OperatorInfo should be stored inside Operator to avoid calling metadata

[Xuanwo]

OperatorInfo will never be changed after Operator been built, we can store it inside an Arc inside Operator to avoid extra cost.

[Lzzzzzt]

If my understanding is right, it just wrap OperatorInfo in Arc<T>.

And if it is better to use OnceCell<T> for lazy init of OperatorInfo and change pub fn info(&self) -> OperatorInfo to pub fn info(&self) -> &OperatorInfo?

[Xuanwo]

Hi, @Lzzzzzt. Thanks for joining the discussion and starting https://github.com/apache/opendal/pull/4883.

After some consideration, I think it would be better to modify Access::info() to return Arc<AccessInfo>, similiar to what you suggested in https://github.com/apache/opendal/pull/4883#issuecomment-2224328372. This will allow all our layers to avid extra copy.

With this change, OperatorInfo could hold an Arc<AccessInfo>, allowing the user API to remain unchanged.

[Lzzzzzt]

Hi, @Lzzzzzt. Thanks for joining the discussion and starting #4883.

After some consideration, I think it would be better to modify Access::info() to return Arc<AccessInfo>, similiar to what you suggested in #4883 (comment). This will allow all our layers to avid extra copy.

With this change, OperatorInfo could hold an Arc<AccessInfo>, allowing the user API to remain unchanged.

Ok, got it

[Lzzzzzt]

Hi, @Lzzzzzt. Thanks for joining the discussion and starting #4883.

After some consideration, I think it would be better to modify Access::info() to return Arc<AccessInfo>, similiar to what you suggested in #4883 (comment). This will allow all our layers to avid extra copy.

With this change, OperatorInfo could hold an Arc<AccessInfo>, allowing the user API to remain unchanged.

It seems need to change a lot, if modify Access::info() to return Arc<AccessInfo>

[Xuanwo]

It seems need to change a lot, if modify Access::info() to return Arc<AccessInfo>

Yes. If we do need API breaking changes, I prefer change opendal::raw API instead of opendal's public API.

[Lzzzzzt]

It seems need to change a lot, if modify Access::info() to return Arc<AccessInfo>

Yes. If we do need API breaking changes, I prefer change opendal::raw API instead of opendal's public API.

if modify Access::info() to return Arc<AccessInfo>, a lot of struct will need a extra field to store the info, is that right?

https://github.com/apache/opendal/blob/740928efffc761a22fdf4bb3300e25ab790616b2/core/src/services/fs/backend.rs#L184-L210

[Xuanwo]

if modify Access::info() to return Arc, a lot of struct will need a extra field to store the info, is that right?

We can start by simply adding an into() and refactor them later based on our feedback.

[Lzzzzzt]

some layers need a mutable AccessorInfo, so Arc<T> may not work

https://github.com/apache/opendal/blob/740928efffc761a22fdf4bb3300e25ab790616b2/core/src/layers/blocking.rs#L168-L185

[Xuanwo]

some layers need a mutable AccessorInfo, so Arc<T> may not work

Those layers can build a new AccessorInfo with changed value.

[Lzzzzzt]

some layers need a mutable AccessorInfo, so Arc<T> may not work

Those layers can build a new AccessorInfo with changed value.

ok

[Lzzzzzt]

I change the signature of Access::info and AccessDyn::info and related layers implement, and fs service. PTAL

[Xuanwo]

Has been implemented, closing.