diff --git a/lib/bumblebee.ex b/lib/bumblebee.ex index 51f2330f..66d1eb54 100644 --- a/lib/bumblebee.ex +++ b/lib/bumblebee.ex @@ -170,6 +170,8 @@ defmodule Bumblebee do "MistralModel" => {Bumblebee.Text.Mistral, :base}, "MistralForCausalLM" => {Bumblebee.Text.Mistral, :for_causal_language_modeling}, "MistralForSequenceClassification" => {Bumblebee.Text.Mistral, :for_sequence_classification}, + "MPNetModel" => {Bumblebee.Text.MPNet, :base}, + "MPNetForMaskedLM" => {Bumblebee.Text.MPNet, :for_masked_language_modeling}, "PhiModel" => {Bumblebee.Text.Phi, :base}, "PhiForCausalLM" => {Bumblebee.Text.Phi, :for_causal_language_modeling}, "PhiForSequenceClassification" => {Bumblebee.Text.Phi, :for_sequence_classification}, diff --git a/lib/bumblebee/text/mpnet.ex b/lib/bumblebee/text/mpnet.ex new file mode 100644 index 00000000..d74c06ff --- /dev/null +++ b/lib/bumblebee/text/mpnet.ex @@ -0,0 +1,458 @@ +defmodule Bumblebee.Text.MPNet do + alias Bumblebee.Shared + + options = + [ + vocab_size: [ + default: 30527, + doc: """ + the vocabulary size of the token embedding. This corresponds to the number of distinct + tokens that can be represented in model input and output + """ + ], + max_positions: [ + default: 514, + doc: """ + the vocabulary size of the position embedding. This corresponds to the maximum sequence + length that this model can process. Typically this is set to a large value just in case, + such as 512, 1024 or 2048 + """ + ], + max_token_types: [ + default: 2, + doc: """ + the vocabulary size of the token type embedding (also referred to as segment embedding). + This corresponds to how many different token groups can be distinguished in the input + """ + ], + hidden_size: [ + default: 768, + doc: "the dimensionality of hidden layers" + ], + num_blocks: [ + default: 12, + doc: "the number of Transformer blocks in the encoder" + ], + num_attention_heads: [ + default: 12, + doc: "the number of attention heads for each attention layer in the encoder" + ], + intermediate_size: [ + default: 3072, + doc: + "the dimensionality of the intermediate layer in the transformer feed-forward network (FFN) in the encoder" + ], + activation: [ + default: :gelu, + doc: "the activation function" + ], + dropout_rate: [ + default: 0.1, + doc: "the dropout rate for embedding and encoder" + ], + attention_dropout_rate: [ + default: 0.1, + doc: "the dropout rate for attention weights" + ], + classifier_dropout_rate: [ + default: nil, + doc: + "the dropout rate for the classification head. If not specified, the value of `:dropout_rate` is used instead" + ], + layer_norm_epsilon: [ + default: 1.0e-05, + doc: "the epsilon used by the layer normalization layers" + ], + initializer_scale: [ + default: 0.02, + doc: + "the standard deviation of the normal initializer used for initializing kernel parameters" + ] + ] ++ Shared.common_options([:use_cross_attention, :num_labels, :id_to_label]) + + @moduledoc """ + MPNet model family. + + ## Architectures + + * `:base` - plain MPNet without any head on top + + * `:for_masked_language_modeling` - MPNet with a language modeling + head. The head returns logits for each token in the original + sequence + + ## Inputs + + * `"input_ids"` - `{batch_size, sequence_length}` + + Indices of input sequence tokens in the vocabulary. + + * `"attention_mask"` - `{batch_size, sequence_length}` + + Mask indicating which tokens to attend to. This is used to ignore + padding tokens, which are added when processing a batch of sequences + with different length. + + * `"token_type_ids"` - `{batch_size, sequence_length}` + + Mask distinguishing groups in the input sequence. This