457 lines
20 KiB
Python
457 lines
20 KiB
Python
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# coding=utf-8
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# Copyright 2024 Cohere Inc. HuggingFace Inc. team. All rights reserved.
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#
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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import warnings
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from typing import Callable, Optional
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import torch
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import torch.nn as nn
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from ...cache_utils import Cache, DynamicCache
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from ...configuration_utils import PretrainedConfig, layer_type_validation
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from ...masking_utils import create_causal_mask, create_sliding_window_causal_mask
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from ...modeling_flash_attention_utils import FlashAttentionKwargs
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from ...modeling_outputs import BaseModelOutputWithPast
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from ...modeling_rope_utils import rope_config_validation
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from ...modeling_utils import ALL_ATTENTION_FUNCTIONS
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from ...processing_utils import Unpack
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from ...utils import TransformersKwargs, logging
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from ...utils.deprecation import deprecate_kwarg
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from ..cohere.modeling_cohere import (
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CohereAttention,
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CohereDecoderLayer,
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CohereForCausalLM,
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CohereLayerNorm,
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CoherePreTrainedModel,
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CohereRotaryEmbedding,
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apply_rotary_pos_emb,
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eager_attention_forward,
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)
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from ..gemma2.modeling_gemma2 import Gemma2Model
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logger = logging.get_logger(__name__)
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class Cohere2Config(PretrainedConfig):
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r"""
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This is the configuration class to store the configuration of a [`CohereModel`]. It is used to instantiate an Cohere
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model according to the specified arguments, defining the model architecture.
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Configuration objects inherit from [`PretrainedConfig`] and can be used to control the model outputs. Read the
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documentation from [`PretrainedConfig`] for more information. Instantiating a configuration
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with the defaults will yield a similar configuration to that of the [CohereForAI/c4ai-command-r-v01](https://huggingface.co/CohereForAI/c4ai-command-r-v01) model.
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Args:
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vocab_size (`int`, *optional*, defaults to 256000):
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Vocabulary size of the Cohere model. Defines the number of different tokens that can be represented by the
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`inputs_ids` passed when calling [`CohereModel`]
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hidden_size (`int`, *optional*, defaults to 8192):
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Dimension of the hidden representations.
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intermediate_size (`int`, *optional*, defaults to 22528):
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Dimension of the MLP representations.
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logit_scale (`float`, *optional*, defaults to 0.0625):
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The scaling factor for the output logits.
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num_hidden_layers (`int`, *optional*, defaults to 40):
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Number of hidden layers in the Transformer decoder.
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num_attention_heads (`int`, *optional*, defaults to 64):
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Number of attention heads for each attention layer in the Transformer decoder.
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num_key_value_heads (`int`, *optional*):
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This is the number of key_value heads that should be used to implement Grouped Query Attention. If
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`num_key_value_heads=num_attention_heads`, the model will use Multi Head Attention (MHA), if
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`num_key_value_heads=1` the model will use Multi Query Attention (MQA) otherwise GQA is used. When
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converting a multi-head checkpoint to a GQA checkpoint, each group key and value head should be constructed
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by meanpooling all the original heads within that group. For more details, check out [this
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paper](https://huggingface.co/papers/2305.13245). If it is not specified, will default to
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`num_attention_heads`.
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hidden_act (`str` or `function`, *optional*, defaults to `"silu"`):
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The non-linear activation function (function or string) in the decoder.
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max_position_embeddings (`int`, *optional*, defaults to 8192):
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The maximum sequence length that this model might ever be used with.
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initializer_range (`float`, *optional*, defaults to 0.02):
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The standard deviation of the truncated_normal_initializer for initializing all weight matrices.
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layer_norm_eps (`float`, *optional*, defaults to 1e-05):
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The epsilon used by the layer normalization.
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use_cache (`bool`, *optional*, defaults to `True`):
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Whether or not the model should return the last key/values attentions (not used by all models). Only
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relevant if `config.is_decoder=True`.
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pad_token_id (`int`, *optional*, defaults to 0):
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Padding token id.
