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# Licensed under the Apache License, Version 2.0 (the "License");
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#     http://www.apache.org/licenses/LICENSE-2.0
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from transformers import PretrainedConfig


class Ernie4_5_Config(PretrainedConfig):
    """
    Configuration class.

    This class stores the configuration of an Ernie model, defining the model architecture.
    It inherits from PretrainedConfig and can be used to control model outputs.
    """

    model_type = "ernie4_5"
    keys_to_ignore_at_inference = ["past_key_values"]

    # Default tensor parallel plan for base model `Qwen3`
    base_model_tp_plan = {
        "layers.*.self_attn.q_proj": "colwise",
        "layers.*.self_attn.k_proj": "colwise",
        "layers.*.self_attn.v_proj": "colwise",
        "layers.*.self_attn.o_proj": "rowwise",
        "layers.*.mlp.gate_proj": "colwise",
        "layers.*.mlp.up_proj": "colwise",
        "layers.*.mlp.down_proj": "rowwise",
    }
    base_model_pp_plan = {
        "embed_tokens": (["input_ids"], ["inputs_embeds"]),
        "layers": (["hidden_states", "attention_mask"], ["hidden_states"]),
        "norm": (["hidden_states"], ["hidden_states"]),
    }

    def __init__(
        self,
        vocab_size=32000,
        hidden_size=768,
        intermediate_size=11008,
        max_position_embeddings=32768,
        num_hidden_layers=2,
        num_attention_heads=2,
        rms_norm_eps=1e-6,
        use_cache=False,
        use_flash_attention=False,
        pad_token_id=0,
        bos_token_id=1,
        eos_token_id=2,
        use_bias=False,
        rope_theta=10000,
        weight_share_add_bias=True,
        ignored_index=-100,
        attention_probs_dropout_prob=0.0,
        hidden_dropout_prob=0.0,
        compression_ratio: float = 1.0,
        num_key_value_heads=None,
        max_sequence_length=None,
        **kwargs,
    ):
        """
        Initialize configuration with default or specified parameters.

        Args:
            vocab_size (int): Size of the vocabulary (number of unique tokens)
            hidden_size (int): Dimensionality of the encoder layers and the pooler layer
            intermediate_size (int): Dimensionality of the "intermediate" (feed-forward) layer
            max_position_embeddings (int): Maximum sequence length the model can handle
            num_hidden_layers (int): Number of hidden layers in the Transformer encoder
            num_attention_heads (int): Number of attention heads for each attention layer
            rms_norm_eps (float): The epsilon used by the RMS normalization layers
            use_cache (bool): Whether to use caching for faster generation (decoding)
            use_flash_attention (bool): Whether to use FlashAttention for optimized attention computation
            pad_token_id (int): Token ID used for padding sequences
            bos_token_id (int): Token ID used for beginning-of-sequence
            eos_token_id (int): Token ID used for end-of-sequence
            use_bias (bool): Whether to use bias terms in linear layers
            rope_theta (float): The base period of the RoPE embeddings
            weight_share_add_bias (bool): Whether to share bias weights in certain layers
            ignored_index (int): Target value that is ignored during loss computation
            attention_probs_dropout_prob (float): Dropout probability for attention weights
            hidden_dropout_prob (float): Dropout probability for hidden layers
            compression_ratio (float): Ratio for KV cache compression (1.0 = no compression)
            num_key_value_heads (int): Number of key/value heads (for Grouped Query Attention)
            max_sequence_length (int): Maximum sequence length for positional embeddings
            **kwargs: Additional keyword arguments passed to parent class
        """

        # Set default for tied embeddings if not specified.
        if "tie_word_embeddings" not in kwargs:
            kwargs["tie_word_embeddings"] = False
        super().__init__(
            pad_token_id=pad_token_id,
            bos_token_id=bos_token_id,
            eos_token_id=eos_token_id,
            **kwargs,
        )
        self.vocab_size = vocab_size
        self.hidden_size = hidden_size
        self.intermediate_size = intermediate_size
        self.max_position_embeddings = max_position_embeddings
        self.num_hidden_layers = num_hidden_layers
        self.num_attention_heads = num_attention_heads
        self.rms_norm_eps = rms_norm_eps
        self.use_cache = use_cache
        self.use_flash_attention = use_flash_attention
        self.pad_token_id = pad_token_id
        self.bos_token_id = bos_token_id
        self.eos_token_id = eos_token_id
        self.use_bias = use_bias
        self.weight_share_add_bias = weight_share_add_bias
        self.rope_theta = rope_theta
        self.ignored_index = ignored_index
        self.attention_probs_dropout_prob = attention_probs_dropout_prob
        self.hidden_dropout_prob = hidden_dropout_prob
        self.compression_ratio = compression_ratio
        self.num_key_value_heads = num_key_value_heads
        self.max_sequence_length = max_sequence_length