Request

Background

At Presto, there's a need to project file-level (IR) metadata such as $_filename in a given archive, this is for the sake of metadata projection. Given that $_filename is not part of the log record schema — it lives in the archive range index. Rather than implementing $_filename as a schema column in the log event (which we agreed doesn't make sense), we'd like an API on ArchiveReader to resolve file-level metadata using log_event_idx, this would allow us to extract $_filename, as well as other file-level metadata preserved in the archive.

Timeline:
We'd need this by early the week after next. No rush to merge into main — the snapshot branch works for now if that's easier.

Possible implementation

Subject to implementer's decision