockDevice', entry, stat)
that.doneOne()
} else if (stat.isCharacterDevice()) {
that.emit('entry', entry, stat)
that.emit('characterDevice', entry, stat)
that.doneOne()
} else if (stat.isFIFO()) {
that.emit('entry', entry, stat)
that.emit('fifo', entry, stat)
that.doneOne()
} else if (stat.isSocket()) {
that.emit('entry', entry, stat)
that.emit('socket', entry, stat)
that.doneOne()
} else if (stat.isFile()) {
that.emit('entry', entry, stat)
that.emit('file', entry, stat)
that.doneOne()
} else {
that.emit('error', UnknownFileTypeError(), entry, stat)
that.doneOne()
}
})
return this
}
Walker.prototype.doneOne = function() {
if (--this._pending === 0) this.emit('end')
return this
}