431393e361
We could make it inside wal_storage.rs, but taking into account that - wal_storage.rs reading is async - we don't need s3 here - error handling is different; error during decoding is normal I decided to put it separately. Test cargo test test_find_end_of_wal_last_crossing_segment prepared earlier by @yeputons passes now. Fixes https://github.com/neondatabase/neon/issues/544 https://github.com/neondatabase/cloud/issues/2004 Supersedes https://github.com/neondatabase/neon/pull/2066
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.