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Merged
joshua-spacetime merged 4 commits into from
Dec 4, 2025
Merged

[Rust] update module bindings to use new view abi #3819

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09656a6
Update rust bindings to use new view abi
joshua-spacetime Dec 4, 2025
2b3a433
Update negative module compilation tests
joshua-spacetime Dec 4, 2025
2f56bc7
Update the return code for __call_view__
joshua-spacetime Dec 4, 2025
32dc701
impl ViewReturn for Query builder
joshua-spacetime Dec 4, 2025
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102 changes: 69 additions & 33 deletions crates/bindings/src/rt.rs
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Original file line number Diff line number Diff line change
@@ -1,9 +1,11 @@
#![deny(unsafe_op_in_unsafe_fn)]

use crate::query_builder::Query;
use crate::table::IndexAlgo;
use crate::{sys, AnonymousViewContext, IterBuf, ReducerContext, ReducerResult, SpacetimeType, Table, ViewContext};
use spacetimedb_lib::bsatn::EncodeError;
pub use spacetimedb_lib::db::raw_def::v9::Lifecycle as LifecycleReducer;
use spacetimedb_lib::db::raw_def::v9::{RawIndexAlgorithm, RawModuleDefV9Builder, TableType};
use spacetimedb_lib::db::raw_def::v9::{RawIndexAlgorithm, RawModuleDefV9Builder, TableType, ViewResultHeader};
use spacetimedb_lib::de::{self, Deserialize, DeserializeOwned, Error as _, SeqProductAccess};
use spacetimedb_lib::sats::typespace::TypespaceBuilder;
use spacetimedb_lib::sats::{impl_deserialize, impl_serialize, ProductTypeElement};
Expand Down Expand Up @@ -80,16 +82,16 @@ pub trait Reducer<'de, A: Args<'de>> {

/// Invoke a caller-specific view.
/// Returns a BSATN encoded `Vec` of rows.
pub fn invoke_view<'a, A: Args<'a>, T: SpacetimeType + Serialize>(
pub fn invoke_view<'a, A: Args<'a>, T: ViewReturn>(
view: impl View<'a, A, T>,
ctx: ViewContext,
args: &'a [u8],
) -> Vec<u8> {
// Deserialize the arguments from a bsatn encoding.
let SerDeArgs(args) = bsatn::from_slice(args).expect("unable to decode args");
let rows: Vec<T> = view.invoke(&ctx, args);
let retn = view.invoke(&ctx, args);
let mut buf = IterBuf::take();
buf.serialize_into(&rows).expect("unable to encode rows");
retn.to_writer(&mut buf).expect("unable to encode view return value");
std::mem::take(&mut *buf)
}
/// A trait for types representing the execution logic of a caller-specific view.
Expand All @@ -102,22 +104,22 @@ pub fn invoke_view<'a, A: Args<'a>, T: SpacetimeType + Serialize>(
note = "where each `Ti` implements `SpacetimeType`.",
note = ""
)]
pub trait View<'de, A: Args<'de>, T: SpacetimeType + Serialize> {
fn invoke(&self, ctx: &ViewContext, args: A) -> Vec<T>;
pub trait View<'de, A: Args<'de>, T: ViewReturn> {
fn invoke(&self, ctx: &ViewContext, args: A) -> T;
}

