1 files changed, 196 insertions, 0 deletions
diff --git a/gfx/wgpu/wgpu-core/src/id.rs b/gfx/wgpu/wgpu-core/src/id.rs
new file mode 100644
index 0000000000..7a1201be2e
--- /dev/null
+++ b/gfx/wgpu/wgpu-core/src/id.rs
@@ -0,0 +1,196 @@
+/* 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 crate::{Epoch, Index};
+use std::{cmp::Ordering, fmt, marker::PhantomData, num::NonZeroU64};
+use wgt::Backend;
+
+const BACKEND_BITS: usize = 3;
+const EPOCH_MASK: u32 = (1 << (32 - BACKEND_BITS)) - 1;
+type Dummy = crate::backend::Empty;
+
+#[repr(transparent)]
+#[cfg_attr(feature = "trace", derive(serde::Serialize), serde(into = "SerialId"))]
+#[cfg_attr(
+    feature = "replay",
+    derive(serde::Deserialize),
+    serde(from = "SerialId")
+)]
+#[cfg_attr(
+    all(feature = "serde", not(feature = "trace")),
+    derive(serde::Serialize)
+)]
+#[cfg_attr(
+    all(feature = "serde", not(feature = "replay")),
+    derive(serde::Deserialize)
+)]
+pub struct Id<T>(NonZeroU64, PhantomData<T>);
+
+// This type represents Id in a more readable (and editable) way.
+#[allow(dead_code)]
+#[cfg_attr(feature = "trace", derive(serde::Serialize))]
+#[cfg_attr(feature = "replay", derive(serde::Deserialize))]
+enum SerialId {
+    // The only variant forces RON to not ignore "Id"
+    Id(Index, Epoch, Backend),
+}
+#[cfg(feature = "trace")]
+impl<T> From<Id<T>> for SerialId {
+    fn from(id: Id<T>) -> Self {
+        let (index, epoch, backend) = id.unzip();
+        Self::Id(index, epoch, backend)
+    }
+}
+#[cfg(feature = "replay")]
+impl<T> From<SerialId> for Id<T> {
+    fn from(id: SerialId) -> Self {
+        match id {
+            SerialId::Id(index, epoch, backend) => TypedId::zip(index, epoch, backend),
+        }
+    }
+}
+
+impl<T> Id<T> {
+    #[cfg(test)]
+    pub(crate) fn dummy() -> Valid<Self> {
+        Valid(Id(NonZeroU64::new(1).unwrap(), PhantomData))
+    }
+
+    pub fn backend(self) -> Backend {
+        match self.0.get() >> (64 - BACKEND_BITS) as u8 {
+            0 => Backend::Empty,
+            1 => Backend::Vulkan,
+            2 => Backend::Metal,
+            3 => Backend::Dx12,
+            4 => Backend::Dx11,
+            5 => Backend::Gl,
+            _ => unreachable!(),
+        }
+    }
+}
+
+impl<T> Copy for Id<T> {}
+
+impl<T> Clone for Id<T> {
+    fn clone(&self) -> Self {
+        Self(self.0, PhantomData)
+    }
+}
+
+impl<T> fmt::Debug for Id<T> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        self.unzip().fmt(formatter)
+    }
+}
+
+impl<T> std::hash::Hash for Id<T> {
+    fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
+        self.0.hash(state);
+    }
+}
+
+impl<T> PartialEq for Id<T> {
+    fn eq(&self, other: &Self) -> bool {
+        self.0 == other.0
+    }
+}
+
+impl<T> Eq for Id<T> {}
+
+impl<T> PartialOrd for Id<T> {
+    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+        self.0.partial_cmp(&other.0)
+    }
+}
+
+impl<T> Ord for Id<T> {
+    fn cmp(&self, other: &Self) -> Ordering {
+        self.0.cmp(&other.0)
+    }
+}
+
+/// An internal ID that has been checked to point to
+/// a valid object in the storages.
