More WIP, still not working

Author: prokopyl

atom/src/atoms.rs

@@ -30,7 +30,7 @@ pub struct AtomURIDCollection {
 }
 
 impl AtomURIDCollection {
-    pub fn vector<S: scalar::ScalarAtom>(&self) -> URID<vector::Vector<S>> {
+    pub fn vector<'a, 'b: 'a, S: scalar::ScalarAtom<'a, 'b>>(&self) -> URID<vector::Vector<S>> {
         unsafe { URID::new_unchecked(self.vector.get()) }
     }
 }

atom/src/atoms/object.rs

@@ -411,11 +411,11 @@ mod tests {
 
             let (header, atom) = properties[0];
             assert_eq!(header.key, first_key);
-            assert_eq!(atom.read(urids.int, ()).unwrap(), first_value);
+            assert_eq!(*atom.read(urids.int, ()).unwrap(), first_value);
 
             let (header, atom) = properties[1];
             assert_eq!(header.key, second_key);
-            assert_eq!(atom.read(urids.float, ()).unwrap(), second_value);
+            assert_eq!(*atom.read(urids.float, ()).unwrap(), second_value);
         }
     }
 }

atom/src/atoms/scalar.rs

@@ -19,7 +19,7 @@
 //! /// Something like a plugin's run method.
 //! fn run(ports: &mut MyPorts, urids: &AtomURIDCollection) {
 //!     // Scalar atoms don't need a reading parameter.
-//!     let read_value: f32 = ports.input.read(urids.float, ()).unwrap();
+//!     let read_value: &f32 = ports.input.read(urids.float, ()).unwrap();
 //!
 //!     // Writing is done with the value of the atom.
 //!     ports.output.init(urids.float, 17.0).unwrap();
@@ -37,7 +37,16 @@ use urid::URID;
 /// An atom that only contains a single, scalar value.
 ///
 /// Since scalar values are so simple, the reading and writing methods are exactly the same.
-pub trait ScalarAtom: UriBound {
+pub trait ScalarAtom<'handle, 'space: 'handle>:
+    Atom<
+        'handle,
+        'space,
+        ReadParameter = (),
+        ReadHandle = &'handle Self::InternalType,
+        WriteParameter = Self::InternalType,
+        WriteHandle = (),
+    > + UriBound
+{
     /// The internal representation of the atom.
     ///
     /// For example, the `Int` atom has the internal type of `i32`, which is `i32` on most platforms.
@@ -47,15 +56,15 @@ pub trait ScalarAtom: UriBound {
     ///
     /// If the space does not contain the atom or is not big enough, return `None`. The second return value is the space behind the atom.
     #[inline]
-    unsafe fn read_scalar(body: &AtomSpace) -> Option<Self::InternalType> {
-        body.read().next_value().copied()
+    unsafe fn read_scalar(body: &AtomSpace) -> Option<&Self::InternalType> {
+        body.read().next_value()
     }
 
     /// Try to write the atom into a space.
     ///
     /// Write an atom with the value of `value` into the space and return a mutable reference to the written value. If the space is not big enough, return `None`.
     #[inline]
-    fn write_scalar<'handle, 'space: 'handle>(
+    fn write_scalar(
         mut frame: AtomSpaceWriter<'handle, 'space>,
         value: Self::InternalType,
     ) -> Option<()> {
@@ -66,31 +75,38 @@ pub trait ScalarAtom: UriBound {
     }
 }
 
-impl<'handle, 'space: 'handle, A: ScalarAtom> Atom<'handle, 'space> for A {
-    type ReadParameter = ();
-    type ReadHandle = A::InternalType;
-    type WriteParameter = A::InternalType;
-    type WriteHandle = ();
-
-    unsafe fn read(body: &'space AtomSpace, _: ()) -> Option<A::InternalType> {
-        <A as ScalarAtom>::read_scalar(body)
-    }
-
-    fn init(frame: AtomSpaceWriter<'handle, 'space>, value: A::InternalType) -> Option<()> {
-        <A as ScalarAtom>::write_scalar(frame, value)
-    }
-}
-
 /// Macro to atomate the definition of scalar atoms.
 macro_rules! make_scalar_atom {
     ($atom:ty, $internal:ty, $uri:expr, $urid:expr) => {
         unsafe impl UriBound for $atom {
             const URI: &'static [u8] = $uri;
         }
 
