diff options
Diffstat (limited to 'node_modules/tar-stream/headers.js')
-rw-r--r-- | node_modules/tar-stream/headers.js | 283 |
1 files changed, 283 insertions, 0 deletions
diff --git a/node_modules/tar-stream/headers.js b/node_modules/tar-stream/headers.js new file mode 100644 index 0000000..6efbc4a --- /dev/null +++ b/node_modules/tar-stream/headers.js @@ -0,0 +1,283 @@ +var toBuffer = require('to-buffer') +var alloc = require('buffer-alloc') + +var ZEROS = '0000000000000000000' +var SEVENS = '7777777777777777777' +var ZERO_OFFSET = '0'.charCodeAt(0) +var USTAR = 'ustar\x0000' +var MASK = parseInt('7777', 8) + +var clamp = function (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 +} + +var toType = function (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 +} + +var toTypeflag = function (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 +} + +var indexOf = function (block, num, offset, end) { + for (; offset < end; offset++) { + if (block[offset] === num) return offset + } + return end +} + +var cksum = function (block) { + var sum = 8 * 32 + for (var i = 0; i < 148; i++) sum += block[i] + for (var j = 156; j < 512; j++) sum += block[j] + return sum +} + +var encodeOct = function (val, n) { + val = val.toString(8) + if (val.length > n) return SEVENS.slice(0, n) + ' ' + else return ZEROS.slice(0, n - val.length) + val + ' ' +} + +/* 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 + var 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 + var zero = false + var tuple = [] + for (var i = buf.length - 1; i > 0; i--) { + var byte = buf[i] + if (positive) tuple.push(byte) + else if (zero && byte === 0) tuple.push(0) + else if (zero) { + zero = false + tuple.push(0x100 - byte) + } else tuple.push(0xFF - byte) + } + + var sum = 0 + var l = tuple.length + for (i = 0; i < l; i++) { + sum += tuple[i] * Math.pow(256, i) + } + + return positive ? sum : -1 * sum +} + +var decodeOct = function (val, offset, length) { + val = val.slice(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++ + var 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(val.slice(offset, end).toString(), 8) + } +} + +var decodeStr = function (val, offset, length, encoding) { + return val.slice(offset, indexOf(val, 0, offset, offset + length)).toString(encoding) +} + +var addLength = function (str) { + var len = Buffer.byteLength(str) + var digits = Math.floor(Math.log(len) / Math.log(10)) + 1 + if (len + digits >= Math.pow(10, digits)) digits++ + + return (len + digits) + str +} + +exports.decodeLongPath = function (buf, encoding) { + return decodeStr(buf, 0, buf.length, encoding) +} + +exports.encodePax = function (opts) { // TODO: encode more stuff in pax + var result = '' + if (opts.name) result += addLength(' path=' + opts.name + '\n') + if (opts.linkname) result += addLength(' linkpath=' + opts.linkname + '\n') + var pax = opts.pax + if (pax) { + for (var key in pax) { + result += addLength(' ' + key + '=' + pax[key] + '\n') + } + } + return toBuffer(result) +} + +exports.decodePax = function (buf) { + var result = {} + + while (buf.length) { + var i = 0 + while (i < buf.length && buf[i] !== 32) i++ + var len = parseInt(buf.slice(0, i).toString(), 10) + if (!len) return result + + var b = buf.slice(i + 1, len - 1).toString() + var keyIndex = b.indexOf('=') + if (keyIndex === -1) return result + result[b.slice(0, keyIndex)] = b.slice(keyIndex + 1) + + buf = buf.slice(len) + } + + return result +} + +exports.encode = function (opts) { + var buf = alloc(512) + var name = opts.name + var prefix = '' + + if (opts.typeflag === 5 && name[name.length - 1] !== '/') name += '/' + if (Buffer.byteLength(name) !== name.length) return null // utf-8 + + while (Buffer.byteLength(name) > 100) { + var i = name.indexOf('/') + if (i === -1) return null + prefix += prefix ? '/' + name.slice(0, i) : name.slice(0, i) + name = name.slice(i + 1) + } + + if (Buffer.byteLength(name) > 100 || Buffer.byteLength(prefix) > 155) return null + if (opts.linkname && Buffer.byteLength(opts.linkname) > 100) return null + + buf.write(name) + buf.write(encodeOct(opts.mode & MASK, 6), 100) + buf.write(encodeOct(opts.uid, 6), 108) + buf.write(encodeOct(opts.gid, 6), 116) + buf.write(encodeOct(opts.size, 11), 124) + buf.write(encodeOct((opts.mtime.getTime() / 1000) | 0, 11), 136) + + buf[156] = ZERO_OFFSET + toTypeflag(opts.type) + + if (opts.linkname) buf.write(opts.linkname, 157) + + buf.write(USTAR, 257) + if (opts.uname) buf.write(opts.uname, 265) + if (opts.gname) buf.write(opts.gname, 297) + buf.write(encodeOct(opts.devmajor || 0, 6), 329) + buf.write(encodeOct(opts.devminor || 0, 6), 337) + + if (prefix) buf.write(prefix, 345) + + buf.write(encodeOct(cksum(buf), 6), 148) + + return buf +} + +exports.decode = function (buf, filenameEncoding) { + var typeflag = buf[156] === 0 ? 0 : buf[156] - ZERO_OFFSET + + var name = decodeStr(buf, 0, 100, filenameEncoding) + var mode = decodeOct(buf, 100, 8) + var uid = decodeOct(buf, 108, 8) + var gid = decodeOct(buf, 116, 8) + var size = decodeOct(buf, 124, 12) + var mtime = decodeOct(buf, 136, 12) + var type = toType(typeflag) + var linkname = buf[157] === 0 ? null : decodeStr(buf, 157, 100, filenameEncoding) + var uname = decodeStr(buf, 265, 32) + var gname = decodeStr(buf, 297, 32) + var devmajor = decodeOct(buf, 329, 8) + var devminor = decodeOct(buf, 337, 8) + + if (buf[345]) name = decodeStr(buf, 345, 155, filenameEncoding) + '/' + name + + // to support old tar versions that use trailing / to indicate dirs + if (typeflag === 0 && name && name[name.length - 1] === '/') typeflag = 5 + + var 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?') + + return { + name: name, + mode: mode, + uid: uid, + gid: gid, + size: size, + mtime: new Date(1000 * mtime), + type: type, + linkname: linkname, + uname: uname, + gname: gname, + devmajor: devmajor, + devminor: devminor + } +} |