Python 推理可以通过 .engine 文件实现。下面的示例从磁盘加载 .trt 文件(实际上与 .engine 文件相同)并执行单个推理。
在这个项目中,我使用以下命令将 ONNX 模型转换为 TRT 模型onnx2trt https://github.com/onnx/onnx-tensorrt使用前可执行。您甚至可以使用 ONNX 作为中间件将 PyTorch 模型转换为 TRT。
import tensorrt as trt
import numpy as np
import os
import pycuda.driver as cuda
import pycuda.autoinit
class HostDeviceMem(object):
def __init__(self, host_mem, device_mem):
self.host = host_mem
self.device = device_mem
def __str__(self):
return "Host:\n" + str(self.host) + "\nDevice:\n" + str(self.device)
def __repr__(self):
return self.__str__()
class TrtModel:
def __init__(self,engine_path,max_batch_size=1,dtype=np.float32):
self.engine_path = engine_path
self.dtype = dtype
self.logger = trt.Logger(trt.Logger.WARNING)
self.runtime = trt.Runtime(self.logger)
self.engine = self.load_engine(self.runtime, self.engine_path)
self.max_batch_size = max_batch_size
self.inputs, self.outputs, self.bindings, self.stream = self.allocate_buffers()
self.context = self.engine.create_execution_context()
@staticmethod
def load_engine(trt_runtime, engine_path):
trt.init_libnvinfer_plugins(None, "")
with open(engine_path, 'rb') as f:
engine_data = f.read()
engine = trt_runtime.deserialize_cuda_engine(engine_data)
return engine
def allocate_buffers(self):
inputs = []
outputs = []
bindings = []
stream = cuda.Stream()
for binding in self.engine:
size = trt.volume(self.engine.get_binding_shape(binding)) * self.max_batch_size
host_mem = cuda.pagelocked_empty(size, self.dtype)
device_mem = cuda.mem_alloc(host_mem.nbytes)
bindings.append(int(device_mem))
if self.engine.binding_is_input(binding):
inputs.append(HostDeviceMem(host_mem, device_mem))
else:
outputs.append(HostDeviceMem(host_mem, device_mem))
return inputs, outputs, bindings, stream
def __call__(self,x:np.ndarray,batch_size=2):
x = x.astype(self.dtype)
np.copyto(self.inputs[0].host,x.ravel())
for inp in self.inputs:
cuda.memcpy_htod_async(inp.device, inp.host, self.stream)
self.context.execute_async(batch_size=batch_size, bindings=self.bindings, stream_handle=self.stream.handle)
for out in self.outputs:
cuda.memcpy_dtoh_async(out.host, out.device, self.stream)
self.stream.synchronize()
return [out.host.reshape(batch_size,-1) for out in self.outputs]
if __name__ == "__main__":
batch_size = 1
trt_engine_path = os.path.join("..","models","main.trt")
model = TrtModel(trt_engine_path)
shape = model.engine.get_binding_shape(0)
data = np.random.randint(0,255,(batch_size,*shape[1:]))/255
result = model(data,batch_size)
大家注意安全!