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bos_token_id (`int`, *optional*, defaults to 5):
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Beginning of stream token id.
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eos_token_id (`int`, *optional*, defaults to 255001):
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End of stream token id.
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tie_word_embeddings (`bool`, *optional*, defaults to `True`):
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Whether to tie weight embeddings
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rope_theta (`float`, *optional*, defaults to 10000.0):
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The base period of the RoPE embeddings.
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rope_scaling (`Dict`, *optional*):
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Dictionary containing the scaling configuration for the RoPE embeddings. NOTE: if you apply new rope type
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and you expect the model to work on longer `max_position_embeddings`, we recommend you to update this value
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accordingly.
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Expected contents:
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`rope_type` (`str`):
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The sub-variant of RoPE to use. Can be one of ['default', 'linear', 'dynamic', 'yarn', 'longrope',
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'llama3'], with 'default' being the original RoPE implementation.
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`factor` (`float`, *optional*):
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Used with all rope types except 'default'. The scaling factor to apply to the RoPE embeddings. In
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most scaling types, a `factor` of x will enable the model to handle sequences of length x *
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original maximum pre-trained length.
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`original_max_position_embeddings` (`int`, *optional*):
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Used with 'dynamic', 'longrope' and 'llama3'. The original max position embeddings used during
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pretraining.
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`attention_factor` (`float`, *optional*):
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Used with 'yarn' and 'longrope'. The scaling factor to be applied on the attention
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computation. If unspecified, it defaults to value recommended by the implementation, using the
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`factor` field to infer the suggested value.
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`beta_fast` (`float`, *optional*):
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Only used with 'yarn'. Parameter to set the boundary for extrapolation (only) in the linear
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ramp function. If unspecified, it defaults to 32.
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`beta_slow` (`float`, *optional*):
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Only used with 'yarn'. Parameter to set the boundary for interpolation (only) in the linear
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ramp function. If unspecified, it defaults to 1.
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`short_factor` (`list[float]`, *optional*):
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Only used with 'longrope'. The scaling factor to be applied to short contexts (<
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`original_max_position_embeddings`). Must be a list of numbers with the same length as the hidden
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size divided by the number of attention heads divided by 2
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`long_factor` (`list[float]`, *optional*):
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Only used with 'longrope'. The scaling factor to be applied to long contexts (<
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`original_max_position_embeddings`). Must be a list of numbers with the same length as the hidden
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size divided by the number of attention heads divided by 2
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`low_freq_factor` (`float`, *optional*):
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Only used with 'llama3'. Scaling factor applied to low frequency components of the RoPE
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`high_freq_factor` (`float`, *optional*):
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Only used with 'llama3'. Scaling factor applied to high frequency components of the RoPE
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attention_bias (`bool`, defaults to `False`, *optional*, defaults to `False`):
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Whether to use a bias in the query, key, value and output projection layers during self-attention.
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attention_dropout (`float`, *optional*, defaults to 0.0):
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The dropout ratio for the attention probabilities.
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sliding_window (`int`, *optional*, defaults to 4096):
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Size of the sliding window attention context.
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layer_types (`list`, *optional*):
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Attention pattern for each layer.
