9bc12f7444
Re-export only things that are used by other modules. In the future, I'm imagining that we run bindgen twice, for Postgres v14 and v15. The two sets of bindings would go into separate 'bindings_v14' and 'bindings_v15' modules. Rearrange postgres_ffi modules. Move function, to avoid Postgres version dependency in timelines.rs Move function to generate a logical-message WAL record to postgres_ffi.
This module contains utilities for working with PostgreSQL file formats. It's a collection of structs that are auto-generated from the PostgreSQL header files using bindgen, and Rust functions to read and manipulate them.
There are also a bunch of constants in pg_constants.rs that are copied
from various PostgreSQL headers, rather than auto-generated. They mostly
should be auto-generated too, but that's a TODO.
The PostgreSQL on-disk file format is not portable across different CPU architectures and operating systems. It is also subject to change in each major PostgreSQL version. Currently, this module is based on PostgreSQL v14, but in the future we will probably need a separate copy for each PostgreSQL version.
TODO: Currently, there is also some code that deals with WAL records in pageserver/src/waldecoder.rs. That should be moved into this module. The rest of the codebase should not have intimate knowledge of PostgreSQL file formats or WAL layout, that knowledge should be encapsulated in this module.