/// <summary>
/// Populates the current instance by reading in a raw APEv2
/// item.
/// </summary>
/// <param name="data">
/// A <see cref="ByteVector" /> object containing the item to
/// read.
/// </param>
/// <param name="offset">
/// A <see cref="int" /> value specifying the offset in
/// <paramref name="data" /> at which the item data begins.
/// </param>
/// <exception cref="ArgumentNullException">
/// <paramref name="data" /> is <see langword="null" />.
/// </exception>
/// <exception cref="ArgumentOutOfRangeException">
/// <paramref name="offset" /> is less than zero.
/// </exception>
/// <exception cref="CorruptFileException">
/// A complete item could not be read.
/// </exception>
protected void Parse(ByteVector data, int offset)
{
if (data == null)
{
throw new ArgumentNullException(nameof(data));
}
if (offset < 0)
{
throw new ArgumentOutOfRangeException(nameof(offset));
}
// 11 bytes is the minimum size for an APE item
if (data.Count < offset + 11)
{
throw new CorruptFileException(
"Not enough data for APE Item");
}
var value_length = data.Mid(offset, 4)
.ToUInt(false);
var flags = data.Mid(offset + 4, 4)
.ToUInt(false);
ReadOnly = (flags & 1) == 1;
Type = (ItemType)((flags >> 1) & 3);
var pos = data.Find(ByteVector.TextDelimiter(
StringType.UTF8), offset + 8);
Key = data.ToString(StringType.UTF8,
offset + 8, pos - offset - 8);
if (value_length > data.Count - pos - 1)
{
throw new CorruptFileException(
"Invalid data length.");
}
Size = pos + 1 + (int)value_length - offset;
if (Type == ItemType.Binary)
{
this.data = new ReadOnlyByteVector(
data.Mid(pos + 1, (int)value_length));
}
else
{
text = data.Mid(pos + 1,
(int)value_length)
.ToStrings(
StringType.UTF8, 0);
}
}
