hf_text-generation-inference/server/text_generation_server/models/seq2seq_lm.py

649 lines
23 KiB
Python

import torch
from dataclasses import dataclass
from opentelemetry import trace
from transformers import AutoTokenizer, AutoModelForSeq2SeqLM, PreTrainedTokenizerBase
from typing import Optional, Tuple, List, Type, Dict
from text_generation_server.models import Model
from text_generation_server.models.types import (
GeneratedText,
Batch,
Generation,
PrefillTokens,
)
from text_generation_server.pb import generate_pb2
from text_generation_server.utils import NextTokenChooser, StoppingCriteria, Sampling
tracer = trace.get_tracer(__name__)
@dataclass
class Seq2SeqLMBatch(Batch):
batch_id: int
requests: List[generate_pb2.Request]
requests_idx_mapping: Dict[int, int]
# Encoder values
input_ids: torch.Tensor
attention_mask: torch.Tensor
# Decoder values
decoder_input_ids: torch.Tensor
decoder_attention_mask: Optional[torch.Tensor]
encoder_last_hidden_state: Optional[torch.Tensor]
# All tokens
all_decoder_input_ids: List[torch.Tensor]
# Seq2SeqLM keeps track of both encoder and decoder attention keys and values
past_key_values: Optional[List[Tuple]]
# Lengths of all generations present in the batch
input_lengths: List[int]
decoder_input_lengths: List[int]
offsets: List[Optional[int]]
token_offsets: List[Optional[int]]
# Generation helpers
next_token_choosers: List[NextTokenChooser]
stopping_criterias: List[StoppingCriteria]
# Metadata used for padding
max_input_length: int
max_decoder_input_length: int
padding_right_offset: int
def to_pb(self) -> generate_pb2.Batch:
"""Convert a Seq2SeqLMBatch to a text_generation_server.v1.Batch protobuf"""
return generate_pb2.Batch(
id=self.batch_id, requests=self.requests, size=len(self)
)
@classmethod
def from_pb(
cls,
pb: generate_pb2.Batch,
tokenizer: PreTrainedTokenizerBase,
device: torch.device,
) -> "Seq2SeqLMBatch":
"""Convert a text_generation_server.v1.Batch protobuf to a Seq2SeqLMBatch"""
inputs = []
next_token_choosers = []
stopping_criterias = []
decoder_input_lengths = []
offsets = []
token_offsets = []
requests_idx_mapping = {}
# Parse batch
max_truncation = 0
padding_right_offset = 0
for i, r in enumerate(pb.requests):
inputs.append(r.inputs)
requests_idx_mapping[r.id] = i
decoder_input_lengths.append(1)
offsets.append(None)
token_offsets.append(None)
next_token_choosers.append(NextTokenChooser.from_pb(r.parameters, device))
stopping_criteria = StoppingCriteria.from_pb(
r.stopping_parameters, tokenizer
)
stopping_criterias.append(stopping_criteria)
max_truncation = max(max_truncation, r.truncate)
padding_right_offset = max(
padding_right_offset, stopping_criteria.max_new_tokens
)
# Tokenize batch
tokenized_inputs = tokenizer(
inputs,
return_tensors="pt",
padding=True,
return_token_type_ids=False,
truncation=True,
max_length=max_truncation,
).to(device)
input_lengths = tokenized_inputs["attention_mask"].sum(1)
max_input_length = input_lengths.max()
# Decoder sequence only contains the bos_token
decoder_input_ids = (
torch.tensor(tokenizer.bos_token_id, device=device)
.repeat(len(pb.requests))
.view(-1, 1)
)
all_decoder_input_ids = decoder_input_ids.view(-1).split(1)
return cls(
batch_id=pb.id,
requests=pb.requests,
requests_idx_mapping=requests_idx_mapping,
input_ids=tokenized_inputs["input_ids"],
attention_mask=tokenized_inputs["attention_mask"],
decoder_input_ids=decoder_input_ids,
all_decoder_input_ids=list(all_decoder_input_ids),
decoder_attention_mask=None,
encoder_last_hidden_state=None,
past_key_values=None,
input_lengths=input_lengths.tolist(),
