webgpu: Divide message code into separate files (#32700)

* Spilt webgpu ipc messages even more

* Add license to mod.rs

* file docs

components/webgpu/ipc_messages/to_dom.rs

@@ -0,0 +1,78 @@
+/* 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 https://mozilla.org/MPL/2.0/. */
+
+//! IPC messages that are send to WebGPU DOM objects.
+
+use ipc_channel::ipc::IpcSharedMemory;
+use serde::{Deserialize, Serialize};
+use wgc::pipeline::CreateShaderModuleError;
+pub use {wgpu_core as wgc, wgpu_types as wgt};
+
+use crate::identity::*;
+use crate::{Error, PopError, WebGPU};
+
+#[derive(Clone, Debug, Default, Deserialize, Serialize)]
+pub struct ShaderCompilationInfo {
+    pub line_number: u64,
+    pub line_pos: u64,
+    pub offset: u64,
+    pub length: u64,
+    pub message: String,
+}
+
+impl ShaderCompilationInfo {
+    pub fn from(error: &CreateShaderModuleError, source: &str) -> Self {
+        let location = match error {
+            CreateShaderModuleError::Parsing(e) => e.inner.location(source),
+            CreateShaderModuleError::Validation(e) => e.inner.location(source),
+            _ => None,
+        };
+
+        if let Some(location) = location {
+            // Naga reports locations in UTF-8 code units, but spec requires location in UTF-16 code units
+            // Based on https://searchfox.org/mozilla-central/rev/5b037d9c6ecdb0729f39ad519f0b867d80a92aad/gfx/wgpu_bindings/src/server.rs#353
+            fn len_utf16(s: &str) -> u64 {
+                s.chars().map(|c| c.len_utf16() as u64).sum()
+            }
+            let start = location.offset as usize;
+            let end = start + location.length as usize;
+            let line_start = source[0..start].rfind('\n').map(|pos| pos + 1).unwrap_or(0);
+            Self {
+                line_number: location.line_number as u64,
+                line_pos: len_utf16(&source[line_start..start]) + 1,
+                offset: len_utf16(&source[0..start]),
+                length: len_utf16(&source[start..end]),
+                message: error.to_string(),
+            }
+        } else {
+            Self {
+                message: error.to_string(),
+                ..Default::default()
+            }
+        }
+    }
+}
+
+#[derive(Debug, Deserialize, Serialize)]
+#[allow(clippy::large_enum_variant)]
+pub enum WebGPUResponse {
+    RequestAdapter {
+        adapter_info: wgt::AdapterInfo,
+        adapter_id: WebGPUAdapter,
+        features: wgt::Features,
+        limits: wgt::Limits,
+        channel: WebGPU,
+    },
+    RequestDevice {
+        device_id: WebGPUDevice,
+        queue_id: WebGPUQueue,
+        descriptor: wgt::DeviceDescriptor<Option<String>>,
+    },
+    BufferMapAsync(IpcSharedMemory),
+    SubmittedWorkDone,
+    PoppedErrorScope(Result<Option<Error>, PopError>),
+    CompilationInfo(Option<ShaderCompilationInfo>),
+}
+
+pub type WebGPUResponseResult = Result<WebGPUResponse, String>;