[onert/python] Support static shape modification across inference API (#15184)

This commit supports static shape modification across inference API and samples.
- common/basesession.py: add typed get_inputs_tensorinfo/get_outputs_tensorinfo helpers
- infer/session.py:
  - normalize any `-1` dims to `1` then call `update_inputs_tensorinfo` in `__init__`
  - remove obsolete `compile()` method
  - provide `update_inputs_tensorinfo` and `run_inference` with full type hints
- samples:
  - minimal sample: build dummy inputs from tensorinfo and use `run_inference`
  - static_shape_inference example: demonstrate modifying input tensorinfo (e.g. batch size → 10) and running inference with static shapes

ONE-DCO-1.0-Signed-off-by: ragmani <ragmani0216@gmail.com>

Author: ragmani

runtime/onert/api/python/package/common/basesession.py

@@ -1,6 +1,7 @@
+from typing import List
 import numpy as np
 
-from ..native import libnnfw_api_pybind
+from ..native.libnnfw_api_pybind import infer, tensorinfo
 
 
 def num_elems(tensor_info):
@@ -52,6 +53,32 @@ def _recreate_session(self, backend_session):
             del self.session  # Clean up the existing session
         self.session = backend_session
 
+    def get_inputs_tensorinfo(self) -> List[tensorinfo]:
+        """
+        Retrieve tensorinfo for all input tensors.
+
+        Returns:
+            list[tensorinfo]: A list of tensorinfo objects for each input.
+        """
+        num_inputs: int = self.session.input_size()
+        infos: List[tensorinfo] = []
+        for i in range(num_inputs):
+            infos.append(self.session.input_tensorinfo(i))
+        return infos
+
+    def get_outputs_tensorinfo(self) -> List[tensorinfo]:
+        """
+        Retrieve tensorinfo for all output tensors.
+
+        Returns:
+            list[tensorinfo]: A list of tensorinfo objects for each output.
+        """
+        num_outputs: int = self.session.output_size()
+        infos: List[tensorinfo] = []
+        for i in range(num_outputs):
+            infos.append(self.session.output_tensorinfo(i))
+        return infos
+
     def set_inputs(self, size, inputs_array=[]):
         """
         Set the input tensors for the session.
@@ -97,4 +124,4 @@ def set_outputs(self, size):
 
 
 def tensorinfo():
-    return libnnfw_api_pybind.infer.nnfw_tensorinfo()
+    return infer.nnfw_tensorinfo()

runtime/onert/api/python/package/infer/session.py

@@ -1,46 +1,97 @@
-from ..native import libnnfw_api_pybind
+from typing import List, Any
+import numpy as np
+
+from ..native.libnnfw_api_pybind import infer, tensorinfo
 from ..common.basesession import BaseSession
 
 
 class session(BaseSession):
     """
     Class for inference using nnfw_session.
     """
-    def __init__(self, path: str = None, backends: str = "cpu"):
+    def __init__(self, path: str, backends: str = "cpu") -> None:
         """
         Initialize the inference session.
+
         Args:
             path (str): Path to the model file or nnpackage directory.
             backends (str): Backends to use, default is "cpu".
         """
-        if path is not None:
-            super().__init__(libnnfw_api_pybind.infer.nnfw_session(path, backends))
-            self.session.prepare()
-            self.set_outputs(self.session.output_size())
-        else:
-            super().__init__()
+        super().__init__(infer.nnfw_session(path, backends))
+        self._prepared: bool = False
+
+        # TODO: Revise this after discussion to properly support dynamic shapes
+        # This is a temporary workaround to prevent prepare() errors when tensorinfo dims include -1
+        original_infos: List[tensorinfo] = self.get_inputs_tensorinfo()
+        fixed_infos: List[tensorinfo] = []
+        for info in original_infos:
+            dims = list(info.dims)
+            # replace -1 with 1
+            dims = [1 if d == -1 else d for d in dims]
+            info.dims = dims  # assume setter accepts a list
+            fixed_infos.append(info)
+        # update tensorinfo in session
+        self.update_inputs_tensorinfo(fixed_infos)
 
