Group "pointer to struct" and "struct to pointer" functions

bindings/java/rs_src/limbo_connection.rs

@@ -0,0 +1,135 @@
+use crate::errors::{
+    LimboError, Result, LIMBO_ETC, LIMBO_FAILED_TO_PARSE_BYTE_ARRAY,
+    LIMBO_FAILED_TO_PREPARE_STATEMENT,
+};
+use crate::limbo_statement::CoreStatement;
+use crate::utils::utf8_byte_arr_to_str;
+use jni::objects::{JByteArray, JClass, JObject};
+use jni::sys::jlong;
+use jni::JNIEnv;
+use std::rc::Rc;
+
+#[allow(dead_code)]
+#[derive(Clone)]
+pub struct LimboConnection {
+    pub(crate) conn: Rc<limbo_core::Connection>,
+    pub(crate) io: Rc<dyn limbo_core::IO>,
+}
+
+impl LimboConnection {
+    pub fn to_ptr(self) -> jlong {
+        Box::into_raw(Box::new(self)) as jlong
+    }
+
+    #[allow(dead_code)]
+    pub fn drop(ptr: jlong) {
+        let _boxed = unsafe { Box::from_raw(ptr as *mut LimboConnection) };
+    }
+}
+
+pub fn to_limbo_connection(ptr: jlong) -> Result<&'static mut LimboConnection> {
+    if ptr == 0 {
+        Err(LimboError::InvalidConnectionPointer)
+    } else {
+        unsafe { Ok(&mut *(ptr as *mut LimboConnection)) }
+    }
+}
+
+/// Returns a pointer to a `Cursor` object.
+///
+/// The Java application will pass this pointer to native functions,
+/// which will use it to reference the `Cursor` object.
+///
+/// # Arguments
+///
+/// * `_env` - The JNI environment pointer.
+/// * `_class` - The Java class calling this function.
+/// * `connection_ptr` - A pointer to the `Connection` object.
+///
+/// # Returns
+///
+/// A `jlong` representing the pointer to the newly created `Cursor` object.
+#[no_mangle]
+pub extern "system" fn Java_org_github_tursodatabase_core_LimboConnection_prepareUtf8<'local>(
+    mut env: JNIEnv<'local>,
+    obj: JObject<'local>,
+    connection_ptr: jlong,
+    sql_bytes: JByteArray<'local>,
+) -> jlong {
+    let connection = match to_limbo_connection(connection_ptr) {
+        Ok(conn) => conn,
+        Err(e) => {
+            set_err_msg_and_throw_exception(&mut env, obj, LIMBO_ETC, e.to_string());
+            return 0;
+        }
+    };
+
+    let sql = match utf8_byte_arr_to_str(&env, sql_bytes) {
+        Ok(sql) => sql,
+        Err(e) => {
+            set_err_msg_and_throw_exception(
+                &mut env,
+                obj,
+                LIMBO_FAILED_TO_PARSE_BYTE_ARRAY,
+                e.to_string(),
+            );
+            return 0;
+        }
+    };
+
+    match connection.conn.prepare(sql) {
+        Ok(stmt) => CoreStatement::new(stmt).to_ptr(),
+        Err(e) => {
+            set_err_msg_and_throw_exception(
+                &mut env,
+                obj,
+                LIMBO_FAILED_TO_PREPARE_STATEMENT,
+                e.to_string(),
+            );
+            0
+        }
+    }
+}
+
+/// Closes the connection and releases the associated resources.
+///
+/// This function is called from the Java side to close the connection
+/// and free the memory allocated for the `Connection` object.
+///
+/// # Arguments
+///
+/// * `_env` - The JNI environment pointer.
+/// * `_class` - The Java class calling this function.
+/// * `connection_ptr` - A pointer to the `Connection` object to be closed.
+#[no_mangle]
+pub unsafe extern "system" fn Java_org_github_tursodatabase_limbo_Connection_close<'local>(
+    _env: JNIEnv<'local>,
+    _class: JClass<'local>,
+    connection_ptr: jlong,
+) {
+    LimboConnection::drop(connection_ptr);
+}
+
+fn set_err_msg_and_throw_exception<'local>(
+    env: &mut JNIEnv<'local>,
+    obj: JObject<'local>,
+    err_code: i32,
+    err_msg: String,
+) {
+    let error_message_bytes = env
+        .byte_array_from_slice(err_msg.as_bytes())
+        .expect("Failed to convert to byte array");
+    match env.call_method(
+        obj,
+        "throwLimboException",
+        "(I[B)V",
+        &[err_code.into(), (&error_message_bytes).into()],
+    ) {
+        Ok(_) => {
+            // do nothing because above method will always return Err
+        }
+        Err(_e) => {
+            // do nothing because our java app will handle Err
+        }
+    }
+}