var Utils = require("../util"),
Constants = Utils.Constants;
/* The central directory file header */
module.exports = function () {
var _verMade = 0x0A,
_version = 0x0A,
_flags = 0,
_method = 0,
_time = 0,
_crc = 0,
_compressedSize = 0,
_size = 0,
_fnameLen = 0,
_extraLen = 0,
_comLen = 0,
_diskStart = 0,
_inattr = 0,
_attr = 0,
_offset = 0;
var _dataHeader = {};
function setTime(val) {
var val = new Date(val);
_time = (val.getFullYear() - 1980 & 0x7f) << 25 // b09-16 years from 1980
| (val.getMonth() + 1) << 21 // b05-08 month
| val.getDay() << 16 // b00-04 hour
// 2 bytes time
| val.getHours() << 11 // b11-15 hour
| val.getMinutes() << 5 // b05-10 minute
| val.getSeconds() >> 1; // b00-04 seconds divided by 2
}
setTime(+new Date());
return {
get made () { return _verMade; },
set made (val) { _verMade = val; },
get version () { return _version; },
set version (val) { _version = val },
get flags () { return _flags },
set flags (val) { _flags = val; },
get method () { return _method; },
set method (val) { _method = val; },
get time () { return new Date(
((_time >> 25) & 0x7f) + 1980,
((_time >> 21) & 0x0f) - 1,
(_time >> 16) & 0x1f,
(_time >> 11) & 0x1f,
(_time >> 5) & 0x3f,
(_time & 0x1f) << 1
);
},
set time (val) {
setTime(val);
},
get crc () { return _crc; },
set crc (val) { _crc = val; },
get compressedSize () { return _compressedSize; },
set compressedSize (val) { _compressedSize = val; },
get size () { return _size; },
set size (val) { _size = val; },
get fileNameLength () { return _fnameLen; },
set fileNameLength (val) { _fnameLen = val; },
get extraLength () { return _extraLen },
set extraLength (val) { _extraLen = val; },
get commentLength () { return _comLen },
set commentLength (val) { _comLen = val },
get diskNumStart () { return _diskStart },
set diskNumStart (val) { _diskStart = val },
get inAttr () { return _inattr },
set inAttr (val) { _inattr = val },
get attr () { return _attr },
set attr (val) { _attr = val },
get offset () { return _offset },
set offset (val) { _offset = val },
get encripted () { return (_flags & 1) == 1 },
get entryHeaderSize () {
return Constants.CENHDR + _fnameLen + _extraLen + _comLen;
},
get realDataOffset () {
return _offset + Constants.LOCHDR + _dataHeader.fnameLen + _dataHeader.extraLen;
},
get dataHeader () {
return _dataHeader;
},
loadDataHeaderFromBinary : function(/*Buffer*/input) {
var data = input.slice(_offset, _offset + Constants.LOCHDR);
// 30 bytes and should start with "PK\003\004"
if (data.readUInt32LE(0) != Constants.LOCSIG) {
throw Utils.Errors.INVALID_LOC;
}
_dataHeader = {
// version needed to extract
version : data.readUInt16LE(Constants.LOCVER),
// general purpose bit flag
flags : data.readUInt16LE(Constants.LOCFLG),
// compression method
method : data.readUInt16LE(Constants.LOCHOW),
// modification time (2 bytes time, 2 bytes date)
time : data.readUInt32LE(Constants.LOCTIM),
// uncompressed file crc-32 value
crc : data.readUInt32LE(Constants.LOCCRC),
// compressed size
compressedSize : data.readUInt32LE(Constants.LOCSIZ),
// uncompressed size
size : data.readUInt32LE(Constants.LOCLEN),
// filename length
fnameLen : data.readUInt16LE(Constants.LOCNAM),
// extra field length
extraLen : data.readUInt16LE(Constants.LOCEXT)
}
},
loadFromBinary : function(/*Buffer*/data) {
// data should be 46 bytes and start with "PK 01 02"
if (data.length != Constants.CENHDR || data.readUInt32LE(0) != Constants.CENSIG) {
throw Utils.Errors.INVALID_CEN;
}
// version made by
_verMade = data.readUInt16LE(Constants.CENVEM);
// version needed to extract
_version = data.readUInt16LE(Constants.CENVER);
// encrypt, decrypt flags
_flags = data.readUInt16LE(Constants.CENFLG);
// compression method
_method = data.readUInt16LE(Constants.CENHOW);
// modification time (2 bytes time, 2 bytes date)
