Bug 1704235 - Cache and share shader program name. r=jnicol,gfx-reviewers

This computes the shader's name only once and then stores it inside an Rc so
that we can pass it around by reference outside of the Program, rather than
always having to reallocate or copy it.

Differential Revision: https://phabricator.services.mozilla.com/D111524

gfx/wr/webrender/src/device/gl.rs

@@ -662,6 +662,7 @@ enum ProgramSourceType {
 pub struct ProgramSourceInfo {
     base_filename: &'static str,
     features: Vec<&'static str>,
+    full_name: Rc<String>,
     source_type: ProgramSourceType,
     digest: ProgramSourceDigest,
 }
@@ -686,11 +687,11 @@ impl ProgramSourceInfo {
         // Hash the renderer name.
         hasher.write(device.capabilities.renderer_name.as_bytes());
 
-        let full_name = &Self::make_full_name(name, features);
+        let full_name = Rc::new(Self::make_full_name(name, features));
 
         let optimized_source = if device.use_optimized_shaders {
-            OPTIMIZED_SHADERS.get(&(gl_version, full_name)).or_else(|| {
-                warn!("Missing optimized shader source for {}", full_name);
+            OPTIMIZED_SHADERS.get(&(gl_version, &full_name)).or_else(|| {
+                warn!("Missing optimized shader source for {}", &full_name);
                 None
             })
         } else {
@@ -762,6 +763,7 @@ impl ProgramSourceInfo {
         ProgramSourceInfo {
             base_filename: name,
             features: features.to_vec(),
+            full_name,
             source_type,
             digest: hasher.into(),
         }
@@ -801,8 +803,8 @@ impl ProgramSourceInfo {
         }
     }
 
-    fn full_name(&self) -> String {
-        Self::make_full_name(self.base_filename, &self.features)
+    fn full_name(&self) -> &Rc<String> {
+        &self.full_name
     }
 }
 
@@ -1060,7 +1062,7 @@ pub struct Device {
     // device state
     bound_textures: [gl::GLuint; 16],
     bound_program: gl::GLuint,
-    bound_program_name: String,
+    bound_program_name: Rc<String>,
     bound_vao: gl::GLuint,
     bound_read_fbo: (FBOId, DeviceIntPoint),
     bound_draw_fbo: FBOId,
@@ -1762,7 +1764,7 @@ impl Device {
 
             bound_textures: [0; 16],
             bound_program: 0,
-            bound_program_name: String::new(),
+            bound_program_name: Rc::new(String::new()),
             bound_vao: 0,
             bound_read_fbo: (FBOId(0), DeviceIntPoint::zero()),
             bound_draw_fbo: FBOId(0),
@@ -2383,7 +2385,7 @@ impl Device {
         if self.bound_program != program.id {
             self.gl.use_program(program.id);
             self.bound_program = program.id;
-            self.bound_program_name = program.source_info.full_name();
+            self.bound_program_name = program.source_info.full_name().clone();
             self.program_mode_id = UniformLocation(program.u_mode);
         }
         true