More intelligent and flexible input and output tensor naming for `Tor…

…chScript` Exporter (#62)

* support direct torchscript export from ScriptModule

* add tests of new naming behavior

* guard torch import

* add jit module to handles for onnx and torchscript exporters

* add script module test to exporter utils

hermes/quiver/exporters/exporter.py

@@ -259,7 +259,8 @@ def handles(self):
                 "Platform metaclass has no `handles` property"
             )
 
-    @abc.abstractproperty
+    @property
+    @abc.abstractmethod
     def platform(self) -> "Platform":
         try:
             return type(self).platform

hermes/quiver/exporters/torch_onnx.py

@@ -1,5 +1,4 @@
 import abc
-import inspect
 from collections import OrderedDict
 from io import BytesIO
 
@@ -12,14 +11,7 @@
 
 from hermes.quiver import Platform
 from hermes.quiver.exporters import Exporter
-
-
-def get_input_names_from_script_module(m):
-    graph = m.graph
-    input_names = [node.debugName().split(".")[0] for node in graph.inputs()]
-    if "self" in input_names:
-        input_names.remove("self")
-    return OrderedDict({name: name for name in input_names})
+from hermes.quiver.exporters.utils import get_input_names_from_torch_object
 
 
 class TorchOnnxMeta(abc.ABCMeta):
@@ -29,7 +21,7 @@ def handles(self):
             raise ImportError(
                 "Must have torch installed to use TorchOnnx export platform"
             )
-        return torch.nn.Module
+        return (torch.nn.Module, torch.jit.ScriptModule)
 
     @property
     def platform(self):
@@ -63,14 +55,9 @@ def _get_output_shapes(self, model_fn, output_names):
             # generate an input array of random data
             input_tensors[input.name] = self._get_tensor(input.dims)
 
-        # parse script module to figure out in which order
-        # to pass input tensors to the model_fn
-        if isinstance(model_fn, torch.jit.ScriptModule):
-            parameters = get_input_names_from_script_module(model_fn)
-        # otherwise use function signature from module.forward
-        else:
-            signature = inspect.signature(model_fn.forward)
-            parameters = OrderedDict(signature.parameters)
+        # parse either a `ScriptModule` or `torch.nn.Module`
+        # to figure out in which order to pass input tensors to the model_fn
+        parameters = get_input_names_from_torch_object(model_fn)
 
         # make sure the number of inputs to
         # the model_fn matches the number of

hermes/quiver/exporters/torchscript.py

@@ -1,5 +1,5 @@
 import abc
-import inspect
+import warnings
 from collections import OrderedDict
 from io import BytesIO
 
@@ -12,6 +12,7 @@
 
 from hermes.quiver import Platform
 from hermes.quiver.exporters import Exporter
+from hermes.quiver.exporters.utils import get_input_names_from_torch_object
 
 
 class TorchScriptMeta(abc.ABCMeta):
@@ -21,7 +22,7 @@ def handles(self):
             raise ImportError(
                 "Must have torch installed to use TorchScript export platform"
             )
-        return torch.nn.Module
+        return (torch.nn.Module, torch.jit.ScriptModule)
 
     @property
     def platform(self):
@@ -32,12 +33,26 @@ class TorchScript(Exporter, metaclass=TorchScriptMeta):
     def __call__(
         self, model_fn, version, input_shapes, output_names=None
     ) -> None:
-        if output_names is not None:
-            raise ValueError(
-                "Cannot specify output_names for TorchScript exporter"
+        # if a dictionary is passed
+        # (i.e. user specified names for tensors)
+        # warn the user about specific naming conventions
+        # for tensor input names from triton
+        if isinstance(input_shapes, dict):
+            warnings.warn(
+                "Triton expects specific naming conventions and "
+                "ordering for tensor input names. Be careful. See "
+                "https://docs.nvidia.com/deeplearning/triton-inference-server/"
+                "user-guide/docs/user_guide/model_configuration.html"
+                "#special-conventions-for-pytorch-backend"
             )
-
-        input_shapes = {f"INPUT__{i}": j for i, j in enumerate(input_shapes)}
+            return super().__call__(
+                model_fn, version, input_shapes, output_names
+            )
+        # otherwise, user passed a sequence of shapes:
+        # use tritons recommended naming conventions
+        # by inferring the names from the model_fn
+        parameters = get_input_names_from_torch_object(model_fn)
+        input_shapes = {p: s for p, s in zip(parameters, input_shapes)}
         super().__call__(model_fn, version, input_shapes, output_names)
 
     def _get_tensor(self, shape):
@@ -56,7 +71,7 @@ def _get_tensor(self, shape):
         # and pass them along if they were provided?
         return torch.randn(*tensor_shape)
 
