internal static void Deserialize <TCreation>(ref T instance, SerializationContext context)
where TCreation : class, T
{
uint prefix = 0;
if (context == null)
{
throw new ArgumentNullException("context");
}
#if !CF
try
{
#endif
if (instance != null)
{
Callback(CallbackType.BeforeDeserialization, instance);
}
context.Push();
int propCount = readProps.Length;
//context.CheckSpace();
IExtensible extensible = instance as IExtensible;
IExtension extn = null;
Property <T> prop = propCount == 0 ? null : readProps[0];
int lastIndex = prop == null ? -1 : 0;
uint lastPrefix = prop == null ? uint.MaxValue : prop.FieldPrefix;
while (context.TryReadFieldPrefix(out prefix))
{
// scan for the correct property
bool foundTag = false;
if (prefix == lastPrefix)
{
foundTag = true;
}
else if (prefix > lastPrefix)
{
for (int i = lastIndex + 1; i < propCount; i++)
{
if (readProps[i].FieldPrefix == prefix)
{
prop = readProps[i];
lastIndex = i;
lastPrefix = prefix;
foundTag = true;
break;
}
if (readProps[i].FieldPrefix > prefix)
{
break; // too far
}
}
}
else
{
for (int i = lastIndex - 1; i >= 0; i--)
{
if (readProps[i].FieldPrefix == prefix)
{
prop = readProps[i];
lastIndex = i;
lastPrefix = prefix;
foundTag = true;
break;
}
if (readProps[i].FieldPrefix < prefix)
{
break; // too far
}
}
}
if (!foundTag)
{
// check for subclass creation
foreach (KeyValuePair <Type, Property <T, T> > subclass in subclasses)
{
// deserialize the nested data
if (prefix == subclass.Value.FieldPrefix)
{
foundTag = true;
instance = subclass.Value.DeserializeImpl(instance, context);
break;
}
}
if (foundTag)
{
continue; // nothing more to do for this...
}
}
// not a sub-class, but *some* data there, so create an object
if (instance == null)
{
instance = ObjectFactory <TCreation> .Create();
Callback(CallbackType.ObjectCreation, instance);
extensible = instance as IExtensible;
}
if (foundTag)
{
// found it by seeking; deserialize and continue
// ReSharper disable PossibleNullReferenceException
try
{
prop.Deserialize(instance, context);
}
catch (UnexpectedDataException ex)
{
if (extensible != null)
{
if (extn == null)
{
extn = extensible.GetExtensionObject(true);
}
ex.Serialize(extn);
}
// DON'T re-throw; we've handled this
}
// ReSharper restore PossibleNullReferenceException
continue;
}
WireType wireType;
int fieldTag;
Serializer.ParseFieldToken(prefix, out wireType, out fieldTag);
if (wireType == WireType.EndGroup)
{
context.EndGroup(fieldTag);
break; // this ends the entity, so stop the loop
}
// so we couldn't find it...
if (extensible != null)
{
if (extn == null)
{
extn = extensible.GetExtensionObject(true);
}
Stream extraStream = extn.BeginAppend();
try {
SerializationContext extraData = new SerializationContext(extraStream, null);
// copy the data into the output stream
// ReSharper disable PossibleNullReferenceException
extraData.EncodeUInt32(prefix);
// ReSharper restore PossibleNullReferenceException
ProcessExtraData(context, fieldTag, wireType, extraData);
extraData.Flush();
extn.EndAppend(extraStream, true);
} catch {
extn.EndAppend(extraStream, false);
throw;
}
}
else
{
Debug.WriteLine("Dropping:" + fieldTag);
// unexpected fields for an inextensible object; discard the data
Serializer.SkipData(context, fieldTag, wireType);
}
}
// final chance to create an instance - this only gets invoked for empty
// messages (otherwise instance should already be non-null)
if (instance == null)
{
instance = ObjectFactory <T> .Create();
Callback(CallbackType.ObjectCreation, instance);
}
context.Pop();
Callback(CallbackType.AfterDeserialization, instance);
#if !CF
}
catch (Exception ex)
{
const string ErrorDataKey = "protoSource";
if (!ex.Data.Contains(ErrorDataKey))
{
ex.Data.Add(ErrorDataKey, string.Format("tag={0}; wire-type={1}; offset={2}; depth={3}; type={4}",
(int)(prefix >> 3), (WireType)(prefix & 7),
context.Position, context.Depth, typeof(T).FullName));
}
throw;
}
#endif
}