Issues with Id.*, ProgramType, and ElementType (cdap-cli)
- Id.*
- toString() is inconsistent
- JSON serialization is inconsistent (since sometimes we use NamespacedIdCodec and sometimes we don't)
- Doesn't look pretty in JSON form due to heavy nesting
- Needs lots of extra code to implement JSON codec (NamespacedIdCodec)
- Id.Program vs Id.Flow: two classes that do the same thing
- Constructing a child Id.* requires repetition
- ProgramType
- Inconsistent in JSON form compared to other CDAP entities (using "Flow", "Mapreduce", etc. form instead of "flow", "mapreduce", etc. form to maintain backwards-compatibility)
- SchedulableProgramType duplicates ProgramType
- ElementType
- Only in cdap-cli
- Doesn't cover every type of entity
Changes
- EntityType: enum that describes every type of entity in CDAP (namespace, application, program, program run, flowlet, flowlet queue, schedule, notification feed, artifact, system service, etc.)
- EntityId: base class for entities in CDAP
- No nesting
- Consistent "static EntityId fromString(String)" and "String toString()"
- Consistent JSON serialization and deserialization (still need custom deserializer, but it should have much less code than NamespacedIdCodec, and should support all EntityIds)
- Easier way to construct child Ids (e.g. given a namespace id, construct app id)
- Make ProgramType have consistent JSON and fix duplication between SchedulableProgramType and ProgramType
- Deprecate Id.*, remove ElementType
Examples
EntityId construction
Ids.namespace("foo") Ids.namespace("foo").artifact("art", "1.2.3") Ids.namespace("foo").dataset("zoo") Ids.namespace("foo").datasetModule("moo") Ids.namespace("foo").datasetType("typ") Ids.namespace("foo").stream("t") Ids.namespace("foo").app("app") Ids.namespace("foo").app("app").program(ProgramType.FLOW, "flo") Ids.namespace("foo").app("app").program(ProgramType.FLOW, "flo").run("run1") Ids.namespace("foo").app("app").program(ProgramType.FLOW, "flo").flowlet("flol") Ids.namespace("foo").app("app").program(ProgramType.FLOW, "flo").flowlet("flol").queue("q")
toString()
namespace:foo artifact:foo.art.1.2.3 dataset:foo.zoo dataset_module:foo.moo dataset_type:foo.typ stream:foo.t application:foo.app program:foo.app.flow.flo program_run:foo.app.flow.flo.run1 flowlet:foo.app.flo.flol flowlet_queue:foo.app.flo.flol.q
GSON.toJson()
{"namespace":"foo","entity":"NAMESPACE"} {"namespace":"foo","artifact":"art","version":"1.2.3","entity":"ARTIFACT"} {"namespace":"foo","dataset":"zoo","entity":"DATASET"} {"namespace":"foo","module":"moo","entity":"DATASET_MODULE"} {"namespace":"foo","type":"typ","entity":"DATASET_TYPE"} {"namespace":"foo","stream":"t","entity":"STREAM"} {"namespace":"foo","application":"app","entity":"APPLICATION"} {"namespace":"foo","application":"app","type":"Flow","program":"flo","entity":"PROGRAM"} {"namespace":"foo","application":"app","type":"Flow","program":"flo","run":"run1","entity":"PROGRAM_RUN"} {"namespace":"foo","application":"app","flow":"flo","flowlet":"flol","entity":"FLOWLET"} {"namespace":"foo","application":"app","flow":"flo","flowlet":"flol","queue":"q","entity":"FLOWLET_QUEUE"}