1 files changed, 156 insertions, 0 deletions
diff --git a/gfx/wr/webrender/src/prim_store/storage.rs b/gfx/wr/webrender/src/prim_store/storage.rs
new file mode 100644
index 0000000000..4b99d87556
--- /dev/null
+++ b/gfx/wr/webrender/src/prim_store/storage.rs
@@ -0,0 +1,156 @@
+/* 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 std::{iter::Extend, ops, marker::PhantomData, u32};
+use crate::util::Recycler;
+
+#[derive(Debug, Hash)]
+#[cfg_attr(feature = "capture", derive(Serialize))]
+#[cfg_attr(feature = "replay", derive(Deserialize))]
+pub struct Index<T>(u32, PhantomData<T>);
+
+// We explicitly implement Copy + Clone instead of using #[derive(Copy, Clone)]
+// because we don't want to require that T implements Clone + Copy.
+impl<T> Clone for Index<T> {
+    fn clone(&self) -> Self { *self }
+}
+
+impl<T> Copy for Index<T> {}
+
+impl<T> PartialEq for Index<T> {
+    fn eq(&self, other: &Self) -> bool {
+        self.0 == other.0
+    }
+}
+
+impl<T> Index<T> {
+    fn new(idx: usize) -> Self {
+        debug_assert!(idx < u32::max_value() as usize);
+        Index(idx as u32, PhantomData)
+    }
+
+    pub const INVALID: Index<T> = Index(u32::MAX, PhantomData);
+    pub const UNUSED: Index<T> = Index(u32::MAX-1, PhantomData);
+}
+
+#[derive(Debug)]
+pub struct OpenRange<T> {
+    start: Index<T>,
+}
+
+#[derive(Debug)]
+#[cfg_attr(feature = "capture", derive(Serialize))]
+pub struct Range<T> {
+    pub start: Index<T>,
+    pub end: Index<T>,
+}
+
+// We explicitly implement Copy + Clone instead of using #[derive(Copy, Clone)]
+// because we don't want to require that T implements Clone + Copy.
+impl<T> Clone for Range<T> {
+    fn clone(&self) -> Self {
+        Range { start: self.start, end: self.end }
+    }
+}
+impl<T> Copy for Range<T> {}
+
+impl<T> Range<T> {
+    /// Create an empty `Range`
+    pub fn empty() -> Self {
+        Range {
+            start: Index::new(0),
+            end: Index::new(0),
+        }
+    }
+
+    /// Check for an empty `Range`
+    pub fn is_empty(self) -> bool {
+        self.start.0 >= self.end.0
+    }
+}
+
+#[cfg_attr(feature = "capture", derive(Serialize))]
+pub struct Storage<T> {
+    data: Vec<T>,
+}
+
+impl<T> Storage<T> {
+    pub fn new(initial_capacity: usize) -> Self {
+        Storage {
+            data: Vec::with_capacity(initial_capacity),
+        }
+    }
+
+    pub fn len(&self) -> usize {
+        self.data.len()
+    }
+
+    pub fn clear(&mut self) {
+        self.data.clear();
+    }
+
+    pub fn push(&mut self, t: T) -> Index<T> {
+        let index = self.data.len();
+        self.data.push(t);
+        Index(index as u32, PhantomData)
+    }
+
+    pub fn reserve(&mut self, count: usize) {
+        self.data.reserve(count);
+    }
+
+    pub fn recycle(&mut self, recycler: &mut Recycler) {
+        recycler.recycle_vec(&mut self.data);
+    }
+
+    pub fn extend<II: IntoIterator<Item=T>>(&mut self, iter: II) -> Range<T> {
+        let range = self.open_range();
+        self.data.extend(iter);
+
+        self.close_range(range)
+    }
+
+    pub fn open_range(&self) -> OpenRange<T> {
+        OpenRange {
+            start: Index::new(self.data.len())
+        }
+    }
+
+    pub fn close_range(&self, range: OpenRange<T>) -> Range<T> {
+        Range {
+            start: range.start,
+            end: Index::new(self.data.len()),
+        }
+    }
+}
+
+impl<T> ops::Index<Index<T>> for Storage<T> {
+    type Output = T;
+    fn index(&self, index: Index<T>) -> &Self::Output {
+        &self.data[index.0 as usize]
+    }
+}
+
+impl<T> ops::IndexMut<Index<T>> for Storage<T> {
+    fn index_mut(&mut self, index: Index<T>) -> &mut Self::Output {
+        &mut self.data[index.0 as usize]
+    }
+}
+
+impl<T> ops::Index<Range<T>> for Storage<T> {
+    type Output = [T];
+    fn index(&self, index: Range<T>) -> &Self::Output {
+        let start = index.start.0 as _;
+        let end = index.end.0 as _;
+        &self.data[start..end]
+    }
+}
+
+impl<T> ops::IndexMut<Range<T>> for Storage<T> {
+    fn index_mut(&mut self, index: Range<T>) -> &mut Self::Output {
+        let start = index.start.0 as _;
+        let end = index.end.0 as _;
+        &mut self.data[start..end]
+    }
+}