/// <summary>
/// Collect properties information of the given object.
/// </summary>
private static IEnumerable <ValueToFormat> CollectPropertiesForWriting(object obj)
{
var type = obj.GetType();
return(from prop in type.GetProperties()
let val = prop.GetValue(obj, Array.Empty <object>())
let isArray = prop.PropertyType.IsArray
select new ValueToFormat
{
Value = val,
IsArray = isArray,
Format = val == null
? PiffDataFormats.Skip
: prop.GetCustomAttribute <PiffDataFormatAttribute>()?.Format
?? (isArray
? PiffDataUtility.GetDefaultFormat(prop.PropertyType.GetElementType())
: PiffDataUtility.GetDefaultFormat(prop.PropertyType))
});
}
/// <summary>
/// Read a box if it is of expected type. Back off if it's not.
/// </summary>
/// <param name="expectedType">Expected box type</typeparam>
/// <param name="bytes"></param>
/// <returns>Box object or null</returns>
internal static object ReadBox(Stream bytes, Type expectedType)
{
var length = GetInt32(bytes);
if (length < 8)
{
throw new ArgumentException($"Improper box length {length}.");
}
var id = GetFixedString(bytes, 4);
if (!sBoxes.TryGetValue(id, out var type))
{
throw new ArgumentException($"Inrecognized box type '{id}'.");
}
if (type != expectedType)
{
// Not expected type, back off
bytes.Seek(-8, SeekOrigin.Current);
return(null);
}
var obj = Activator.CreateInstance(type);
var props =
from prop in type.GetProperties()
let isArray = prop.PropertyType.IsArray
select new ValueToRead
{
Property = prop,
IsArray = isArray,
Format = prop.GetCustomAttribute <PiffDataFormatAttribute>()?.Format
?? (isArray
? PiffDataUtility.GetDefaultFormat(prop.PropertyType.GetElementType())
: PiffDataUtility.GetDefaultFormat(prop.PropertyType))
};
ReadBoxValues(bytes, obj, props.ToArray());
return(obj);
}
