1 files changed, 118 insertions, 97 deletions

diff --git a/components/script/dom/imagedata.rs b/components/script/dom/imagedata.rs
index 220ead847e8..d8574a9b666 100644
--- a/components/script/dom/imagedata.rs
+++ b/components/script/dom/imagedata.rs
@@ -1,21 +1,23 @@
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-use core::nonzero::NonZero;
-use dom::bindings::codegen::Bindings::ImageDataBinding;
-use dom::bindings::codegen::Bindings::ImageDataBinding::ImageDataMethods;
-use dom::bindings::error::{Fallible, Error};
-use dom::bindings::js::Root;
-use dom::bindings::reflector::{Reflector, reflect_dom_object};
-use dom::globalscope::GlobalScope;
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+use crate::dom::bindings::codegen::Bindings::ImageDataBinding::ImageDataMethods;
+use crate::dom::bindings::error::{Error, Fallible};
+use crate::dom::bindings::reflector::{reflect_dom_object, Reflector};
+use crate::dom::bindings::root::DomRoot;
+use crate::dom::globalscope::GlobalScope;
+use crate::script_runtime::JSContext;
 use dom_struct::dom_struct;
-use euclid::size::Size2D;
-use js::jsapi::{Heap, JSContext, JSObject};
+use euclid::default::{Rect, Size2D};
+use ipc_channel::ipc::IpcSharedMemory;
+use js::jsapi::{Heap, JSObject};
 use js::rust::Runtime;
-use js::typedarray::{Uint8ClampedArray, CreateWith};
+use js::typedarray::{CreateWith, Uint8ClampedArray};
+use std::borrow::Cow;
 use std::default::Default;
 use std::ptr;
+use std::ptr::NonNull;
 use std::vec::Vec;
 
 #[dom_struct]
@@ -23,126 +25,147 @@ pub struct ImageData {
     reflector_: Reflector,
     width: u32,
     height: u32,
+    #[ignore_malloc_size_of = "mozjs"]
     data: Heap<*mut JSObject>,
 }
 
 impl ImageData {
     #[allow(unsafe_code)]
-    pub fn new(global: &GlobalScope,
-               width: u32,
-               height: u32,
-               mut data: Option<Vec<u8>>)
-               -> Fallible<Root<ImageData>> {
+    pub fn new(
+        global: &GlobalScope,
+        width: u32,
+        height: u32,
+        mut data: Option<Vec<u8>>,
+    ) -> Fallible<DomRoot<ImageData>> {
         let len = width * height * 4;
         unsafe {
             let cx = global.get_cx();
-            rooted!(in (cx) let mut js_object = ptr::null_mut());
-            let data = match data {
-                Some(ref mut d) => {
-                    d.resize(len as usize, 0);
-                    CreateWith::Slice(&d[..])
-                },
-                None => CreateWith::Length(len),
-            };
-            Uint8ClampedArray::create(cx, data, js_object.handle_mut()).unwrap();
-            Self::new_with_jsobject(global, width, Some(height), Some(js_object.get()))
+            rooted!(in (*cx) let mut js_object = ptr::null_mut::<JSObject>());
+            if let Some(ref mut d) = data {
+                d.resize(len as usize, 0);
+                let data = CreateWith::Slice(&d[..]);
+                Uint8ClampedArray::create(*cx, data, js_object.handle_mut()).unwrap();
+                Self::new_with_jsobject(global, width, Some(height), js_object.get())
+            } else {
+                Self::new_without_jsobject(global, width, height)
+            }
         }
     }
 
     #[allow(unsafe_code)]
-    unsafe fn new_with_jsobject(global: &GlobalScope,
-                                width: u32,
-                                mut opt_height: Option<u32>,
-                                opt_jsobject: Option<*mut JSObject>)
-                                -> Fallible<Root<ImageData>> {
-        assert!(opt_jsobject.is_some() || opt_height.is_some());
-
-        if width == 0 {
+    unsafe fn new_with_jsobject(
+        global: &GlobalScope,
+        width: u32,
+        opt_height: Option<u32>,
+        jsobject: *mut JSObject,
+    ) -> Fallible<DomRoot<ImageData>> {
+        // checking jsobject type
+        let cx = global.get_cx();
+        typedarray!(in(*cx) let array_res: Uint8ClampedArray = jsobject);
+        let array = array_res.map_err(|_| {
+            Error::Type("Argument to Image data is not an Uint8ClampedArray".to_owned())
+        })?;
+
+        let byte_len = array.as_slice().len() as u32;
+        if byte_len == 0 || byte_len % 4 != 0 {
+            return Err(Error::InvalidState);
+        }
+
+        let len = byte_len / 4;
+        if width == 0 || len % width != 0 {
             return Err(Error::IndexSize);
         }
 
-        // checking jsobject type and verifying (height * width * 4 == jsobject.byte_len())
-        if let Some(jsobject) = opt_jsobject {
-            let cx = global.get_cx();
-            typedarray!(in(cx) let array_res: Uint8ClampedArray = jsobject);
-            let mut array = try!(array_res
-                .map_err(|_| Error::Type("Argument to Image data is not an Uint8ClampedArray".to_owned())));
+        let height = len / width;
+        if opt_height.map_or(false, |x| height != x) {
+            return Err(Error::IndexSize);
+        }
 
-            let byte_len = array.as_slice().len() as u32;
-            if byte_len % 4 != 0 {
-                return Err(Error::InvalidState);
-            }
+        let imagedata = Box::new(ImageData {
+            reflector_: Reflector::new(),
+            width: width,
+            height: height,
+            data: Heap::default(),
+        });
 
-            let len = byte_len / 4;
-            if width == 0 || len % width != 0 {
-                return Err(Error::IndexSize);
-            }
+        (*imagedata).data.set(jsobject);
 
