from __future__ import annotations
import json
import os
from typing import Iterable, TYPE_CHECKING
if TYPE_CHECKING:
from torch import Tensor
from .base import ModelBase, SentencePieceTokenTypes, TextModel, gguf, logger
@ModelBase.register("T5WithLMHeadModel")
@ModelBase.register("T5ForConditionalGeneration")
@ModelBase.register("MT5ForConditionalGeneration")
@ModelBase.register("UMT5ForConditionalGeneration")
@ModelBase.register("UMT5Model")
@ModelBase.example("google-t5/t5-small", "google/flan-t5-small", "google/umt5-small")
class T5Model(TextModel):
model_arch = gguf.MODEL_ARCH.T5
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.shared_token_embeddings_found = False
def set_vocab(self):
# to avoid TypeError: Descriptors cannot be created directly
# exception when importing sentencepiece_model_pb2
os.environ["PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION"] = "python"
from sentencepiece import SentencePieceProcessor
from sentencepiece import sentencepiece_model_pb2 as model
tokenizer_path = self.dir_model / 'tokenizer.model'
# many older models use spiece.model tokenizer model filename
if not tokenizer_path.is_file():
tokenizer_path = self.dir_model / 'spiece.model'
if not tokenizer_path.is_file():
raise FileNotFoundError(f"File not found: {tokenizer_path}")
sentencepiece_model = model.ModelProto() # pyright: ignore[reportAttributeAccessIssue] # ty: ignore[unresolved-attribute]
sentencepiece_model.ParseFromString(open(tokenizer_path, "rb").read())
# some models like Pile-T5 family use BPE tokenizer instead of Unigram
if sentencepiece_model.trainer_spec.model_type == 2: # BPE
# assure the tokenizer model file name is correct
assert tokenizer_path.name == 'tokenizer.model'
return self._set_vocab_sentencepiece()
else:
assert sentencepiece_model.trainer_spec.model_type == 1 # UNIGRAM
add_prefix = sentencepiece_model.normalizer_spec.add_dummy_prefix
remove_whitespaces = sentencepiece_model.normalizer_spec.remove_extra_whitespaces
precompiled_charsmap = sentencepiece_model.normalizer_spec.precompiled_charsmap
tokenizer = SentencePieceProcessor()
tokenizer.LoadFromFile(str(tokenizer_path))
vocab_size = self.hparams.get('vocab_size', tokenizer.vocab_size())
tokens: list[bytes] = [f"[PAD{i}]".encode("utf-8") for i in range(vocab_size)]
scores: list[float] = [-10000.0] * vocab_size
toktypes: list[int] = [SentencePieceTokenTypes.UNUSED] * vocab_size
for token_id in range(tokenizer.vocab_size()):
piece = tokenizer.IdToPiece(token_id)
text = piece.encode("utf-8")
score = tokenizer.GetScore(token_id)
toktype = SentencePieceTokenTypes.NORMAL
if tokenizer.IsUnknown(token_id):
toktype = SentencePieceTokenTypes.UNKNOWN
elif tokenizer.IsControl(token_id):
toktype = SentencePieceTokenTypes.CONTROL
elif tokenizer.IsUnused(token_id):
toktype = SentencePieceTokenTypes.UNUSED
elif tokenizer.IsByte(token_id):
toktype = SentencePieceTokenTypes.BYTE
tokens[token_id] = text
scores[token_id] = score
toktypes[token_id] = toktype
added_tokens_file = self.dir_model / 'added_tokens.json'
if added_tokens_file.is_file():
with open(added_tokens_file, "r", encoding="utf-8") as f:
added_tokens_json = json.load(f)
for key in added_tokens_json:
token_id = added_tokens_json[key]
if token_id >= vocab_size:
logger.warning(f'ignore token {token_id}: id is out of range, max={vocab_size - 1}')
continue
tokens[token_id] = key.encode("utf-8")
scores[token_id] = -1000.0
toktypes[token_id] = SentencePieceTokenTypes.USER_DEFINED
if vocab_size > len(tokens):
pad_count = vocab_size - len(tokens)
logger.debug(f"Padding vocab with {pad_count} token(s) - [PAD1] through [PAD{pad_count}]")
for i in range(1, pad_count + 1):
tokens.append(bytes(f"[PAD{i}]", encoding="utf-8"))
scores.append(-1000.0)
toktypes.append(SentencePieceTokenTypes.UNUSED)
self.gguf_writer.add_tokenizer_model("t5")
self.gguf_writer.add_tokenizer_pre("default")
self.gguf_writer.add_token_list(tokens)
self.gguf_writer.add_token_scores(scores)
