Overview

Overview

Refactored model loading functionality and added WASM environment support.

Key improvement: Changed load_model signature from accepting &Path to &str, enabling URI-based model loading with support for http://, https://, and file:// schemes. This makes the API more flexible and enables remote model loading from web servers.

Additional improvements include reduced code duplication, improved error handling, and full WASM environment compatibility for HTTP/HTTPS-based model loading.

Main Changes

1. Model Loading Refactoring

• Extracted common parsing logic: Added parse_model_content helper method to eliminate code duplication between load_model_from_file and load_model_from_url (approximately 33% code reduction)
• Improved error handling: Replaced all unwrap() calls with proper error propagation (? operator, map_err), and added detailed error messages with line numbers
• Fixed Clippy warnings:
  • Changed unnecessary format!("{}", e) to e.to_string()
  • Changed std::io::Error::new(ErrorKind::Other, ...) to std::io::Error::other(...)

2. WASM Environment Support

• Added conditional compilation: Implemented proper branching using cfg(target_arch = "wasm32")
• Restricted file:// scheme and local paths: Returns appropriate error messages in WASM environments
• Optimized dependencies: Excluded rayon, tokio, tempfile, and tokio-test from WASM builds

3. Code Organization Improvements

• Separated ModelScheme enum: Moved from adaboost.rs to util.rs to clarify module responsibilities
• Optimized Tokio features: Removed unused time, sync, and io-util features, keeping only the necessary rt-multi-thread and macros

4. Test and Documentation Fixes

• Fixed doctests: Updated to handle async function calls (using tokio_test::block_on)
• Added dependencies: Added tokio-test to dev-dependencies

WASM Environment Behavior

✅ Supported Features

• Model loading from https:// URLs
• Model loading from http:// URLs

❌ Unsupported Features (returns appropriate error messages)

• file:// scheme
• Local file paths

⚠️ CORS Restrictions

When loading models from different origins in WASM environments (browsers), CORS headers must be configured on the server side:

Access-Control-Allow-Origin: *
Access-Control-Allow-Methods: GET

Note: This restriction is a browser security specification and cannot be circumvented on the client side (Litsea).