/// Invoke an anonymous view.
/// Returns a BSATN encoded `Vec` of rows.
pub fn invoke_anonymous_view<'a, A: Args<'a>, T: SpacetimeType + Serialize>(
pub fn invoke_anonymous_view<'a, A: Args<'a>, T: ViewReturn>(
view: impl AnonymousView<'a, A, T>,
ctx: AnonymousViewContext,
args: &'a [u8],
) -> Vec<u8> {
// Deserialize the arguments from a bsatn encoding.
let SerDeArgs(args) = bsatn::from_slice(args).expect("unable to decode args");
let rows: Vec<T> = view.invoke(&ctx, args);
let retn = view.invoke(&ctx, args);
let mut buf = IterBuf::take();
buf.serialize_into(&rows).expect("unable to encode rows");
retn.to_writer(&mut buf).expect("unable to encode view return value");
std::mem::take(&mut *buf)
}
/// A trait for types representing the execution logic of an anonymous view.
Expand All @@ -130,8 +132,8 @@ pub fn invoke_anonymous_view<'a, A: Args<'a>, T: SpacetimeType + Serialize>(
note = "where each `Ti` implements `SpacetimeType`.",
note = ""
)]
pub trait AnonymousView<'de, A: Args<'de>, T: SpacetimeType + Serialize> {
fn invoke(&self, ctx: &AnonymousViewContext, args: A) -> Vec<T>;
pub trait AnonymousView<'de, A: Args<'de>, T: ViewReturn> {
fn invoke(&self, ctx: &AnonymousViewContext, args: A) -> T;
}

/// A trait for types that can *describe* a callable function such as a reducer or view.
Expand Down Expand Up @@ -305,9 +307,29 @@ impl<T: SpacetimeType> ViewArg for T {}
pub trait ViewReturn {
#[doc(hidden)]
const _ITEM: () = ();

fn to_writer(self, w: &mut Vec<u8>) -> Result<(), EncodeError>;
}

impl<T: SpacetimeType + Serialize> ViewReturn for Vec<T> {
fn to_writer(self, buf: &mut Vec<u8>) -> Result<(), EncodeError> {
bsatn::to_writer(buf, &ViewResultHeader::RowData)?;
bsatn::to_writer(buf, &self)
}
}

impl<T: SpacetimeType + Serialize> ViewReturn for Option<T> {
fn to_writer(self, buf: &mut Vec<u8>) -> Result<(), EncodeError> {
bsatn::to_writer(buf, &ViewResultHeader::RowData)?;
bsatn::to_writer(buf, self.as_slice())
}
}

impl<T: SpacetimeType + Serialize> ViewReturn for Query<T> {
fn to_writer(self, buf: &mut Vec<u8>) -> Result<(), EncodeError> {
bsatn::to_writer(buf, &ViewResultHeader::RawSql(self.sql))
}
}
impl<T: SpacetimeType> ViewReturn for Vec<T> {}
impl<T: SpacetimeType> ViewReturn for Option<T> {}

/// Map the correct dispatcher based on the `Ctx` type
pub struct ViewKind<Ctx> {
Expand Down Expand Up @@ -336,7 +358,7 @@ impl ViewDispatcher<ViewContext> {
pub fn invoke<'a, A, T, V>(view: V, ctx: ViewContext, args: &'a [u8]) -> Vec<u8>
where
A: Args<'a>,
T: SpacetimeType + Serialize,
T: ViewReturn,
V: View<'a, A, T>,
{
invoke_view(view, ctx, args)
Expand All @@ -348,7 +370,7 @@ impl ViewDispatcher<AnonymousViewContext> {
pub fn invoke<'a, A, T, V>(view: V, ctx: AnonymousViewContext, args: &'a [u8]) -> Vec<u8>
where
A: Args<'a>,
T: SpacetimeType + Serialize,
T: ViewReturn,
V: AnonymousView<'a, A, T>,
{
invoke_anonymous_view(view, ctx, args)
Expand All @@ -365,7 +387,7 @@ impl ViewRegistrar<ViewContext> {
pub fn register<'a, A, I, T, V>(view: V)
where
A: Args<'a>,
T: SpacetimeType + Serialize,
T: ViewReturn,
I: FnInfo<Invoke = ViewFn>,
V: View<'a, A, T>,
{
Expand All @@ -378,7 +400,7 @@ impl ViewRegistrar<AnonymousViewContext> {
pub fn register<'a, A, I, T, V>(view: V)
where
A: Args<'a>,
T: SpacetimeType + Serialize,
T: ViewReturn,
I: FnInfo<Invoke = AnonymousFn>,
V: AnonymousView<'a, A, T>,
{
Expand Down Expand Up @@ -596,34 +618,32 @@ macro_rules! impl_reducer_procedure_view {
}