self.gguf_writer.add_token_types(toktypes)
self.gguf_writer.add_add_space_prefix(add_prefix)
self.gguf_writer.add_remove_extra_whitespaces(remove_whitespaces)
if precompiled_charsmap:
self.gguf_writer.add_precompiled_charsmap(precompiled_charsmap)
special_vocab = gguf.SpecialVocab(self.dir_model, n_vocab=len(tokens))
special_vocab.add_to_gguf(self.gguf_writer)
def set_gguf_parameters(self):
if (n_ctx := self.find_hparam(["n_positions"], optional=True)) is None:
logger.warning("Couldn't find context length in config.json, assuming default value of 512")
n_ctx = 512
self.gguf_writer.add_context_length(n_ctx)
self.gguf_writer.add_embedding_length(self.hparams["d_model"])
self.gguf_writer.add_feed_forward_length(self.hparams["d_ff"])
self.gguf_writer.add_block_count(self.block_count)
if (dec_n_layer := self.hparams.get("num_decoder_layers")) is not None:
self.gguf_writer.add_decoder_block_count(dec_n_layer)
self.gguf_writer.add_head_count(self.hparams["num_heads"])
self.gguf_writer.add_key_length(self.hparams["d_kv"])
self.gguf_writer.add_value_length(self.hparams["d_kv"])
self.gguf_writer.add_layer_norm_eps(self.hparams["layer_norm_epsilon"])
self.gguf_writer.add_relative_attn_buckets_count(self.hparams["relative_attention_num_buckets"])
self.gguf_writer.add_layer_norm_rms_eps(self.hparams["layer_norm_epsilon"])
self.gguf_writer.add_decoder_start_token_id(self.hparams["decoder_start_token_id"])
self.gguf_writer.add_file_type(self.ftype)
def modify_tensors(self, data_torch: Tensor, name: str, bid: int | None) -> Iterable[tuple[str, Tensor]]:
# T5 based models contain shared token embeddings tensors saved randomly as either "encoder.embed_tokens.weight",
# "decoder.embed_tokens.weight" or "shared.weight" tensor. In some models there are even multiple of them stored
# in the safetensors files. We use the first tensor from these three as the token embeddings for both encoder
# and decoder and ignore the remaining ones.
if name in ["decoder.embed_tokens.weight", "encoder.embed_tokens.weight", "shared.weight"]:
if not self.shared_token_embeddings_found:
name = "shared.weight"
self.shared_token_embeddings_found = True
else:
logger.debug(f"Skipping shared tensor {name!r} in safetensors so that convert can end normally.")
return
yield from super().modify_tensors(data_torch, name, bid)
@ModelBase.register("T5EncoderModel")
@ModelBase.example("sentence-transformers/sentence-t5-base")
class T5EncoderModel(TextModel):
model_arch = gguf.MODEL_ARCH.T5ENCODER
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.shared_token_embeddings_found = False
def set_vocab(self):
# to avoid TypeError: Descriptors cannot be created directly
# exception when importing sentencepiece_model_pb2
os.environ["PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION"] = "python"
from sentencepiece import SentencePieceProcessor
from sentencepiece import sentencepiece_model_pb2 as model
tokenizer_path = self.dir_model / 'tokenizer.model'
# many older models use spiece.model tokenizer model filename
if not tokenizer_path.is_file():
tokenizer_path = self.dir_model / 'spiece.model'
if not tokenizer_path.is_file():
raise FileNotFoundError(f"File not found: {tokenizer_path}")
sentencepiece_model = model.ModelProto() # pyright: ignore[reportAttributeAccessIssue] # ty: ignore[unresolved-attribute]
sentencepiece_model.ParseFromString(open(tokenizer_path, "rb").read())
# some models like Pile-T5 family use BPE tokenizer instead of Unigram
if sentencepiece_model.trainer_spec.model_type == 2: # BPE
# assure the tokenizer model file name is correct
assert tokenizer_path.name == 'tokenizer.model'
return self._set_vocab_sentencepiece()
else:
assert sentencepiece_model.trainer_spec.model_type == 1 # UNIGRAM
add_prefix = sentencepiece_model.normalizer_spec.add_dummy_prefix
remove_whitespaces = sentencepiece_model.normalizer_spec.remove_extra_whitespaces
precompiled_charsmap = sentencepiece_model.normalizer_spec.precompiled_charsmap
tokenizer = SentencePieceProcessor()
