- We introduce two new view types ProtoStringCow and ProtoBytesCow.
- In UPB, for cord field accessors we always return a Cow::Borrowed.
- In C++, for coed field accessors we check if the underlying absl::Cord is flat (contigous) and if so return a Cow::Borrowed. If it's not flat we copy the data to a ProtoString and return a Cow::Owned.
- We expect the absl::Cord to be flat almost all the time. We have experimentally verified that for small strings (<4 KiB) and less than 6 appends the cord is in fact flat [1].
- This change lifts the requirement of all ViewProxy types to be Copy. Our Cow types cannot be Copy because the owned types aren't copy.
[1] https://source.corp.google.com/piper///depot/google3/experimental/users/buchgr/cords/cords.cc
PiperOrigin-RevId: 655485943
When you have a `T: SomeTrait + ?Sized` and `trait SomeTrait:Sized`, the ?Sized has no effect (its not able to "remove" the requirement).
PiperOrigin-RevId: 654836513
Rather than two traits (MutProxy subtrait of ViewProxy), instead have three traits (MutProxy subtrait of Proxy, and ViewProxy subtrait of Proxy).
This makes things more consistent, including that (MutProxied subtraits Proxied) is now more parallel to (MutProxy subtraits Proxy).
ViewProxy is largely a marker trait here but leaves a spot for methods that should be on ViewProxies but not MutProxies if those do show up later.
PiperOrigin-RevId: 653661953
This is currently true and required by the IntoProxied trait. In Rust all type parameters are explicitly marked `Sized`, except for `Self` [1]. By marking `Proxied` as `Sized` we can write `IntoProxied<Self>` in generic code without having to add 'where Self: Sized` clauses.
An implication of this change is that Proxied can no longer be used from a trait object i.e. `let x: dyn &Proxied = &foo` will not compile. We are not anticipating such use cases at this point.
[1] https://doc.rust-lang.org/std/marker/trait.Sized.html
PiperOrigin-RevId: 649010900
Proxied is not marked as Sized yet, because ProtoStr is still dynamically sized. We will wait for clarity for the string types before marking Proxied Sized.
PiperOrigin-RevId: 627707544
- Rename most usage of `'a` to `'msg`
- Remove a no-op unused lifetime param for `remove` in maps
- Elide lifetimes recommended by clippy
PiperOrigin-RevId: 589878364
This change names the lifetime of Mut<'a, T> and requires that T outlives 'a. The motivation for this change came up while implementing `Map<K, ProtoStr>`. The Map implementation makes it so that `V` needs to implement the `MapWithKeyOps` trait which has an associated type with a lifetime (`Value<'a>`. The lifetime bound on `T` ensures that e.g. for `MapWithKeyOps<Value<'b>=&'b ProtoStr>` `'a` outlives `'b`.
PiperOrigin-RevId: 585657154
This is predominantly a wrapper around `BytesMut`, for simplicity.
Bytes and string fields are mostly the same, except for possible UTF-8 handling.
This also implements some minor parts of `ProtoStr` that were missed.
PiperOrigin-RevId: 561422951
None of these methods are necessary for users to use Optional, but they
are particularly useful and mirror the methods inside of
std::collections::hash_map::Entry.
PiperOrigin-RevId: 547038832
This implements the associated type change suggested by dmitrig@.
I don't foresee use cases that would make `ViewFor` allowing multiple `T` to be
useful, rather than confusing.
This also implements some suggested wording changes that I agree with.
PiperOrigin-RevId: 540024883
Protobuf Team Bot
Jakob Buchgraber
Dmitri Gribenko
Marcel Hlopko
Hong Shin
Alyssa Haroldsen
Joshua Haberman