It's been a while since I touched the ROP code. Back in the day Java serialization "kind of worked", but not completely. So you are probably right that it is not a real option. I am just trying to avoid new dependencies (even optional) on third-party libs in the Cayenne core. So perhaps we can simply leave out any "default" serialization and always require an explicit serialization provider.
Andrus > On May 5, 2016, at 8:12 PM, Aristedes Maniatis <a...@maniatis.org> wrote: > > Maybe I'm not understanding correctly, but I don't think Java serialisation > has been implemented in ROP. The work Dima did was to move away from the > Hessian servlet stuff for making the HTTP connection, to plain Java with the > option for plugging in Jetty libraries for HTTP/2. > > The work Savva did just now was to use protostuff for serialisation, but I'm > not sure what's now needed if we wanted plain Java serialisation or whether > that's even possible without some sort of library to handle an object graph > with cycles. > > Or at least that's my understanding. > > Ari > > > On 6/05/2016 9:55am, Andrus Adamchik wrote: >> Thanks for clarification. I would say use Java serialization as a default, >> and make it easy to plugin Hessian and Protostuff as separate modules. >> >> A. >> >>> On May 5, 2016, at 5:39 PM, Savva Kolbachev <s.kolbac...@gmail.com> wrote: >>> >>> Hi Andrus, >>> >>>> So which one is the default, Hessian or Java? >>> We still use Hessian for serialization by default >>> https://github.com/apache/cayenne/blob/master/cayenne-server/src/main/java/org/apache/cayenne/rop/HessianROPSerializationService.java >>> But we use java.net.URLConnection for establish connection and sending >>> messages from client to server >>> https://github.com/apache/cayenne/blob/master/cayenne-client/src/main/java/org/apache/cayenne/rop/http/HttpROPConnector.java >>> So we have escaped from Hessian only in connectivity layer. >>> >>>> I don't have a problem with Protostuff being a recommended default, but >>> for dependency management purposes I'd rather we split all third-party >>> integrations in separate modules, and use whatever provider is hooked up in >>> runtime. Kind of what we do with Joda/Java8 extensions. >>> I already did it in this way. I created separate module for Protostuff >>> serialization. >>> >>> As Hessian serialization has some troubles with Java8 types and provide >>> less efficient serialization than Protostuff, I suggest to use Protostuff >>> as default serialization service or to use Java serialization. So I just >>> suggest to escape from Hessian :) >>> >>> 2016-05-05 19:41 GMT+03:00 Savva Kolbachev <s.kolbac...@gmail.com>: >>> >>>> Hi Ari, >>>> >>>> Looks like Protostuff works faster than Protobuf in some cases. For >>>> example Serializers (no shared refs) and Cross Lang Binary Serializers >>>> sections here http://hperadin.github.io/jvm-serializers-report/report.html >>>> >>>> In our case we need to serialize graph of objects (Full Object Graph >>>> Serializers section in link above). Protobuf can't do it out of the box >>>> but Protostuff can. In my implementation I use protostuff-graph-runtime >>>> which generates a schema from objects at runtime and caches it. >>>> >>>> Protostuff schema is something like .proto files but in Java: >>>> http://www.protostuff.io/documentation/schema/ >>>> Runtime schema: http://www.protostuff.io/documentation/runtime-schema/ >>>> >>>> As you could see in benchmarks there is a small difference in efficiency >>>> between protostuff-graph and protostuff-graph-runtime. The ser/deser >>>> overhead is related to runtime schema generation. The size penalty is that >>>> Protostuff adds class name for objects and than uses those for find >>>> appropriate classes via reflection. >>>> Hessian also adds fields names so the size of Hessian serialization is >>>> much bigger. In my small example with selection of 6 objects Hessian >>>> serialization size is more than 2400 bytes while Protostuff runtime is >>>> about 800 bytes. >>>> >>>> If we don't want to have ser/deser and size overhead we could find a way >>>> to generate schemas via Velocity. And we should provide schemas for some >>>> Cayenne classes. But it will require a lot of efforts. >>>> >>>> >>>> 2016-05-05 13:44 GMT+03:00 Aristedes Maniatis <a...@maniatis.org>: >>>> >>>>> On 5/05/2016 7:35pm, Savva Kolbachev wrote: >>>>>> Protostuff (licensed under Apache 2.0 licence) is based on Google's >>>>>> Protocol-Buffers (Protobuf) but has some optimizations and some cool >>>>> things >>>>>> like runtime serialization graph of objects (like Hessian). It also >>>>> could >>>>>> generate schema on runtime so we shouldn't define .proto files although >>>>> it >>>>>> might increase efficiency. It works faster than Hessian and could handle >>>>>> Java8 Date and Time types. Here is some benchmarks. Take a look at Full >>>>>> Object Graph Serializers section. >>>>>> http://hperadin.github.io/jvm-serializers-report/report.html >>>>>> https://github.com/eishay/jvm-serializers/wiki >>>>> >>>>> According to those benchmarks there appears to be no performance or size >>>>> penalty to using protostuff over protobuffers. Am I reading that right? >>>>> >>>>> I don't really understand... doesn't the serialiser have to construct a >>>>> .proto definition and then include it in the message? So shouldn't it be >>>>> faster/smaller to predefine these? >>>>> >>>>> If we did, we could create them with velocity in the same way we create >>>>> Java _superclasses today. Fairly trivial I'm guessing. >>>>> >>>>> Ari >>>>> >>>>> >>>>> -- >>>>> --------------------------> >>>>> Aristedes Maniatis >>>>> GPG fingerprint CBFB 84B4 738D 4E87 5E5C 5EFA EF6A 7D2E 3E49 102A >>>>> >>>> >>>> >>>> >>>> -- >>>> Thanks and Regards >>>> Savva Kolbachev >>>> >>> >>> >>> >>> -- >>> Thanks and Regards >>> Savva Kolbachev >> > > -- > --------------------------> > Aristedes Maniatis > GPG fingerprint CBFB 84B4 738D 4E87 5E5C 5EFA EF6A 7D2E 3E49 102A
