Expose setting intput/getting output tensors on the model (#106)

Expose setting input/getting output tensors by index

Author: pnehrer

crates/openvino/src/request.rs

@@ -1,9 +1,10 @@
 use crate::tensor::Tensor;
 use crate::{cstr, drop_using_function, try_unsafe, util::Result};
 use openvino_sys::{
-    ov_infer_request_free, ov_infer_request_get_tensor, ov_infer_request_infer,
-    ov_infer_request_set_tensor, ov_infer_request_start_async, ov_infer_request_t,
-    ov_infer_request_wait_for,
+    ov_infer_request_free, ov_infer_request_get_output_tensor_by_index,
+    ov_infer_request_get_tensor, ov_infer_request_infer,
+    ov_infer_request_set_input_tensor_by_index, ov_infer_request_set_tensor,
+    ov_infer_request_start_async, ov_infer_request_t, ov_infer_request_wait_for,
 };
 
 /// See [`InferRequest`](https://docs.openvino.ai/2023.3/api/c_cpp_api/group__ov__infer__request__c__api.html).
@@ -20,6 +21,7 @@ impl InferRequest {
     pub(crate) fn from_ptr(ptr: *mut ov_infer_request_t) -> Self {
         Self { ptr }
     }
+
     /// Assign a [`Tensor`] to the input on the model.
     pub fn set_tensor(&mut self, name: &str, tensor: &Tensor) -> Result<()> {
         try_unsafe!(ov_infer_request_set_tensor(
@@ -41,6 +43,27 @@ impl InferRequest {
         Ok(Tensor::from_ptr(tensor))
     }
 
+    /// Assing an input [`Tensor`] to the model by its index.
+    pub fn set_input_tensor_by_index(&mut self, index: usize, tensor: &Tensor) -> Result<()> {
+        try_unsafe!(ov_infer_request_set_input_tensor_by_index(
+            self.ptr,
+            index,
+            tensor.as_ptr()
+        ))?;
+        Ok(())
+    }
+
+    /// Retrieve an output [`Tensor`] from the model by its index.
+    pub fn get_output_tensor_by_index(&self, index: usize) -> Result<Tensor> {
+        let mut tensor = std::ptr::null_mut();
+        try_unsafe!(ov_infer_request_get_output_tensor_by_index(
+            self.ptr,
+            index,
+            std::ptr::addr_of_mut!(tensor)
+        ))?;
+        Ok(Tensor::from_ptr(tensor))
+    }
+
     /// Execute the inference request.
     pub fn infer(&mut self) -> Result<()> {
         try_unsafe!(ov_infer_request_infer(self.ptr))