parseExtraField.js•1.04 kB
var binary = require('binary');
module.exports = function(extraField, vars) {
var extra;
// Find the ZIP64 header, if present.
while(!extra && extraField && extraField.length) {
var candidateExtra = binary.parse(extraField)
.word16lu('signature')
.word16lu('partsize')
.word64lu('uncompressedSize')
.word64lu('compressedSize')
.word64lu('offset')
.word64lu('disknum')
.vars;
if(candidateExtra.signature === 0x0001) {
extra = candidateExtra;
} else {
// Advance the buffer to the next part.
// The total size of this part is the 4 byte header + partsize.
extraField = extraField.slice(candidateExtra.partsize + 4);
}
}
extra = extra || {};
if (vars.compressedSize === 0xffffffff)
vars.compressedSize = extra.compressedSize;
if (vars.uncompressedSize === 0xffffffff)
vars.uncompressedSize= extra.uncompressedSize;
if (vars.offsetToLocalFileHeader === 0xffffffff)
vars.offsetToLocalFileHeader= extra.offset;
return extra;
};