decoder_input_lengths=decoder_input_lengths,
offsets=offsets,
token_offsets=token_offsets,
next_token_choosers=next_token_choosers,
stopping_criterias=stopping_criterias,
max_input_length=max_input_length.item(),
max_decoder_input_length=1,
padding_right_offset=padding_right_offset,
)
@tracer.start_as_current_span("filter")
def filter(
self, requests: List[generate_pb2.Request]
) -> Optional["Seq2SeqLMBatch"]:
if len(requests) == 0:
raise ValueError("Batch must have at least one request")
if len(requests) == len(self):
return self
keep_indices = []
# New values after filtering
requests_idx_mapping = {}
input_lengths = []
decoder_input_lengths = []
offsets = []
token_offsets = []
all_decoder_input_ids = []
next_token_choosers = []
stopping_criterias = []
max_input_length = 0
max_decoder_input_length = 0
for i, r in enumerate(requests):
idx = self.requests_idx_mapping[r.id]
requests_idx_mapping[r.id] = i
keep_indices.append(idx)
offsets.append(self.offsets[idx])
token_offsets.append(self.token_offsets[idx])
all_decoder_input_ids.append(self.all_decoder_input_ids[idx])
request_input_length = self.input_lengths[idx]
input_lengths.append(request_input_length)
max_input_length = max(max_input_length, request_input_length)
request_decoder_input_length = self.decoder_input_lengths[idx]
decoder_input_lengths.append(request_decoder_input_length)
max_decoder_input_length = max(
max_decoder_input_length, request_decoder_input_length
)
next_token_choosers.append(self.next_token_choosers[idx])
stopping_criterias.append(self.stopping_criterias[idx])
# Apply indices to input_ids, attention mask, past key values and other items that need to be cached
decoder_input_ids = self.decoder_input_ids[keep_indices]
attention_mask = self.attention_mask[keep_indices]
if self.decoder_attention_mask is not None:
decoder_attention_mask = self.decoder_attention_mask[keep_indices]
else:
decoder_attention_mask = None
encoder_last_hidden_state = self.encoder_last_hidden_state[keep_indices]
past_key_values = [
[t[keep_indices] for t in layer] for layer in self.past_key_values
]
return Seq2SeqLMBatch(
batch_id=self.batch_id,
requests=requests,
requests_idx_mapping=requests_idx_mapping,
input_ids=None,
attention_mask=attention_mask,
decoder_input_ids=decoder_input_ids,
all_decoder_input_ids=all_decoder_input_ids,
decoder_attention_mask=decoder_attention_mask,
encoder_last_hidden_state=encoder_last_hidden_state,
past_key_values=past_key_values,
input_lengths=input_lengths,
decoder_input_lengths=decoder_input_lengths,
offsets=offsets,
token_offsets=token_offsets,
next_token_choosers=next_token_choosers,
stopping_criterias=stopping_criterias,
max_input_length=max_input_length,
max_decoder_input_length=max_decoder_input_length,
padding_right_offset=self.padding_right_offset,
)
@classmethod
@tracer.start_as_current_span("concatenate")
def concatenate(cls, batches: List["Seq2SeqLMBatch"]) -> "Seq2SeqLMBatch":
"""Concatenate multiple batches together by padding internal torch tensors"""
# Used for padding
total_batch_size = 0
max_input_length = 0
max_decoder_input_length = 0
padding_right_offset = 0
for batch in batches:
total_batch_size += len(batch)
max_input_length = max(max_input_length, batch.max_input_length)
max_decoder_input_length = max(
max_decoder_input_length, batch.max_decoder_input_length
)
padding_right_offset = max(padding_right_offset, batch.padding_right_offset)
# Batch attributes
requests = []
requests_idx_mapping = {}
all_decoder_input_ids = []
input_lengths = []
decoder_input_lengths = []
offsets = []
token_offsets = []
