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| 1 | +# Copyright © 2025 Apple Inc. |
| 2 | + |
| 3 | +from dataclasses import dataclass |
| 4 | +from typing import Optional |
| 5 | + |
| 6 | +import mlx.core as mx |
| 7 | +import mlx.nn as nn |
| 8 | +from mlx.utils import tree_flatten, tree_unflatten |
| 9 | + |
| 10 | +from . import gemma4_text |
| 11 | +from .base import BaseModelArgs |
| 12 | + |
| 13 | + |
| 14 | +@dataclass |
| 15 | +class ModelArgs(BaseModelArgs): |
| 16 | + model_type: str = "gemma4" |
| 17 | + text_config: dict = None |
| 18 | + vocab_size: int = 262144 |
| 19 | + |
| 20 | + def __post_init__(self): |
| 21 | + if self.text_config is None: |
| 22 | + self.text_config = {} |
| 23 | + self.text_config["vocab_size"] = self.vocab_size |
| 24 | + self.text_config["num_attention_heads"] = self.text_config.get( |
| 25 | + "num_attention_heads", 8 |
| 26 | + ) |
| 27 | + self.text_config["num_key_value_heads"] = self.text_config.get( |
| 28 | + "num_key_value_heads", 1 |
| 29 | + ) |
| 30 | + |
| 31 | + |
| 32 | +class Model(nn.Module): |
| 33 | + def __init__(self, args: ModelArgs): |
| 34 | + super().__init__() |
| 35 | + self.args = args |
| 36 | + self.model_type = args.model_type |
| 37 | + self.language_model = gemma4_text.Model( |
| 38 | + gemma4_text.ModelArgs.from_dict(args.text_config) |
| 39 | + ) |
| 40 | + |
| 41 | + def __call__( |
| 42 | + self, |
| 43 | + inputs: mx.array, |
| 44 | + cache=None, |
| 45 | + input_embeddings: Optional[mx.array] = None, |
| 46 | + per_layer_inputs: Optional[mx.array] = None, |
| 47 | + ): |
| 48 | + return self.language_model( |
| 49 | + inputs, |
| 50 | + cache=cache, |
| 51 | + input_embeddings=input_embeddings, |
| 52 | + per_layer_inputs=per_layer_inputs, |
| 53 | + ) |
| 54 | + |
| 55 | + def sanitize(self, weights): |
| 56 | + new_weights = {} |
| 57 | + for k, v in weights.items(): |
| 58 | + starts_w_model = k.startswith("model.") |
| 59 | + |
| 60 | + k = k.removeprefix("model.") |
| 61 | + if k.startswith( |
| 62 | + ( |
| 63 | + "vision_tower", |
| 64 | + "multi_modal_projector", |
| 65 | + "audio_tower", |
| 66 | + "embed_audio", |
| 67 | + "embed_vision", |
| 68 | + ) |
| 69 | + ): |
| 70 | + continue |
| 71 | + |
| 72 | + if not starts_w_model: |
| 73 | + new_weights[k] = v |
| 74 | + continue |
| 75 | + |
| 76 | + if k.startswith("language_model"): |
| 77 | + k = k.replace("language_model.", "language_model.model.") |
| 78 | + |
| 79 | + new_weights[k] = v |
| 80 | + |
| 81 | + return self.language_model.sanitize(new_weights) |
| 82 | + |
| 83 | + @property |
| 84 | + def layers(self): |
| 85 | + return self.language_model.layers |
| 86 | + |
| 87 | + @property |
| 88 | + def quant_predicate(self): |
| 89 | + return self.language_model.quant_predicate |
| 90 | + |
| 91 | + def make_cache(self): |
| 92 | + return self.language_model.make_cache() |
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