-    def compile(self, path: str, backends: str = "cpu"):
+    def update_inputs_tensorinfo(self, new_infos: List[tensorinfo]) -> None:
         """
-        Prepare the session by recreating it with new parameters.
+        Update all input tensors' tensorinfo at once.
+
         Args:
-            path (str): Path to the model file or nnpackage directory. Defaults to the existing path.
-            backends (str): Backends to use. Defaults to the existing backends.
+            new_infos (list[tensorinfo]): A list of updated tensorinfo objects for the inputs.
+
+        Raises:
+            ValueError: If the number of new_infos does not match the session's input size,
+                        or if any tensorinfo contains a negative dimension.
         """
-        # Update parameters if provided
-        if path is None:
-            raise ValueError("path must not be None.")
-        # Recreate the session with updated parameters
-        self._recreate_session(libnnfw_api_pybind.infer.nnfw_session(path, backends))
-        # Prepare the new session
-        self.session.prepare()
-        self.set_outputs(self.session.output_size())
-
-    def inference(self):
+        num_inputs: int = self.session.input_size()
+        if len(new_infos) != num_inputs:
+            raise ValueError(
+                f"Expected {num_inputs} input tensorinfo(s), but got {len(new_infos)}.")
+
+        for i, info in enumerate(new_infos):
+            # Check for any negative dimension in the specified rank
+            if any(d < 0 for d in info.dims[:info.rank]):
+                raise ValueError(
+                    f"Input tensorinfo at index {i} contains negative dimension(s): "
+                    f"{info.dims[:info.rank]}")
+            self.session.set_input_tensorinfo(i, info)
+
+    def infer(self, inputs_array: List[np.ndarray]) -> List[np.ndarray]:
         """
-        Perform model and get outputs
+        Run a complete inference cycle:
+         - If the session has not been prepared or outputs have not been set, call prepare() and set_outputs().
+         - Automatically configure input buffers based on the provided numpy arrays.
+         - Execute the inference session.
+         - Return the output tensors with proper multi-dimensional shapes.
+
+        This method supports both static and dynamic shape modification:
+         - If update_inputs_tensorinfo() has been called before running inference, the model is compiled
+           with the fixed static input shape.
+         - Otherwise, the input shapes can be adjusted dynamically.
+
+        Args:
+            inputs_array (list[np.ndarray]): List of numpy arrays representing the input data.
+
         Returns:
-            list: Outputs from the model.
+            list[np.ndarray]: A list containing the output numpy arrays.
         """
+        # Check if the session is prepared. If not, call prepare() and set_outputs() once.
+        if not self._prepared:
+            self.session.prepare()
+            self.set_outputs(self.session.output_size())
+            self._prepared = True
+
+        # Verify that the number of provided inputs matches the session's expected input count.
+        expected_input_size: int = self.session.input_size()
+        if len(inputs_array) != expected_input_size:
+            raise ValueError(
+                f"Expected {expected_input_size} input(s), but received {len(inputs_array)}."
+            )
+
+        # Configure input buffers using the current session's input size and provided data.
+        self.set_inputs(expected_input_size, inputs_array)
+        # Execute the inference.
         self.session.run()
+        # Return the output buffers.
         return self.outputs

runtime/onert/sample/minimal-python/src/minimal.py

@@ -1,4 +1,5 @@
 from onert import infer
+import numpy as np
 import sys
 
 
@@ -8,10 +9,17 @@ def main(nnpackage_path, backends="cpu"):
     session = infer.session(nnpackage_path, backends)
 
     # Prepare input. Here we just allocate dummy input arrays.
-    input_size = session.input_size()
-    session.set_inputs(input_size)
+    input_infos = session.get_inputs_tensorinfo()
+    dummy_inputs = []
+    for info in input_infos:
+        # Retrieve the dimensions list from tensorinfo property.
+        dims = list(info.dims)
+        # Build the shape tuple from tensorinfo dimensions.
+        shape = tuple(dims[:info.rank])
+        # Create a dummy numpy array filled with zeros.
+        dummy_inputs.append(np.zeros(shape, dtype=info.dtype))
 
-    outputs = session.inference()
+    outputs = session.infer(dummy_inputs)
 
     print(f"nnpackage {nnpackage_path.split('/')[-1]} runs successfully.")
     return

runtime/onert/sample/minimal-python/src/static_shape_inference.py

@@ -0,0 +1,52 @@
+from onert import infer
+import numpy as np
+import sys
+
+
+def main(nnpackage_path, backends="cpu"):
+    # Create session and load the nnpackage
+    sess = infer.session(nnpackage_path, backends)
+
+    # Retrieve the current tensorinfo for all inputs.
+    current_input_infos = sess.get_inputs_tensorinfo()
+
+    # Create new tensorinfo objects with a static shape modification.
+    # For this example, assume we change the first dimension (e.g., batch size) to 10.
+    new_input_infos = []
+    for info in current_input_infos:
+        # For example, if the current shape is (?, 4), update it to (10, 4).
+        # We copy the current info and modify the rank and dims.
+        # (Note: Depending on your model, you may want to modify additional dimensions.)
+        new_shape = [10] + list(info.dims[1:info.rank])
+        info.rank = len(new_shape)
+        for i, dim in enumerate(new_shape):
+            info.dims[i] = dim
+        # For any remaining dimensions up to NNFW_MAX_RANK, set them to a default (1).
+        for i in range(len(new_shape), len(info.dims)):
+            info.dims[i] = 1
+        new_input_infos.append(info)
+
+    # Update all input tensorinfos in the session at once.
+    # This will call prepare() and set_outputs() internally.
+    sess.update_inputs_tensorinfo(new_input_infos)
+
+    # Create dummy input arrays based on the new static shapes.
+    dummy_inputs = []
+    for info in new_input_infos:
+        # Build the shape tuple from tensorinfo dimensions.
+        shape = tuple(info.dims[:info.rank])
+        # Create a dummy numpy array filled with zeros.
+        dummy_inputs.append(np.zeros(shape, dtype=info.dtype))
+
+    # Run inference with the new static input shapes.
+    outputs = sess.infer(dummy_inputs)
+
+    print(
+        f"Static shape modification sample: nnpackage {nnpackage_path.split('/')[-1]} runs successfully."
+    )
+    return
+
+
+if __name__ == "__main__":
+    argv = sys.argv[1:]
+    main(*argv)