+#[repr(transparent)]
+#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq, PartialOrd, Ord)]
+#[cfg_attr(feature = "trace", derive(serde::Serialize))]
+#[cfg_attr(feature = "replay", derive(serde::Deserialize))]
+pub(crate) struct Valid<I>(pub I);
+
+pub trait TypedId {
+    fn zip(index: Index, epoch: Epoch, backend: Backend) -> Self;
+    fn unzip(self) -> (Index, Epoch, Backend);
+}
+
+impl<T> TypedId for Id<T> {
+    fn zip(index: Index, epoch: Epoch, backend: Backend) -> Self {
+        assert_eq!(0, epoch >> (32 - BACKEND_BITS));
+        let v = index as u64 | ((epoch as u64) << 32) | ((backend as u64) << (64 - BACKEND_BITS));
+        Id(NonZeroU64::new(v).unwrap(), PhantomData)
+    }
+
+    fn unzip(self) -> (Index, Epoch, Backend) {
+        (
+            self.0.get() as u32,
+            (self.0.get() >> 32) as u32 & EPOCH_MASK,
+            self.backend(),
+        )
+    }
+}
+
+pub type AdapterId = Id<crate::instance::Adapter<Dummy>>;
+pub type SurfaceId = Id<crate::instance::Surface>;
+// Device
+pub type DeviceId = Id<crate::device::Device<Dummy>>;
+pub type QueueId = DeviceId;
+// Resource
+pub type BufferId = Id<crate::resource::Buffer<Dummy>>;
+pub type TextureViewId = Id<crate::resource::TextureView<Dummy>>;
+pub type TextureId = Id<crate::resource::Texture<Dummy>>;
+pub type SamplerId = Id<crate::resource::Sampler<Dummy>>;
+// Binding model
+pub type BindGroupLayoutId = Id<crate::binding_model::BindGroupLayout<Dummy>>;
+pub type PipelineLayoutId = Id<crate::binding_model::PipelineLayout<Dummy>>;
+pub type BindGroupId = Id<crate::binding_model::BindGroup<Dummy>>;
+// Pipeline
+pub type ShaderModuleId = Id<crate::pipeline::ShaderModule<Dummy>>;
+pub type RenderPipelineId = Id<crate::pipeline::RenderPipeline<Dummy>>;
+pub type ComputePipelineId = Id<crate::pipeline::ComputePipeline<Dummy>>;
+// Command
+pub type CommandEncoderId = CommandBufferId;
+pub type CommandBufferId = Id<crate::command::CommandBuffer<Dummy>>;
+pub type RenderPassEncoderId = *mut crate::command::RenderPass;
+pub type ComputePassEncoderId = *mut crate::command::ComputePass;
+pub type RenderBundleEncoderId = *mut crate::command::RenderBundleEncoder;
+pub type RenderBundleId = Id<crate::command::RenderBundle>;
+// Swap chain
+pub type SwapChainId = Id<crate::swap_chain::SwapChain<Dummy>>;
+
+impl SurfaceId {
+    pub(crate) fn to_swap_chain_id(self, backend: Backend) -> SwapChainId {
+        let (index, epoch, _) = self.unzip();
+        Id::zip(index, epoch, backend)
+    }
+}
+impl SwapChainId {
+    pub fn to_surface_id(self) -> SurfaceId {
+        let (index, epoch, _) = self.unzip();
+        Id::zip(index, epoch, Backend::Empty)
+    }
+}
+
+#[test]
+fn test_id_backend() {
+    for &b in &[
+        Backend::Empty,
+        Backend::Vulkan,
+        Backend::Metal,
+        Backend::Dx12,
+        Backend::Dx11,
+        Backend::Gl,
+    ] {
+        let id: Id<()> = Id::zip(1, 0, b);
+        assert_eq!(id.backend(), b);
+    }
+}