next_token_choosers = []
stopping_criterias = []
# Batch tensors
attention_mask = None
decoder_input_ids = None
decoder_attention_mask = None
encoder_last_hidden_state = None
past_key_values = []
# Used for slicing correctly inside the tensors
# Equivalent to a cumsum on batch sizes
start_index = 0
for i, batch in enumerate(batches):
# Extend all list attributes
requests.extend(batch.requests)
all_decoder_input_ids.extend(batch.all_decoder_input_ids)
input_lengths.extend(batch.input_lengths)
decoder_input_lengths.extend(batch.decoder_input_lengths)
offsets.extend(batch.offsets)
token_offsets.extend(batch.token_offsets)
next_token_choosers.extend(batch.next_token_choosers)
stopping_criterias.extend(batch.stopping_criterias)
if i == 0:
requests_idx_mapping = batch.requests_idx_mapping
else:
# We need to offset the mapping for each batch by the cumulative batch size
for k, v in batch.requests_idx_mapping.items():
requests_idx_mapping[k] = v + start_index
# Slicing end index for this batch
end_index = start_index + len(batch)
# We only concatenate batches that did at least one step
if batch.encoder_last_hidden_state is None:
raise ValueError("Batch encoder_last_hidden_state cannot be None")
# Create padded tensor
if attention_mask is None:
attention_mask = batch.attention_mask.new_zeros(
(total_batch_size, max_input_length),
)
# Copy to correct indices
attention_mask[
start_index:end_index, -batch.max_input_length :
] = batch.attention_mask[:, -batch.max_input_length :]
# Create padded tensor
if decoder_input_ids is None:
decoder_input_ids = batch.decoder_input_ids.new_zeros(
(total_batch_size, 1),
)
# Copy to correct indices
decoder_input_ids[start_index:end_index] = batch.decoder_input_ids
# Create padded tensor
if decoder_attention_mask is None:
# As decoder_attention_mask might not exist, we use `batch.attention_mask` for device here
decoder_attention_mask = batch.attention_mask.new_zeros(
(total_batch_size, max_decoder_input_length + padding_right_offset),
)
# If the decoder mask does not exist yet, all generations started at the same time and we never concatenated
# this batch. All generations are of length `batch.max_decoder_input_length`.
left_offset = max_decoder_input_length - batch.max_decoder_input_length
if batch.decoder_attention_mask is None:
decoder_attention_mask[
start_index:end_index,
left_offset:-padding_right_offset,
] = 1
# If it exists, we need to index
else:
batch_left_offset = (
batch.decoder_attention_mask.shape[1]
- batch.max_decoder_input_length
- batch.padding_right_offset
)
decoder_attention_mask[
start_index:end_index,
left_offset:-padding_right_offset,
] = batch.decoder_attention_mask[
:,
batch_left_offset : -batch.padding_right_offset,
]
# Create padded tensor
if encoder_last_hidden_state is None:
encoder_last_hidden_state = batch.encoder_last_hidden_state.new_zeros(
(
total_batch_size,
max_input_length,
batch.encoder_last_hidden_state.shape[-1],
),
)
# Copy to correct indices
encoder_last_hidden_state[
start_index:end_index, -batch.max_input_length :, :
] = batch.encoder_last_hidden_state[:, -batch.max_input_length :, :]
# Iterate over attention layers
for j, past in enumerate(batch.past_key_values):
_, num_heads, _, head_dim = past[0].shape
# This will run only once per layer
if j == len(past_key_values):
past_key_values.append([])
# Decoder past
for k, t in enumerate(past[:2]):
padded_t_shape = (
total_batch_size,
num_heads,
(max_decoder_input_length - 1),
head_dim,
)
# Initialize tensors
# This will run only once per layer and per past tensor
if k == len(past_key_values[j]):
