Initial

resources/app/node_modules/tar-stream/headers.js

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+const b4a = require('b4a')
+
+const ZEROS = '0000000000000000000'
+const SEVENS = '7777777777777777777'
+const ZERO_OFFSET = '0'.charCodeAt(0)
+const USTAR_MAGIC = b4a.from([0x75, 0x73, 0x74, 0x61, 0x72, 0x00]) // ustar\x00
+const USTAR_VER = b4a.from([ZERO_OFFSET, ZERO_OFFSET])
+const GNU_MAGIC = b4a.from([0x75, 0x73, 0x74, 0x61, 0x72, 0x20]) // ustar\x20
+const GNU_VER = b4a.from([0x20, 0x00])
+const MASK = 0o7777
+const MAGIC_OFFSET = 257
+const VERSION_OFFSET = 263
+
+exports.decodeLongPath = function decodeLongPath (buf, encoding) {
+  return decodeStr(buf, 0, buf.length, encoding)
+}
+
+exports.encodePax = function encodePax (opts) { // TODO: encode more stuff in pax
+  let result = ''
+  if (opts.name) result += addLength(' path=' + opts.name + '\n')
+  if (opts.linkname) result += addLength(' linkpath=' + opts.linkname + '\n')
+  const pax = opts.pax
+  if (pax) {
+    for (const key in pax) {
+      result += addLength(' ' + key + '=' + pax[key] + '\n')
+    }
+  }
+  return b4a.from(result)
+}
+
+exports.decodePax = function decodePax (buf) {
+  const result = {}
+
+  while (buf.length) {
+    let i = 0
+    while (i < buf.length && buf[i] !== 32) i++
+    const len = parseInt(b4a.toString(buf.subarray(0, i)), 10)
+    if (!len) return result
+
+    const b = b4a.toString(buf.subarray(i + 1, len - 1))
+    const keyIndex = b.indexOf('=')
+    if (keyIndex === -1) return result
+    result[b.slice(0, keyIndex)] = b.slice(keyIndex + 1)
+
+    buf = buf.subarray(len)
+  }
+
+  return result
+}
+
+exports.encode = function encode (opts) {
+  const buf = b4a.alloc(512)
+  let name = opts.name
+  let prefix = ''
+
+  if (opts.typeflag === 5 && name[name.length - 1] !== '/') name += '/'
+  if (b4a.byteLength(name) !== name.length) return null // utf-8
+
+  while (b4a.byteLength(name) > 100) {
+    const i = name.indexOf('/')
+    if (i === -1) return null
+    prefix += prefix ? '/' + name.slice(0, i) : name.slice(0, i)
+    name = name.slice(i + 1)
+  }
+
+  if (b4a.byteLength(name) > 100 || b4a.byteLength(prefix) > 155) return null
+  if (opts.linkname && b4a.byteLength(opts.linkname) > 100) return null
+
+  b4a.write(buf, name)
+  b4a.write(buf, encodeOct(opts.mode & MASK, 6), 100)
+  b4a.write(buf, encodeOct(opts.uid, 6), 108)
+  b4a.write(buf, encodeOct(opts.gid, 6), 116)
+  encodeSize(opts.size, buf, 124)
+  b4a.write(buf, encodeOct((opts.mtime.getTime() / 1000) | 0, 11), 136)
+
+  buf[156] = ZERO_OFFSET + toTypeflag(opts.type)
+
+  if (opts.linkname) b4a.write(buf, opts.linkname, 157)
+
+  b4a.copy(USTAR_MAGIC, buf, MAGIC_OFFSET)
+  b4a.copy(USTAR_VER, buf, VERSION_OFFSET)
+  if (opts.uname) b4a.write(buf, opts.uname, 265)
+  if (opts.gname) b4a.write(buf, opts.gname, 297)
+  b4a.write(buf, encodeOct(opts.devmajor || 0, 6), 329)
+  b4a.write(buf, encodeOct(opts.devminor || 0, 6), 337)
+
+  if (prefix) b4a.write(buf, prefix, 345)
+
+  b4a.write(buf, encodeOct(cksum(buf), 6), 148)
+
+  return buf
+}
+
+exports.decode = function decode (buf, filenameEncoding, allowUnknownFormat) {
+  let typeflag = buf[156] === 0 ? 0 : buf[156] - ZERO_OFFSET
+
+  let name = decodeStr(buf, 0, 100, filenameEncoding)
+  const mode = decodeOct(buf, 100, 8)
+  const uid = decodeOct(buf, 108, 8)
+  const gid = decodeOct(buf, 116, 8)
+  const size = decodeOct(buf, 124, 12)
+  const mtime = decodeOct(buf, 136, 12)
+  const type = toType(typeflag)
+  const linkname = buf[157] === 0 ? null : decodeStr(buf, 157, 100, filenameEncoding)
+  const uname = decodeStr(buf, 265, 32)
+  const gname = decodeStr(buf, 297, 32)
+  const devmajor = decodeOct(buf, 329, 8)
+  const devminor = decodeOct(buf, 337, 8)
+
+  const c = cksum(buf)
+
+  // checksum is still initial value if header was null.
+  if (c === 8 * 32) return null
+
+  // valid checksum
+  if (c !== decodeOct(buf, 148, 8)) throw new Error('Invalid tar header. Maybe the tar is corrupted or it needs to be gunzipped?')
+
+  if (isUSTAR(buf)) {
+    // ustar (posix) format.
+    // prepend prefix, if present.
+    if (buf[345]) name = decodeStr(buf, 345, 155, filenameEncoding) + '/' + name
+  } else if (isGNU(buf)) {
+    // 'gnu'/'oldgnu' format. Similar to ustar, but has support for incremental and
+    // multi-volume tarballs.
