system_assignation/node_modules/tar/lib/extract.js

108 lines
2.7 KiB
JavaScript

'use strict'
// tar -x
const hlo = require('./high-level-opt.js')
const Unpack = require('./unpack.js')
const fs = require('fs')
const fsm = require('fs-minipass')
const path = require('path')
const stripSlash = require('./strip-trailing-slashes.js')
module.exports = (opt_, files, cb) => {
if (typeof opt_ === 'function')
cb = opt_, files = null, opt_ = {}
else if (Array.isArray(opt_))
files = opt_, opt_ = {}
if (typeof files === 'function')
cb = files, files = null
if (!files)
files = []
else
files = Array.from(files)
const opt = hlo(opt_)
if (opt.sync && typeof cb === 'function')
throw new TypeError('callback not supported for sync tar functions')
if (!opt.file && typeof cb === 'function')
throw new TypeError('callback only supported with file option')
if (files.length)
filesFilter(opt, files)
return opt.file && opt.sync ? extractFileSync(opt)
: opt.file ? extractFile(opt, cb)
: opt.sync ? extractSync(opt)
: extract(opt)
}
// construct a filter that limits the file entries listed
// include child entries if a dir is included
const filesFilter = (opt, files) => {
const map = new Map(files.map(f => [stripSlash(f), true]))
const filter = opt.filter
const mapHas = (file, r) => {
const root = r || path.parse(file).root || '.'
const ret = file === root ? false
: map.has(file) ? map.get(file)
: mapHas(path.dirname(file), root)
map.set(file, ret)
return ret
}
opt.filter = filter
? (file, entry) => filter(file, entry) && mapHas(stripSlash(file))
: file => mapHas(stripSlash(file))
}
const extractFileSync = opt => {
const u = new Unpack.Sync(opt)
const file = opt.file
const stat = fs.statSync(file)
// This trades a zero-byte read() syscall for a stat
// However, it will usually result in less memory allocation
const readSize = opt.maxReadSize || 16 * 1024 * 1024
const stream = new fsm.ReadStreamSync(file, {
readSize: readSize,
size: stat.size,
})
stream.pipe(u)
}
const extractFile = (opt, cb) => {
const u = new Unpack(opt)
const readSize = opt.maxReadSize || 16 * 1024 * 1024
const file = opt.file
const p = new Promise((resolve, reject) => {
u.on('error', reject)
u.on('close', resolve)
// This trades a zero-byte read() syscall for a stat
// However, it will usually result in less memory allocation
fs.stat(file, (er, stat) => {
if (er)
reject(er)
else {
const stream = new fsm.ReadStream(file, {
readSize: readSize,
size: stat.size,
})
stream.on('error', reject)
stream.pipe(u)
}
})
})
return cb ? p.then(cb, cb) : p
}
const extractSync = opt => new Unpack.Sync(opt)
const extract = opt => new Unpack(opt)