_time = data.readUInt32LE(Constants.CENTIM);
// uncompressed file crc-32 value
_crc = data.readUInt32LE(Constants.CENCRC);
// compressed size
_compressedSize = data.readUInt32LE(Constants.CENSIZ);
// uncompressed size
_size = data.readUInt32LE(Constants.CENLEN);
// filename length
_fnameLen = data.readUInt16LE(Constants.CENNAM);
// extra field length
_extraLen = data.readUInt16LE(Constants.CENEXT);
// file comment length
_comLen = data.readUInt16LE(Constants.CENCOM);
// volume number start
_diskStart = data.readUInt16LE(Constants.CENDSK);
// internal file attributes
_inattr = data.readUInt16LE(Constants.CENATT);
// external file attributes
_attr = data.readUInt32LE(Constants.CENATX);
// LOC header offset
_offset = data.readUInt32LE(Constants.CENOFF);
},
dataHeaderToBinary : function() {
// LOC header size (30 bytes)
var data = new Buffer(Constants.LOCHDR);
// "PK\003\004"
data.writeUInt32LE(Constants.LOCSIG, 0);
// version needed to extract
data.writeUInt16LE(_version, Constants.LOCVER);
// general purpose bit flag
data.writeUInt16LE(_flags, Constants.LOCFLG);
// compression method
data.writeUInt16LE(_method, Constants.LOCHOW);
// modification time (2 bytes time, 2 bytes date)
data.writeUInt32LE(_time, Constants.LOCTIM);
// uncompressed file crc-32 value
data.writeUInt32LE(_crc, Constants.LOCCRC);
// compressed size
data.writeUInt32LE(_compressedSize, Constants.LOCSIZ);
// uncompressed size
data.writeUInt32LE(_size, Constants.LOCLEN);
// filename length
data.writeUInt16LE(_fnameLen, Constants.LOCNAM);
// extra field length
data.writeUInt16LE(_extraLen, Constants.LOCEXT);
return data;
},
entryHeaderToBinary : function() {
// CEN header size (46 bytes)
var data = new Buffer(Constants.CENHDR + _fnameLen + _extraLen + _comLen);
// "PK\001\002"
data.writeUInt32LE(Constants.CENSIG, 0);
// version made by
data.writeUInt16LE(_verMade, Constants.CENVEM);
// version needed to extract
data.writeUInt16LE(_version, Constants.CENVER);
// encrypt, decrypt flags
data.writeUInt16LE(_flags, Constants.CENFLG);
// compression method
data.writeUInt16LE(_method, Constants.CENHOW);
// modification time (2 bytes time, 2 bytes date)
data.writeUInt32LE(_time, Constants.CENTIM);
// uncompressed file crc-32 value
data.writeInt32LE(_crc, Constants.CENCRC, true);
// compressed size
data.writeUInt32LE(_compressedSize, Constants.CENSIZ);
// uncompressed size
data.writeUInt32LE(_size, Constants.CENLEN);
// filename length
data.writeUInt16LE(_fnameLen, Constants.CENNAM);
// extra field length
data.writeUInt16LE(_extraLen, Constants.CENEXT);
// file comment length
data.writeUInt16LE(_comLen, Constants.CENCOM);
// volume number start
data.writeUInt16LE(_diskStart, Constants.CENDSK);
// internal file attributes
data.writeUInt16LE(_inattr, Constants.CENATT);
// external file attributes
data.writeUInt32LE(_attr, Constants.CENATX);
// LOC header offset
data.writeUInt32LE(_offset, Constants.CENOFF);
// fill all with
data.fill(0x00, Constants.CENHDR);
return data;
},
toString : function() {
return '{\n' +
'\t"made" : ' + _verMade + ",\n" +
'\t"version" : ' + _version + ",\n" +
'\t"flags" : ' + _flags + ",\n" +
'\t"method" : ' + Utils.methodToString(_method) + ",\n" +
'\t"time" : ' + _time + ",\n" +
'\t"crc" : 0x' + _crc.toString(16).toUpperCase() + ",\n" +
'\t"compressedSize" : ' + _compressedSize + " bytes,\n" +
'\t"size" : ' + _size + " bytes,\n" +
'\t"fileNameLength" : ' + _fnameLen + ",\n" +
'\t"extraLength" : ' + _extraLen + " bytes,\n" +
'\t"commentLength" : ' + _comLen + " bytes,\n" +
'\t"diskNumStart" : ' + _diskStart + ",\n" +
'\t"inAttr" : ' + _inattr + ",\n" +
'\t"attr" : ' + _attr + ",\n" +
'\t"offset" : ' + _offset + ",\n" +
'\t"entryHeaderSize" : ' + (Constants.CENHDR + _fnameLen + _extraLen + _comLen) + " bytes\n" +
'}';
}
}
};