feat(bindings/java): add layers onto ops

[tisonkun]

• This closes Support extend layers for Java binding #3367.
• This closes bindings/java: Enable retry layer by default in behavior test #3458.

While we may investigate how to add Java layer support, native layers should use different tech solutions as explained in this PR.

[tisonkun]

As for #3363 (comment), I'm not sure if we should enable RetryLayer in BehaviorExtension for all ops in tests.

[Zheaoli]

I'm not sure if we should enable RetryLayer in BehaviorExtension for all ops in tests.

I think we just need to keep the same behavior with https://github.com/apache/incubator-opendal/blob/main/core/tests/behavior/utils.rs#L88-L91

[Xuanwo]

As for #3363 (comment), I'm not sure if we should enable RetryLayer in BehaviorExtension for all ops in tests.

This is required since it's normal that services returns errors.

[tisonkun]

It's possible to have a native layer wrapper with API -

public abstract class NativeLayer {
    public abstract long layer(long operatorNativeHandle);
}

I implement it locally, while the visibility and clone issue is suboptimal from my perspective. I don't have too much time now to dive into the trade-off so close this PR as won't do.

[tisonkun]

... and something like -

    public static Operator of(String schema, Map<String, String> map, List<NativeLayer> layers) {
        final long nativeHandle = constructor(schema, map);
        final OperatorInfo info = makeOperatorInfo(nativeHandle);

        Operator op = new Operator(nativeHandle, info);
        for (NativeLayer layer : layers) {
            op = new Operator(layer.layer(op.nativeHandle), info);
        }

        return op;
    }

If as @Xuanwo stated, layer to be outside of constructor API but standalone API, it can be a bit complicated. FYI, in Rust core, BlockingOperator cannot be layered but always construct from a (layered) op. I highly suspect the scenario to layer a op after it's constructed and used.

[Xuanwo]

FYI, in Rust core, BlockingOperator cannot be layered but always construct from a (layered) op. I highly suspect the scenario to layer a op after it's constructed and used.

BlockingOperator has the exactly same in-memory layout with Operator, we add this new sturct just for seperate APIs. It's ok to add layer API for BlockingOperator.

[tisonkun]

@Xuanwo the ownership issue is the major issue here. Reopen for reference.

[tisonkun]

Passing layer as -

protected abstract Operator layer(Operator op);

The implementation is more than awful. I don't want to push the change..

[Xuanwo]

Thanks! We can enable the retry layer for behavior tests now.

[tisonkun]

We can enable the retry layer for behavior tests now.

It's already enabled in this patch.