Compiling with a new object store fails because trait-bounds not satisfied

[thhapke]

After cloning the object_store crate I have added a new object store type for SAP HANA Datalake Files (HDLFS, not HDFS ;)) . HDLFS is a governance layer on-top of the other hyperscaler that complies closely to webhdfs. I have added the object_store traits by using the ideas of the http-API. Testing the APIs works smooth.

Then I was testing if the datafusion integration with my object_store implementation works. For this I created a file that registered my object_store implementation of HDLFS:

let hdl_store = HDLStore::new(&endpoint, cert, key, true, true);
ctx.runtime_env().register_object_store(&endpoint, Arc::new(hdl_store));

The compilation fails with:

error[E0277]: the trait bound `Result<HDLStore, object_store::Error>: object_store::ObjectStore` is not satisfied
  --> src/main.rs:31:56
   |
31 |     ctx.runtime_env().register_object_store(&endpoint, Arc::new(hdl_store));
   |                                                        ^^^^^^^^^^^^^^^^^^^ the trait `object_store::ObjectStore` is not implemented for `Result<HDLStore, object_store::Error>`
   |
   = help: the following other types implement trait `object_store::ObjectStore`:
             Box<(dyn object_store::ObjectStore + 'static)>
             object_store::chunked::ChunkedStore
             object_store::limit::LimitStore<T>
             object_store::local::LocalFileSystem
             object_store::memory::InMemory
             object_store::prefix::PrefixStore<T>
             object_store::throttle::ThrottledStore<T>
             Arc<(dyn object_store::ObjectStore + 'static)>

To cargo.toml and lib.rs I have added a feature=saphdlfs according to the feature=http.

It somehow looks that the complaints are caused by the feature of "wasm64" that requires these trait bounds. Therefore I tried to compile explicitly with the target of my macos system, with no effect.

I am not the most proficient rust programmer and do not know if this is basically an issue with my compiler settings or do I need to add these trait implementations. Could you give me a hint how to further proceed? Cheers

[tustvold]

The error would suggest the HDLStore::new is returning a Result that needs to be unpacked to yield the underlying store

[thhapke]

Sorry what a stupid error. Somehow I have lost the unpacking and missed to read the error carefully. When passing the HDLStore I still get the error:

error[E0277]: the trait bound `HDLStore: object_store::ObjectStore` is not satisfied
  --> src/main.rs:30:56
   |
30 |     ctx.runtime_env().register_object_store(&endpoint, Arc::new(hdl_store));
   |                                                        ^^^^^^^^^^^^^^^^^^^ the trait `object_store::ObjectStore` is not implemented for `HDLStore`
   |
help: trait impl with same name found
  --> /Users/D051079/GitHub/rust/arrow-rs/object_store/src/saphdlfs/mod.rs:66:1
   |
66 | impl ObjectStore for HDLStore {
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   = note: perhaps two different versions of crate `object_store` are being used?
   = help: the following other types implement trait `object_store::ObjectStore`:
             Box<(dyn object_store::ObjectStore + 'static)>
             object_store::chunked::ChunkedStore
             object_store::limit::LimitStore<T>
             object_store::local::LocalFileSystem
             object_store::memory::InMemory
             object_store::prefix::PrefixStore<T>
             object_store::throttle::ThrottledStore<T>
             Arc<(dyn object_store::ObjectStore + 'static)>
   = note: required for the cast from `Arc<HDLStore>` to `Arc<(dyn object_store::ObjectStore + 'static)>`

error: aborting due to previous error

I am importing use object_store::saphdlfs::HDLStore;
and the impl of ObjectStore in mod.rs:

#[async_trait]
impl ObjectStore for HDLStore {

    async fn put(&self, location: &Path, payload:PutPayload) -> Result<PutResult, Error> {
        self.put_opts(location, payload, PutOptions::default()).await
    }

    async fn put_opts(&self, location: &Path, payload:PutPayload, opts: PutOptions) -> Result<PutResult, Error> {
        match  opts.mode {
            PutMode::Overwrite | PutMode::Create  => self.client.put(&location.to_string(), Bytes::from(payload)).await?,
            PutMode::Update(_) => self.client.append(&location.to_string(), Bytes::from(payload)).await?,

        };
        Ok(PutResult {e_tag: None, version: None})
    }
......

[tustvold]

perhaps two different versions of crate object_store are being used?

[thhapke]

Thanks you have been right. First I was ensuring that my calling app and the implementation crate was using the same version, but then I realized that datafusion was also using object_store, but 0.9.1.