feat(mge/utils): add GraphInference in cgtools

GitOrigin-RevId: 72f22011691a23f50a966480829ac6744753d563

imperative/python/megengine/utils/comp_graph_tools.py

@@ -6,7 +6,8 @@
 # software distributed under the License is distributed on an
 # "AS IS" BASIS, WITHOUT ARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 import collections
-from typing import Dict, List
+from collections import OrderedDict
+from typing import Dict, List, Optional
 
 import numpy
 
@@ -27,6 +28,7 @@ __all__ = [
     "replace_oprs",
     "set_priority_to_id",
     "load_and_inference",
+    "GraphInference",
 ]
 
 
@@ -46,7 +48,7 @@ def get_dep_vars(var: VarNode, var_type: str = None) -> List[VarNode]:
 
     q = list(var)
     while q:
-        v = q.pop()
+        v = q.pop(0)
         if v in memo:
             continue
         memo.add(v)
@@ -281,23 +283,77 @@ def load_and_inference(file, inp_data_list: List[numpy.ndarray]) -> List[numpy.n
     :return: list of inference results.
 
     """
-    *_, out_list = G.load_graph(file)
-    inputs = get_dep_vars(out_list, "Host2DeviceCopy")
-    replace_dict = {}
-    inp_node_list = []
-    for i in inputs:
-        inp_node = G.InputNode(
-            device="xpux", dtype=inputs[0].dtype, graph=inputs[0].graph
-        )
-        replace_dict[i] = inp_node.outputs[0]
-        inp_node_list.append(inp_node)
-    new_out = replace_vars(out_list, replace_dict)
-    out_node_list = [G.OutputNode(i) for i in new_out]
-    new_out_list = [i.outputs[0] for i in out_node_list]
-    cg = new_out_list[0].graph
-    func = cg.compile(new_out_list)
-    for node, value in zip(inp_node_list, inp_data_list):
-        node.set_value(Tensor(value)._dev_tensor())
-    func.execute()
-    out_data_list = [o.get_value().numpy() for o in out_node_list]
+    graph = GraphInference(file)
+    result = graph.run(*inp_data_list)
+    out_data_list = list(result.values())
     return out_data_list
+
+
+class GraphInference:
+    """
+    Loads a serialized computing graph as a GraphInference object which can be used to execute the computing graph.
+    The `GraphInference.run()` accepts a list `inp_args` or a dict `inp_dict` {input_name: input_value} as input and returns a dict {output_name: output_value}.
+
+    :param file: could be file object or filename.
+    :param outputs: only compile the subgraph with outputs as its endpoints.
+    """
+
+    def __init__(self, file, outputs: Optional[List[str]] = None):
+        *_, output_nodes = G.load_graph(file)
+        if outputs is not None:
+            output_name = outputs.copy()
+            all_vars = get_dep_vars(output_nodes) + output_nodes
+            new_outputs = {}
+            for i in all_vars:
+                if i.name in output_name:
+                    new_outputs[i.name] = i
+                    output_name.remove(i.name)
+            assert (
+                len(output_name) == 0
+            ), "Can not find varnode {} in this model".format(output_name)
+            output_nodes = [new_outputs[i] for i in outputs]
+        inputs = get_dep_vars(output_nodes, "Host2DeviceCopy")
+        self._inp_dict = OrderedDict()
+        replace_dict = {}
+        for i in inputs:
+            inp_node = G.InputNode(
+                device="xpux", dtype=inputs[0].dtype, graph=inputs[0].graph
+            )
+            self._inp_dict[i.name] = inp_node
+            replace_dict[i] = inp_node.outputs[0]
+        new_output_nodes = replace_vars(output_nodes, replace_dict)
+        for old, new in zip(output_nodes, new_output_nodes):
+            new.name = old.name
+        self._out_dict = OrderedDict(
+            [(i.name, G.OutputNode(i)) for i in new_output_nodes]
+        )
+        new_out_list = [i.outputs[0] for i in self._out_dict.values()]
+        cg = new_out_list[0].graph
+        self._func = cg.compile(new_out_list)
+
+    def run(
+        self,
+        *inp_args: numpy.ndarray,
+        inp_dict: Optional[Dict[str, numpy.ndarray]] = None
+    ):
+        assert len(inp_args) <= len(
+            self._inp_dict
+        ), "This model expects {} inputs".format(len(self._inp_dict))
+        inputs = {}
+        inp_keys = list(self._inp_dict.keys())
+        for ind, data in enumerate(inp_args):
+            inputs[inp_keys[ind]] = data
+        if inp_dict is not None:
+            inputs.update(inp_dict)
+        assert (
+            inputs.keys() == self._inp_dict.keys()
+        ), "This model expects inputs {}, but gets inputs {}".format(
+            list(self._inp_dict.keys()), list(inputs.keys())
+        )
+        for key in self._inp_dict:
+            self._inp_dict[key].set_value(Tensor(inputs[key])._dev_tensor())
+        self._func.execute()
+        result = OrderedDict()
+        for key in self._out_dict:
+            result[key] = self._out_dict[key].get_value().numpy()
+        return result

imperative/python/test/unit/test_cgtools.py

@@ -139,3 +139,48 @@ def test_get_opr_seq():
 
     seq_2 = cgtools.get_oprs_seq(outputs, False)
     assert len(seq_2) == 6
+
+
+def test_graph_function():
+    class Net(M.Module):
+        def forward(self, a, b):
+            return a - b, a * b
+
+    net = Net()
+
+    @trace(symbolic=True, capture_as_const=True)
+    def function(a, b, *, net=None):
+        return net(a, b)
+
+    a = np.array([1, 2, 3])
+    b = np.array([3])
+    x, y = function(megengine.tensor(a), megengine.tensor(b), net=net)
+
+    file = io.BytesIO()
+    function.dump(
+        file,
+        arg_names=["a", "b"],
+        output_names=["x", "y"],
+        optimize_for_inference=False,
+    )
+    file.seek(0)
+
+    graph = cgtools.GraphInference(file)
+    results = graph.run(inp_dict={"a": a, "b": b})
+    np.testing.assert_equal(x.numpy(), results["x"])
+    np.testing.assert_equal(y.numpy(), results["y"])
+
+    results = graph.run(a, inp_dict={"b": b})
+    np.testing.assert_equal(x.numpy(), results["x"])
+    np.testing.assert_equal(y.numpy(), results["y"])
+
+    results = graph.run(a, b)
+    np.testing.assert_equal(x.numpy(), results["x"])
+    np.testing.assert_equal(y.numpy(), results["y"])
+
+    file.seek(0)
+
+    graph1 = cgtools.GraphInference(file, outputs=["x"])
+    results = graph1.run(inp_dict={"a": a, "b": b})
+    np.testing.assert_equal(x.numpy(), results["x"])
+    assert "y" not in results