feat(jni): implement JNI object registry and string memory management

crates/molotov-core/src/jni/mod.rs

@@ -1,4 +1,5 @@
 // SPDX-License-Identifier: GPL-3.0-or-later
 pub mod env;
+pub mod objects;
 pub mod types;
 pub mod vm;

crates/molotov-core/src/jni/objects.rs

@@ -0,0 +1,64 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+#![allow(dead_code)]
+use std::collections::HashMap;
+use std::ffi::{CStr, CString};
+
+#[derive(Debug, Clone)]
+pub enum JniObject {
+    Class(String),
+    String(String, CString),
+    Instance { class_name: String },
+}
+
+pub struct JniObjectRegistry {
+    objects: HashMap<usize, JniObject>,
+    next_handle: usize,
+}
+
+impl Default for JniObjectRegistry {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl JniObjectRegistry {
+    pub fn new() -> Self {
+        Self {
+            objects: HashMap::new(),
+            next_handle: 1000,
+        }
+    }
+
+    pub fn alloc_class(&mut self, class_name: &str) -> usize {
+        let handle = self.next_handle;
+        self.next_handle += 1;
+        self.objects.insert(handle, JniObject::Class(class_name.to_string()));
+        handle
+    }
+
+    pub fn alloc_string(&mut self, text: &str) -> usize {
+        let handle = self.next_handle;
+        self.next_handle += 1;
+        let c_str = CString::new(text).unwrap_or_default();
+        self.objects.insert(handle, JniObject::String(text.to_string(), c_str));
+        handle
+    }
+
+    pub fn get_string(&self, handle: usize) -> Option<&str> {
+        match self.objects.get(&handle) {
+            Some(JniObject::String(text, _)) => Some(text.as_str()),
+            _ => None,
+        }
+    }
+
+    pub fn get_string_c_str(&self, handle: usize) -> Option<&CStr> {
+        match self.objects.get(&handle) {
+            Some(JniObject::String(_, c_str)) => Some(c_str.as_c_str()),
+            _ => None,
+        }
+    }
+
+    pub fn release_object(&mut self, handle: usize) -> bool {
+        self.objects.remove(&handle).is_some()
+    }
+}

crates/molotov-core/tests/jni_objects_test.rs

@@ -0,0 +1,12 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+use molotov_core::jni::objects::JniObjectRegistry;
+
+#[test]
+fn test_jni_string_allocation_and_read() {
+    let mut registry = JniObjectRegistry::new();
+    let str_handle = registry.alloc_string("hello_roblox");
+
+    assert_eq!(registry.get_string(str_handle), Some("hello_roblox"));
+    registry.release_object(str_handle);
+    assert_eq!(registry.get_string(str_handle), None);
+}