const getFlags = function(fileView, offset, version) {
let tagAlterPreservation = false;
let fileAlterPreservation = false;
let readOnly = false;
let containsGroupInfo = false;
let isCompressed = false;
let isEncrypted = false;
let hasBeenUnsynchronized = false;
let hasDataLengthIndicator = false;
if (version >= 3) {
const bits = fileView.getUint16(offset);
tagAlterPreservation = readBit(bits, 14);
fileAlterPreservation = readBit(bits, 13);
readOnly = readBit(bits, 12);
containsGroupInfo = readBit(bits, 6);
isCompressed = readBit(bits, 3);
isEncrypted = readBit(bits, 2);
hasBeenUnsynchronized = readBit(bits, 1);
hasDataLengthIndicator = readBit(bits, 0);
}
return {
tagAlterPreservation,
fileAlterPreservation,
readOnly,
containsGroupInfo,
isCompressed,
isEncrypted,
hasBeenUnsynchronized,
hasDataLengthIndicator
};
};
const getMainFlags = function(fileView, offset) {
const bits = fileView.getUint8(offset + 5);
const hasBeenUnsynchronized = readBit(bits, 7);
const isExtended = readBit(bits, 6);
const isExperimental = readBit(bits, 5);
const hasFooter = readBit(bits, 4);
return {
hasBeenUnsynchronized,
isExtended,
isExperimental,
hasFooter,
invalidBits: (bits & 0xF) !== 0
};
};