Modular backends (#138)

* Add some trait to formalize backends.

* Use the generic backend trait.

candle-core/src/dummy_cuda_backend.rs

@@ -1,98 +1,62 @@
 #![allow(dead_code)]
 use crate::{CpuStorage, DType, Error, Layout, Result, Shape};
 
-#[derive(thiserror::Error, Debug)]
-pub enum DummyError {}
-pub type CudaError = DummyError;
-
 #[derive(Debug, Clone)]
 pub struct CudaDevice;
 
+#[derive(Debug)]
+pub struct CudaStorage;
+
 macro_rules! fail {
     () => {
         unimplemented!("cuda support has not been enabled")
     };
 }
 
-impl CudaDevice {
-    pub(crate) fn new(_: usize) -> Result<Self> {
+impl crate::backend::BackendStorage for CudaStorage {
+    type Device = CudaDevice;
+
+    fn try_clone(&self, _: &Layout) -> Result<Self> {
         Err(Error::NotCompiledWithCudaSupport)
     }
 
-    pub(crate) fn same_id(&self, _: &Self) -> bool {
-        true
-    }
-
-    pub(crate) fn ordinal(&self) -> usize {
+    fn dtype(&self) -> DType {
         fail!()
     }
 
-    pub(crate) fn zeros_impl(&self, _shape: &Shape, _dtype: DType) -> Result<CudaStorage> {
-        Err(Error::NotCompiledWithCudaSupport)
-    }
-
-    pub(crate) fn ones_impl(&self, _shape: &Shape, _dtype: DType) -> Result<CudaStorage> {
-        Err(Error::NotCompiledWithCudaSupport)
-    }
-
-    pub(crate) fn cuda_from_cpu_storage(&self, _: &CpuStorage) -> Result<CudaStorage> {
-        Err(Error::NotCompiledWithCudaSupport)
-    }
-
-    pub(crate) fn rand_uniform(&self, _: &Shape, _: DType, _: f64, _: f64) -> Result<CudaStorage> {
-        Err(Error::NotCompiledWithCudaSupport)
-    }
-
-    pub(crate) fn rand_normal(&self, _: &Shape, _: DType, _: f64, _: f64) -> Result<CudaStorage> {
-        Err(Error::NotCompiledWithCudaSupport)
-    }
-}
-
-#[derive(Debug)]
-pub struct CudaStorage;
-
-impl CudaStorage {
-    pub fn try_clone(&self, _: &Layout) -> Result<Self> {
-        Err(Error::NotCompiledWithCudaSupport)
-    }
-
-    pub fn dtype(&self) -> DType {
+    fn device(&self) -> &Self::Device {
         fail!()
     }
 
-    pub fn device(&self) -> &CudaDevice {
-        fail!()
-    }
-
-    pub(crate) fn to_cpu_storage(&self) -> Result<CpuStorage> {
+    fn to_cpu_storage(&self) -> Result<CpuStorage> {
         Err(Error::NotCompiledWithCudaSupport)
     }
 
-    pub(crate) fn affine(&self, _: &Layout, _: f64, _: f64) -> Result<Self> {
+    fn affine(&self, _: &Layout, _: f64, _: f64) -> Result<Self> {
         Err(Error::NotCompiledWithCudaSupport)
     }
 
-    pub(crate) fn elu(&self, _: &Layout, _: f64) -> Result<Self> {
+    fn elu(&self, _: &Layout, _: f64) -> Result<Self> {
         Err(Error::NotCompiledWithCudaSupport)
     }
 
-    pub(crate) fn sum(&self, _: &Layout, _: &[usize]) -> Result<Self> {
+    fn sum(&self, _: &Layout, _: &[usize]) -> Result<Self> {
         Err(Error::NotCompiledWithCudaSupport)
     }
 
-    pub(crate) fn divide_by_sum_over_dim(&mut self, _: &Shape, _: usize) -> Result<()> {
+    fn divide_by_sum_over_dim(&mut self, _: &Shape, _: usize) -> Result<()> {
         Err(Error::NotCompiledWithCudaSupport)
     }
 