// Implement `View<..., ViewContext>` for the tuple type `($($T,)*)`.
impl<'de, Func, Elem, Retn, $($T),*>
View<'de, ($($T,)*), Elem> for Func
impl<'de, Func, Retn, $($T),*>
View<'de, ($($T,)*), Retn> for Func
where
$($T: SpacetimeType + Deserialize<'de> + Serialize,)*
Func: Fn(&ViewContext, $($T),*) -> Retn,
Retn: IntoVec<Elem>,
Elem: SpacetimeType + Serialize,
Retn: ViewReturn,
{
#[allow(non_snake_case)]
fn invoke(&self, ctx: &ViewContext, args: ($($T,)*)) -> Vec<Elem> {
fn invoke(&self, ctx: &ViewContext, args: ($($T,)*)) -> Retn {
let ($($T,)*) = args;
self(ctx, $($T),*).into_vec()
self(ctx, $($T),*)
}
}

// Implement `View<..., AnonymousViewContext>` for the tuple type `($($T,)*)`.
impl<'de, Func, Elem, Retn, $($T),*>
AnonymousView<'de, ($($T,)*), Elem> for Func
impl<'de, Func, Retn, $($T),*>
AnonymousView<'de, ($($T,)*), Retn> for Func
where
$($T: SpacetimeType + Deserialize<'de> + Serialize,)*
Func: Fn(&AnonymousViewContext, $($T),*) -> Retn,
Retn: IntoVec<Elem>,
Elem: SpacetimeType + Serialize,
Retn: ViewReturn,
{
#[allow(non_snake_case)]
fn invoke(&self, ctx: &AnonymousViewContext, args: ($($T,)*)) -> Vec<Elem> {
fn invoke(&self, ctx: &AnonymousViewContext, args: ($($T,)*)) -> Retn {
let ($($T,)*) = args;
self(ctx, $($T),*).into_vec()
self(ctx, $($T),*)
}
}
};
Expand Down Expand Up @@ -754,7 +774,7 @@ pub fn register_view<'a, A, I, T>(_: impl View<'a, A, T>)
where
A: Args<'a>,
I: FnInfo<Invoke = ViewFn>,
T: SpacetimeType + Serialize,
T: ViewReturn,
{
register_describer(|module| {
let params = A::schema::<I>(&mut module.inner);
Expand All @@ -771,7 +791,7 @@ pub fn register_anonymous_view<'a, A, I, T>(_: impl AnonymousView<'a, A, T>)
where
A: Args<'a>,
I: FnInfo<Invoke = AnonymousFn>,
T: SpacetimeType + Serialize,
T: ViewReturn,
{
register_describer(|module| {
let params = A::schema::<I>(&mut module.inner);
Expand Down Expand Up @@ -1046,14 +1066,22 @@ extern "C" fn __call_procedure__(
///
/// The output of the view is written to a `BytesSink`,
/// registered on the host side, with `bytes_sink_write`.
///
/// Note, a previous version of the abi used a different return format for views.
/// We used to write the return rows of the view directly to the sink.
/// However the current version first writes a [`ViewResultHeader`].
/// This is to distinguish between views that return rows vs ones that return queries.
///
/// The current abi is identified by a return code of 2.
/// The previous abi, which we still support, is identified by a return code of 0.
#[no_mangle]
extern "C" fn __call_view_anon__(id: usize, args: BytesSource, sink: BytesSink) -> i16 {
let views = ANONYMOUS_VIEWS.get().unwrap();
write_to_sink(
sink,
&with_read_args(args, |args| views[id](AnonymousViewContext::default(), args)),
);
0
2
}