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```python
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>>> from transformers import Cohere2Model, Cohere2Config
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>>> # Initializing a Cohere Nextmodel configuration
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>>> configuration = Cohere2Config()
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>>> # Initializing a model from the Cohere2 configuration
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>>> model = Cohere2Model(configuration) # doctest: +SKIP
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>>> # Accessing the model configuration
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>>> configuration = model.config # doctest: +SKIP
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```
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"""
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model_type = "cohere2"
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keys_to_ignore_at_inference = ["past_key_values"]
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base_model_tp_plan = {
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"layers.*.self_attn.q_proj": "colwise",
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"layers.*.self_attn.k_proj": "colwise",
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"layers.*.self_attn.v_proj": "colwise",
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"layers.*.self_attn.o_proj": "rowwise",
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"layers.*.mlp.gate_proj": "colwise",
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"layers.*.mlp.up_proj": "colwise",
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"layers.*.mlp.down_proj": "rowwise",
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}
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base_model_pp_plan = {
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"embed_tokens": (["input_ids"], ["inputs_embeds"]),
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"layers": (["hidden_states", "attention_mask"], ["hidden_states"]),
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"norm": (["hidden_states"], ["hidden_states"]),
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}
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def __init__(
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self,
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vocab_size=256000,
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hidden_size=8192,
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intermediate_size=22528,
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logit_scale=0.0625,
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num_hidden_layers=40,
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num_attention_heads=64,
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num_key_value_heads=None,
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hidden_act="silu",
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max_position_embeddings=8192,
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initializer_range=0.02,
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layer_norm_eps=1e-5,
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use_cache=True,
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pad_token_id=0,
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bos_token_id=5,
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eos_token_id=255001,
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tie_word_embeddings=True,
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rope_theta=10000.0,
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rope_scaling=None,
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attention_bias=False,
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attention_dropout=0.0,
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sliding_window=4096,
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layer_types=None,
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**kwargs,
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):
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self.vocab_size = vocab_size
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self.max_position_embeddings = max_position_embeddings
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self.hidden_size = hidden_size
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self.logit_scale = logit_scale
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self.intermediate_size = intermediate_size
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self.num_hidden_layers = num_hidden_layers
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self.num_attention_heads = num_attention_heads
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# for backward compatibility
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if num_key_value_heads is None:
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num_key_value_heads = num_attention_heads
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self.num_key_value_heads = num_key_value_heads
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self.hidden_act = hidden_act
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self.initializer_range = initializer_range
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self.layer_norm_eps = layer_norm_eps
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self.use_cache = use_cache
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self.rope_theta = rope_theta
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self.rope_scaling = rope_scaling
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self.attention_bias = attention_bias
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self.attention_dropout = attention_dropout
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self.sliding_window = sliding_window
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self.layer_types = layer_types
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# Need to specify head_dim in the config so it can be used in the attention forward functions
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self.head_dim = hidden_size // num_attention_heads
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# Validate the correctness of rotary position embeddings parameters
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rope_config_validation(self)
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super().__init__(
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pad_token_id=pad_token_id,
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bos_token_id=bos_token_id,
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eos_token_id=eos_token_id,
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tie_word_embeddings=tie_word_embeddings,
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**kwargs,
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)
