Hello Pavel,
The IEP looks good to me in general. It is a good addition to the service
API.
One suggestion is to improve control over service method execution within
the interceptor:
1. Bypass service call without throwing an exception.
2. Convert service call result in some way
This can be achieved by a different interface, with a single method:
public interface ServiceCallInterceptor extends Serializable {
public default Object onInvoke(Supplier delegate, String mtd, Object[]
args, ServiceContext ctx) throws ServiceInterceptException {
return delegate.get();
}
}
which can be implemented like this:
public class MyInterceptor implements ServiceCallInterceptor {
@Override
public Object onInvoke(Supplier delegate, String mtd, Object[] args,
ServiceContext ctx) throws Exception {
AuditProvider.get().recordStartEvent(mtd,
ctx.currentCallContext().attribute("sessionId"));
try {
if (!checkAuthorization(ctx))
return notAuthorizedResult();
Object value = delegate.get();
return convert(value);
}
catch (Exception e) {
// Log error
return errorResult(...);
}
finally {
AuditProvider.get().recordEndEvent(mtd,
ctx.currentCallContext().attribute("sessionId"));
}
}
}
As you can see, this way the user has full control over all aspects of the
service call.
Thoughts?
On Tue, Jun 28, 2022 at 6:33 PM Pavel Pereslegin <[email protected]> wrote:
> Hello Igniters!
>
> I want to continue discussing a feature that allows users to create
> their own middleware for Ignite services [1].
> Earlier was added the ability to implicitly pass a set of user
> parameters (ServiceCallContext) to the service [2].
> This feature allows users to track the origin of a service call.
> Now I'd like to add a service call interceptor to allow the user to
> separate the "middleware" logic from the business code and reduce
> boilerplate code [3].
>
> I've prepared an IEP for this feature, please take a look [4].
> I will prepare patches for Java and .NET for this feature soon.
>
> [1] https://lists.apache.org/thread/wqlvskxr0fvdo6rbo64bnct4zz53kpr0
> [2] https://issues.apache.org/jira/browse/IGNITE-15572
> [3] https://issues.apache.org/jira/browse/IGNITE-17022
> [4]
> https://cwiki.apache.org/confluence/pages/viewpage.action?pageId=191334119
>
