conversions: Make a `is_type_compatible` method for ArrayBufferViews.

components/script/dom/bindings/conversions.rs

@@ -339,15 +339,62 @@ impl<T: Reflectable> ToJSValConvertible for Root<T> {
 }
 
 /// A JS ArrayBufferView contents can only be viewed as the types marked with this trait
-pub unsafe trait ArrayBufferViewContents: Clone {}
-unsafe impl ArrayBufferViewContents for u8 {}
-unsafe impl ArrayBufferViewContents for i8 {}
-unsafe impl ArrayBufferViewContents for u16 {}
-unsafe impl ArrayBufferViewContents for i16 {}
-unsafe impl ArrayBufferViewContents for u32 {}
-unsafe impl ArrayBufferViewContents for i32 {}
-unsafe impl ArrayBufferViewContents for f32 {}
-unsafe impl ArrayBufferViewContents for f64 {}
+pub unsafe trait ArrayBufferViewContents: Clone {
+    /// Check if the JS ArrayBufferView type is compatible with the implementor of the
+    /// trait
+    fn is_type_compatible(ty: Type) -> bool;
+}
+
+unsafe impl ArrayBufferViewContents for u8 {
+    fn is_type_compatible(ty: Type) -> bool {
+        match ty {
+            Type::Uint8 |
+            Type::Uint8Clamped => true,
+            _ => false,
+        }
+    }
+}
+
+unsafe impl ArrayBufferViewContents for i8 {
+    fn is_type_compatible(ty: Type) -> bool {
+        ty as i32 == Type::Int8 as i32
+    }
+}
+
+unsafe impl ArrayBufferViewContents for u16 {
+    fn is_type_compatible(ty: Type) -> bool {
+        ty as i32 == Type::Uint16 as i32
+    }
+}
+
+unsafe impl ArrayBufferViewContents for i16 {
+    fn is_type_compatible(ty: Type) -> bool {
+        ty as i32 == Type::Int16 as i32
+    }
+}
+
+unsafe impl ArrayBufferViewContents for u32 {
+    fn is_type_compatible(ty: Type) -> bool {
+        ty as i32 == Type::Uint32 as i32
+    }
+}
+
+unsafe impl ArrayBufferViewContents for i32 {
+    fn is_type_compatible(ty: Type) -> bool {
+        ty as i32 == Type::Int32 as i32
+    }
+}
+
+unsafe impl ArrayBufferViewContents for f32 {
+    fn is_type_compatible(ty: Type) -> bool {
+        ty as i32 == Type::Float32 as i32
+    }
+}
+unsafe impl ArrayBufferViewContents for f64 {
+    fn is_type_compatible(ty: Type) -> bool {
+        ty as i32 == Type::Float64 as i32
+    }
+}
 
 /// Returns a mutable slice of the Array Buffer View data, viewed as T, without checking the real
 /// type of it.
@@ -370,11 +417,10 @@ pub fn array_buffer_view_to_vec<T: ArrayBufferViewContents>(abv: *mut JSObject)
 
 /// Returns a mutable slice of the Array Buffer View data, viewed as T, checking that the real type
 /// of it is ty.
-pub unsafe fn array_buffer_view_data_checked<'a, T: ArrayBufferViewContents>(abv: *mut JSObject,
-                                                                             ty: Type) -> Option<&'a mut [T]> {
+pub unsafe fn array_buffer_view_data_checked<'a, T: ArrayBufferViewContents>(abv: *mut JSObject)
+                                                                             -> Option<&'a mut [T]> {
     array_buffer_view_data::<T>(abv).and_then(|data| {
-        let real_ty = JS_GetArrayBufferViewType(abv);
-        if real_ty as i32 == ty as i32 {
+        if T::is_type_compatible(JS_GetArrayBufferViewType(abv)) {
             Some(data)
         } else {
             None
@@ -384,8 +430,8 @@ pub unsafe fn array_buffer_view_data_checked<'a, T: ArrayBufferViewContents>(abv
 
