[tor-bugs] #24028 [Metrics/Library]: Provide a modernized API for metrics-lib

[Tor Bug Tracker & Wiki]

#24028: Provide a modernized API for metrics-lib
-----------------------------+--------------------------
 Reporter:  iwakeh           |          Owner:  iwakeh
     Type:  enhancement      |         Status:  accepted
 Priority:  Medium           |      Milestone:
Component:  Metrics/Library  |        Version:
 Severity:  Normal           |     Resolution:
 Keywords:  metrics-2017     |  Actual Points:
Parent ID:                   |         Points:
 Reviewer:                   |        Sponsor:
-----------------------------+--------------------------

Old description:

> In order to provide a more modern API in metrics-lib the interface
> hierarchy needs to be renewed/restructured/changed in backwards
> compatible ways.
>
> A separate discussion led to the following results:
>
> * The new interfaces will be placed in new packages, which allows for
> keeping good names and improving other w/o disturbing the existing
> classes.  Suggested packages:
>   - org.torproject.metrics.descriptor
>   - org.torproject.metrics.descriptor.impl
>   - org.torproject.metrics.index
>   - org.torproject.metrics.internal
>
> * Besides improving the general structure consider different return types
> for all time related values and use java.util.Optional for all optional
> values and other java 8 features (as mentioned in summary ticket #23752).
>

> Possible next steps:
>
> * Use a small, i.e., limited to few classes/interfaces, prototype example
> for finding the right approach to make these two interface hierarchies
> live beside each other and minimize additional implementation.
> * Use the working prototype approach to try new naming rules for methods.
> * Extend the found solution to the entire public API.
> * Choose first code base to use the new interface hierarchy.
> * Possibly improve new interface hierarchy.
> * Use new interfaces in all Metrics products.
>
> The other ticket related to an improved metrics-lib API is obsolete with
> this new approach; for reference: #19640.  There is a pending new
> interfaces, which should be only implemented with the new hierarchy (if
> demand permits): #17861.
> The work-in-progress interfaces (and implementations) for webstats could
> be moved into the new hierarchy already, but could also be easily moved
> later.

New description:

 In order to provide a more modern API in metrics-lib the interface
 hierarchy needs to be renewed/restructured/changed in backwards compatible
 ways.

 A separate discussion led to the following results:

 * The new interfaces will be placed in new packages, which allows for
 keeping good names and improving other w/o disturbing the existing
 classes.  Suggested packages:
   - org.torproject.metrics.descriptor
   - org.torproject.metrics.descriptor.impl
   - org.torproject.metrics.index
   - org.torproject.metrics.internal

 * Besides improving the general structure consider different return types
 for all time related values and use java.util.Optional for all optional
 values and other java 8 features (as mentioned in summary ticket #23752).


 Possible next steps:

 * Use a small, i.e., limited to few classes/interfaces, prototype example
 for finding the right approach to make these two interface hierarchies
 live beside each other and minimize additional implementation.
 * Use the working prototype approach to try new naming rules for methods.
 * Extend the found solution to the entire public API.
 * Choose first code base to use the new interface hierarchy.
 * Possibly improve new interface hierarchy.
 * Use new interfaces in all Metrics products.

 The other ticket related to an improved metrics-lib API is obsolete with
 this new approach; for reference and as improvement-idea resource: #19640.
 There is a pending new interfaces, which should be only implemented with
 the new hierarchy (if demand permits): #17861.
 The work-in-progress interfaces (and implementations) for webstats could
 be moved into the new hierarchy already, but could also be easily moved
 later.

--

Comment (by iwakeh):

 Replying to [comment:2 karsten]:
 > Sounds great. But let's not ignore all the work we put into #19640. The
 ideas on that ticket might be very relevant for the step "Possibly improve
 new interface hierarchy."

 Yes, that's what I intended too.  I'll rephrase the description a bit.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/24028#comment:3>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
The Tor Project: anonymity online