djkelleher / duckdb.mojo Goto Github PK

This internally uses the DuckDB C API and currently has some FFI/ABI issues.

Specific things failing:

1. Loading Pointer[struct] (and AnyPointer[struct]) value into Mojo, where the struct instance is assigned on the C side. Only basic fields are needed (int and void pointers).
   Current behavior: After load or take_value (Mojo side), only some int fields will have correct value, but if a shallow copy of the pointer to the struct (as in __moveinit__) is done before load/take_value, then all int fields will have correct values 🤷‍♂️
2. Pass simple structs by value to C functions. (currently results in either SIGBUS or SIGSEGV)

• Download and unzip the DuckDB C/C++ library
• Edit and run main.mojo

Any one of:

• Figure out this is actually somehow currently possible in Mojo
• Wait for Modular to document/further implement FFI and AnyPointer
• Wait (probably a long time?) for C++ Module interop. This would be cool since DuckDB is written in C++ (C API is a wrapper).
• Write custom C functions (as replacement for some current C API functions) so we can pass all arguments as void pointers

Then:

1. Finish MVP/POC code for reading columnar chunks/vectors from DuckDB to Mojo.
2. Implement prepared statements, 'appender' API, support Mojo parallelism as alterative to DuckDB CPP thread pool.