/// Called by the host to execute a view when the `sender` calls the view identified by `id` with `args`.
Expand All @@ -1066,6 +1094,14 @@ extern "C" fn __call_view_anon__(id: usize, args: BytesSource, sink: BytesSink)
///
/// The output of the view is written to a `BytesSink`,
/// registered on the host side, with `bytes_sink_write`.
///
/// Note, a previous version of the abi used a different return format for views.
/// We used to write the return rows of the view directly to the sink.
/// However the current version first writes a [`ViewResultHeader`].
/// This is to distinguish between views that return rows vs ones that return queries.
///
/// The current abi is identified by a return code of 2.
/// The previous abi, which we still support, is identified by a return code of 0.
#[no_mangle]
extern "C" fn __call_view__(
id: usize,
Expand All @@ -1087,7 +1123,7 @@ extern "C" fn __call_view__(
sink,
&with_read_args(args, |args| views[id](ViewContext::new(sender), args)),
);
0
2
}

/// Run `logic` with `args` read from the host into a `&[u8]`.
Expand Down
99 changes: 26 additions & 73 deletions crates/bindings/tests/ui/views.stderr
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -237,6 +237,7 @@ error[E0277]: Views must return `Vec<T>` or `Option<T>` where `T` is a `Spacetim
|
= help: the following other types implement trait `ViewReturn`:
Option<T>
Query<T>
Vec<T>

error[E0277]: invalid view signature
Expand All @@ -261,51 +262,18 @@ note: required by a bound in `ViewDispatcher::<ViewContext>::invoke`
| ^^^^^^^^^^^^^^ required by this bound in `ViewDispatcher::<ViewContext>::invoke`
= note: this error originates in the attribute macro `view` (in Nightly builds, run with -Z macro-backtrace for more info)

error[E0277]: the trait bound `NotSpacetimeType: SpacetimeType` is not satisfied
--> tests/ui/views.rs:136:1
|
136 | #[view(name = view_def_returns_not_a_spacetime_type, public)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `SpacetimeType` is not implemented for `NotSpacetimeType`
|
= note: if you own the type, try adding `#[derive(SpacetimeType)]` to its definition
= help: the following other types implement trait `SpacetimeType`:
&T
()
AlgebraicType
AlgebraicTypeRef
Arc<T>
ArrayType
Box<T>
ColId
and $N others
= note: required for `for<'a> fn(&'a AnonymousViewContext) -> Option<NotSpacetimeType> {view_def_returns_not_a_spacetime_type}` to implement `AnonymousView<'_, (), NotSpacetimeType>`
note: required by a bound in `ViewRegistrar::<AnonymousViewContext>::register`
--> src/rt.rs
|
| pub fn register<'a, A, I, T, V>(view: V)
| -------- required by a bound in this associated function
...
| V: AnonymousView<'a, A, T>,
| ^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `ViewRegistrar::<AnonymousViewContext>::register`
= note: this error originates in the attribute macro `view` (in Nightly builds, run with -Z macro-backtrace for more info)

error[E0277]: the trait bound `NotSpacetimeType: Serialize` is not satisfied
error[E0277]: invalid anonymous view signature
--> tests/ui/views.rs:136:1
|
136 | #[view(name = view_def_returns_not_a_spacetime_type, public)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Serialize` is not implemented for `NotSpacetimeType`
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ this view signature is not valid
|
= help: the following other types implement trait `Serialize`:
&T
()
(T0, T1)
(T0, T1, T2)
(T0, T1, T2, T3)
(T0, T1, T2, T3, T4)
(T0, T1, T2, T3, T4, T5)
(T0, T1, T2, T3, T4, T5, T6)
and $N others
= note: required for `for<'a> fn(&'a AnonymousViewContext) -> Option<NotSpacetimeType> {view_def_returns_not_a_spacetime_type}` to implement `AnonymousView<'_, (), NotSpacetimeType>`
= help: the trait `AnonymousView<'_, _, _>` is not implemented for fn item `for<'a> fn(&'a AnonymousViewContext) -> Option<NotSpacetimeType> {view_def_returns_not_a_spacetime_type}`
= note:
= note: anonymous view signatures must match:
= note: `Fn(&AnonymousViewContext, [T1, ...]) -> Vec<Tn> | Option<Tn>`
= note: where each `Ti` implements `SpacetimeType`.
= note:
note: required by a bound in `ViewRegistrar::<AnonymousViewContext>::register`
--> src/rt.rs
|
Expand Down Expand Up @@ -335,39 +303,11 @@ error[E0277]: the trait bound `NotSpacetimeType: SpacetimeType` is not satisfied
and $N others
= note: required for `Option<NotSpacetimeType>` to implement `ViewReturn`

