regionclip-demo / detectron2 /export /caffe2_export.py
jwyang
first commit
4121bec
# Copyright (c) Facebook, Inc. and its affiliates.
import copy
import io
import logging
import numpy as np
from typing import List
import onnx
import torch
from caffe2.proto import caffe2_pb2
from caffe2.python import core
from caffe2.python.onnx.backend import Caffe2Backend
from tabulate import tabulate
from termcolor import colored
from torch.onnx import OperatorExportTypes
from .shared import (
ScopedWS,
construct_init_net_from_params,
fuse_alias_placeholder,
fuse_copy_between_cpu_and_gpu,
get_params_from_init_net,
group_norm_replace_aten_with_caffe2,
infer_device_type,
remove_dead_end_ops,
remove_reshape_for_fc,
save_graph,
)
logger = logging.getLogger(__name__)
def export_onnx_model(model, inputs):
"""
Trace and export a model to onnx format.
Args:
model (nn.Module):
inputs (tuple[args]): the model will be called by `model(*inputs)`
Returns:
an onnx model
"""
assert isinstance(model, torch.nn.Module)
# make sure all modules are in eval mode, onnx may change the training state
# of the module if the states are not consistent
def _check_eval(module):
assert not module.training
model.apply(_check_eval)
# Export the model to ONNX
with torch.no_grad():
with io.BytesIO() as f:
torch.onnx.export(
model,
inputs,
f,
operator_export_type=OperatorExportTypes.ONNX_ATEN_FALLBACK,
# verbose=True, # NOTE: uncomment this for debugging
# export_params=True,
)
onnx_model = onnx.load_from_string(f.getvalue())
# Apply ONNX's Optimization
all_passes = onnx.optimizer.get_available_passes()
passes = ["fuse_bn_into_conv"]
assert all(p in all_passes for p in passes)
onnx_model = onnx.optimizer.optimize(onnx_model, passes)
return onnx_model
def _op_stats(net_def):
type_count = {}
for t in [op.type for op in net_def.op]:
type_count[t] = type_count.get(t, 0) + 1
type_count_list = sorted(type_count.items(), key=lambda kv: kv[0]) # alphabet
type_count_list = sorted(type_count_list, key=lambda kv: -kv[1]) # count
return "\n".join("{:>4}x {}".format(count, name) for name, count in type_count_list)
def _assign_device_option(
predict_net: caffe2_pb2.NetDef, init_net: caffe2_pb2.NetDef, tensor_inputs: List[torch.Tensor]
):
"""
ONNX exported network doesn't have concept of device, assign necessary
device option for each op in order to make it runable on GPU runtime.
"""
def _get_device_type(torch_tensor):
assert torch_tensor.device.type in ["cpu", "cuda"]
assert torch_tensor.device.index == 0
return torch_tensor.device.type
def _assign_op_device_option(net_proto, net_ssa, blob_device_types):
for op, ssa_i in zip(net_proto.op, net_ssa):
if op.type in ["CopyCPUToGPU", "CopyGPUToCPU"]:
op.device_option.CopyFrom(core.DeviceOption(caffe2_pb2.CUDA, 0))
else:
devices = [blob_device_types[b] for b in ssa_i[0] + ssa_i[1]]
assert all(d == devices[0] for d in devices)
if devices[0] == "cuda":
op.device_option.CopyFrom(core.DeviceOption(caffe2_pb2.CUDA, 0))
# update ops in predict_net
predict_net_input_device_types = {
(name, 0): _get_device_type(tensor)
for name, tensor in zip(predict_net.external_input, tensor_inputs)
}
predict_net_device_types = infer_device_type(
predict_net, known_status=predict_net_input_device_types, device_name_style="pytorch"
)
predict_net_ssa, _ = core.get_ssa(predict_net)
_assign_op_device_option(predict_net, predict_net_ssa, predict_net_device_types)
# update ops in init_net
init_net_ssa, versions = core.get_ssa(init_net)
init_net_output_device_types = {
(name, versions[name]): predict_net_device_types[(name, 0)]
for name in init_net.external_output
}
init_net_device_types = infer_device_type(
init_net, known_status=init_net_output_device_types, device_name_style="pytorch"
)
_assign_op_device_option(init_net, init_net_ssa, init_net_device_types)
def export_caffe2_detection_model(model: torch.nn.Module, tensor_inputs: List[torch.Tensor]):
"""
Export a caffe2-compatible Detectron2 model to caffe2 format via ONNX.
