ai.djl.modality.nlp

Class Decoder

java.lang.Object

ai.djl.nn.AbstractBlock

ai.djl.modality.nlp.Decoder

All Implemented Interfaces:

Block

public abstract class Decoder
extends AbstractBlock

Decoder is an abstract block that be can used as decoder in encoder-decoder architecture. This abstraction, along with Encoder, comes into play in the EncoderDecoder class, and facilitate implementing encoder-decoder models for different tasks and inputs.

Field Summary

Fields

Modifier and Type	Field and Description
protected Block	block

Fields inherited from class ai.djl.nn.AbstractBlock

inputNames, inputShapes

Constructor Summary

Constructors

Constructor and Description
Decoder(Block block) Constructs a new instance of Decoder with the given block.

Method Summary

Modifier and Type	Method and Description
NDList	forward(ParameterStore parameterStore, NDList inputs, boolean training, ai.djl.util.PairList<java.lang.String,java.lang.Object> params) Applies the operating function of the block once.
BlockList	getChildren() Returns a list of all the children of the block.
java.util.List<Parameter>	getDirectParameters() Returns a list of all the direct parameters of the block.
Shape[]	getOutputShapes(NDManager manager, Shape[] inputShapes) Returns the expected output shapes of the block for the specified input shapes.
Shape	getParameterShape(java.lang.String name, Shape[] inputShapes) Returns the shape of the specified direct parameter of this block given the shapes of the input to the block.
Shape[]	initialize(NDManager manager, DataType dataType, Shape... inputShapes) Initializes the parameters of the block.
abstract void	initState(NDList encoderStates) Sets the state of the encoder as the initial state of the decoder.
void	loadParameters(NDManager manager, java.io.DataInputStream is) Loads the parameters from the given input stream.
void	saveParameters(java.io.DataOutputStream os) Writes the parameters of the block to the given outputStream.

Methods inherited from class ai.djl.nn.AbstractBlock

beforeInitialize, cast, clear, describeInput, getParameters, isInitialized, readInputShapes, saveInputShapes, setInitializer, setInitializer

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface ai.djl.nn.Block

forward, validateLayout

Field Detail

block

protected Block block

Constructor Detail

Decoder

public Decoder(Block block)

Constructs a new instance of Decoder with the given block. Use this constructor if you are planning to use pre-trained embeddings that don't need further training.

Parameters:

block - the block to be used to decode

Method Detail

initState

public abstract void initState(NDList encoderStates)

Sets the state of the encoder as the initial state of the decoder.

Parameters:

encoderStates - the states of the encoder

forward

public NDList forward(ParameterStore parameterStore,
                      NDList inputs,
                      boolean training,
                      ai.djl.util.PairList<java.lang.String,java.lang.Object> params)

Applies the operating function of the block once. This method should be called only on blocks that are initialized.

Parameters:

parameterStore - the parameter store

inputs - the input NDList

training - true for a training forward pass

params - optional parameters

Returns:

the output of the forward pass

initialize

public Shape[] initialize(NDManager manager,
                          DataType dataType,
                          Shape... inputShapes)

Initializes the parameters of the block. This method must be called before calling `forward`.

Parameters:

manager - the NDManager to initialize the parameters

dataType - the datatype of the parameters

inputShapes - the shapes of the inputs to the block

Returns:

the shapes of the outputs of the block

getChildren

public BlockList getChildren()

Returns a list of all the children of the block.

Returns:

the list of child blocks

getDirectParameters

public java.util.List<Parameter> getDirectParameters()

Returns a list of all the direct parameters of the block.

Returns:

the list of Parameter

getParameterShape

public Shape getParameterShape(java.lang.String name,
                               Shape[] inputShapes)

Returns the shape of the specified direct parameter of this block given the shapes of the input to the block.

Parameters:

name - the name of the parameter

inputShapes - the shapes of the input to the block

Returns:

the shape of the parameter specified

getOutputShapes

public Shape[] getOutputShapes(NDManager manager,
                               Shape[] inputShapes)

Returns the expected output shapes of the block for the specified input shapes.

Parameters:

manager - an NDManager

inputShapes - the shapes of the inputs

Returns:

the expected output shapes of the block

saveParameters

public void saveParameters(java.io.DataOutputStream os)
                    throws java.io.IOException

Writes the parameters of the block to the given outputStream.

Parameters:

os - the outputstream to save the parameters to

Throws:

java.io.IOException - if an I/O error occurs

loadParameters

public void loadParameters(NDManager manager,
                           java.io.DataInputStream is)
                    throws java.io.IOException,
                           MalformedModelException

Loads the parameters from the given input stream.

Parameters:

manager - an NDManager to create the parameter arrays

is - the inputstream that stream the parameter values

Throws:

java.io.IOException - if an I/O error occurs

MalformedModelException - if the model file is corrupted or unsupported