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# BC -> the pattern used to be a simple int, and it's still present in configs on the Hub
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self._sliding_window_pattern = kwargs.get("sliding_window_pattern", 4)
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if self.layer_types is None:
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# BC -> the pattern used to be a simple int, and it's still present in configs on the Hub
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self._sliding_window_pattern = getattr(self, "sliding_window_pattern", 4)
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self.layer_types = [
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"sliding_attention" if bool((i + 1) % self._sliding_window_pattern) else "full_attention"
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for i in range(self.num_hidden_layers)
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]
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layer_type_validation(self.layer_types)
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@property
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def sliding_window_pattern(self):
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warnings.warn(
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"The `sliding_window_pattern` attribute is deprecated and will be removed in v4.55.0.",
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FutureWarning,
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)
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return self._sliding_window_pattern
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@sliding_window_pattern.setter
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def sliding_window_pattern(self, value):
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self._sliding_window_pattern = value
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class Cohere2RotaryEmbedding(CohereRotaryEmbedding):
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pass
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class Cohere2LayerNorm(CohereLayerNorm):
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pass
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class Cohere2Attention(CohereAttention, nn.Module):
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"""Multi-headed attention from 'Attention Is All You Need' paper"""
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def __init__(self, config: Cohere2Config, layer_idx: Optional[int] = None):
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nn.Module.__init__()
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self.config = config
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self.layer_idx = layer_idx
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self.head_dim = getattr(config, "head_dim", config.hidden_size // config.num_attention_heads)
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self.num_key_value_groups = config.num_attention_heads // config.num_key_value_heads
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self.scaling = self.head_dim**-0.5
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self.attention_dropout = config.attention_dropout
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self.is_causal = True
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self.sliding_window = config.sliding_window if config.layer_types[layer_idx] == "sliding_attention" else None
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self.q_proj = nn.Linear(
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config.hidden_size, config.num_attention_heads * self.head_dim, bias=config.attention_bias
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)
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self.k_proj = nn.Linear(
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config.hidden_size, config.num_key_value_heads * self.head_dim, bias=config.attention_bias
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)
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self.v_proj = nn.Linear(
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config.hidden_size, config.num_key_value_heads * self.head_dim, bias=config.attention_bias
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)
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self.o_proj = nn.Linear(
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config.num_attention_heads * self.head_dim, config.hidden_size, bias=config.attention_bias
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)
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def forward(
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self,
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hidden_states: torch.Tensor,
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position_embeddings: tuple[torch.Tensor, torch.Tensor],
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attention_mask: Optional[torch.Tensor],
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past_key_value: Optional[Cache] = None,
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cache_position: Optional[torch.LongTensor] = None,
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**kwargs: Unpack[FlashAttentionKwargs],
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) -> tuple[torch.Tensor, Optional[torch.Tensor], Optional[tuple[torch.Tensor]]]:
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input_shape = hidden_states.shape[:-1]
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hidden_shape = (*input_shape, -1, self.head_dim)
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query_states = self.q_proj(hidden_states).view(hidden_shape).transpose(1, 2)
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key_states = self.k_proj(hidden_states).view(hidden_shape).transpose(1, 2)
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value_states = self.v_proj(hidden_states).view(hidden_shape).transpose(1, 2)
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cos, sin = position_embeddings
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if self.sliding_window is not None:
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query_states, key_states = apply_rotary_pos_emb(query_states, key_states, cos, sin)
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if past_key_value is not None:
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cache_kwargs = {"sin": sin, "cos": cos, "cache_position": cache_position}
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key_states, value_states = past_key_value.update(key_states, value_states, self.layer_idx, cache_kwargs)
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attention_interface: Callable = eager_attention_forward
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if self.config._attn_implementation != "eager":
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attention_interface = ALL_ATTENTION_FUNCTIONS[self.config._attn_implementation]