tokenizer.LoadFromFile(str(tokenizer_path))
vocab_size = self.hparams.get('vocab_size', tokenizer.vocab_size())
tokens: list[bytes] = [f"[PAD{i}]".encode("utf-8") for i in range(vocab_size)]
scores: list[float] = [-10000.0] * vocab_size
toktypes: list[int] = [SentencePieceTokenTypes.UNUSED] * vocab_size
for token_id in range(tokenizer.vocab_size()):
piece = tokenizer.IdToPiece(token_id)
text = piece.encode("utf-8")
score = tokenizer.GetScore(token_id)
toktype = SentencePieceTokenTypes.NORMAL
if tokenizer.IsUnknown(token_id):
toktype = SentencePieceTokenTypes.UNKNOWN
elif tokenizer.IsControl(token_id):
toktype = SentencePieceTokenTypes.CONTROL
elif tokenizer.IsUnused(token_id):
toktype = SentencePieceTokenTypes.UNUSED
elif tokenizer.IsByte(token_id):
toktype = SentencePieceTokenTypes.BYTE
tokens[token_id] = text
scores[token_id] = score
toktypes[token_id] = toktype
added_tokens_file = self.dir_model / 'added_tokens.json'
if added_tokens_file.is_file():
with open(added_tokens_file, "r", encoding="utf-8") as f:
added_tokens_json = json.load(f)
for key in added_tokens_json:
token_id = added_tokens_json[key]
if token_id >= vocab_size:
logger.warning(f'ignore token {token_id}: id is out of range, max={vocab_size - 1}')
continue
tokens[token_id] = key.encode("utf-8")
scores[token_id] = -1000.0
toktypes[token_id] = SentencePieceTokenTypes.USER_DEFINED
if vocab_size > len(tokens):
pad_count = vocab_size - len(tokens)
logger.debug(f"Padding vocab with {pad_count} token(s) - [PAD1] through [PAD{pad_count}]")
for i in range(1, pad_count + 1):
tokens.append(bytes(f"[PAD{i}]", encoding="utf-8"))
scores.append(-1000.0)
toktypes.append(SentencePieceTokenTypes.UNUSED)
self.gguf_writer.add_tokenizer_model("t5")
self.gguf_writer.add_tokenizer_pre("default")
self.gguf_writer.add_token_list(tokens)
self.gguf_writer.add_token_scores(scores)
self.gguf_writer.add_token_types(toktypes)
self.gguf_writer.add_add_space_prefix(add_prefix)
self.gguf_writer.add_remove_extra_whitespaces(remove_whitespaces)
if precompiled_charsmap:
self.gguf_writer.add_precompiled_charsmap(precompiled_charsmap)
special_vocab = gguf.SpecialVocab(self.dir_model, n_vocab=len(tokens))
special_vocab.add_to_gguf(self.gguf_writer)
def set_gguf_parameters(self):
if (n_ctx := self.find_hparam(["n_positions"], optional=True)) is None:
logger.warning("Couldn't find context length in config.json, assuming default value of 512")
n_ctx = 512
self.gguf_writer.add_context_length(n_ctx)
self.gguf_writer.add_embedding_length(self.hparams["d_model"])
self.gguf_writer.add_feed_forward_length(self.hparams["d_ff"])
self.gguf_writer.add_block_count(self.block_count)
self.gguf_writer.add_head_count(self.hparams["num_heads"])
self.gguf_writer.add_key_length(self.hparams["d_kv"])
self.gguf_writer.add_value_length(self.hparams["d_kv"])
self.gguf_writer.add_layer_norm_eps(self.hparams["layer_norm_epsilon"])
self.gguf_writer.add_relative_attn_buckets_count(self.hparams["relative_attention_num_buckets"])
self.gguf_writer.add_layer_norm_rms_eps(self.hparams["layer_norm_epsilon"])
self.gguf_writer.add_file_type(self.ftype)
def modify_tensors(self, data_torch: Tensor, name: str, bid: int | None) -> Iterable[tuple[str, Tensor]]:
# T5 based models contain shared token embeddings tensors saved randomly as either "encoder.embed_tokens.weight",
# "decoder.embed_tokens.weight" or "shared.weight" tensor. In some models there are even multiple of them stored
# in the safetensors files. We use the first tensor from these three as the token embeddings for both encoder
# and decoder and ignore the remaining ones.
if name in ["decoder.embed_tokens.weight", "encoder.embed_tokens.weight", "shared.weight"]:
if not self.shared_token_embeddings_found:
name = "shared.weight"
self.shared_token_embeddings_found = True
else:
logger.debug(f"Skipping shared tensor {name!r} in safetensors so that convert can end normally.")
return
yield from super().modify_tensors(data_torch, name, bid)