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// A passthrough read/write stream that sets its properties
// based on a header, extendedHeader, and globalHeader
//
// Can be either a file system object of some sort, or
// a pax/ustar metadata entry.
module.exports = Entry
var TarHeader = require("./header.js")
, tar = require("../tar")
, assert = require("assert").ok
, Stream = require("stream").Stream
, inherits = require("inherits")
, fstream = require("fstream").Abstract
function Entry (header, extended, global) {
Stream.call(this)
this.readable = true
this.writable = true
this._needDrain = false
this._paused = false
this._reading = false
this._ending = false
this._ended = false
this._remaining = 0
this._queue = []
this._index = 0
this._queueLen = 0
this._read = this._read.bind(this)
this.props = {}
this._header = header
this._extended = extended || {}
// globals can change throughout the course of
// a file parse operation. Freeze it at its current state.
this._global = {}
var me = this
Object.keys(global || {}).forEach(function (g) {
me._global[g] = global[g]
})
this._setProps()
}
inherits(Entry, Stream)
Entry.prototype.write = function (c) {
if (this._ending) this.error("write() after end()", null, true)
if (this._remaining === 0) {
this.error("invalid bytes past eof")
}
// often we'll get a bunch of \0 at the end of the last write,
// since chunks will always be 512 bytes when reading a tarball.
if (c.length > this._remaining) {
c = c.slice(0, this._remaining)
}
this._remaining -= c.length
// put it on the stack.
var ql = this._queueLen
this._queue.push(c)
this._queueLen ++
this._read()
// either paused, or buffered
if (this._paused || ql > 0) {
this._needDrain = true
return false
}
return true
}
Entry.prototype.end = function (c) {
if (c) this.write(c)
this._ending = true
this._read()
}
Entry.prototype.pause = function () {
this._paused = true
this.emit("pause")
}
Entry.prototype.resume = function () {
// console.error(" Tar Entry resume", this.path)
this.emit("resume")
this._paused = false
this._read()
return this._queueLen - this._index > 1
}
// This is bound to the instance
Entry.prototype._read = function () {
// console.error(" Tar Entry _read", this.path)
if (this._paused || this._reading || this._ended) return
// set this flag so that event handlers don't inadvertently
// get multiple _read() calls running.
this._reading = true
// have any data to emit?
while (this._index < this._queueLen && !this._paused) {
var chunk = this._queue[this._index ++]
this.emit("data", chunk)
}
// check if we're drained
if (this._index >= this._queueLen) {
this._queue.length = this._queueLen = this._index = 0
if (this._needDrain) {
this._needDrain = false
this.emit("drain")
}
if (this._ending) {
this._ended = true
this.emit("end")
}
}
// if the queue gets too big, then pluck off whatever we can.
// this should be fairly rare.
var mql = this._maxQueueLen
if (this._queueLen > mql && this._index > 0) {
mql = Math.min(this._index, mql)
this._index -= mql
this._queueLen -= mql
this._queue = this._queue.slice(mql)
}
this._reading = false
}
Entry.prototype._setProps = function () {
// props = extended->global->header->{}
var header = this._header
, extended = this._extended
, global = this._global
, props = this.props
// first get the values from the normal header.
var fields = tar.fields
for (var f = 0; fields[f] !== null; f ++) {
var field = fields[f]
, val = header[field]
if (typeof val !== "undefined") props[field] = val
}
// next, the global header for this file.
// numeric values, etc, will have already been parsed.
;[global, extended].forEach(function (p) {
Object.keys(p).forEach(function (f) {
if (typeof p[f] !== "undefined") props[f] = p[f]
})
})
// no nulls allowed in path or linkpath
;["path", "linkpath"].forEach(function (p) {
if (props.hasOwnProperty(p)) {
props[p] = props[p].split("\0")[0]
}
})
// set date fields to be a proper date
;["mtime", "ctime", "atime"].forEach(function (p) {
if (props.hasOwnProperty(p)) {
props[p] = new Date(props[p] * 1000)
}
})
// set the type so that we know what kind of file to create
var type
switch (tar.types[props.type]) {
case "OldFile":
case "ContiguousFile":
type = "File"
break
case "GNUDumpDir":
type = "Directory"
break
case undefined:
type = "Unknown"
break
case "Link":
case "SymbolicLink":
case "CharacterDevice":
case "BlockDevice":
case "Directory":
case "FIFO":
default:
type = tar.types[props.type]
}
this.type = type
this.path = props.path
this.size = props.size
// size is special, since it signals when the file needs to end.
this._remaining = props.size
}
Entry.prototype.warn = fstream.warn
Entry.prototype.error = fstream.error