past_key_values[j].append(t.new_zeros(padded_t_shape))
# We slice the past keys and values to remove the padding from previous batches
past_key_values[j][k][
start_index:end_index,
:,
-(batch.max_decoder_input_length - 1) :,
:,
] = t[:, :, -(batch.max_decoder_input_length - 1) :, :]
# encoder past
for k, t in enumerate(past[2:]):
padded_t_shape = (
total_batch_size,
num_heads,
max_input_length,
head_dim,
)
idx = k + 2
# Initialize tensors
# This will run only once per layer and per past tensor
if idx == len(past_key_values[j]):
past_key_values[j].append(t.new_zeros(padded_t_shape))
past_key_values[j][idx][
start_index:end_index, :, -batch.max_input_length :, :
] = t[:, :, -batch.max_input_length :, :]
start_index += len(batch)
return cls(
batch_id=batches[0].batch_id,
requests=requests,
requests_idx_mapping=requests_idx_mapping,
input_ids=None,
attention_mask=attention_mask,
decoder_input_ids=decoder_input_ids,
all_decoder_input_ids=all_decoder_input_ids,
decoder_attention_mask=decoder_attention_mask,
encoder_last_hidden_state=encoder_last_hidden_state,
past_key_values=past_key_values,
input_lengths=input_lengths,
decoder_input_lengths=decoder_input_lengths,
offsets=offsets,
token_offsets=token_offsets,
next_token_choosers=next_token_choosers,
stopping_criterias=stopping_criterias,
max_input_length=max_input_length,
max_decoder_input_length=max_decoder_input_length,
padding_right_offset=padding_right_offset,
)
def __len__(self):
return len(self.requests)
class Seq2SeqLM(Model):
def __init__(
self,
model_id: str,
revision: Optional[str] = None,
quantize: bool = False,
decode_buffer: int = 3,
):
if torch.cuda.is_available():
device = torch.device("cuda")
dtype = torch.bfloat16 if torch.cuda.is_bf16_supported() else torch.float32
else:
if quantize:
raise ValueError("quantization is not available on CPU")
device = torch.device("cpu")
dtype = torch.float32
self.model = AutoModelForSeq2SeqLM.from_pretrained(
model_id,
revision=revision,
torch_dtype=dtype,
device_map="auto" if torch.cuda.is_available() else None,
load_in_8bit=quantize,
).eval()
tokenizer = AutoTokenizer.from_pretrained(
model_id, revision=revision, padding_side="left", truncation_side="left"
)
tokenizer.bos_token_id = self.model.config.decoder_start_token_id
super(Seq2SeqLM, self).__init__(
tokenizer=tokenizer, device=device, decode_buffer=decode_buffer
)
@property
def batch_type(self) -> Type[Seq2SeqLMBatch]:
return Seq2SeqLMBatch
def decode(self, decoder_ids: List[int]) -> str:
return self.tokenizer.decode(
decoder_ids, skip_special_tokens=True, clean_up_tokenization_spaces=False
)
def forward(
self,
input_ids,
attention_mask,
decoder_input_ids,
decoder_attention_mask: Optional,
encoder_last_hidden_state: Optional,
past_key_values: Optional = None,
) -> Tuple[
torch.Tensor,
torch.Tensor,
List[Tuple[torch.Tensor, torch.Tensor, torch.Tensor, torch.Tensor]],
]:
# Model Forward
outputs = self.model.forward(
input_ids=input_ids,
attention_mask=attention_mask,
decoder_input_ids=decoder_input_ids,
decoder_attention_mask=decoder_attention_mask,
encoder_outputs=encoder_last_hidden_state,
past_key_values=past_key_values,
use_cache=True,
)
return (
outputs.logits,
outputs.encoder_last_hidden_state,
outputs.past_key_values,
)
@tracer.start_as_current_span("generate_token")
def generate_token(
self, batch: Seq2SeqLMBatch
) -> Tuple[List[Generation], Optional[Seq2SeqLMBatch]]:
if batch.decoder_attention_mask is not None:
# slice to the correct shape
decoder_attention_mask = batch.decoder_attention_mask[
:, : -batch.padding_right_offset
]
else:
decoder_attention_mask = None
# Wrap `encoder_last_hidden_state` because for some reason, Transformers does a `encoder_last_hidden_state[0]`
# internally...
if batch.encoder_last_hidden_state is not None:
encoder_last_hidden_state = [batch.encoder_last_hidden_state]
else:
encoder_last_hidden_state = None
logits, encoder_last_hidden_state, past = self.forward(
batch.input_ids,
batch.attention_mask,
batch.decoder_input_ids,
decoder_attention_mask,
encoder_last_hidden_state,
batch.past_key_values,
)
# Finished requests
generations: List[Generation] = []
stopped = True
# Zipped iterator
iterator = zip(
batch.requests,
batch.input_lengths,
batch.offsets,
batch.token_offsets,
batch.decoder_input_lengths,
logits,
batch.next_token_choosers,
batch.stopping_criterias,
batch.all_decoder_input_ids,
)
# For each member of the batch
for i, (
request,
input_length,
offset,
token_offset,
decoder_input_length,
logits,
next_token_chooser,
stopping_criteria,
all_decoder_input_ids,
) in enumerate(iterator):
# Select next token
next_token_id, logprobs = next_token_chooser(
all_decoder_input_ids.view(1, -1), logits
)
# Append next token to decoder tokens
all_decoder_input_ids = torch.cat(
[all_decoder_input_ids, next_token_id.squeeze(1)]
)
new_decoder_input_length = decoder_input_length + 1
# Generated token
next_token_logprob = logprobs[-1, next_token_id]
next_token_id_squeezed = next_token_id.squeeze()
next_token_text, offset, token_offset = self.decode_token(
all_decoder_input_ids, offset, token_offset
)
# Evaluate stopping criteria
stop, reason = stopping_criteria(next_token_id, next_token_text)
if stop:
# Slice with decoder_input_length to remove padding
# Decode all tokens
output_text = self.decode(all_decoder_input_ids[-decoder_input_length:])
# Get seed
if isinstance(next_token_chooser.choice, Sampling):
seed = next_token_chooser.choice.seed
else:
seed = None
generated_text = GeneratedText(
output_text, stopping_criteria.current_tokens, reason, seed
)
else:
# Keep request in the batch
generated_text = None
stopped = False
# Prefill
if stopping_criteria.current_tokens == 1:
prefill_tokens = PrefillTokens(
[self.tokenizer.bos_token_id],
[float("nan")],
[self.tokenizer.bos_token],
)
else:
prefill_tokens = None
generation = Generation(
request.id,
prefill_tokens,
next_token_id_squeezed,
next_token_logprob,
next_token_text,
next_token_id_squeezed.item() in self.all_special_ids,
generated_text,
)
generations.append(generation)
# Update values
batch.decoder_input_ids[i] = next_token_id
batch.all_decoder_input_ids[i] = all_decoder_input_ids
batch.input_lengths[i] = input_length
batch.decoder_input_lengths[i] = new_decoder_input_length
batch.offsets[i] = offset
batch.token_offsets[i] = token_offset
batch.max_input_length = max(batch.max_input_length, input_length)
batch.max_decoder_input_length = max(
batch.max_decoder_input_length, new_decoder_input_length
)
# We finished all generations in the batch; there is no next batch
if stopped:
return generations, None
# We don't need input_ids after the prefill forward
batch.input_ids = None
batch.encoder_last_hidden_state = encoder_last_hidden_state
batch.past_key_values = past
# Update decoder_attention_mask as we added a new token to input_ids
if batch.decoder_attention_mask is not None:
batch.decoder_attention_mask[:, -batch.padding_right_offset] = 1
batch.padding_right_offset -= 1
return generations, batch