-        impl ScalarAtom for $atom {
+        impl<'handle, 'space: 'handle> ScalarAtom<'handle, 'space> for $atom {
             type InternalType = $internal;
         }
+
+        impl<'handle, 'space: 'handle> Atom<'handle, 'space> for $atom {
+            type ReadParameter = ();
+            type ReadHandle = &'handle $internal;
+            type WriteParameter = $internal;
+            type WriteHandle = ();
+
+            unsafe fn read(body: &'space AtomSpace, _: ()) -> Option<&'handle $internal> {
+                <Self as ScalarAtom>::read_scalar(body)
+            }
+
+            fn init(frame: AtomSpaceWriter<'handle, 'space>, value: $internal) -> Option<()> {
+                <Self as ScalarAtom>::write_scalar(frame, value)
+            }
+        }
+
+        impl<'handle, 'space: 'handle> BackAsSpace<'handle, 'space> for $atom {
+            fn back_as_space(value: &'handle $internal) -> &'handle AlignedSpace<u8> {
+                let bytes = AlignedSpace::from_slice(::core::slice::from_ref(value)).as_bytes();
+                AlignedSpace::from_slice(bytes)
+            }
+        }
     };
 }
 
@@ -165,33 +181,33 @@ mod tests {
     use std::convert::TryFrom;
     use urid::*;
 
-    fn test_scalar<A: ScalarAtom>(value: A::InternalType)
+    fn test_scalar<A, T>(value: T)
     where
-        A::InternalType: PartialEq<A::InternalType>,
-        A::InternalType: std::fmt::Debug,
+        for<'space> A: ScalarAtom<'space, 'space, InternalType = T>,
+        T: PartialEq<T>,
+        T: std::fmt::Debug,
     {
         let map = HashURIDMapper::new();
         let urid: URID<A> = map.map_type().unwrap();
 
         let mut raw_space = VecSpace::<AtomHeader>::new_with_capacity(64);
-        let raw_space = raw_space.as_space_mut();
 
         // writing
         {
             let mut space = SpaceCursor::new(raw_space.as_bytes_mut());
-            space.init_atom(urid, value).unwrap();
+            let foo = space.init_atom(urid, value).unwrap();
         }
 
         // verifying
-        {
+        /*{
             /// Generic version of the scalar atom structs.
             #[repr(C, align(8))]
             struct Scalar<B: Sized> {
                 atom: sys::LV2_Atom,
                 body: B,
             }
 
-            let scalar: &Scalar<A::InternalType> =
+            let scalar: &Scalar<A::WriteParameter> =
                 unsafe { raw_space.read().next_value().unwrap() };
 
             assert_eq!(scalar.atom.type_, urid);
@@ -206,17 +222,17 @@ mod tests {
                 .read(urid, ())
                 .unwrap();
 
-            assert_eq!(read_value, value);
-        }
+            assert_eq!(*read_value, value);
+        }*/
     }
 
     #[test]
     fn test_scalars() {
-        test_scalar::<Double>(42.0);
-        test_scalar::<Float>(42.0);
-        test_scalar::<Long>(42);
-        test_scalar::<Int>(42);
-        test_scalar::<Bool>(1);
-        test_scalar::<AtomURID>(URID::try_from(1).unwrap());
+        test_scalar::<Double, _>(42.0);
+        test_scalar::<Float, _>(42.0);
+        test_scalar::<Long, _>(42);
+        test_scalar::<Int, _>(42);
+        test_scalar::<Bool, _>(1);
+        test_scalar::<AtomURID, _>(URID::try_from(1).unwrap());
     }
 }

atom/src/atoms/sequence.rs

@@ -360,11 +360,11 @@ mod tests {
 
             let (stamp, atom) = reader.next().unwrap();
             assert_eq!(stamp, TimeStamp::Frames(0));
-            assert_eq!(atom.read::<Int>(urids.atom.int, ()).unwrap(), 42);
+            assert_eq!(*atom.read::<Int>(urids.atom.int, ()).unwrap(), 42);
 
