fix(tract): support external data

closes #543

backends/tract/api.rs

@@ -2,7 +2,9 @@
 
 use std::{
 	ffi::{CStr, CString, OsString},
-	fs, ptr
+	fs,
+	path::Path,
+	ptr
 };
 
 use ort_sys::*;
@@ -71,12 +73,12 @@ unsafe extern "system" fn CreateSession(
 	#[cfg(not(target_os = "windows"))]
 	let path = OsString::from_encoded_bytes_unchecked(path.iter().map(|c| *c as u8).collect::<Vec<_>>());
 
-	let buf = match fs::read(path) {
+	let buf = match fs::read(&path) {
 		Ok(buf) => buf,
 		Err(e) => return Error::new_sys(OrtErrorCode::ORT_NO_SUCHFILE, format!("Failed to read model file: {e}"))
 	};
 
-	match Session::from_buffer(env, options, &buf) {
+	match Session::from_buffer(env, options, &buf, Some(Path::new(&path))) {
 		Ok(session) => {
 			*out = (Box::leak(Box::new(session)) as *mut Session).cast();
 			OrtStatusPtr::default()
@@ -97,7 +99,7 @@ unsafe extern "system" fn CreateSessionFromArray(
 
 	let buf = std::slice::from_raw_parts(model_data.cast::<u8>(), model_data_length);
 
-	match Session::from_buffer(env, options, buf) {
+	match Session::from_buffer(env, options, buf, None) {
 		Ok(session) => {
 			*out = (Box::leak(Box::new(session)) as *mut Session).cast();
 			OrtStatusPtr::default()

backends/tract/session.rs

@@ -1,13 +1,15 @@
 use std::{
 	collections::{HashMap, hash_map::Entry},
 	hash::{BuildHasher, DefaultHasher, Hasher},
+	path::Path,
 	sync::Arc
 };
 
 use parking_lot::Mutex;
 use tract_onnx::{
+	model::ParseResult,
 	pb::ValueInfoProto,
-	prelude::{Framework, Graph, InferenceModelExt, IntoTensor, SimplePlan, Tensor, TractResult, TypedFact, TypedOp}
+	prelude::{Framework, Graph, InferenceModelExt, IntoTensor, SimplePlan, Tensor, TractError, TractResult, TypedFact, TypedOp}
 };
 
 use crate::Environment;
@@ -54,12 +56,15 @@ pub struct Session {
 }
 
 impl Session {
-	pub fn from_buffer(env: &Environment, options: &SessionOptions, mut data: &[u8]) -> TractResult<Session> {
+	pub fn from_buffer(env: &Environment, options: &SessionOptions, mut data: &[u8], path: Option<&Path>) -> TractResult<Session> {
 		let proto_model = env.onnx.proto_model_for_read(&mut data)?;
 		let inputs = proto_model.graph.as_ref().map(|graph| graph.input.clone()).unwrap_or_default();
 		let outputs = proto_model.graph.as_ref().map(|graph| graph.output.clone()).unwrap_or_default();
 
-		let model = env.onnx.model_for_proto_model(&proto_model)?;
+		let ParseResult { model, unresolved_inputs, .. } = env.onnx.parse(&proto_model, path.and_then(|p| p.parent()).and_then(|p| p.to_str()))?;
+		if unresolved_inputs.len() > 0 {
+			return Err(TractError::msg("failed to resolve some inputs"));
+		}
 		let graph = Arc::new(if options.perform_optimizations { model.into_optimized()? } else { model.into_typed()? });
 		Ok(Session {
 			inputs,

backends/tract/standalone/lib.rs

@@ -12,7 +12,7 @@ unsafe extern "system" fn get_api(version: u32) -> *const ort_sys::OrtApi {
 	if version <= ort_sys::ORT_API_VERSION { &API as *const _ } else { core::ptr::null() }
 }
 
-#[no_mangle]
+#[unsafe(no_mangle)]
 pub unsafe extern "C" fn OrtGetApiBase() -> *const ort_sys::OrtApiBase {
 	&API_BASE as *const _
 }