-    def _get_output_shapes(self, model_fn, _):
+    def _get_output_shapes(self, model_fn, output_names=None):
         # now that we know we have inputs added to our
         # model config, use that config to generate
         # framework tensors that we'll feed through
@@ -66,11 +81,9 @@ def _get_output_shapes(self, model_fn, _):
             # generate an input array of random data
             input_tensors[input.name] = self._get_tensor(input.dims)
 
-        # use function signature from module.forward
-        # to figure out in which order to pass input
-        # tensors to the model_fn
-        signature = inspect.signature(model_fn.forward)
-        parameters = OrderedDict(signature.parameters)
+        # parse either a `ScriptModule` or `torch.nn.Module`
+        # to figure out in which order to pass input tensors to the model_fn
+        parameters = get_input_names_from_torch_object(model_fn)
 
         # make sure the number of inputs to
         # the model_fn matches the number of
@@ -122,9 +135,22 @@ def _get_output_shapes(self, model_fn, _):
         if any([x.dims[0] == -1 for x in self.config.input]):
             shapes = [(None,) + s[1:] for s in shapes]
 
-        # if we provided names for the outputs, return them
-        # as a dict for validation against the config
-        shapes = {f"OUTPUT__{i}": j for i, j in enumerate(shapes)}
+        # if we didn't provide names for the outputs,
+        # use the "OUTPUT__{i}" format
+        if output_names is None:
+            shapes = {f"OUTPUT__{i}": j for i, j in enumerate(shapes)}
+        else:
+            warnings.warn(
+                "Triton expects specific naming conventions "
+                "and ordering for tensor output names. Be careful. See "
+                "https://docs.nvidia.com/deeplearning/triton-inference-server/"
+                "user-guide/docs/user_guide/model_configuration.html"
+                "#special-conventions-for-pytorch-backend"
+            )
+            shapes = {
+                name: shape
+                for i, (name, shape) in enumerate(zip(output_names, shapes))
+            }
         return shapes
 
     def export(self, model_fn, export_path, verbose=0, **kwargs):

hermes/quiver/exporters/utils.py

@@ -1,7 +1,16 @@
+import inspect
+from collections import OrderedDict
 from typing import TYPE_CHECKING, Callable, Union
 
 from .exporter import Exporter
 
+try:
+    import torch
+
+    _has_torch = True
+except ImportError:
+    _has_torch = False
+
 if TYPE_CHECKING:
     from hermes.quiver.model import Model
 
@@ -19,6 +28,9 @@ class to find the first for which `model_fn` is an instance of
         model_fn:
             The framework-specific function which performs the
             neural network's input/output mapping
+        model:
+            The `Model` object which specifies the desired export platform
+            and configuration information for the model
     Returns:
         An exporter to export `model_fn` to the format specified
         by this models' inference platform
@@ -53,3 +65,22 @@ def _get_all_subclasses(cls):
                 type(model_fn), model.platform
             )
         )
+
+
+def get_input_names_from_torch_object(
+    model_fn: Union["torch.nn.Module", "torch.jit.ScriptModule"]
+):
+    """
+    Parse either a torch.nn.Module or torch.ScriptModule for input names
+    """
+
+    if isinstance(model_fn, torch.jit.ScriptModule):
+        graph = model_fn.graph
+        input_names = [
+            node.debugName().split(".")[0] for node in graph.inputs()
+        ]
+        if "self" in input_names:
+            input_names.remove("self")
+        return OrderedDict({name: name for name in input_names})
+    signature = inspect.signature(model_fn.forward)
+    return OrderedDict(signature.parameters)

tests/quiver/conftest.py

@@ -97,3 +97,19 @@ def forward(self, x):
             return torch.matmul(x, self.W)
 
     return Model(dim)
+
+
+@pytest.fixture
+def torch_model_2(dim):
+    import torch
+
+    class Model(torch.nn.Module):
+        def __init__(self, size: int = 10):
+            super().__init__()
+            self.size = size
+            self.W = torch.eye(size)
+
+        def forward(self, x, y):
+            return torch.matmul(x, self.W), y
+
+    return Model(dim)

tests/quiver/exporters/test_exporter_utils.py

@@ -2,7 +2,12 @@
 
 import pytest
 
-from hermes.quiver.exporters import KerasSavedModel, TorchOnnx, utils
+from hermes.quiver.exporters import (
+    KerasSavedModel,
+    TorchOnnx,
+    TorchScript,
+    utils,
+)
 from hermes.quiver.platform import Platform
 