Arg:
model: a caffe2-compatible version of detectron2 model, defined in caffe2_modeling.py
tensor_inputs: a list of tensors that caffe2 model takes as input.
"""
model = copy.deepcopy(model)
assert isinstance(model, torch.nn.Module)
assert hasattr(model, "encode_additional_info")
# Export via ONNX
logger.info(
"Exporting a {} model via ONNX ...".format(type(model).__name__)
+ " Some warnings from ONNX are expected and are usually not to worry about."
)
onnx_model = export_onnx_model(model, (tensor_inputs,))
# Convert ONNX model to Caffe2 protobuf
init_net, predict_net = Caffe2Backend.onnx_graph_to_caffe2_net(onnx_model)
ops_table = [[op.type, op.input, op.output] for op in predict_net.op]
table = tabulate(ops_table, headers=["type", "input", "output"], tablefmt="pipe")
logger.info(
"ONNX export Done. Exported predict_net (before optimizations):\n" + colored(table, "cyan")
)
# Apply protobuf optimization
fuse_alias_placeholder(predict_net, init_net)
if any(t.device.type != "cpu" for t in tensor_inputs):
fuse_copy_between_cpu_and_gpu(predict_net)
remove_dead_end_ops(init_net)
_assign_device_option(predict_net, init_net, tensor_inputs)
params, device_options = get_params_from_init_net(init_net)
predict_net, params = remove_reshape_for_fc(predict_net, params)
init_net = construct_init_net_from_params(params, device_options)
group_norm_replace_aten_with_caffe2(predict_net)
# Record necessary information for running the pb model in Detectron2 system.
model.encode_additional_info(predict_net, init_net)
logger.info("Operators used in predict_net: \n{}".format(_op_stats(predict_net)))
logger.info("Operators used in init_net: \n{}".format(_op_stats(init_net)))
return predict_net, init_net
def run_and_save_graph(predict_net, init_net, tensor_inputs, graph_save_path):
"""
Run the caffe2 model on given inputs, recording the shape and draw the graph.
predict_net/init_net: caffe2 model.
tensor_inputs: a list of tensors that caffe2 model takes as input.
graph_save_path: path for saving graph of exported model.
"""
logger.info("Saving graph of ONNX exported model to {} ...".format(graph_save_path))
save_graph(predict_net, graph_save_path, op_only=False)
# Run the exported Caffe2 net
logger.info("Running ONNX exported model ...")
with ScopedWS("__ws_tmp__", True) as ws:
ws.RunNetOnce(init_net)
initialized_blobs = set(ws.Blobs())
uninitialized = [inp for inp in predict_net.external_input if inp not in initialized_blobs]
for name, blob in zip(uninitialized, tensor_inputs):
ws.FeedBlob(name, blob)
try:
ws.RunNetOnce(predict_net)
except RuntimeError as e:
logger.warning("Encountered RuntimeError: \n{}".format(str(e)))
ws_blobs = {b: ws.FetchBlob(b) for b in ws.Blobs()}
blob_sizes = {b: ws_blobs[b].shape for b in ws_blobs if isinstance(ws_blobs[b], np.ndarray)}
logger.info("Saving graph with blob shapes to {} ...".format(graph_save_path))
save_graph(predict_net, graph_save_path, op_only=False, blob_sizes=blob_sizes)
return ws_blobs