1use jrsonnet_evaluator::{2 error::{Error, LocError},3 native::{NativeCallback, NativeCallbackHandler},4 EvaluationState, Val,5};6use jrsonnet_gc::{unsafe_empty_trace, Finalize, Gc, Trace};7use jrsonnet_parser::{Param, ParamsDesc};8use std::{9 ffi::{c_void, CStr},10 os::raw::{c_char, c_int},11 path::Path,12 rc::Rc,13};1415type JsonnetNativeCallback = unsafe extern "C" fn(16 ctx: *const c_void,17 argv: *const *const Val,18 success: *mut c_int,19) -> *mut Val;2021struct JsonnetNativeCallbackHandler {22 ctx: *const c_void,23 cb: JsonnetNativeCallback,24}25impl Finalize for JsonnetNativeCallbackHandler {}26unsafe impl Trace for JsonnetNativeCallbackHandler {27 unsafe_empty_trace!();28}29impl NativeCallbackHandler for JsonnetNativeCallbackHandler {30 fn call(&self, _from: Option<Rc<Path>>, args: &[Val]) -> Result<Val, LocError> {31 let mut n_args = Vec::new();32 for a in args {33 n_args.push(Some(Box::new(a.clone())));34 }35 n_args.push(None);36 let mut success = 1;37 let v = unsafe {38 (self.cb)(39 self.ctx,40 &n_args as *const _ as *const *const Val,41 &mut success,42 )43 };44 let v = unsafe { *Box::from_raw(v) };45 if success == 1 {46 Ok(v)47 } else {48 let e = v.try_cast_str("native error").expect("error msg");49 Err(Error::RuntimeError(e).into())50 }51 }52}535455#[no_mangle]56pub unsafe extern "C" fn jsonnet_native_callback(57 vm: &EvaluationState,58 name: *const c_char,59 cb: JsonnetNativeCallback,60 ctx: *const c_void,61 mut raw_params: *const *const c_char,62) {63 let name = CStr::from_ptr(name).to_str().expect("utf8 name").into();64 let mut params = Vec::new();65 loop {66 if (*raw_params).is_null() {67 break;68 }69 let param = CStr::from_ptr(*raw_params).to_str().expect("not utf8");70 params.push(Param(param.into(), None));71 raw_params = raw_params.offset(1);72 }73 let params = ParamsDesc(Rc::new(params));7475 vm.add_native(76 name,77 Gc::new(NativeCallback::new(78 params,79 Box::new(JsonnetNativeCallbackHandler { ctx, cb }),80 )),81 )82}