 
@@ -33,3 +38,12 @@ def test_find_torch_exporter(torch_model):
     good_model = make_model(Platform.ONNX)
     bad_model = make_model(Platform.SAVEDMODEL)
     _test_find_exporter(torch_model, good_model, bad_model, TorchOnnx)
+
+    good_model = make_model(Platform.TORCHSCRIPT)
+    _test_find_exporter(torch_model, good_model, bad_model, TorchScript)
+
+    import torch
+
+    script_module = torch.jit.trace(torch_model, torch.randn(1, 10))
+    good_model = make_model(Platform.TORCHSCRIPT)
+    _test_find_exporter(script_module, good_model, bad_model, TorchScript)

tests/quiver/exporters/test_torchscript.py

@@ -5,28 +5,28 @@
 
 
 @pytest.mark.torch
-def test_torchscript_exporter(temp_local_repo, torch_model):
+def test_torchscript_exporter(temp_local_repo, torch_model, torch_model_2):
     model_fn = torch_model
 
     model = Model("identity", temp_local_repo, Platform.TORCHSCRIPT)
     exporter = TorchScript(model.config, model.fs)
 
-    input_shapes = {"x": (None, 10)}
+    input_shapes = {"input0": (None, 10)}
     exporter._check_exposed_tensors("input", input_shapes)
     assert len(model.config.input) == 1
-    assert model.config.input[0].name == "x"
+    assert model.config.input[0].name == "input0"
     assert model.config.input[0].dims[0] == -1
 
     bad_input_shapes = {"x": (None, 12)}
     with pytest.raises(ValueError):
         exporter._check_exposed_tensors("input", bad_input_shapes)
 
     output_shapes = exporter._get_output_shapes(model_fn, "y")
-    assert output_shapes["OUTPUT__0"] == (None, 10)
+    assert output_shapes["y"] == (None, 10)
 
     exporter._check_exposed_tensors("output", output_shapes)
     assert len(model.config.output) == 1
-    assert model.config.output[0].name == "OUTPUT__0"
+    assert model.config.output[0].name == "y"
     assert model.config.output[0].dims[0] == -1
 
     version_path = temp_local_repo.fs.join("identity", "1")
@@ -39,8 +39,67 @@ def test_torchscript_exporter(temp_local_repo, torch_model):
     exporter = TorchScript(model2.config, model2.fs)
 
     model_path = temp_local_repo.fs.root
-    with pytest.raises(ValueError):
-        exporter(model_fn, model_path, [(None, 10)], ["BAD_NAME"])
+
+    # if a dictionary if input_shapes is not passed
+    # (i.e. no user specified name) it should default
+    # to the name of the input tensor in the forward call of the model
+    # in this case, "x"
     exporter(model_fn, model_path, [(None, 10)])
-    assert "INPUT__0" in model2.inputs
+    assert "x" in model2.inputs
     assert "OUTPUT__0" in model2.outputs
+
+    # if a dictionary of input_shapes is passed, it should
+    # use the user specified names
+    model3 = Model("identity3", temp_local_repo, Platform.TORCHSCRIPT)
+    exporter = TorchScript(model3.config, model3.fs)
+    model_path = temp_local_repo.fs.root
+
+    exporter(model_fn, model_path, input_shapes={"my_name": (None, 10)})
+    assert "my_name" in model3.inputs
+    assert "OUTPUT__0" in model3.outputs
+
+    # now check using non-default output names
+    model4 = Model("identity4", temp_local_repo, Platform.TORCHSCRIPT)
+    exporter = TorchScript(model4.config, model4.fs)
+    model_path = temp_local_repo.fs.root
+
+    exporter(
+        model_fn,
+        model_path,
+        input_shapes={"my_name": (None, 10)},
+        output_names=["my_output"],
+    )
+    assert "my_name" in model4.inputs
+    assert "my_output" in model4.outputs
+
+    # test a model with multiple inputs and outputs
+    model_fn = torch_model_2
+
+    model = Model("identity", temp_local_repo, Platform.TORCHSCRIPT)
+    exporter = TorchScript(model.config, model.fs)
+
+    input_shapes = {"input0": (None, 10), "input1": (None, 10)}
+    exporter._check_exposed_tensors("input", input_shapes)
+    assert len(model.config.input) == 2
+    assert model.config.input[0].name == "input0"
+    assert model.config.input[1].name == "input1"
+    assert model.config.input[0].dims[0] == -1
+    assert model.config.input[1].dims[0] == -1
+
+    bad_input_shapes = {"x": (None, 12)}
+    with pytest.raises(ValueError):
+        exporter._check_exposed_tensors("input", bad_input_shapes)
+
+    output_shapes = exporter._get_output_shapes(
+        model_fn, ["output1", "output2"]
+    )
+    assert output_shapes["output1"] == (None, 10)
+    assert output_shapes["output2"] == (None, 10)
+
+    model4 = Model("identity4", temp_local_repo, Platform.TORCHSCRIPT)
+    exporter = TorchScript(model4.config, model4.fs)
+    model_path = temp_local_repo.fs.root
+
+    exporter(model_fn, model_path, input_shapes=[(None, 10), (None, 10)])
+    assert "x" in model4.inputs and "y" in model4.inputs
+    assert "OUTPUT__0" in model4.outputs and "OUTPUT__1" in model4.outputs