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https://issues.apache.org/jira/browse/KAFKA-7918?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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YeLiang updated KAFKA-7918:
---------------------------
Description:
Currently, the fundamental layer of stores in Streams is the "bytes store".
The easiest way to identify this is in `org.apache.kafka.streams.state.Stores`,
all the `StoreBuilder`s require a `XXBytesStoreSupplier`.
We provide several implementations of these bytes stores, typically an
in-memory one and a persistent one (aka RocksDB).
Inside these bytes stores, the key is always `Bytes` and the value is always
`byte[]` (serialization happens at a higher level). However, the store
implementations are generically typed, just `K` and `V`.
This is good for flexibility, but it makes the code a little harder to
understand. I think that we used to do serialization at a lower level, so the
generics are a hold-over from that.
It would simplify the code if we just inlined the actual k/v types and maybe
even renamed the classes from (e.g.) `InMemoryKeyValueStore<K,V>` to
`InMemoryKeyValueBytesStore`, and so forth.
was:
Currently, the fundamental layer of stores in Streams is the "bytes store".
The easiest way to identify this is in `org.apache.kafka.streams.state.Stores`,
all the `StoreBuilder`s require a `XXBytesStoreSupplier`.
We provide several implementations of these bytes stores, typically an
in-memory one and a persistent one (aka RocksDB).
Inside these bytes stores, the key is always `Bytes` and the value is always
`byte[]` (serialization happens at a higher level). However, the store
implementations are generically typed, just `K` and `V`.
This is good for flexibility, but it makes the code a little harder to
understand. I think that we used to do serialization at a lower level, so the
generics are a hold-over from that.
It would simplify the code if we just inlined the actual k/v types and maybe
even renamed the classes from (e.g.) `InMemoryKeyValueStore<K,V>` to
`InMemoryKeyValueBytesStore`, and so forth.
> Streams store cleanup: inline byte-store generic parameters
> -----------------------------------------------------------
>
> Key: KAFKA-7918
> URL: https://issues.apache.org/jira/browse/KAFKA-7918
> Project: Kafka
> Issue Type: Improvement
> Components: streams
> Reporter: John Roesler
> Assignee: Sophie Blee-Goldman
> Priority: Major
>
> Currently, the fundamental layer of stores in Streams is the "bytes store".
> The easiest way to identify this is in
> `org.apache.kafka.streams.state.Stores`, all the `StoreBuilder`s require a
> `XXBytesStoreSupplier`.
> We provide several implementations of these bytes stores, typically an
> in-memory one and a persistent one (aka RocksDB).
> Inside these bytes stores, the key is always `Bytes` and the value is always
> `byte[]` (serialization happens at a higher level). However, the store
> implementations are generically typed, just `K` and `V`.
> This is good for flexibility, but it makes the code a little harder to
> understand. I think that we used to do serialization at a lower level, so the
> generics are a hold-over from that.
> It would simplify the code if we just inlined the actual k/v types and maybe
> even renamed the classes from (e.g.) `InMemoryKeyValueStore<K,V>` to
> `InMemoryKeyValueBytesStore`, and so forth.
>
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