Use Bytes as the Container of ImageBuffer

Since we don't need to mutate images once loaded,
we avoid unnecessary extra allocations.

core/src/image.rs

@@ -4,90 +4,12 @@ pub use bytes::Bytes;
 use crate::{Rectangle, Size};
 
 use rustc_hash::FxHasher;
-use std::hash::{Hash, Hasher as _};
+use std::hash::{Hash, Hasher};
 use std::path::PathBuf;
 
 /// A handle of some image data.
-#[derive(Debug, Clone, PartialEq, Eq)]
-pub struct Handle {
-    id: u64,
-    data: Data,
-}
-
-impl Handle {
-    /// Creates an image [`Handle`] pointing to the image of the given path.
-    ///
-    /// Makes an educated guess about the image format by examining the data in the file.
-    pub fn from_path<T: Into<PathBuf>>(path: T) -> Handle {
-        Self::from_data(Data::Path(path.into()))
-    }
-
-    /// Creates an image [`Handle`] containing the image pixels directly. This
-    /// function expects the input data to be provided as a `Vec<u8>` of RGBA
-    /// pixels.
-    ///
-    /// This is useful if you have already decoded your image.
-    pub fn from_pixels(
-        width: u32,
-        height: u32,
-        pixels: impl Into<Bytes>,
-    ) -> Handle {
-        Self::from_data(Data::Rgba {
-            width,
-            height,
-            pixels: pixels.into(),
-        })
-    }
-
-    /// Creates an image [`Handle`] containing the image data directly.
-    ///
-    /// Makes an educated guess about the image format by examining the given data.
-    ///
-    /// This is useful if you already have your image loaded in-memory, maybe
-    /// because you downloaded or generated it procedurally.
-    pub fn from_memory(bytes: impl Into<Bytes>) -> Handle {
-        Self::from_data(Data::Bytes(bytes.into()))
-    }
-
-    fn from_data(data: Data) -> Handle {
-        let mut hasher = FxHasher::default();
-        data.hash(&mut hasher);
-
-        Handle {
-            id: hasher.finish(),
-            data,
-        }
-    }
-
-    /// Returns the unique identifier of the [`Handle`].
-    pub fn id(&self) -> u64 {
-        self.id
-    }
-
-    /// Returns a reference to the image [`Data`].
-    pub fn data(&self) -> &Data {
-        &self.data
-    }
-}
-
-impl<T> From<T> for Handle
-where
-    T: Into<PathBuf>,
-{
-    fn from(path: T) -> Handle {
-        Handle::from_path(path.into())
-    }
-}
-
-impl Hash for Handle {
-    fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
-        self.id.hash(state);
-    }
-}
-
-/// The data of a raster image.
-#[derive(Clone, PartialEq, Eq, Hash)]
-pub enum Data {
+#[derive(Clone, PartialEq, Eq)]
+pub enum Handle {
     /// File data
     Path(PathBuf),
 
@@ -105,12 +27,75 @@ pub enum Data {
     },
 }
 
-impl std::fmt::Debug for Data {
+impl Handle {
+    /// Creates an image [`Handle`] pointing to the image of the given path.
+    ///
+    /// Makes an educated guess about the image format by examining the data in the file.
+    pub fn from_path<T: Into<PathBuf>>(path: T) -> Handle {
+        Self::Path(path.into())
+    }
+
+    /// Creates an image [`Handle`] containing the image pixels directly. This
+    /// function expects the input data to be provided as a `Vec<u8>` of RGBA
+    /// pixels.
+    ///
+    /// This is useful if you have already decoded your image.
+    pub fn from_pixels(
+        width: u32,
+        height: u32,
+        pixels: impl Into<Bytes>,
+    ) -> Handle {
+        Self::Rgba {
+            width,
+            height,
+            pixels: pixels.into(),
+        }
+    }
+
+    /// Creates an image [`Handle`] containing the image data directly.
+    ///
+    /// Makes an educated guess about the image format by examining the given data.
+    ///
+    /// This is useful if you already have your image loaded in-memory, maybe
+    /// because you downloaded or generated it procedurally.
+    pub fn from_memory(bytes: impl Into<Bytes>) -> Handle {
+        Self::Bytes(bytes.into())
+    }
+
+    /// Returns the unique identifier of the [`Handle`].
+    pub fn id(&self) -> u64 {
+        let mut hasher = FxHasher::default();
+        self.hash(&mut hasher);
+
+        hasher.finish()
+    }
+}
+
+impl Hash for Handle {
+    fn hash<H: Hasher>(&self, state: &mut H) {
+        match self {
+            Self::Path(path) => path.hash(state),
+            Self::Bytes(bytes) => bytes.as_ptr().hash(state),
+            Self::Rgba { pixels, .. } => pixels.as_ptr().hash(state),
+        }
+    }
+}
+
+impl<T> From<T> for Handle
+where
+    T: Into<PathBuf>,
+{
+    fn from(path: T) -> Handle {
+        Handle::from_path(path.into())
+    }
+}
+
+impl std::fmt::Debug for Handle {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match self {
-            Data::Path(path) => write!(f, "Path({path:?})"),
-            Data::Bytes(_) => write!(f, "Bytes(...)"),
-            Data::Rgba { width, height, .. } => {
+            Self::Path(path) => write!(f, "Path({path:?})"),
+            Self::Bytes(_) => write!(f, "Bytes(...)"),
+            Self::Rgba { width, height, .. } => {
                 write!(f, "Pixels({width} * {height})")
             }
         }