Adds support for zero-copy FromSql derive #1070
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Similar in spirit and implementation to how `serde` supports borrowed deserialization lifetimes. Like `serde`, it uses `'de` as the lifetime of the trait (`FromoSql<'de>`) and it adds all borrowed liftimes as lifetime bounds on `'de`. Also like `serde` all top level references automatically have their lifetimes borrowed, but container types carrying references must explicity be borrowed with the `#[postgres(borrow)]` annotation.
sfackler
reviewed
Oct 30, 2023
| fn build_generics(source: &Generics, borrowed_lifetimes: HashSet<Lifetime>) -> (Generics, Lifetime) { | ||
| // This is the same parent lifetime name serde uses | ||
| let lifetime = Lifetime::new("'de", Span::call_site()); | ||
| // Sort lifetimes for deterministic code-gen |
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This could also preserve the declared order of lifetimes rather than going through a hashset and then sorting.
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You're right. I was over-optimizing on the extraction path to handle lifetime dedup. In the real-world though, a simple borrowed_lifetimes.contains(lifetime) shouldn't ever be a problem. I made the changes to go through a vec instead of a hashset and preserve declaration order.
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Can anyone w/ maintainer privileges please kick off the test workflow 🙏 |
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Similar in spirit and implementation to how
serdesupports borrowed deserialization lifetimes. Likeserde, it uses'deas the lifetime of the trait (FromSql<'de>) and it adds all borrowed liftimes as lifetime bounds on'de.Also like
serdeall top level references automatically have their lifetimes borrowed, but container types carrying references must explicity be borrowed with the#[postgres(borrow)]annotation.Follows up on: #574