model : Nomic Embed Text V2 with Mixture-of-Experts (MoE) architecture (#12466)

* Nomic Embed Text V2 with Mixture-of-Experts (MoE) architecture

- Adds MoE-based embedding model supporting multilingual embeddings.
- Selects architecture variant based on hyperparameter detection (MoE layers).
- Removes unnecessary subclass initialization checks for clarity.

https://www.nomic.ai/blog/posts/nomic-embed-text-v2

Co-authored-by: Jared Van Bortel <jared@nomic.ai>

* fix tokenizer

* don't rename this tensor

---------

Co-authored-by: Jared Van Bortel <jared@nomic.ai>
This commit is contained in:
AT 2025-04-28 15:52:15 -04:00 committed by GitHub
parent eaea325324
commit 5f5e39e1ba
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9 changed files with 247 additions and 110 deletions

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@ -78,7 +78,7 @@ class ModelBase:
# subclasses should define this!
model_arch: gguf.MODEL_ARCH
def __init__(self, dir_model: Path, ftype: gguf.LlamaFileType, fname_out: Path, is_big_endian: bool = False,
def __init__(self, dir_model: Path, ftype: gguf.LlamaFileType, fname_out: Path, *, is_big_endian: bool = False,
use_temp_file: bool = False, eager: bool = False,
metadata_override: Path | None = None, model_name: str | None = None,
split_max_tensors: int = 0, split_max_size: int = 0, dry_run: bool = False,
@ -454,13 +454,6 @@ class ModelBase:
class TextModel(ModelBase):
@classmethod
def __init_subclass__(cls):
# can't use an abstract property, because overriding it without type errors
# would require using decorated functions instead of simply defining the property
if "model_arch" not in cls.__dict__:
raise TypeError(f"Missing property 'model_arch' for {cls.__name__!r}")
def set_vocab(self):
self._set_vocab_gpt2()
@ -3373,14 +3366,7 @@ class BertModel(TextModel):
return [(self.map_tensor_name(name), data_torch)]
@ModelBase.register("RobertaModel")
class RobertaModel(BertModel):
model_arch = gguf.MODEL_ARCH.BERT
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
def _xlmroberta_tokenizer_init(self) -> None:
# we need the pad_token_id to know how to chop down position_embd matrix
if (pad_token_id := self.hparams.get("pad_token_id")) is not None:
self._position_offset = 1 + pad_token_id
@ -3389,82 +3375,7 @@ class RobertaModel(BertModel):
else:
self._position_offset = None
def set_vocab(self):
"""Support BPE tokenizers for roberta models"""
bpe_tok_path = self.dir_model / "tokenizer.json"
if bpe_tok_path.exists():
self._set_vocab_gpt2()
self.gguf_writer.add_add_bos_token(True)
self.gguf_writer.add_add_eos_token(True)
# we need this to validate the size of the token_type embeddings
# though currently we are passing all zeros to the token_type embeddings
# "Sequence A" or "Sequence B"
self.gguf_writer.add_token_type_count(self.hparams.get("type_vocab_size", 1))
else:
return super().set_vocab()
def modify_tensors(self, data_torch: Tensor, name: str, bid: int | None) -> Iterable[tuple[str, Tensor]]:
# if name starts with "roberta.", remove the prefix
# e.g. https://huggingface.co/BAAI/bge-reranker-v2-m3/tree/main
if name.startswith("roberta."):
name = name[8:]
# position embeddings start at pad_token_id + 1, so just chop down the weight tensor
if name == "embeddings.position_embeddings.weight":
if self._position_offset is not None:
data_torch = data_torch[self._position_offset:,:]
return super().modify_tensors(data_torch, name, bid)
@ModelBase.register("NomicBertModel")
class NomicBertModel(BertModel):
model_arch = gguf.MODEL_ARCH.NOMIC_BERT
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
# the HF config claims n_ctx=8192, but it uses RoPE scaling
self.hparams["n_ctx"] = 2048
# SwigLU activation
assert self.hparams["activation_function"] == "swiglu"
# this doesn't do anything in the HF version
assert self.hparams["causal"] is False
# no bias tensors
assert self.hparams["qkv_proj_bias"] is False
assert self.hparams["mlp_fc1_bias"] is False
assert self.hparams["mlp_fc2_bias"] is False
# norm at end of layer
assert self.hparams["prenorm"] is False
# standard RoPE
assert self.hparams["rotary_emb_fraction"] == 1.0
assert self.hparams["rotary_emb_interleaved"] is False
assert self.hparams["rotary_emb_scale_base"] is None
def set_gguf_parameters(self):
super().set_gguf_parameters()
self.gguf_writer.add_rope_freq_base(self.hparams["rotary_emb_base"])
@ModelBase.register("XLMRobertaModel", "XLMRobertaForSequenceClassification")
class XLMRobertaModel(BertModel):
model_arch = gguf.MODEL_ARCH.BERT
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
# we need the pad_token_id to know how to chop down position_embd matrix
if (pad_token_id := self.hparams.get("pad_token_id")) is not None:
self._position_offset = 1 + pad_token_id
if "max_position_embeddings" in self.hparams:
self.hparams["max_position_embeddings"] -= self._position_offset
else:
self._position_offset = None
def set_vocab(self):
def _xlmroberta_set_vocab(self) -> None:
# to avoid TypeError: Descriptors cannot be created directly
# exception when importing sentencepiece_model_pb2
os.environ["PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION"] = "python"
