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151 lines
4.0 KiB
JavaScript

'use strict'
const Header = require('./header.js')
const path = require('path')
class Pax {
constructor (obj, global) {
this.atime = obj.atime || null
this.charset = obj.charset || null
this.comment = obj.comment || null
this.ctime = obj.ctime || null
this.gid = obj.gid || null
this.gname = obj.gname || null
this.linkpath = obj.linkpath || null
this.mtime = obj.mtime || null
this.path = obj.path || null
this.size = obj.size || null
this.uid = obj.uid || null
this.uname = obj.uname || null
this.dev = obj.dev || null
this.ino = obj.ino || null
this.nlink = obj.nlink || null
this.global = global || false
}
encode () {
const body = this.encodeBody()
if (body === '') {
return null
}
const bodyLen = Buffer.byteLength(body)
// round up to 512 bytes
// add 512 for header
const bufLen = 512 * Math.ceil(1 + bodyLen / 512)
const buf = Buffer.allocUnsafe(bufLen)
// 0-fill the header section, it might not hit every field
for (let i = 0; i < 512; i++) {
buf[i] = 0
}
new Header({
// XXX split the path
// then the path should be PaxHeader + basename, but less than 99,
// prepend with the dirname
path: ('PaxHeader/' + path.basename(this.path)).slice(0, 99),
mode: this.mode || 0o644,
uid: this.uid || null,
gid: this.gid || null,
size: bodyLen,
mtime: this.mtime || null,
type: this.global ? 'GlobalExtendedHeader' : 'ExtendedHeader',
linkpath: '',
uname: this.uname || '',
gname: this.gname || '',
devmaj: 0,
devmin: 0,
atime: this.atime || null,
ctime: this.ctime || null,
}).encode(buf)
buf.write(body, 512, bodyLen, 'utf8')
// null pad after the body
for (let i = bodyLen + 512; i < buf.length; i++) {
buf[i] = 0
}
return buf
}
encodeBody () {
return (
this.encodeField('path') +
this.encodeField('ctime') +
this.encodeField('atime') +
this.encodeField('dev') +
this.encodeField('ino') +
this.encodeField('nlink') +
this.encodeField('charset') +
this.encodeField('comment') +
this.encodeField('gid') +
this.encodeField('gname') +
this.encodeField('linkpath') +
this.encodeField('mtime') +
this.encodeField('size') +
this.encodeField('uid') +
this.encodeField('uname')
)
}
encodeField (field) {
if (this[field] === null || this[field] === undefined) {
return ''
}
const v = this[field] instanceof Date ? this[field].getTime() / 1000
: this[field]
const s = ' ' +
(field === 'dev' || field === 'ino' || field === 'nlink'
? 'SCHILY.' : '') +
field + '=' + v + '\n'
const byteLen = Buffer.byteLength(s)
// the digits includes the length of the digits in ascii base-10
// so if it's 9 characters, then adding 1 for the 9 makes it 10
// which makes it 11 chars.
let digits = Math.floor(Math.log(byteLen) / Math.log(10)) + 1
if (byteLen + digits >= Math.pow(10, digits)) {
digits += 1
}
const len = digits + byteLen
return len + s
}
}
Pax.parse = (string, ex, g) => new Pax(merge(parseKV(string), ex), g)
const merge = (a, b) =>
b ? Object.keys(a).reduce((s, k) => (s[k] = a[k], s), b) : a
const parseKV = string =>
string
.replace(/\n$/, '')
.split('\n')
.reduce(parseKVLine, Object.create(null))
const parseKVLine = (set, line) => {
const n = parseInt(line, 10)
// XXX Values with \n in them will fail this.
// Refactor to not be a naive line-by-line parse.
if (n !== Buffer.byteLength(line) + 1) {
return set
}
line = line.slice((n + ' ').length)
const kv = line.split('=')
const k = kv.shift().replace(/^SCHILY\.(dev|ino|nlink)/, '$1')
if (!k) {
return set
}
const v = kv.join('=')
set[k] = /^([A-Z]+\.)?([mac]|birth|creation)time$/.test(k)
? new Date(v * 1000)
: /^[0-9]+$/.test(v) ? +v
: v
return set
}
module.exports = Pax