Overview

This issue tracks the remaining work needed to fully implement the object_store trait in OpenDAL's integration layer. While the core functionality is working, several methods return NotSupported errors and some implementations could be enhanced.

Current Status

✅ Implemented

• put_opts with full PutMode support (Overwrite, Create, Update)
• put_multipart (basic implementation)
• get_opts with GetOptions support (range, conditionals, version)
• delete
• list, list_with_offset, list_with_delimiter
• MultipartUpload trait
• Error mapping between OpenDAL and object_store
• Amazon S3 builder support

❌ Not Implemented

The following methods currently return NotSupported errors:

1. put_multipart_opts (store.rs:165)

   • Required for advanced multipart upload options
   • Currently returns: "put_multipart_opts is not implemented so far"

2. copy (store.rs:248)

   • Server-side copy operation
   • Currently returns: "copy is not implemented so far"

3. rename (store.rs:255)

   • Server-side rename operation
   • Currently returns: "rename is not implemented so far"

4. copy_if_not_exists (store.rs:262)

   • Conditional server-side copy
   • Currently returns: "copy_if_not_exists is not implemented so far"

⚠️ Incomplete Implementations

1. PutResult metadata

   • Always returns e_tag: None, version: None
   • Should return actual ETag and version when available from backend

2. GetResult attributes

   • Always returns Default::default() for attributes
   • Should include object metadata/attributes from backend

3. Test coverage

   • Missing behavior tests for list operations
   • No tests for list_with_delimiter and list_with_offset

Tasks

High Priority

• Implement copy method using OpenDAL's copy operation
• Implement rename method using OpenDAL's rename operation
• Return proper ETag in PutResult when available
• Return proper version in PutResult when backend supports versioning

Medium Priority

• Implement put_multipart_opts with proper options handling
• Implement copy_if_not_exists with conditional logic
• Populate GetResult.attributes with object metadata

Low Priority

• Add comprehensive tests for list operations
• Add integration tests with different storage backends
• Document any limitations compared to native object_store implementations

Implementation Notes

1. Copy/Rename Operations: Check if OpenDAL's backend supports native copy/rename. If not, consider fallback to client-side implementation with appropriate warnings.

2. ETag/Version Support: Different backends have varying support for ETags and versioning. Implementation should gracefully handle backends that don't support these features.

3. Attributes Mapping: Need to define how OpenDAL's metadata maps to object_store's attributes.

References

• object_store documentation
• OpenDAL object_store integration

Acceptance Criteria

• All object_store trait methods return meaningful results instead of NotSupported
• Metadata (ETag, version, attributes) is properly populated when available
• Comprehensive test coverage for all implemented methods
• Documentation clearly states any limitations or backend-specific behavior