banmoy commented on a change in pull request #8611: [FLINK-12693][state] Store state per key-group in CopyOnWriteStateTable URL: https://github.com/apache/flink/pull/8611#discussion_r300210740
########## File path: flink-runtime/src/main/java/org/apache/flink/runtime/state/heap/AbstractStateTableSnapshot.java ########## @@ -19,34 +19,106 @@ package org.apache.flink.runtime.state.heap; import org.apache.flink.annotation.Internal; +import org.apache.flink.api.common.typeutils.TypeSerializer; +import org.apache.flink.core.memory.DataOutputView; import org.apache.flink.runtime.state.StateSnapshot; +import org.apache.flink.runtime.state.StateSnapshotTransformer; +import org.apache.flink.runtime.state.metainfo.StateMetaInfoSnapshot; import org.apache.flink.util.Preconditions; +import javax.annotation.Nonnull; +import javax.annotation.Nullable; + +import java.io.IOException; + /** * Abstract base class for snapshots of a {@link StateTable}. Offers a way to serialize the snapshot (by key-group). * All snapshots should be released after usage. */ @Internal -abstract class AbstractStateTableSnapshot<K, N, S, T extends StateTable<K, N, S>> implements StateSnapshot { +abstract class AbstractStateTableSnapshot<K, N, S, T extends StateTable<K, N, S>> Review comment: I think there is no need to introduce `getStateMapSnapshotArray` for `NestedStateTable`. For `CopyOnWriteStateTable`, we should create snapshots for all `StateMap`s in the sync part of the snapshot for backend, hold them somewhere like in an array, and use them to write state to output in the async part. But for `NestedStateTable` which only supports synchronous snapshot, we can create the snapshot of `StateMap` and write state to output one by one, and there is no need to hold all `StateMap`'s snapshots firstly and then write state to output ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org With regards, Apache Git Services