feat: Manifest File Reader

[OussamaSaoudi]

🥞 Stacked PR

Use this link to review incremental changes.

• stack/dlr_commit [Files changed]
  • stack/dlr_manifest [Files changed]
    • stack/dlr_leaf [Files changed]
      • stack/dlr_driver [Files changed]
        • stack/dlr_serde [Files changed]
          • stack/dlr_executor

---

What changes are proposed in this pull request?

How was this change tested?

[scovich]

Suggested change

	batch_result.and_then(|batch| {
	self.sidecar_visitor.visit_rows_of(batch.actions())?;
	Ok(batch)
	})
	let batch = batch_result?;
	self.sidecar_visitor.visit_rows_of(batch.actions())?;
	Ok(batch)

[scovich]

Suggested change

	ext => {
	return Err(Error::generic(format!(
	"Unsupported checkpoint extension: {}",
	ext
	_ => {
	return Err(Error::generic(format!(
	"Unsupported checkpoint extension: {extension}",

[scovich]

aside: I'm a bit surprised fmt treated these so differently?
(but it's the same number of lines of code either way, so meh)

[scovich]

Technically, we don't need to unwrap... just match as:

let actions = match extension {
    Some("json") => { ... }
    Some("parquet") => { ... }

[scovich]

Seems like a reasonable place for a tuple enum variant, since the field name is redundant?

Suggested change

	Sidecars { sidecars: Vec<FileMeta> },
	Sidecars(Vec<FileMeta>),

[scovich]

Suggested change

	"Finalized called on ManifestReader for file {:?}",
	"Cannot finalize in-progress ManifestReader for file {:?}",

[scovich]

Type annotation shouldn't be necessary here because AfterManifest::Sidecars forces it

Suggested change

	let sidecars: Vec<_> = self
	let sidecars = self