Const Operator Definition

The Const operator implements constant tensors, such as the weight and offset.

Const operator prototype definition:

REG_OP(Const)
    .OUTPUT(y, TensorType({DT_FLOAT, DT_FLOAT16, DT_INT8, DT_INT16, DT_UINT16, \
        DT_UINT8, DT_INT32, DT_INT64, DT_UINT32, DT_UINT64, DT_BOOL, DT_DOUBLE}))
    .ATTR(value, Tensor, Tensor())
    .OP_END_FACTORY_REG(Const)

//Construct weighttensor1.
TensorDesc weight_desc(ge::Shape({1,3,3,3}), FORMAT_NCHW, DT_INT8);
int bs_size_weight=27;
int8_t * bs_inputData_weight = nullptr;
bs_inputData_weight = new int8_t[bs_size_weight];
for (int i=0; i<bs_size_weight; ++i) {
        *(bs_inputData_weight+i) = 1;
    }
Tensor weighttensor1(weight_desc, (uint8_t*)bs_inputData_weight, bs_size_weight*sizeof(int8_t));

// Create a Const operator, and set the attribute value to weighttensor1.
auto weight1 = op::Const().set_attr_value(weighttensor1);

//Construct weight_tensor.
auto weight_shape = ge::Shape({ 5,17,1,1 });
TensorDesc desc_weight_1(weight_shape, FORMAT_NCHW, DT_INT8);
Tensor weight_tensor(desc_weight_1);
uint32_t weight_1_len = weight_shape.GetShapeSize();
bool res = GetConstTensorFromBin(PATH+"const_0.bin", weight_tensor, weight_1_len);

// Create a Const operator, and set the attribute value to weight_tensor .
auto conv_weight = op::Const("const_0").set_attr_value(weight_tensor);

The implementation of the GetConstTensorFromBin function is as follows.

bool GetConstTensorFromBin(string path, Tensor &weight, uint32_t len) {
    ifstream in_file(path.c_str(), std::ios::in | std::ios::binary);
    if (!in_file.is_open()) {
        std::cout << "failed to open" << path.c_str() << '\n';
        return false;
    }
    in_file.seekg(0, ios_base::end);
    istream::pos_type file_size = in_file.tellg();
    in_file.seekg(0, ios_base::beg);

    if (len != file_size) {
        cout << "Invalid Param.len: "<< len << " is not equal with binary size (" << file_size << ") \n";
        in_file.close();
        return false;
    }
    char* pdata = new(std::nothrow) char[len];
    if (pdata == nullptr) {
        cout << "Invalid Param.len: "<< len << " is not equal with binary size (" << file_size << ") \n";
        in_file.close();
        return false;
    }
    in_file.read(reinterpret_cast<char*>(pdata), len);
    auto status = weight.SetData(reinterpret_cast<uint8_t*>(pdata), len);
    if (status != ge::GRAPH_SUCCESS) {
        cout << "Set Tensor Data Failed"<< "\n";
        in_file.close();
        return false;
    }
    in_file.close();
    return true;
}