-            let height = len / width;
-            if opt_height.map_or(false, |x| height != x) {
-                return Err(Error::IndexSize);
-            } else {
-                opt_height = Some(height);
-            }
-        }
+        Ok(reflect_dom_object(imagedata, global))
+    }
 
-        let height = opt_height.unwrap();
-        if height == 0 {
+    #[allow(unsafe_code)]
+    unsafe fn new_without_jsobject(
+        global: &GlobalScope,
+        width: u32,
+        height: u32,
+    ) -> Fallible<DomRoot<ImageData>> {
+        if width == 0 || height == 0 {
             return Err(Error::IndexSize);
         }
 
-        let imagedata = box ImageData {
+        let imagedata = Box::new(ImageData {
             reflector_: Reflector::new(),
             width: width,
             height: height,
             data: Heap::default(),
-        };
+        });
 
-        if let Some(jsobject) = opt_jsobject {
-            (*imagedata).data.set(jsobject);
-        } else {
-            let len = width * height * 4;
-            let cx = global.get_cx();
-            rooted!(in (cx) let mut array = ptr::null_mut());
-            Uint8ClampedArray::create(cx, CreateWith::Length(len), array.handle_mut()).unwrap();
-            (*imagedata).data.set(array.get());
-        }
+        let len = width * height * 4;
+        let cx = global.get_cx();
+        rooted!(in (*cx) let mut array = ptr::null_mut::<JSObject>());
+        Uint8ClampedArray::create(*cx, CreateWith::Length(len as usize), array.handle_mut())
+            .unwrap();
+        (*imagedata).data.set(array.get());
 
-        Ok(reflect_dom_object(imagedata, global, ImageDataBinding::Wrap))
+        Ok(reflect_dom_object(imagedata, global))
     }
-
     // https://html.spec.whatwg.org/multipage/#pixel-manipulation:dom-imagedata-3
-    #[allow(unsafe_code)]
-    pub fn Constructor(global: &GlobalScope, width: u32, height: u32) -> Fallible<Root<Self>> {
-        unsafe { Self::new_with_jsobject(global, width, Some(height), None) }
+    #[allow(unsafe_code, non_snake_case)]
+    pub fn Constructor(global: &GlobalScope, width: u32, height: u32) -> Fallible<DomRoot<Self>> {
+        unsafe { Self::new_without_jsobject(global, width, height) }
     }
 
     // https://html.spec.whatwg.org/multipage/#pixel-manipulation:dom-imagedata-4
+    #[allow(unsafe_code, unused_variables, non_snake_case)]
+    pub unsafe fn Constructor_(
+        cx: JSContext,
+        global: &GlobalScope,
+        jsobject: *mut JSObject,
+        width: u32,
+        opt_height: Option<u32>,
+    ) -> Fallible<DomRoot<Self>> {
+        Self::new_with_jsobject(global, width, opt_height, jsobject)
+    }
+
+    /// Nothing must change the array on the JS side while the slice is live.
     #[allow(unsafe_code)]
-    #[allow(unused_variables)]
-    pub unsafe fn Constructor_(cx: *mut JSContext,
-                               global: &GlobalScope,
-                               jsobject: *mut JSObject,
-                               width: u32,
-                               opt_height: Option<u32>)
-                               -> Fallible<Root<Self>> {
-        Self::new_with_jsobject(global, width, opt_height, Some(jsobject))
+    pub unsafe fn as_slice(&self) -> &[u8] {
+        assert!(!self.data.get().is_null());
+        let cx = Runtime::get();
+        assert!(!cx.is_null());
+        typedarray!(in(cx) let array: Uint8ClampedArray = self.data.get());
+        let array = array.as_ref().unwrap();
+        // NOTE(nox): This is just as unsafe as `as_slice` itself even though we
+        // are extending the lifetime of the slice, because the data in
+        // this ImageData instance will never change. The method is thus unsafe
+        // because the array may be manipulated from JS while the reference
+        // is live.
+        let ptr = array.as_slice() as *const _;
+        &*ptr
     }
 
     #[allow(unsafe_code)]
-    pub fn get_data_array(&self) -> Vec<u8> {
-        unsafe {
-            assert!(!self.data.get().is_null());
-            let cx = Runtime::get();
-            assert!(!cx.is_null());
-            typedarray!(in(cx) let array: Uint8ClampedArray = self.data.get());
-            let vec = array.unwrap().as_slice().to_vec();
-            vec
-        }
+    pub fn to_shared_memory(&self) -> IpcSharedMemory {
+        IpcSharedMemory::from_bytes(unsafe { self.as_slice() })
+    }
+
+    #[allow(unsafe_code)]
+    pub unsafe fn get_rect(&self, rect: Rect<u64>) -> Cow<[u8]> {
+        pixels::rgba8_get_rect(self.as_slice(), self.get_size().to_u64(), rect)
     }
 
-    pub fn get_size(&self) -> Size2D<i32> {
-        Size2D::new(self.Width() as i32, self.Height() as i32)
+    pub fn get_size(&self) -> Size2D<u32> {
+        Size2D::new(self.Width(), self.Height())
     }
 }
 
@@ -157,10 +180,8 @@ impl ImageDataMethods for ImageData {
         self.height
     }
 
-    #[allow(unsafe_code)]
     // https://html.spec.whatwg.org/multipage/#dom-imagedata-data
-    unsafe fn Data(&self, _: *mut JSContext) -> NonZero<*mut JSObject> {
-        assert!(!self.data.get().is_null());
-        NonZero::new(self.data.get())
+    fn Data(&self, _: JSContext) -> NonNull<JSObject> {
+        NonNull::new(self.data.get()).expect("got a null pointer")
     }
 }