+  } else {
+    if (!allowUnknownFormat) {
+      throw new Error('Invalid tar header: unknown format.')
+    }
+  }
+
+  // to support old tar versions that use trailing / to indicate dirs
+  if (typeflag === 0 && name && name[name.length - 1] === '/') typeflag = 5
+
+  return {
+    name,
+    mode,
+    uid,
+    gid,
+    size,
+    mtime: new Date(1000 * mtime),
+    type,
+    linkname,
+    uname,
+    gname,
+    devmajor,
+    devminor,
+    pax: null
+  }
+}
+
+function isUSTAR (buf) {
+  return b4a.equals(USTAR_MAGIC, buf.subarray(MAGIC_OFFSET, MAGIC_OFFSET + 6))
+}
+
+function isGNU (buf) {
+  return b4a.equals(GNU_MAGIC, buf.subarray(MAGIC_OFFSET, MAGIC_OFFSET + 6)) &&
+    b4a.equals(GNU_VER, buf.subarray(VERSION_OFFSET, VERSION_OFFSET + 2))
+}
+
+function clamp (index, len, defaultValue) {
+  if (typeof index !== 'number') return defaultValue
+  index = ~~index // Coerce to integer.
+  if (index >= len) return len
+  if (index >= 0) return index
+  index += len
+  if (index >= 0) return index
+  return 0
+}
+
+function toType (flag) {
+  switch (flag) {
+    case 0:
+      return 'file'
+    case 1:
+      return 'link'
+    case 2:
+      return 'symlink'
+    case 3:
+      return 'character-device'
+    case 4:
+      return 'block-device'
+    case 5:
+      return 'directory'
+    case 6:
+      return 'fifo'
+    case 7:
+      return 'contiguous-file'
+    case 72:
+      return 'pax-header'
+    case 55:
+      return 'pax-global-header'
+    case 27:
+      return 'gnu-long-link-path'
+    case 28:
+    case 30:
+      return 'gnu-long-path'
+  }
+
+  return null
+}
+
+function toTypeflag (flag) {
+  switch (flag) {
+    case 'file':
+      return 0
+    case 'link':
+      return 1
+    case 'symlink':
+      return 2
+    case 'character-device':
+      return 3
+    case 'block-device':
+      return 4
+    case 'directory':
+      return 5
+    case 'fifo':
+      return 6
+    case 'contiguous-file':
+      return 7
+    case 'pax-header':
+      return 72
+  }
+
+  return 0
+}
+
+function indexOf (block, num, offset, end) {
+  for (; offset < end; offset++) {
+    if (block[offset] === num) return offset
+  }
+  return end
+}
+
+function cksum (block) {
+  let sum = 8 * 32
+  for (let i = 0; i < 148; i++) sum += block[i]
+  for (let j = 156; j < 512; j++) sum += block[j]
+  return sum
+}
+
+function encodeOct (val, n) {
+  val = val.toString(8)
+  if (val.length > n) return SEVENS.slice(0, n) + ' '
+  return ZEROS.slice(0, n - val.length) + val + ' '
+}
+
+function encodeSizeBin (num, buf, off) {
+  buf[off] = 0x80
+  for (let i = 11; i > 0; i--) {
+    buf[off + i] = num & 0xff
+    num = Math.floor(num / 0x100)
+  }
+}
+
+function encodeSize (num, buf, off) {
+  if (num.toString(8).length > 11) {
+    encodeSizeBin(num, buf, off)
+  } else {
+    b4a.write(buf, encodeOct(num, 11), off)
+  }
+}
+
+/* Copied from the node-tar repo and modified to meet
+ * tar-stream coding standard.
+ *
+ * Source: https://github.com/npm/node-tar/blob/51b6627a1f357d2eb433e7378e5f05e83b7aa6cd/lib/header.js#L349
+ */
+function parse256 (buf) {
+  // first byte MUST be either 80 or FF
+  // 80 for positive, FF for 2's comp
+  let positive
+  if (buf[0] === 0x80) positive = true
+  else if (buf[0] === 0xFF) positive = false
+  else return null
+
+  // build up a base-256 tuple from the least sig to the highest
+  const tuple = []
+  let i
+  for (i = buf.length - 1; i > 0; i--) {
+    const byte = buf[i]
+    if (positive) tuple.push(byte)
+    else tuple.push(0xFF - byte)
+  }
+
+  let sum = 0
+  const l = tuple.length
+  for (i = 0; i < l; i++) {
+    sum += tuple[i] * Math.pow(256, i)
+  }
+
+  return positive ? sum : -1 * sum
+}
+
+function decodeOct (val, offset, length) {
+  val = val.subarray(offset, offset + length)
+  offset = 0
+
+  // If prefixed with 0x80 then parse as a base-256 integer
+  if (val[offset] & 0x80) {
+    return parse256(val)
+  } else {
+    // Older versions of tar can prefix with spaces
+    while (offset < val.length && val[offset] === 32) offset++
+    const end = clamp(indexOf(val, 32, offset, val.length), val.length, val.length)
+    while (offset < end && val[offset] === 0) offset++
+    if (end === offset) return 0
+    return parseInt(b4a.toString(val.subarray(offset, end)), 8)
+  }
+}
+
+function decodeStr (val, offset, length, encoding) {
+  return b4a.toString(val.subarray(offset, indexOf(val, 0, offset, offset + length)), encoding)
+}
+
+function addLength (str) {
+  const len = b4a.byteLength(str)
+  let digits = Math.floor(Math.log(len) / Math.log(10)) + 1
+  if (len + digits >= Math.pow(10, digits)) digits++
+
+  return (len + digits) + str
+}