             let (stamp, atom) = reader.next().unwrap();
             assert_eq!(stamp, TimeStamp::Frames(1));
-            assert_eq!(atom.read::<Long>(urids.atom.long, ()).unwrap(), 17);
+            assert_eq!(*atom.read::<Long>(urids.atom.long, ()).unwrap(), 17);
 
             assert!(reader.next().is_none());
         }

atom/src/atoms/vector.rs

@@ -38,15 +38,15 @@ use std::mem::{size_of, MaybeUninit};
 /// An atom containg an array of scalar atom bodies.
 ///
 /// [See also the module documentation.](index.html)
-pub struct Vector<C: ScalarAtom> {
+pub struct Vector<C> {
     child: PhantomData<C>,
 }
 
-unsafe impl<C: ScalarAtom> UriBound for Vector<C> {
+unsafe impl<C> UriBound for Vector<C> {
     const URI: &'static [u8] = sys::LV2_ATOM__Vector;
 }
 
-impl<'handle, 'space: 'handle, C: ScalarAtom> Atom<'handle, 'space> for Vector<C>
+impl<'handle, 'space: 'handle, C: ScalarAtom<'handle, 'space>> Atom<'handle, 'space> for Vector<C>
 where
     C: 'space,
 {
@@ -92,12 +92,12 @@ where
 /// Handle to append elements to a vector.
 ///
 /// This works by allocating a slice of memory behind the vector and then writing your data to it.
-pub struct VectorWriter<'handle, 'space, A: ScalarAtom> {
+pub struct VectorWriter<'handle, 'space, A: ScalarAtom<'handle, 'space>> {
     frame: AtomSpaceWriter<'handle, 'space>,
     type_: PhantomData<A>,
 }
 
-impl<'handle, 'space, A: ScalarAtom> VectorWriter<'handle, 'space, A> {
+impl<'handle, 'space, A: ScalarAtom<'handle, 'space>> VectorWriter<'handle, 'space, A> {
     /// Push a single value to the vector.
     #[inline]
     pub fn push(&mut self, child: A::InternalType) -> Option<&mut A::InternalType> {

atom/src/lib.rs

@@ -92,12 +92,16 @@ pub mod prelude {
     pub use crate::{atoms::AtomURIDCollection, Atom, UnidentifiedAtom};
 }
 
+trait AtomHandle<'a> {
+    type Handle: 'a;
+}
+
 /// Atom type.
 ///
 /// This is the foundation of this crate: Types that implement `Atom` define the reading and writing functions for an atom type. However, these types will never be constructed; They are only names to be used for generic type arguments.
 ///
 /// This trait has two lifetime parameters: The first one is the lifetime of the atom in memory. In practice, this will often be `'static`, but it's good to keep it generic for testing purposes. The second parameter is the lifetime of the `MutSpace` borrowed by the `FramedMutSpace` parameter in the `write` method. Since the `WriteParameter` may contain this `FramedMutSpace`, it has to be assured that it lives long enough. Since the referenced `MutSpace` also has to borrow the atom, it may not live longer than the atom.
-pub trait Atom<'handle, 'space: 'handle>: UriBound {
+pub trait Atom: UriBound {
     /// The atom-specific parameter of the `read` function.
     ///
     /// If your atom does not need a reading parameter, you may set it to `()`.
@@ -106,7 +110,7 @@ pub trait Atom<'handle, 'space: 'handle>: UriBound {
     /// The return value of the `read` function.
     ///
     /// It may contain a reference to the atom and therefore may not outlive it.
-    type ReadHandle: 'handle;
+    type ReadHandle: for<'a> AtomHandle<'a>;
 
     /// The atom-specific parameter of the `write` function.
     ///
@@ -116,7 +120,7 @@ pub trait Atom<'handle, 'space: 'handle>: UriBound {
     /// The return value of the `write` function.
     ///
     /// It may contain a reference to a `MutSpace` and therefore may not outlive it.
-    type WriteHandle: 'handle;
+    type WriteHandle: for<'a> AtomHandle<'a>;
 
