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# Copyright 2023 The OpenAI Team Authors and HuggingFace Inc. team.
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"""RWKV configuration"""

from ...configuration_utils import PreTrainedConfig
from ...utils import logging


logger = logging.get_logger(__name__)


class RwkvConfig(PreTrainedConfig):
    """
    This is the configuration class to store the configuration of a [`RwkvModel`]. It is used to instantiate a RWKV
    model according to the specified arguments, defining the model architecture. Instantiating a configuration with the
    defaults will yield a similar configuration to that of the RWVK-4
    [RWKV/rwkv-4-169m-pile](https://huggingface.co/RWKV/rwkv-4-169m-pile) architecture.

    Configuration objects inherit from [`PreTrainedConfig`] and can be used to control the model outputs. Read the
    documentation from [`PreTrainedConfig`] for more information.


    Args:
        vocab_size (`int`, *optional*, defaults to 50277):
            Vocabulary size of the RWKV model. Defines the number of different tokens that can be represented by the
            `inputs_ids` passed when calling [`RwkvModel`].
        context_length (`int`, *optional*, defaults to 1024):
            The maximum sequence length that this model can be used with in a single forward (using it in RNN mode
            lets use any sequence length).
        hidden_size (`int`, *optional*, defaults to 4096):
            Dimensionality of the embeddings and hidden states.
        num_hidden_layers (`int`, *optional*, defaults to 32):
            Number of hidden layers in the model.
        attention_hidden_size (`int`, *optional*):
            Dimensionality of the attention hidden states. Will default to `hidden_size` if unset.
        intermediate_size (`int`, *optional*):
            Dimensionality of the inner feed-forward layers. Will default to 4 times `hidden_size` if unset.
        layer_norm_epsilon (`float`, *optional*, defaults to 1e-05):
            The epsilon to use in the layer normalization layers.
        bos_token_id (`int`, *optional*, defaults to 0):
            The id of the beginning of sentence token in the vocabulary. Defaults to 0 as RWKV uses the same tokenizer
            as GPTNeoX.
        eos_token_id (`int`, *optional*, defaults to 0):
            The id of the end of sentence token in the vocabulary. Defaults to 0 as RWKV uses the same tokenizer as
            GPTNeoX.
        rescale_every (`int`, *optional*, defaults to 6):
            At inference, the hidden states (and weights of the corresponding output layers) are divided by 2 every
            `rescale_every` layer. If set to 0 or a negative number, no rescale is done.
        tie_word_embeddings (`bool`, *optional*, defaults to `False`):
            Whether or not to tie the word embeddings with the input token embeddings.
        use_cache (`bool`, *optional*, defaults to `True`):
            Whether or not the model should return the last state.


    Example:

    ```python
    >>> from transformers import RwkvConfig, RwkvModel

    >>> # Initializing a Rwkv configuration
    >>> configuration = RwkvConfig()

    >>> # Initializing a model (with random weights) from the configuration
    >>> model = RwkvModel(configuration)

    >>> # Accessing the model configuration
    >>> configuration = model.config
    ```"""

    model_type = "rwkv"
    attribute_map = {"max_position_embeddings": "context_length"}

    def __init__(
        self,
        vocab_size=50277,
        context_length=1024,
        hidden_size=4096,
        num_hidden_layers=32,
        attention_hidden_size=None,
        intermediate_size=None,
        layer_norm_epsilon=1e-5,
        bos_token_id=0,
        eos_token_id=0,
        rescale_every=6,
        tie_word_embeddings=False,
        use_cache=True,
        **kwargs,
    ):
        self.vocab_size = vocab_size
        self.context_length = context_length
        self.hidden_size = hidden_size
        self.num_hidden_layers = num_hidden_layers
        self.attention_hidden_size = attention_hidden_size if attention_hidden_size is not None else hidden_size
        self.intermediate_size = intermediate_size if intermediate_size is not None else 4 * hidden_size
        self.layer_norm_epsilon = layer_norm_epsilon
        self.rescale_every = rescale_every
        self.use_cache = use_cache

        self.bos_token_id = bos_token_id
        self.eos_token_id = eos_token_id

        super().__init__(
            tie_word_embeddings=tie_word_embeddings, bos_token_id=bos_token_id, eos_token_id=eos_token_id, **kwargs
        )


__all__ = ["RwkvConfig"]
