ReadValue

Versioned name: ReadValue-6

Category: Infrastructure

Short description: ReadValue returns value of the variable_id variable.

Detailed description:

ReadValue, Assign, and Variable define a coherent mechanism for reading, writing, and storing some memory buffer between inference calls. More details can be found on the StateAPI documentation page.

If the 1st input is provided and this is the first inference or reset has been called, ReadValue returns the value from the 1st input.

If the 1st input is not provided and this is the first inference or reset has been called, ReadValue returns the tensor with the variable_shape and variable_type and zero values.

In all other cases ReadValue returns the value from the corresponding variable_id variable.

If the 1st input has been provided, the operation checks if variable_shape and variable_type extend (relax) the shape and type inferred from the 1st input. If not, it returns an error. For example, if variable_type is specified as dynamic, it means that any type for 1st input is allowed but if it is specified as f32, only f32 type is allowed.

Only one pair of ReadValue and Assign operations is expected for each Variable in the model.

Attributes:

• variable_id

  • Description: identifier of the variable to be read.

  • Range of values: any non-empty string

  • Type: string

  • Required: yes

• variable_type

  • Description: the type of the variable

  • Range of values: : u1, u4, u8, u16, u32, u64, i4, i8, i16, i32, i64, f16, f32, boolean, bf16

  • Type: string

  • Required: yes

• variable_shape

  • Description: the shape of the variable

  • Range of values: list of integers, empty list is allowed, which means 0D or scalar tensor

  • Type: int[]

  • Required: yes

Inputs

• 1: init_value - input tensor whose values are used in the first inference or after a reset call. Optional.

Outputs

• 1: tensor with the same shape and type as specified in variable_type, variable_shape.

Example

 <layer ... type="ReadValue" ...>
     <data variable_id="lstm_state_1" variable_type="f32" variable_shape="1,3,224,224"/>
     <input>
         <port id="0">
             <dim>1</dim>
             <dim>3</dim>
             <dim>224</dim>
             <dim>224</dim>
         </port>
     </input>
     <output>
         <port id="1">
             <dim>1</dim>
             <dim>3</dim>
             <dim>224</dim>
             <dim>224</dim>
         </port>
     </output>
 </layer>