Use Binary Archives as a pipeline cache on the metal backend (#3719)

* First draft of a pipeline cache for metal using binary archives!

* Load pipeline caches from disk!

* Clean up quad example a little bit

* Add warning to merge_pipeline_caches

* Handle empty data inputs to create_pipeline_cache

* Tested that pipeline caching does indeed work!

* Do the same for compute pipelines

* Make the binary archive optional based on features

* Don't use a Mutex for the BinaryArchive.

* Add a spv->msl cache

* Switch to git patches

* Serialize/Deserialize both caches

* use a spv->msl cache for naga instead.

* Use a git patch for naga instead of a path

* Apply some suggestions

* Make a lot of things dependent on a pipeline-cache feature

* Update naga

* Use latest naga on the gl and vulkan backends

* Apply suggestions wrt u8s

* Move pipeline cache stuff to its own module

* Switch to naga gfx-22

examples/quad/main.rs

@@ -180,6 +180,7 @@ struct Renderer<B: hal::Backend> {
     framebuffer: ManuallyDrop<B::Framebuffer>,
     pipeline: ManuallyDrop<B::GraphicsPipeline>,
     pipeline_layout: ManuallyDrop<B::PipelineLayout>,
+    pipeline_cache: ManuallyDrop<B::PipelineCache>,
     desc_set: Option<B::DescriptorSet>,
     set_layout: ManuallyDrop<B::DescriptorSetLayout>,
     submission_complete_semaphores: Vec<B::Semaphore>,
@@ -707,6 +708,25 @@ where
             cmd_buffers.push(unsafe { cmd_pools[i].allocate_one(command::Level::Primary) });
         }
 
+        let pipeline_cache_path = "quad_pipeline_cache";
+
+        let previous_pipeline_cache_data = std::fs::read(pipeline_cache_path);
+
+        if let Err(error) = previous_pipeline_cache_data.as_ref() {
+            println!("Error loading the previous pipeline cache data: {}", error);
+        }
+
+        let pipeline_cache = ManuallyDrop::new(unsafe {
+            device
+                .create_pipeline_cache(
+                    previous_pipeline_cache_data
+                        .as_ref()
+                        .ok()
+                        .map(|vec| &vec[..]),
+                )
+                .expect("Can't create pipeline cache")
+        });
+
         let pipeline_layout = ManuallyDrop::new(
             unsafe { device.create_pipeline_layout(iter::once(&*set_layout), iter::empty()) }
                 .expect("Can't create pipeline layout"),
@@ -793,7 +813,7 @@ where
                     blend: Some(pso::BlendState::ALPHA),
                 });
 
-                unsafe { device.create_graphics_pipeline(&pipeline_desc, None) }
+                unsafe { device.create_graphics_pipeline(&pipeline_desc, Some(&pipeline_cache)) }
             };
 
             unsafe {
@@ -806,6 +826,16 @@ where
             ManuallyDrop::new(pipeline.unwrap())
         };
 
+        let pipeline_cache_data =
+            unsafe { device.get_pipeline_cache_data(&pipeline_cache).unwrap() };
+
+        std::fs::write(pipeline_cache_path, &pipeline_cache_data).unwrap();
+        log::info!(
+            "Wrote the pipeline cache to {} ({} bytes)",
+            pipeline_cache_path,
+            pipeline_cache_data.len()
+        );
+
         // Rendering setup
         let viewport = pso::Viewport {
             rect: pso::Rect {
@@ -831,6 +861,7 @@ where
             framebuffer,
             pipeline,
             pipeline_layout,
+            pipeline_cache,
             desc_set: Some(desc_set),
             set_layout,
             submission_complete_semaphores,
@@ -1029,6 +1060,8 @@ where
                 .destroy_pipeline_layout(ManuallyDrop::into_inner(ptr::read(
                     &self.pipeline_layout,
                 )));
+            self.device
+                .destroy_pipeline_cache(ManuallyDrop::into_inner(ptr::read(&self.pipeline_cache)));
             let surface = ManuallyDrop::into_inner(ptr::read(&self.surface));
             self.instance.destroy_surface(surface);
         }

src/backend/gl/Cargo.toml

@@ -47,7 +47,7 @@ optional = true
 
 [dependencies.naga]
 git = "https://github.com/gfx-rs/naga"
-tag = "gfx-21"
+tag = "gfx-22"
 features = ["spv-in", "glsl-out"]
 
 [target.'cfg(target_arch = "wasm32")'.dependencies]

src/backend/metal/Cargo.toml

@@ -16,6 +16,7 @@ edition = "2018"
 default = []
 signpost = []
 cross = ["spirv_cross", "auxil", "naga/spv-out"]
+pipeline-cache = ["tempfile", "serde", "bincode", "naga/serialize", "naga/deserialize", "naga/spv-out"]
 
 [lib]
 name = "gfx_backend_metal"
@@ -29,7 +30,7 @@ copyless = "0.1.4"
 fxhash = "0.2.1"
 log = { version = "0.4" }
 dispatch = { version = "0.2", optional = true }
-metal = { git = "https://github.com/gfx-rs/metal-rs", rev="439c986eb7a9b91e88b61def2daa66e4043fcbef", features = ["private"] }
+metal = { git = "https://github.com/gfx-rs/metal-rs", rev="78f632d194c7c16d18b71d7373c4080847d110b0", features = ["private"] }
 foreign-types = "0.3"
 objc = "0.2.5"
 block = "0.1"
@@ -38,6 +39,9 @@ parking_lot = "0.11"
 storage-map = "0.3"
 raw-window-handle = "0.3"
 profiling = { version = "0.1.10", default-features = false }
+tempfile = { version = "3.2", optional = true }
+serde = { version = "1", features = ["serde_derive"], optional = true }
+bincode = { version = "1", optional = true }
 
 [dependencies.auxil]
 package = "gfx-auxil"
@@ -53,7 +57,7 @@ optional = true
 
 [dependencies.naga]
 git = "https://github.com/gfx-rs/naga"
-tag = "gfx-21"
+tag = "gfx-22"
 features = ["spv-in", "msl-out"]
 
 # This forces docs.rs to build the crate on mac, otherwise the build fails