-    pub(crate) fn to_dtype(&self, _: &Layout, _: DType) -> Result<Self> {
+    fn to_dtype(&self, _: &Layout, _: DType) -> Result<Self> {
         Err(Error::NotCompiledWithCudaSupport)
     }
 
-    pub(crate) fn unary_impl<B: crate::op::UnaryOp>(&self, _: &Layout) -> Result<Self> {
+    fn unary_impl<B: crate::op::UnaryOp>(&self, _: &Layout) -> Result<Self> {
         Err(Error::NotCompiledWithCudaSupport)
     }
 
-    pub(crate) fn binary_impl<B: crate::op::BinaryOp>(
+    fn binary_impl<B: crate::op::BinaryOp>(
         &self,
         _: &Self,
         _: &Layout,
@@ -101,32 +65,25 @@ impl CudaStorage {
         Err(Error::NotCompiledWithCudaSupport)
     }
 
-    pub(crate) fn where_cond(
+    fn where_cond(&self, _: &Layout, _: &Self, _: &Layout, _: &Self, _: &Layout) -> Result<Self> {
+        Err(Error::NotCompiledWithCudaSupport)
+    }
+
+    fn conv1d(
         &self,
         _: &Layout,
         _: &Self,
         _: &Layout,
-        _: &Self,
-        _: &Layout,
+        _: &crate::conv::ParamsConv1D,
     ) -> Result<Self> {
         Err(Error::NotCompiledWithCudaSupport)
     }
 
-    pub(crate) fn conv1d(
-        &self,
-        _l: &Layout,
-        _kernel: &Self,
-        _kernel_l: &Layout,
-        _params: &crate::conv::ParamsConv1D,
-    ) -> Result<Self> {
+    fn embedding(&self, _: &Layout, _: &Self, _: &Layout) -> Result<Self> {
         Err(Error::NotCompiledWithCudaSupport)
     }
 
-    pub(crate) fn embedding(&self, _: &Layout, _: &Self, _: &Layout) -> Result<Self> {
-        Err(Error::NotCompiledWithCudaSupport)
-    }
-
-    pub(crate) fn matmul(
+    fn matmul(
         &self,
         _: &Self,
         _: (usize, usize, usize, usize),
@@ -136,7 +93,42 @@ impl CudaStorage {
         Err(Error::NotCompiledWithCudaSupport)
     }
 
-    pub(crate) fn copy_strided_src(&self, _: &mut Self, _: usize, _: &Layout) -> Result<()> {
+    fn copy_strided_src(&self, _: &mut Self, _: usize, _: &Layout) -> Result<()> {
+        Err(Error::NotCompiledWithCudaSupport)
+    }
+}
+
+impl crate::backend::BackendDevice for CudaDevice {
+    type Storage = CudaStorage;
+    fn new(_: usize) -> Result<Self> {
+        Err(Error::NotCompiledWithCudaSupport)
+    }
+
+    fn location(&self) -> crate::DeviceLocation {
+        fail!()
+    }
+
+    fn same_device(&self, _: &Self) -> bool {
+        fail!()
+    }
+
+    fn zeros_impl(&self, _shape: &Shape, _dtype: DType) -> Result<Self::Storage> {
+        Err(Error::NotCompiledWithCudaSupport)
+    }
+
+    fn ones_impl(&self, _shape: &Shape, _dtype: DType) -> Result<Self::Storage> {
+        Err(Error::NotCompiledWithCudaSupport)
+    }
+
+    fn storage_from_cpu_storage(&self, _: &CpuStorage) -> Result<Self::Storage> {
+        Err(Error::NotCompiledWithCudaSupport)
+    }
+
+    fn rand_uniform(&self, _: &Shape, _: DType, _: f64, _: f64) -> Result<Self::Storage> {
+        Err(Error::NotCompiledWithCudaSupport)
+    }
+
+    fn rand_normal(&self, _: &Shape, _: DType, _: f64, _: f64) -> Result<Self::Storage> {
         Err(Error::NotCompiledWithCudaSupport)
     }
 }