@ -3546,6 +3457,138 @@ class XLMRobertaModel(BertModel):
self.gguf_writer.add_add_bos_token(True)
self.gguf_writer.add_add_eos_token(True)
@ModelBase.register("RobertaModel")
class RobertaModel(BertModel):
model_arch = gguf.MODEL_ARCH.BERT
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
# we need the pad_token_id to know how to chop down position_embd matrix
if (pad_token_id := self.hparams.get("pad_token_id")) is not None:
self._position_offset = 1 + pad_token_id
if "max_position_embeddings" in self.hparams:
self.hparams["max_position_embeddings"] -= self._position_offset
else:
self._position_offset = None
def set_vocab(self):
"""Support BPE tokenizers for roberta models"""
bpe_tok_path = self.dir_model / "tokenizer.json"
if bpe_tok_path.exists():
self._set_vocab_gpt2()
self.gguf_writer.add_add_bos_token(True)
self.gguf_writer.add_add_eos_token(True)
# we need this to validate the size of the token_type embeddings
# though currently we are passing all zeros to the token_type embeddings
# "Sequence A" or "Sequence B"
self.gguf_writer.add_token_type_count(self.hparams.get("type_vocab_size", 1))
else:
return super().set_vocab()
def modify_tensors(self, data_torch: Tensor, name: str, bid: int | None) -> Iterable[tuple[str, Tensor]]:
# if name starts with "roberta.", remove the prefix
# e.g. https://huggingface.co/BAAI/bge-reranker-v2-m3/tree/main
if name.startswith("roberta."):
name = name[8:]
# position embeddings start at pad_token_id + 1, so just chop down the weight tensor
if name == "embeddings.position_embeddings.weight":
if self._position_offset is not None:
data_torch = data_torch[self._position_offset:,:]
return super().modify_tensors(data_torch, name, bid)
@ModelBase.register("NomicBertModel")
class NomicBertModel(BertModel):
def __init__(self, dir_model: Path, ftype: gguf.LlamaFileType, fname_out: Path, **kwargs: Any):
hparams = kwargs.pop("hparams", None)
if hparams is None:
hparams = ModelBase.load_hparams(dir_model)
self.is_moe = bool(hparams.get("moe_every_n_layers"))
self.model_arch = gguf.MODEL_ARCH.NOMIC_BERT_MOE if self.is_moe else gguf.MODEL_ARCH.NOMIC_BERT
super().__init__(dir_model, ftype, fname_out, hparams=hparams, **kwargs)
self._tokenizer_is_xlmroberta = self._is_tokenizer_xlmroberta()
if self._tokenizer_is_xlmroberta:
self._xlmroberta_tokenizer_init()
# the HF config claims n_ctx=8192, but it uses RoPE scaling
self.hparams["n_ctx"] = 2048
assert self.hparams["activation_function"] == "gelu" if self.is_moe else "swiglu"
# this doesn't do anything in the HF version
assert self.hparams["causal"] is False
# no bias tensors unless MoE
assert self.hparams["qkv_proj_bias"] == self.is_moe
assert self.hparams["mlp_fc1_bias"] == self.is_moe
assert self.hparams["mlp_fc2_bias"] == self.is_moe
# norm at end of layer
assert self.hparams["prenorm"] is False
# standard RoPE
assert self.hparams["rotary_emb_fraction"] == 1.0
assert self.hparams["rotary_emb_interleaved"] is False
assert self.hparams["rotary_emb_scale_base"] is None
def set_vocab(self) -> None:
if self._tokenizer_is_xlmroberta:
return self._xlmroberta_set_vocab()
return super().set_vocab()
def modify_tensors(self, data_torch: torch.Tensor, name: str, bid: int | None) -> Iterable[tuple[str, torch.Tensor]]:
# If the tensor is an experts bias tensor, skip it by returning an empty list.
if "mlp.experts.bias" in name:
return [] # Explicitly return an empty list.
if "mlp.experts.mlp.w1" in name:
data_torch = data_torch.view(self.hparams["num_experts"], self.hparams["n_inner"], self.hparams["n_embd"])
name += ".weight"
if "mlp.experts.mlp.w2" in name:
data_torch = data_torch.view(self.hparams["num_experts"], self.hparams["n_inner"], self.hparams["n_embd"])
data_torch = data_torch.transpose(1, 2)
name += ".weight"
return [(self.map_tensor_name(name), data_torch)]
def set_gguf_parameters(self):
super().set_gguf_parameters()
self.gguf_writer.add_rope_freq_base(self.hparams["rotary_emb_base"])
if self.is_moe:
self.gguf_writer.add_moe_every_n_layers(self.hparams["moe_every_n_layers"])
self.gguf_writer.add_expert_count(self.hparams["num_experts"])
self.gguf_writer.add_expert_used_count(self.hparams["moe_top_k"])
def _is_tokenizer_xlmroberta(self) -> bool:
with open(self.dir_model / "tokenizer.json") as f:
tokenizer_json = json.load(f)
toktyp = tokenizer_json["model"]["type"]
if toktyp == "Unigram":
return True
if toktyp == "WordPiece":
return False
raise ValueError(f"unknown tokenizer: {toktyp}")
@ModelBase.register("XLMRobertaModel", "XLMRobertaForSequenceClassification")
class XLMRobertaModel(BertModel):
model_arch = gguf.MODEL_ARCH.BERT
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self._xlmroberta_tokenizer_init()
def set_vocab(self):
self._xlmroberta_set_vocab()
def modify_tensors(self, data_torch: Tensor, name: str, bid: int | None) -> Iterable[tuple[str, Tensor]]:
# if name starts with "roberta.", remove the prefix
# e.g. https://huggingface.co/BAAI/bge-reranker-v2-m3/tree/main