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Navina Ramesh commented on SAMZA-1160: -------------------------------------- [~fredji] This is a bold proposal considering the number of places where we need to make the change. But you are right that the result of using inheritance has polluted the config scopes. +1 for composition approach, although in-time we should have a more elaborate proposal. Thanks! > Migrate MapConfig inherited Java classes to use composition over inheritance > ---------------------------------------------------------------------------- > > Key: SAMZA-1160 > URL: https://issues.apache.org/jira/browse/SAMZA-1160 > Project: Samza > Issue Type: Task > Reporter: Fred Ji > > In Samza code, we have a lot of classes with the name "*Config" which > inherits from MapConfig but only intending to exposing the APIs for the > specific configuration. > For example, JavaStorageConfig, it currently extends MapConfig, but it only > intends to manage/fetch storeNames and store related configs, but not other > configs. With the inheritance, it does not have good encapsulation and it > allows the object JavaStorageConfig to call any public API from MapConfig as > well, for example, javaStorageConfig.get("yarn.resources.package.path"). With > it, it mixes up the business logic for different types of Config. > A proposal for addressing this is to do composition over inheritance, each > type of Config, for example, JavaStorageConfig can have a member variable > config which can leverage the interface of Config class (or the > implementation of MapConfig) but not exposing the APIs of Config further > down. -- This message was sent by Atlassian JIRA (v6.3.15#6346)