is used + in when the input sequence is a semantically a pair of sequences. + + * `"position_ids"` - `{batch_size, sequence_length}` + + Indices of positions of each input sequence tokens in the position + embeddings. + + * `"attention_head_mask"` - `{num_blocks, num_attention_heads}` + + Mask to nullify selected heads of the self-attention blocks in + the encoder. + + ### Exceptions + + The `:for_causal_language_modeling` model is a decoder and accepts + the following additional inputs: `"encoder_hidden_state"`, + `"encoder_attention_mask"`, `"cross_attention_head_mask"`, `"cache"`. + + ## Global layer options + + #{Shared.global_layer_options_doc([:output_hidden_states, :output_attentions])} + + ## Configuration + + #{Shared.options_doc(options)} + + ## References + + * [MPNet: MPNet: Masked and Permuted Pre-training for Language Understanding](https://arxiv.org/pdf/2004.09297) + + """ + + defstruct [architecture: :base] ++ Shared.option_defaults(options) + + @behaviour Bumblebee.ModelSpec + @behaviour Bumblebee.Configurable + @behaviour Bumblebee.Text.Generation + + import Bumblebee.Utils.Model, only: [join: 2] + + alias Bumblebee.Layers + + @impl true + def architectures(), + do: [ + :base, + :for_masked_language_modeling, + ] + + @impl true + def config(spec, opts) do + spec + |> Shared.put_config_attrs(opts) + |> Shared.validate_label_options() + end + + def input_template(_spec) do + %{"input_ids" => Nx.template({1, 1}, :u32)} + end + + @impl true + def model(%__MODULE__{architecture: :base} = spec) do + inputs = inputs(spec) + + inputs + |> core(spec) + |> Layers.output() + end + + def model(%__MODULE__{architecture: :for_masked_language_modeling} = spec) do + inputs = inputs(spec) + outputs = core(inputs, spec) + + logits = language_modeling_head(outputs.hidden_state, spec, name: "language_modeling_head") + + Layers.output(%{ + logits: logits, + hidden_states: outputs.hidden_states, + attentions: outputs.attentions + }) + end + + @impl true + def init_cache(spec, batch_size, max_length, inputs) do + encoder_sequence_length = + if encoder_hidden_state = inputs["encoder_hidden_state"] do + Nx.axis_size(encoder_hidden_state, 1) + end + + Layers.Decoder.init_cache(batch_size, max_length, + hidden_size: spec.hidden_size, + decoder_num_attention_heads: spec.num_attention_heads, + encoder_num_attention_heads: spec.num_attention_heads, + decoder_num_blocks: spec.num_blocks, + encoder_sequence_length: encoder_sequence_length + ) + end + + @impl true + def traverse_cache(_spec, cache, fun) do + Layers.Decoder.traverse_cache(cache, fun) + end + + defp inputs(spec, opts \\ []) do + shape = Keyword.get(opts, :shape, {nil, nil}) + decoder? = Keyword.get(opts, :decoder?, false) + + hidden_shape = Tuple.append(shape, spec.hidden_size) + attention_head_mask_shape = {spec.num_blocks, spec.num_attention_heads} + + inputs = + Bumblebee.Utils.Model.inputs_to_map([ + Axon.input("input_ids", shape: shape), + Axon.input("attention_mask", optional: true, shape: shape), + Axon.input("token_type_ids", optional: true, shape: shape), + Axon.input("position_ids", optional: true, shape: shape), + Axon.input("attention_head_mask", optional: true, shape: attention_head_mask_shape) + ]) + + extra_decoder_inputs = + Bumblebee.Utils.Model.inputs_to_map([ + Axon.input("encoder_hidden_state", optional: true, shape: hidden_shape), + Axon.input("encoder_attention_mask", optional: true, shape: shape), + Axon.input("cross_attention_head_mask", optional: true, shape: attention_head_mask_shape), + Axon.input("cache", optional: true) + ]) + + extra_decoder_inputs = + if decoder? do + extra_decoder_inputs + else + Map.new(extra_decoder_inputs, fn {name, _input} -> {name, Layers.none()} end) + end + + Map.merge(inputs, extra_decoder_inputs) + end + + defp core(inputs, spec, opts \\ []) do + decoder? = Keyword.get(opts, :decoder?, false) + + embeddings = + embedder(inputs["input_ids"], inputs["position_ids"], inputs["token_type_ids"], spec, + name: "embedder" + ) + + encoder_outputs = + encoder( + embeddings, + inputs["attention_mask"], + inputs["attention_head_mask"], + inputs["encoder_hidden_state"], + inputs["encoder_attention_mask"], + inputs["cross_attention_head_mask"], + inputs["cache"], + spec, + decoder?: decoder?, + name: "encoder" + ) + + pooled_state = pooler(encoder_outputs.hidden_state, spec, name: "pooler") + + %{ + hidden_state: encoder_outputs.hidden_state, + pooled_state: pooled_state, + hidden_states: encoder_outputs.hidden_states, + attentions: encoder_outputs.attentions, + cross_attentions: encoder_outputs.cross_attentions, + cache: encoder_outputs.cache + } + end + + defp embedder(input_ids, position_ids, token_type_ids, spec, opts) do + name = opts[:name] + + position_ids = + Layers.default position_ids do + Layers.default_position_ids(input_ids) + end + + token_type_ids = + Layers.default token_type_ids do + Layers.default_token_type_ids(input_ids) + end + + inputs_embeddings = + Axon.embedding(input_ids, spec.vocab_size, spec.hidden_size, + kernel_initializer: kernel_initializer(spec), + name: join(name, "token_embedding") + ) + + position_embeddings = + Axon.embedding(position_ids, spec.max_positions, spec.hidden_size, + kernel_initializer: kernel_initializer(spec), + name: join(name, "position_embedding") + ) + + token_type_embeddings = + Axon.embedding(token_type_ids, spec.max_token_types, spec.hidden_size, + kernel_initializer: kernel_initializer(spec), + name: join(name, "token_type_embedding") + ) + + Axon.add([inputs_embeddings, position_embeddings, token_type_embeddings]) + |> Axon.layer_norm(epsilon: spec.layer_norm_epsilon, name: join(name, "norm")) + |> Axon.dropout(rate: spec.dropout_rate, name: join(name, "dropout")) + end + + defp encoder( + hidden_state, + attention_mask, + attention_head_mask, + encoder_hidden_state, + encoder_attention_mask, + cross_attention_head_mask, + cache, + spec, + opts + ) do + name = opts[:name] + decoder? = opts[:decoder?] + + cross_attention? = decoder? and spec.use_cross_attention + + Layers.Transformer.blocks( + hidden_state, + [ + attention_mask: attention_mask, + attention_head_mask: attention_head_mask, + cache: cache, + causal: decoder?, + num_blocks: spec.num_blocks, + num_attention_heads: spec.num_attention_heads, + hidden_size: spec.hidden_size, + kernel_initializer: kernel_initializer(spec), + dropout_rate: spec.dropout_rate, + attention_dropout_rate: spec.attention_dropout_rate, + layer_norm: [ + epsilon: spec.layer_norm_epsilon + ], + ffn: [ + intermediate_size: spec.intermediate_size, + activation: spec.activation + ], + name: join(name, "blocks") + ] ++ + if(cross_attention?, + do: [ + cross_hidden_state: encoder_hidden_state, + cross_attention_mask: encoder_attention_mask, + cross_attention_head_mask: cross_attention_head_mask + ], + else: [] + ) + ) + end + + defp pooler(hidden_state, spec, opts) do + name = opts[:name] + + hidden_state + |> Layers.take_token(index: 0, axis: 1) + |> Axon.dense(spec.hidden_size, + kernel_initializer: kernel_initializer(spec), + name: join(name, "output") + ) + |> Axon.tanh() + end + + defp language_modeling_head(hidden_state, spec, opts) do + name = opts[:name] + + # TODO: use a shared parameter with embeddings.word_embeddings.kernel + # if spec.tie_word_embeddings