On 26.05.2015 23:04, Vladimir Ozerov wrote:
> Brane,
>
> There are two key features we are planning to address with platforms
> integration efforts apart of trivial cache/compue APIs;
> 1) Portability, so that objects can freely travel between Java, C++, etc..
> Also portability is mandatory to support queries because our query engine
> is tightly coupled to Java.
> 2) Zero changes to existing models in user apps, so that Ignite could be
> integrated into legacy apps with minimal efforts. On Java side our
> OptimizedMarshaller is already in a very good shape to handle this. This is
> why I would prefer to develop marshaller from scratch instead of using
> existing solutions.
Hmmm ... so, in this case I really see only two possible approaches:
1. Use an IDL-like approach, where users would describe their C++
types, e.g., in Java, and you could use the existing introspection
code to generate a specialized C++ marshaller.
2. Use a C++ parser (e.g., from LLVM) to generate a machine-readable
structure description, and generate the marshalling code from that.
Option 2 is by far the most user-friendly, because users could just
point the generator to their existing class definitions. But it's
probably a huge amount of work.
Both approaches have one nasty problem: In C++, unlike in Java with
reflection, there's no universal way to construct an object without
using the available constructors, nor is there a universal way to set
values to class attributes. It's likely that users would have to modify
their existing classes by adding marshaller-friendly constructors or
factory methods (where such don't yet exist).
-- Brane
