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module.exports = Reader
var fs = require("graceful-fs")
, Stream = require("stream").Stream
, inherits = require("inherits")
, path = require("path")
, getType = require("./get-type.js")
, hardLinks = Reader.hardLinks = {}
, Abstract = require("./abstract.js")
// Must do this *before* loading the child classes
inherits(Reader, Abstract)
var DirReader = require("./dir-reader.js")
, FileReader = require("./file-reader.js")
, LinkReader = require("./link-reader.js")
, SocketReader = require("./socket-reader.js")
, ProxyReader = require("./proxy-reader.js")
function Reader (props, currentStat) {
var me = this
if (!(me instanceof Reader)) return new Reader(props, currentStat)
if (typeof props === "string") {
props = { path: props }
}
if (!props.path) {
me.error("Must provide a path", null, true)
}
// polymorphism.
// call fstream.Reader(dir) to get a DirReader object, etc.
// Note that, unlike in the Writer case, ProxyReader is going
// to be the *normal* state of affairs, since we rarely know
// the type of a file prior to reading it.
var type
, ClassType
if (props.type && typeof props.type === "function") {
type = props.type
ClassType = type
} else {
type = getType(props)
ClassType = Reader
}
if (currentStat && !type) {
type = getType(currentStat)
props[type] = true
props.type = type
}
switch (type) {
case "Directory":
ClassType = DirReader
break
case "Link":
// XXX hard links are just files.
// However, it would be good to keep track of files' dev+inode
// and nlink values, and create a HardLinkReader that emits
// a linkpath value of the original copy, so that the tar
// writer can preserve them.
// ClassType = HardLinkReader
// break
case "File":
ClassType = FileReader
break
case "SymbolicLink":
ClassType = LinkReader
break
case "Socket":
ClassType = SocketReader
break
case null:
ClassType = ProxyReader
break
}
if (!(me instanceof ClassType)) {
return new ClassType(props)
}
Abstract.call(me)
me.readable = true
me.writable = false
me.type = type
me.props = props
me.depth = props.depth = props.depth || 0
me.parent = props.parent || null
me.root = props.root || (props.parent && props.parent.root) || me
me._path = me.path = path.resolve(props.path)
if (process.platform === "win32") {
me.path = me._path = me.path.replace(/\?/g, "_")
if (me._path.length >= 260) {
// how DOES one create files on the moon?
// if the path has spaces in it, then UNC will fail.
me._swallowErrors = true
//if (me._path.indexOf(" ") === -1) {
me._path = "\\\\?\\" + me.path.replace(/\//g, "\\")
//}
}
}
me.basename = props.basename = path.basename(me.path)
me.dirname = props.dirname = path.dirname(me.path)
// these have served their purpose, and are now just noisy clutter
props.parent = props.root = null
// console.error("\n\n\n%s setting size to", props.path, props.size)
me.size = props.size
me.filter = typeof props.filter === "function" ? props.filter : null
if (props.sort === "alpha") props.sort = alphasort
// start the ball rolling.
// this will stat the thing, and then call me._read()
// to start reading whatever it is.
// console.error("calling stat", props.path, currentStat)
me._stat(currentStat)
}
function alphasort (a, b) {
return a === b ? 0
: a.toLowerCase() > b.toLowerCase() ? 1
: a.toLowerCase() < b.toLowerCase() ? -1
: a > b ? 1
: -1
}
Reader.prototype._stat = function (currentStat) {
var me = this
, props = me.props
, stat = props.follow ? "stat" : "lstat"
// console.error("Reader._stat", me._path, currentStat)
if (currentStat) process.nextTick(statCb.bind(null, null, currentStat))
else fs[stat](me._path, statCb)
function statCb (er, props_) {
// console.error("Reader._stat, statCb", me._path, props_, props_.nlink)
if (er) return me.error(er)
Object.keys(props_).forEach(function (k) {
props[k] = props_[k]
})
// if it's not the expected size, then abort here.
if (undefined !== me.size && props.size !== me.size) {
return me.error("incorrect size")
}
me.size = props.size
var type = getType(props)
var handleHardlinks = props.hardlinks !== false
// special little thing for handling hardlinks.
if (handleHardlinks && type !== "Directory" && props.nlink && props.nlink > 1) {
var k = props.dev + ":" + props.ino
// console.error("Reader has nlink", me._path, k)
if (hardLinks[k] === me._path || !hardLinks[k]) hardLinks[k] = me._path
else {
// switch into hardlink mode.
type = me.type = me.props.type = "Link"
me.Link = me.props.Link = true
me.linkpath = me.props.linkpath = hardLinks[k]
// console.error("Hardlink detected, switching mode", me._path, me.linkpath)
// Setting __proto__ would arguably be the "correct"
// approach here, but that just seems too wrong.
me._stat = me._read = LinkReader.prototype._read
}
}
if (me.type && me.type !== type) {
me.error("Unexpected type: " + type)
}
// if the filter doesn't pass, then just skip over this one.
// still have to emit end so that dir-walking can move on.
if (me.filter) {
var who = me._proxy || me
// special handling for ProxyReaders
if (!me.filter.call(who, who, props)) {
if (!me._disowned) {
me.abort()
me.emit("end")
me.emit("close")
}
return
}
}
// last chance to abort or disown before the flow starts!
var events = ["_stat", "stat", "ready"]
var e = 0
;(function go () {
if (me._aborted) {
me.emit("end")
me.emit("close")
return
}
if (me._paused && me.type !== "Directory") {
me.once("resume", go)
return
}
var ev = events[e ++]
if (!ev) {
return me._read()
}
me.emit(ev, props)
go()
})()
}
}
Reader.prototype.pipe = function (dest, opts) {
var me = this
if (typeof dest.add === "function") {
// piping to a multi-compatible, and we've got directory entries.
me.on("entry", function (entry) {
var ret = dest.add(entry)
if (false === ret) {
me.pause()
}
})
}
// console.error("R Pipe apply Stream Pipe")
return Stream.prototype.pipe.apply(this, arguments)
}
Reader.prototype.pause = function (who) {
this._paused = true
who = who || this
this.emit("pause", who)
if (this._stream) this._stream.pause(who)
}
Reader.prototype.resume = function (who) {
this._paused = false
who = who || this
this.emit("resume", who)
if (this._stream) this._stream.resume(who)
this._read()
}
Reader.prototype._read = function () {
this.error("Cannot read unknown type: "+this.type)
}