is true (relevant for training) + + hidden_state + |> Axon.dense(spec.hidden_size, + kernel_initializer: kernel_initializer(spec), + name: join(name, "dense") + ) + |> Layers.activation(spec.activation, name: join(name, "activation")) + |> Axon.layer_norm(epsilon: spec.layer_norm_epsilon, name: join(name, "norm")) + # We reuse the kernel of input embeddings and add bias for each token + |> Layers.dense_transposed(spec.vocab_size, + kernel_initializer: kernel_initializer(spec), + name: join(name, "output") + ) + |> Axon.bias(name: join(name, "bias")) + end + + defp classifier_dropout_rate(spec) do + spec.classifier_dropout_rate || spec.dropout_rate + end + + defp kernel_initializer(spec) do + Axon.Initializers.normal(scale: spec.initializer_scale) + end + + defimpl Bumblebee.HuggingFace.Transformers.Config do + def load(spec, data) do + import Shared.Converters + + opts = + convert!(data, + vocab_size: {"vocab_size", number()}, + max_positions: {"max_position_embeddings", number()}, + max_token_types: {"type_vocab_size", number()}, + hidden_size: {"hidden_size", number()}, + num_blocks: {"num_hidden_layers", number()}, + num_attention_heads: {"num_attention_heads", number()}, + intermediate_size: {"intermediate_size", number()}, + activation: {"hidden_act", activation()}, + dropout_rate: {"hidden_dropout_prob", number()}, + attention_dropout_rate: {"attention_probs_dropout_prob", number()}, + classifier_dropout_rate: {"classifier_dropout", optional(number())}, + layer_norm_epsilon: {"layer_norm_eps", number()}, + initializer_scale: {"initializer_range", number()} + ) ++ Shared.common_options_from_transformers(data, spec) + + @for.config(spec, opts) + end + end + + defimpl Bumblebee.HuggingFace.Transformers.Model do + def params_mapping(_spec) do + %{ + "embedder.token_embedding" => "mpnet.embeddings.word_embeddings", + "embedder.position_embedding" => "mpnet.embeddings.position_embeddings", + "embedder.token_type_embedding" => "mpnet.embeddings.token_type_embeddings", + "embedder.norm" => "mpnet.embeddings.LayerNorm", + "encoder.blocks.{n}.self_attention.query" => + "mpnet.encoder.layer.{n}.attention.self.query", + "encoder.blocks.{n}.self_attention.key" => "mpnet.encoder.layer.{n}.attention.self.key", + "encoder.blocks.{n}.self_attention.value" => + "mpnet.encoder.layer.{n}.attention.self.value", + "encoder.blocks.{n}.self_attention.output" => + "mpnet.encoder.layer.{n}.attention.output.dense", + "encoder.blocks.{n}.self_attention_norm" => + "mpnet.encoder.layer.{n}.attention.output.LayerNorm", + "encoder.blocks.{n}.cross_attention.query" => + "mpnet.encoder.layer.{n}.crossattention.self.query", + "encoder.blocks.{n}.cross_attention.key" => + "mpnet.encoder.layer.{n}.crossattention.self.key", + "encoder.blocks.{n}.cross_attention.value" => + "mpnet.encoder.layer.{n}.crossattention.self.value", + "encoder.blocks.{n}.cross_attention.output" => + "mpnet.encoder.layer.{n}.crossattention.output.dense", + "encoder.blocks.{n}.cross_attention_norm" => + "mpnet.encoder.layer.{n}.crossattention.output.LayerNorm", + "encoder.blocks.{n}.ffn.intermediate" => "mpnet.encoder.layer.{n}.intermediate.dense", + "encoder.blocks.{n}.ffn.output" => "mpnet.encoder.layer.{n}.output.dense", + "encoder.blocks.{n}.output_norm" => "mpnet.encoder.layer.{n}.output.LayerNorm", + "pooler.output" => "mpnet.pooler.dense", + "language_modeling_head.dense" => "cls.predictions.transform.dense", + "language_modeling_head.norm" => "cls.predictions.transform.LayerNorm", + "language_modeling_head.output" => "cls.predictions.decoder", + "language_modeling_head.bias" => "cls.predictions" + } + end + end +end