fix: stabilize web loading and paper rendering

crates/ocs_web_worker/Cargo.toml

@@ -10,6 +10,7 @@ crate-type = ["cdylib"]
 [dependencies]
 acadrust = { version = "0.4", features = ["serde"] }
 bincode = "1.3"
+console_error_panic_hook = "0.1"
 getrandom = { version = "0.3", features = ["wasm_js"] }
 js-sys = "0.3"
 wasm-bindgen = "0.2"

crates/ocs_web_worker/src/lib.rs

@@ -2,15 +2,22 @@ use std::io::Cursor;
 
 use acadrust::io::dwg::DwgReader;
 use acadrust::DxfReader;
-use js_sys::Uint8Array;
+use js_sys::{Function, Uint8Array};
 use wasm_bindgen::prelude::*;
 
 /// Parse DWG/DXF on a dedicated browser worker and return a compact serialized
 /// document. The main wasm instance only deserializes and installs it, so the
 /// expensive bit/handle/object decode never occupies the browser UI thread.
 #[wasm_bindgen]
-pub fn parse_document(name: String, bytes: Uint8Array) -> Result<Uint8Array, JsValue> {
+pub fn parse_document(
+    name: String,
+    bytes: Uint8Array,
+    report_stage: &Function,
+) -> Result<Uint8Array, JsValue> {
+    console_error_panic_hook::set_once();
+    report_stage.call1(&JsValue::NULL, &JsValue::from_str("copy input"))?;
     let bytes = bytes.to_vec();
+    report_stage.call1(&JsValue::NULL, &JsValue::from_str("parse document"))?;
     let ext = name.rsplit('.').next().unwrap_or_default().to_lowercase();
     let document = match ext.as_str() {
         "dwg" => DwgReader::from_stream(Cursor::new(bytes))
@@ -26,7 +33,9 @@ pub fn parse_document(name: String, bytes: Uint8Array) -> Result<Uint8Array, JsV
             )))
         }
     };
+    report_stage.call1(&JsValue::NULL, &JsValue::from_str("serialize document"))?;
     let encoded =
         bincode::serialize(&document).map_err(|error| JsValue::from_str(&error.to_string()))?;
+    report_stage.call1(&JsValue::NULL, &JsValue::from_str("copy output"))?;
     Ok(Uint8Array::from(encoded.as_slice()))
 }