Comparison with protobuf net and migration

In short, protobuf-net serializes data but AqlaSerializer is intended to serialize objects. What the difference? Data serializers don't care much about language runtime specifics like references, inheritance, etc. In contrast, an object serializer should take such things into account.

Reference tracking

Are you tired of endless ProtoExceptions like Internal error; a key mismatch occurred? Think AqlaSerializer is a solution.

For Aqla and third party attributes reference tracking and null support are enabled by default where appropriate.

Collections

Nested collections
Multidimensional arrays
Empty array is not the same as null and vice versa
More compact
Versioning between arrays and lists
Better handling of collection subtypes
You can control serialization separately for collection member and for its elements (and even for their inner elements if they are collections too)

Attributes

You may reference both protobuf-net dll and AqlaSerializer because attributes have different names.
AqlaSerializer supports protobuf-net attributes.
To control AqlaSerializer features use its new attributes.

To allow users reference both protobuf-net dll and AqlaSerializer it contains new attributes in AqlaSerializer namespace. I want to make the migration as much easy as I can so AqlaSerializer supports all the protobuf-net legacy attributes. You don't need to remove protobuf-net reference and can use both AqlaSerializer and protobuf-net in the same project. Legacy attributes are supported when you reference protobuf-net.dll. Mind that some new features may be enabled only for new Aqla attributes to ensure legacy behavior for protobuf-net members.

AqlaSerializer.dll	protobuf-net.dll
SerializableType	ProtoContract
SerializeDerivedType	ProtoInclude
(Partial)SerializableMember	Proto(Partial)Member
SerializableMemberNested	-
(Partial)NonSerializableMember	Proto(Partial)Ignore
EnumSerializableValue	ProtoEnum
(Before\|After)(Des\|S)erializationCallback	Proto(Before\|After)(Des\|S)erialization
SurrogateConverter	ProtoConverter
BinarySerializationBehavior	ProtoBehavior

Attribute	Purpose
SerializableType	Marks a type and specifies its settings
SerializeDerivedType	Specifies a derived type field number
(Partial)SerializableMember	Marks a member and specifies its settings
SerializableMemberNested	Specifies settings for collection item
(Partial)NonSerializableMember	Excludes a member from serialization
EnumSerializableValue	Specifies a field number for an enum value
(Before\|After)(Des\|S)erializationCallback	Marks custom callbacks
SurrogateConverter	Converter between a value and its surrogate
BinarySerializationBehavior	WCF

Attributes behavior is controlled by a current auto-add behavior.

Implicit Fields

AqlaSerializer new attributes have improved behavior which you need to take into account when migrating: SerializableType assumes ImplicitFields behavior by default which means all properties of type are considered serializable automatically (even with no explicit SerializableMember attribute). You can change this with [SerializableType(ImplicitFields = ...)].

The legacy attributes are not affected by this.

And there are more ImplicitFields options are available now.

Internals

Serializers generate more correct and faster IL with Compile() or CompileInPlace()
Using RunSharp instead of pure IL generation to make serializers compilation code easier to maintain
Performance improvements
Significant refactorings for better maintainability and extensibility
More control of serialization and type-registration behavior
For long data when output stream supports seeking doesn't keep things in internal buffer

Tests

As AqlaSerializer is basically a fork of protobuf-net, it's checked against the same tests. The behavior should be nearly the same for legacy attributes as it passes practically all protobuf-net tests which are not related to its write format.

Compatibility

Be aware that you can't directly serialize objects with protobuf-net and than deserialize them with AqlaSerializer and opposite unless you use a compatibility mode.