 /// Returns a copy of the ArrayBufferView data, viewed as T, checking that the real type
 /// of it is ty.
-pub fn array_buffer_view_to_vec_checked<T: ArrayBufferViewContents>(abv: *mut JSObject, ty: Type) -> Option<Vec<T>> {
+pub fn array_buffer_view_to_vec_checked<T: ArrayBufferViewContents>(abv: *mut JSObject) -> Option<Vec<T>> {
     unsafe {
-        array_buffer_view_data_checked(abv, ty).map(|data| data.to_vec())
+        array_buffer_view_data_checked(abv).map(|data| data.to_vec())
     }
 }

components/script/dom/webglrenderingcontext.rs

@@ -28,7 +28,7 @@ use dom::webgltexture::{TexParameterValue, WebGLTexture};
 use dom::webgluniformlocation::WebGLUniformLocation;
 use euclid::size::Size2D;
 use ipc_channel::ipc::{self, IpcSender};
-use js::jsapi::{JSContext, JSObject, RootedValue, Type};
+use js::jsapi::{JSContext, JSObject, RootedValue};
 use js::jsval::{BooleanValue, DoubleValue, Int32Value, JSVal, NullValue, UndefinedValue};
 use net_traits::image::base::PixelFormat;
 use net_traits::image_cache_task::ImageResponse;
@@ -948,7 +948,7 @@ impl WebGLRenderingContextMethods for WebGLRenderingContext {
             None => return,
         };
 
-        if let Some(data_vec) = array_buffer_view_to_vec_checked::<f32>(data, Type::Float32) {
+        if let Some(data_vec) = array_buffer_view_to_vec_checked::<f32>(data) {
             if data_vec.len() < 4 {
                 return self.webgl_error(InvalidOperation);
             }
@@ -976,7 +976,7 @@ impl WebGLRenderingContextMethods for WebGLRenderingContext {
     #[allow(unsafe_code)]
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.10
     fn VertexAttrib1fv(&self, _cx: *mut JSContext, indx: u32, data: *mut JSObject) {
-        if let Some(data_vec) = array_buffer_view_to_vec_checked::<f32>(data, Type::Float32) {
+        if let Some(data_vec) = array_buffer_view_to_vec_checked::<f32>(data) {
             if data_vec.len() < 4 {
                 return self.webgl_error(InvalidOperation);
             }
@@ -994,7 +994,7 @@ impl WebGLRenderingContextMethods for WebGLRenderingContext {
     #[allow(unsafe_code)]
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.10
     fn VertexAttrib2fv(&self, _cx: *mut JSContext, indx: u32, data: *mut JSObject) {
-        if let Some(data_vec) = array_buffer_view_to_vec_checked::<f32>(data, Type::Float32) {
+        if let Some(data_vec) = array_buffer_view_to_vec_checked::<f32>(data) {
             if data_vec.len() < 2 {
                 return self.webgl_error(InvalidOperation);
             }
@@ -1012,7 +1012,7 @@ impl WebGLRenderingContextMethods for WebGLRenderingContext {
     #[allow(unsafe_code)]
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.10
     fn VertexAttrib3fv(&self, _cx: *mut JSContext, indx: u32, data: *mut JSObject) {
-        if let Some(data_vec) = array_buffer_view_to_vec_checked::<f32>(data, Type::Float32) {
+        if let Some(data_vec) = array_buffer_view_to_vec_checked::<f32>(data) {
             if data_vec.len() < 3 {
                 return self.webgl_error(InvalidOperation);
             }
@@ -1029,7 +1029,7 @@ impl WebGLRenderingContextMethods for WebGLRenderingContext {
 
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.10
     fn VertexAttrib4fv(&self, _cx: *mut JSContext, indx: u32, data: *mut JSObject) {
-        if let Some(data_vec) = array_buffer_view_to_vec_checked::<f32>(data, Type::Float32) {
+        if let Some(data_vec) = array_buffer_view_to_vec_checked::<f32>(data) {
             if data_vec.len() < 4 {
                 return self.webgl_error(InvalidOperation);
             }