[FLINK-31708][API / Type Serialization System] make DataInputView#read(byte[], int, int) return 0 if len is 0.

[Shenjiaqi]

What is the purpose of the change

Refine semantic of DataInputView#read(byte[] b, int off, int len) interface when len is 0 and no more data is available.
There are 4 Classes that implement this method, and their hehavior is different when len is 0 and no more data is available:

• AbstractPagedInputView: return 0
• DataInputDeserializer: return -1
• InternalDeSerializer: return -1
• NonSpanningWrapper: return 0

There is a chance that when deserializing an protobuf generated empty object, DataInputDeserializer#read(byte[],int,int) would return -1, and then cause job failure. (Detail is posted in issue)
The reason cause this problem is much like: #20860.

I think the interface should be clarified, and we can use the same semantic as InputStream:

If len is zero, then no bytes are read and 0 is returned;
otherwise, there is an attempt to read at least one byte.
If no byte is available because the stream is at end of file, the value -1 is returned
...

Brief change log

• Add comment in DataInputView#read(byte[] byte, int off, int len) and clarify behavior when len == 0 and no more data available.
• Make DataInputDeserializer#read(byte[] byte, int off, int len) return 0 if len == 0 and no more data available.
• Make InternalDeSerializer#read(byte[] byte, int off, int len) return 0 if len == 0 and no more data available.

Verifying this change

This change added tests and can be verified as follows:

• Unittest is added for DataInputDeserializer#read

Does this pull request potentially affect one of the following parts:

• Dependencies (does it add or upgrade a dependency): (no)
• The public API, i.e., is any changed class annotated with @Public(Evolving): (no)
• The serializers: (yes)
• The runtime per-record code paths (performance sensitive): (no)
• Anything that affects deployment or recovery: JobManager (and its components), Checkpointing, Kubernetes/Yarn, ZooKeeper: (no)
• The S3 file system connector: (no)

Documentation

• Does this pull request introduce a new feature? (no)
• If yes, how is the feature documented? (not applicable)

[flinkbot]

CI report:

• 5a3ce46 Azure: SUCCESS

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[pltbkd]

Thanks for the contribution @Shenjiaqi .

This PR LGTM. And I think unifying the behavior of implementations of DataInputView#read is a great idea.

Would you like take another look @gaoyunhaii ?

[gaoyunhaii]

Thanks @Shenjiaqi for the PR and @pltbkd for the review! I have two minor comments.

[Shenjiaqi]

Thanks @gaoyunhaii for review. Now code is fixed.

[gaoyunhaii]

Thanks @Shenjiaqi for the changes! LGTM