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attn_output, attn_weights = attention_interface(
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self,
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query_states,
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key_states,
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value_states,
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attention_mask,
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dropout=0.0 if not self.training else self.attention_dropout,
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scaling=self.scaling,
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sliding_window=self.sliding_window,
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**kwargs,
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)
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attn_output = attn_output.reshape(*input_shape, -1).contiguous()
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attn_output = self.o_proj(attn_output)
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return attn_output, attn_weights
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class Cohere2DecoderLayer(CohereDecoderLayer):
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def __init__(self, config: Cohere2Config, layer_idx: int):
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super().__init__(config, layer_idx)
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self.attention_type = config.layer_types[layer_idx]
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@deprecate_kwarg("last_cache_position", version="4.53.0")
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def forward(
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self,
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hidden_states: torch.Tensor,
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position_embeddings: tuple[torch.Tensor, torch.Tensor],
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attention_mask: Optional[torch.Tensor] = None,
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past_key_value: Optional[Cache] = None,
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use_cache: Optional[bool] = False,
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cache_position: Optional[torch.LongTensor] = None,
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**kwargs: Unpack[FlashAttentionKwargs],
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) -> tuple[torch.FloatTensor, Optional[tuple[torch.FloatTensor, torch.FloatTensor]]]:
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residual = hidden_states
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hidden_states = self.input_layernorm(hidden_states)
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hidden_states_attention, _ = self.self_attn(
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hidden_states=hidden_states,
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position_embeddings=position_embeddings,
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attention_mask=attention_mask,
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past_key_value=past_key_value,
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use_cache=use_cache,
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cache_position=cache_position,
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**kwargs,
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)
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hidden_states_mlp = self.mlp(hidden_states)
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hidden_states = residual + hidden_states_attention + hidden_states_mlp
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|
return hidden_states
|
||
|
|
||
|
|
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|
class Cohere2PreTrainedModel(CoherePreTrainedModel):
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|
config: Cohere2Config
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|
|
||
|
|
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|
class Cohere2Model(Gemma2Model):
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|
def __init__(self, config: Cohere2Config):
|
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|
super().__init__(config)
|
||
|
self.norm = Cohere2LayerNorm(hidden_size=(config.hidden_size), eps=config.layer_norm_eps)
|
||
|
self.rotary_emb = Cohere2RotaryEmbedding(config=config)
|
||
|
|
||
|
def forward(
|
||
|
self,
|
||
|
input_ids: Optional[torch.LongTensor] = None,
|
||
|
attention_mask: Optional[torch.Tensor] = None,
|
||
|
position_ids: Optional[torch.LongTensor] = None,
|
||
|
past_key_values: Optional[Cache] = None,
|
||
|
inputs_embeds: Optional[torch.FloatTensor] = None,
|
||
|
use_cache: Optional[bool] = None,
|
||
|
cache_position: Optional[torch.LongTensor] = None,
|
||
|
**kwargs: Unpack[TransformersKwargs],
|
||
|
) -> BaseModelOutputWithPast:
|
||
|
if (input_ids is None) ^ (inputs_embeds is not None):
|
||
|
raise ValueError("You must specify exactly one of input_ids or inputs_embeds")
|
||
|
|
||
|
if inputs_embeds is None:
|
||
|
inputs_embeds = self.embed_tokens(input_ids)
|
||
|
|
||
|
if use_cache and past_key_values is None and not self.training:
|
||
|
past_key_values = DynamicCache()
|
||
|
|
||
|
if cache_position is None:
|
||
|
past_seen_tokens = past_key_values.get_seq_length() if past_key_values is not None else 0
|
||
|
cache_position = torch.arange(
|
||
|
past_seen_tokens, past_seen_tokens + inputs_embeds.shape[1], device=inputs_embeds.device
|
||
|
)
|
||
|
if position_ids is None:
|
||
|
position_ids = cache_position.unsqueeze(0)
|
||
|
|
||
|
if not isinstance(causal_mask_mapping := attention_mask, dict):
|
||
|
mask_kwargs = {
|
||
|
"config": self.config,
|
||
|
"input_embeds": inputs_embeds,
|
||
|
"attention_mask": attention_mask,
|
||
|
"cache_position": cache_position,
|
||
|
"past_key_values": past_key_values,
|
||
|
"position_ids": position_ids,
|
||
|
}
|
||
|
causal_mask_mapping = {
|
||
|
"full_attention": create_causal_mask(**mask_kwargs),
|
||
|
"sliding_attention": create_sliding_window_causal_mask(**mask_kwargs),
|
||
|
}
|
||
|
|
||
|
hidden_states = inputs_embeds
|
||
|
position_embeddings = self.rotary_emb(hidden_states, position_ids)
|
||
|
|
||
|
for decoder_layer in self.layers:
|
||
|
hidden_states = decoder_layer(
|
||
|
hidden_states,
|
||
|
position_embeddings=position_embeddings,
|
||
|
attention_mask=causal_mask_mapping[decoder_layer.attention_type],
|
||
|
past_key_value=past_key_values,
|
||
|
use_cache=use_cache,
|
||
|
cache_position=cache_position,
|
||
|
**kwargs,
|
||
|
)
|
||
|
|
||
|
hidden_states = self.norm(hidden_states)
|
||
|
return BaseModelOutputWithPast(
|
||
|
last_hidden_state=hidden_states,
|
||
|
past_key_values=past_key_values,
|
||
|
)
|
||
|
|
||
|
|
||
|
class Cohere2ForCausalLM(CohereForCausalLM):
|
||
|
pass
|
||
|
|
||
|
|
||
|
__all__ = ["Cohere2Config", "Cohere2ForCausalLM", "Cohere2Model", "Cohere2PreTrainedModel"]
|