- 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
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
Calling into_proxied() already does a copy and before this change we were doing a second one.
I am not using set_allocated_<field(std::string* s) because the method is not generated when [features.(pb.cpp).string_type = VIEW] is specified.
PiperOrigin-RevId: 650612909
* The public Repeated::{push, set} and Map::insert methods now accept any value that implements IntoProxied<T>, allowing us to move owned values instead of copying them.
* This change also updates the FFI layer for strings/bytes in the repeated and maps thunks to accept a std::string* that can be moved rather than a PtrAndLen type that needs to be copied.
* Tests are updated to no longer .as_view() when setting a message / string on a repeated / map field. The IntoProxied trait makes calling .as_view() obsolete.
PiperOrigin-RevId: 650580788
This change removes the only remaining instance of SettableValue in a generated accessor. The principled fix is to implement IntoProxied for ProtoStr/[u8], but this will have to wait until we have agreed on & implemented the 1.0 string types. So we'll use AsRef in the meantime in order to not break any user code while allowing us to make progress on IntoProxied and Proxied changes.
PiperOrigin-RevId: 627735404
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
The intent of this directory would be for a layer of Rust bindings that directly map to upb semantics; Rust Protobuf runtime would be layer on top of that Rust, instead of directly on the upb C api.
PiperOrigin-RevId: 624282429
- 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
This makes a few changes:
- It changes generated messages to reference message innards as a type in `__runtime` instead of branching on what fields should be there. That results in much less bifurcation in gencode and lets runtime-agnostic code reference raw message innards.
- It adds a generic mechanism for creating vtable-based mutators. These vtables point to thunks generated for interacting with C++ or upb fields. Right now, the design results in 2-word (msg+vtable) mutators for C++ and 3-word mutators (msg+arena+vtable) for UPB. See upb.rs for an explanation of the design options. I chose the `RawMessage+&Arena` design for mutator data as opposed to a `&MessageInner` design because it did not result in extra-indirection layout changes for message mutators. We could revisit this in the future with performance data, since this results in all field mutators being 3 words large instead of the register-friendly 2 words.
- And lastly, as a nearby change that touches on many of the same topics, it adds some extra SAFETY comments for Send/Sync in message gencode.
PiperOrigin-RevId: 559483437
This adds `#![deny(unsafe_op_in_unsafe_fn)]` which removes the
implicit `unsafe` block that `unsafe fn` does.
It also adds many more `SAFETY` docs, corrects some incomplete
ones, and catches a null pointer returned by `upb_Arena_New`.
PiperOrigin-RevId: 549067106
These are invalid for UPB which uses immutable string views.
This also adjusts some docs:
- removes a promise in the language of `truncate`
that no reallocation will occur.
- removes language about DerefMut and replaces the `&mut Vec<u8>` analogy
PiperOrigin-RevId: 547603918