     /// Reads the body of the atom.
     ///
@@ -128,10 +132,10 @@ pub trait Atom<'handle, 'space: 'handle>: UriBound {
     ///
     /// The caller needs to ensure that the given [`Space`] contains a valid instance of this atom,
     /// or the resulting `ReadHandle` will be completely invalid, and Undefined Behavior will happen.
-    unsafe fn read(
+    unsafe fn read<'handle, 'space: 'handle>(
         body: &'space AtomSpace,
         parameter: Self::ReadParameter,
-    ) -> Option<Self::ReadHandle>;
+    ) -> Option<<Self::ReadHandle as AtomHandle<'handle>>::Handle>;
 
     /// Initialize the body of the atom.
     ///
@@ -141,10 +145,14 @@ pub trait Atom<'handle, 'space: 'handle>: UriBound {
     /// The frame of the atom was already initialized, containing the URID.
     ///
     /// If space is insufficient, you may not panic and return `None` instead. The written results are assumed to be malformed.
-    fn init(
+    fn init<'handle, 'space: 'handle>(
         frame: AtomSpaceWriter<'handle, 'space>,
         parameter: Self::WriteParameter,
-    ) -> Option<Self::WriteHandle>;
+    ) -> Option<<Self::WriteHandle as AtomHandle<'handle>>::Handle>;
+}
+
+pub trait BackAsSpace: Atom {
+    fn back_as_space(value: Self::ReadHandle) -> &'handle AlignedSpace<u8>;
 }
 
 /// An atom of yet unknown type.

atom/src/port.rs

@@ -165,7 +165,7 @@ mod tests {
                 .read(urids.chunk, ())
                 .unwrap();
             let reader = unsafe { AtomPort::input_from_raw(NonNull::from(chunk).cast(), 0) };
-            assert_eq!(reader.read::<Int>(urids.int, ()).unwrap(), 42);
+            assert_eq!(*reader.read::<Int>(urids.int, ()).unwrap(), 42);
         }
     }
 }

atom/src/space/allocatable.rs

@@ -68,8 +68,8 @@ pub trait SpaceAllocator<'space>: SpaceAllocatorImpl<'space> + Sized {
     }
 
     #[inline]
-    fn init_atom<'handle, A: Atom<'handle, 'space>>(
-        &'handle mut self,
+    fn init_atom<'handle, 'a: 'handle, A: Atom<'handle, 'space>>(
+        &'a mut self,
         atom_type: URID<A>,
         write_parameter: A::WriteParameter,
     ) -> Option<A::WriteHandle>

atom/src/space/cursor.rs

@@ -6,7 +6,7 @@ pub struct SpaceCursor<'a> {
 }
 
 impl<'a> SpaceCursor<'a> {
-    pub fn new(data: &'a mut [u8]) -> Self {
+    pub fn new<'b: 'a>(data: &'b mut [u8]) -> Self {
         Self {
             data,
             allocated_length: 0,

buf-size/src/buffer_sizes.rs

@@ -33,7 +33,8 @@ impl BufferSizes {
         options: &OptionsList,
         urids: &BufferSizesURIDCollection,
     ) -> Self {
-        BufferSizes {
+        todo!()
+        /*BufferSizes {
             min_block_length: options
                 .read(urids.min_block_length, urids.atom_int, ())
                 .map(|x| x.get()),
@@ -46,6 +47,6 @@ impl BufferSizes {
             sequence_size: options
                 .read(urids.sequence_size, urids.atom_int, ())
                 .map(|x| x.get()),
-        }
+        }*/
     }
 }

buf-size/src/options.rs

@@ -18,17 +18,19 @@ macro_rules! make_option {
         }
 
         impl lv2_options::OptionType for $name {
-            type AtomType = lv2_atom::scalar::Int;
+            type AtomType = lv2_atom::atoms::scalar::Int;
 
             #[inline]
             fn from_option_value<'a>(
-                value: <lv2_atom::scalar::Int as Atom<'a, 'a>>::ReadHandle,
+                value: <lv2_atom::atoms::scalar::Int as Atom<'a, 'a>>::ReadHandle,
             ) -> Option<Self> {
                 Some(Self((*value)))
             }
 
             #[inline]
-            fn as_option_value<'a>(&'a self) -> <lv2_atom::scalar::Int as Atom<'a, 'a>>::ReadHandle {
+            fn as_option_value<'a>(
+                &'a self,
+            ) -> <lv2_atom::atoms::scalar::Int as Atom<'a, 'a>>::ReadHandle {
                 &self.0
             }
         }