Add resource management functions to runtime #22
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This commit extends the V8 JavaScript runtime with built-in resource functions that provide sandboxed file system access within JavaScript code. Features: - resource.read(uri): Read file contents - resource.list(uri): List directory contents - resource.write(uri, content): Write to files - resource.delete(uri): Delete files or directories Implementation details: - New ResourceStorage trait with FileResourceStorage implementation - V8 function callbacks bridge JavaScript to Rust async operations - Path traversal protection and directory sandboxing - Configurable resource directory via --resource-directory CLI flag - Default resource directory: /tmp/mcp-v8-resources Changes: - server/src/mcp/resource_storage.rs: New module implementing resource storage - server/src/mcp.rs: Added V8 callbacks and integrated into execution context - server/src/main.rs: Added CLI argument and wired resource storage to services - README.md: Documented new resource functions and updated limitations All resource operations are sandboxed to prevent unauthorized file access.
Tests cover: - resource.write() and resource.read() basic operations - resource.list() for directory listing - resource.delete() for file deletion - Nested directory creation and access - Error handling for non-existent files/directories - file:// URI scheme support - Complex JSON operations with resource functions Also adds: - common.rs test utilities module - StdioServer::start_with_resources() helper method - Temporary directory creation for resource storage
- Use v8::Context::new() instead of non-existent new_from_template() - Remove unused Path import from resource_storage.rs - Remove unused FileResourceStorage import from mcp.rs
Use v8::ContextOptions struct with global_template field instead of passing the template directly to v8::Context::new()
Fixes: - Added resource test functions to correct location (server/tests/) - Added start_with_resources() helper to StdioServer - Added create_temp_resource_dir() and cleanup_resource_dir() to common module - Removed incorrectly placed test files in wrong directory Tests added (8 comprehensive test cases): - test_stdio_resource_write_and_read: Basic read/write operations - test_stdio_resource_list: Directory listing functionality - test_stdio_resource_delete: File deletion - test_stdio_resource_nested_directories: Nested directory handling - test_stdio_resource_error_handling: Error cases validation - test_stdio_resource_file_uri_scheme: URI scheme support - test_stdio_resource_json_operations: Complex JSON workflows All tests properly create isolated temp directories for resource storage.
Capture tokio runtime handle before entering spawn_blocking context in both StatelessService and StatefulService. This prevents EOF errors that occur when trying to access Handle::current() from within blocking threads where the runtime context is not available. The runtime handle is now passed as a parameter to execute_stateless() and execute_stateful() functions, ensuring async resource operations can be bridged correctly from V8 callbacks.
Changed ResourceStorage trait and implementation from async to sync using std::fs instead of tokio::fs. This eliminates the need for block_on() calls from V8 callbacks, which was causing deadlocks in stdio transport. V8 callbacks are inherently synchronous, so using blocking I/O is appropriate and avoids the complexity and pitfalls of bridging async/sync contexts within the tokio runtime. Changes: - Removed async_trait and async/await from ResourceStorage trait - Updated FileResourceStorage to use std::fs instead of tokio::fs - Removed runtime_handle from IsolateData struct - Updated V8 callbacks to call storage methods directly - Simplified execute_stateless and execute_stateful function signatures
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This commit extends the V8 JavaScript runtime with built-in resource functions that provide sandboxed file system access within JavaScript code.
Features:
Implementation details:
Changes:
All resource operations are sandboxed to prevent unauthorized file access.