error[E0277]: the trait bound `NotSpacetimeType: SpacetimeType` is not satisfied
--> tests/ui/views.rs:136:1
|
136 | #[view(name = view_def_returns_not_a_spacetime_type, public)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `SpacetimeType` is not implemented for `NotSpacetimeType`
|
= note: if you own the type, try adding `#[derive(SpacetimeType)]` to its definition
= help: the following other types implement trait `SpacetimeType`:
&T
()
AlgebraicType
AlgebraicTypeRef
Arc<T>
ArrayType
Box<T>
ColId
and $N others
= note: required for `for<'a> fn(&'a AnonymousViewContext) -> Option<NotSpacetimeType> {view_def_returns_not_a_spacetime_type}` to implement `AnonymousView<'_, (), NotSpacetimeType>`
note: required by a bound in `ViewDispatcher::<AnonymousViewContext>::invoke`
--> src/rt.rs
|
| pub fn invoke<'a, A, T, V>(view: V, ctx: AnonymousViewContext, args: &'a [u8]) -> Vec<u8>
| ------ required by a bound in this associated function
...
| V: AnonymousView<'a, A, T>,
| ^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `ViewDispatcher::<AnonymousViewContext>::invoke`
= note: this error originates in the attribute macro `view` (in Nightly builds, run with -Z macro-backtrace for more info)

error[E0277]: the trait bound `NotSpacetimeType: Serialize` is not satisfied
--> tests/ui/views.rs:136:1
--> tests/ui/views.rs:137:71
|
136 | #[view(name = view_def_returns_not_a_spacetime_type, public)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Serialize` is not implemented for `NotSpacetimeType`
137 | fn view_def_returns_not_a_spacetime_type(_: &AnonymousViewContext) -> Option<NotSpacetimeType> {
| ^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Serialize` is not implemented for `NotSpacetimeType`
|
= help: the following other types implement trait `Serialize`:
&T
Expand All @@ -379,7 +319,20 @@ error[E0277]: the trait bound `NotSpacetimeType: Serialize` is not satisfied
(T0, T1, T2, T3, T4, T5)
(T0, T1, T2, T3, T4, T5, T6)
and $N others
= note: required for `for<'a> fn(&'a AnonymousViewContext) -> Option<NotSpacetimeType> {view_def_returns_not_a_spacetime_type}` to implement `AnonymousView<'_, (), NotSpacetimeType>`
= note: required for `Option<NotSpacetimeType>` to implement `ViewReturn`

error[E0277]: invalid anonymous view signature
--> tests/ui/views.rs:136:1
|
136 | #[view(name = view_def_returns_not_a_spacetime_type, public)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ this view signature is not valid
|
= help: the trait `AnonymousView<'_, _, _>` is not implemented for fn item `for<'a> fn(&'a AnonymousViewContext) -> Option<NotSpacetimeType> {view_def_returns_not_a_spacetime_type}`
= note:
= note: anonymous view signatures must match:
= note: `Fn(&AnonymousViewContext, [T1, ...]) -> Vec<Tn> | Option<Tn>`
= note: where each `Ti` implements `SpacetimeType`.
= note:
note: required by a bound in `ViewDispatcher::<AnonymousViewContext>::invoke`
--> src/rt.rs
|
Expand Down