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Ahh, I see where the confusion comes from. I meant initializing in the Ruby way...which is analogous to construction. There's no way for you to specify how to c

by headius 16y ago

Ahh, I see where the confusion comes from. I meant initializing in the Ruby way...which is analogous to construction. There's no way for you to specify how to construct the object being deserialized from the stream, and so you need a no-arg version of the constructor (or can allow JOS to generate one for you) and have to do the logic that would be in-constructor in a separate piece of code like readObject. And in my latest experiments with Externalizable, the JOS code being unable to construct objects the way I want it to has become the latest bottleneck. It also interferes with us serializing objects for which we do want to have final fields initialized on construction. If we want to avoid the reflective construction, we need a no-arg constructor. To have a no-arg constructor, we can't make important fields final. And if we want a particular value to be passed into the constructor, we always need to do it in readObject, without any context provided as to where and when serialization is being called. That's so cumbersome that we simply can't do it.

10ren 16y ago
To check I understand: you need to deserialize objects, and you also want to pass in some arguments to some of those objects, so that their initialization is based on both the serialized data and the arguments? Is that to do with currying (is currying in Ruby?) In a complex object graph, how do you know which arguments should go to which objects? You could use a global object to hold these arguments (or, subclass Thread, and associate the data with that, and yield while the deserialization runs in that thread). Ugly, yes. BTW: it is possible to set final fields outside a constructor, using some black hacking (by accessing the same hooks that JOS uses internally). A few serialization tools use this, and I recall a project that consisted entirely of providing nicer access to these hooks (I searched for it, but couldn't find it).

by headius 16y ago

10ren 16y ago

To check I understand: you need to deserialize objects, and you also want to pass in some arguments to some of those objects, so that their initialization is based on both the serialized data and the arguments? Is that to do with currying (is currying in Ruby?) In a complex object graph, how do you know which arguments should go to which objects? You could use a global object to hold these arguments (or, subclass Thread, and associate the data with that, and yield while the deserialization runs in that thread). Ugly, yes. BTW: it is possible to set final fields outside a constructor, using some black hacking (by accessing the same hooks that JOS uses internally). A few serialization tools use this, and I recall a project that consisted entirely of providing nicer access to these hooks (I searched for it, but couldn't find it).