tabbyAPI-ollama/backends/exllamav2/model.py
DocShotgun a1df22668b API: Add min_tokens
Bans the EOS token until the generation reaches a minimum length. This will not prevent the model from otherwise ending the generation early by outputting other stop conditions.
2024-05-10 12:30:17 -07:00

1100 lines
40 KiB
Python

"""The model container class for ExLlamaV2 models."""
import gc
import math
import pathlib
import threading
import time
import traceback
import torch
from exllamav2 import (
ExLlamaV2,
ExLlamaV2Config,
ExLlamaV2Cache,
ExLlamaV2Cache_8bit,
ExLlamaV2Cache_Q4,
ExLlamaV2Tokenizer,
ExLlamaV2Lora,
)
from exllamav2.generator import ExLlamaV2StreamingGenerator, ExLlamaV2Sampler
from inspect import signature
from itertools import zip_longest
from loguru import logger
from typing import List, Optional, Union
from backends.exllamav2.grammar import ExLlamaV2Grammar
from common.concurrency import iterate_in_threadpool
from common.gen_logging import (
log_generation_params,
log_metrics,
log_prompt,
log_response,
)
from common.templating import (
PromptTemplate,
TemplateLoadError,
find_template_from_model,
)
from common.transformers_utils import GenerationConfig
from common.utils import coalesce, unwrap
class ExllamaV2Container:
"""The model container class for ExLlamaV2 models."""
# Exl2 vars
config: Optional[ExLlamaV2Config] = None
draft_config: Optional[ExLlamaV2Config] = None
model: Optional[ExLlamaV2] = None
draft_model: Optional[ExLlamaV2] = None
cache: Optional[ExLlamaV2Cache] = None
draft_cache: Optional[ExLlamaV2Cache] = None
tokenizer: Optional[ExLlamaV2Tokenizer] = None
generator: Optional[ExLlamaV2StreamingGenerator] = None
prompt_template: Optional[PromptTemplate] = None
active_loras: List[ExLlamaV2Lora] = []
# Internal config vars
cache_mode: str = "FP16"
use_cfg: bool = False
generation_config: Optional[GenerationConfig] = None
# GPU split vars
gpu_split: Optional[list] = None
gpu_split_auto: bool = True
autosplit_reserve: List[float] = [96 * 1024**2]
# Load state
model_is_loading: bool = False
model_loaded: bool = False
def __init__(self, model_directory: pathlib.Path, quiet=False, **kwargs):
"""
Create model container
Args:
model_dir (int): Model directory containing config.json,
tokenizer.model etc.
quiet (bool): Suppress console output
load_progress_callback (function, optional): A function to call for
each module loaded. Prototype:
def progress(loaded_modules: int, total_modules: int,
loading_draft: bool)
**kwargs:
`cache_mode` (str): Sets cache mode, "FP16" or "FP8"
(defaulf: "FP16")
'max_seq_len' (int): Override model's default max sequence
length (default: 4096)
'rope_scale' (float): Set RoPE scaling factor for model
(default: 1.0)
'rope_alpha' (float): Set RoPE alpha (NTK) factor for model
(default: 1.0)
'prompt_template' (str): Manually sets the prompt template for
this model (default: None)
'chunk_size' (int): Sets the maximum chunk size for the model
(default: 2048)
Inferencing in chunks reduces overall VRAM overhead by
processing very long sequences in smaller batches. This
limits the size of temporary buffers needed for the hidden
state and attention weights.
'draft_model_dir' (str): Draft model directory
'draft_rope_scale' (float): Set RoPE scaling factor for draft
model (default: 1.0)
'draft_rope_alpha' (float): RoPE alpha (NTK) factor for draft
model. By default, the draft model's alpha value is
calculated automatically to scale to the size of the
full model.
'lora_dir' (str): LoRA directory
'loras' (list[dict]): List of loras to be loaded, consisting of
'name' and 'scaling'
'gpu_split_auto' (bool): Automatically split model across
available devices (default: True)
'gpu_split' (list[float]): Allocation for weights and (some)
tensors, per device
'no_flash_attn' (bool): Turns off flash attention
(increases vram usage) (default: False)
'use_cfg" (bool): Enables CFG support. Disables flash attention
(default: False)
"""
self.quiet = quiet
self.cache_mode = unwrap(kwargs.get("cache_mode"), "FP16")
# Turn off GPU split if the user is using 1 GPU
gpu_count = torch.cuda.device_count()
gpu_split_auto = unwrap(kwargs.get("gpu_split_auto"), True)
if gpu_count > 1 and gpu_split_auto:
# Auto GPU split parameters
self.gpu_split_auto = gpu_split_auto
autosplit_reserve_megabytes = unwrap(kwargs.get("autosplit_reserve"), [96])
self.autosplit_reserve = list(
map(
lambda value: int(math.ceil(value * 1024**2)),
autosplit_reserve_megabytes,
)
)
elif gpu_count > 1:
# Manual GPU split
self.gpu_split = kwargs.get("gpu_split")
self.gpu_split_auto = False
else:
# One GPU setup
self.gpu_split_auto = False
logger.info("Disabling GPU split because one GPU is in use.")
self.config = ExLlamaV2Config()
self.config.model_dir = str(model_directory.resolve())
# Make the max seq len 4096 before preparing the config
# This is a better default than 2048
self.config.max_seq_len = 4096
# Hardcode max output length to 16
self.config.max_output_len = 16
self.config.prepare()
# Then override the base_seq_len if present
override_base_seq_len = kwargs.get("override_base_seq_len")
if override_base_seq_len:
self.config.max_seq_len = override_base_seq_len
# Grab the base model's sequence length before overrides for
# rope calculations
base_seq_len = self.config.max_seq_len
# Set the target seq len if present
target_max_seq_len = kwargs.get("max_seq_len")
if target_max_seq_len:
self.config.max_seq_len = target_max_seq_len
# Set the rope scale
self.config.scale_pos_emb = unwrap(
kwargs.get("rope_scale"), self.config.scale_pos_emb
)
# Automatically calculate rope alpha
self.config.scale_alpha_value = unwrap(
kwargs.get("rope_alpha"), self.calculate_rope_alpha(base_seq_len)
)
# Enable CFG if present
self.use_cfg = unwrap(kwargs.get("use_cfg"), False)
# Enable fasttensors loading if present
self.config.fasttensors = unwrap(kwargs.get("fasttensors"), False)
# Turn off flash attention if CFG is on
# Workaround until batched FA2 is fixed in exllamav2 upstream
self.config.no_flash_attn = (
True if self.use_cfg else unwrap(kwargs.get("no_flash_attention"), False)
)
# Try to set prompt template
self.prompt_template = self.find_prompt_template(
kwargs.get("prompt_template"), model_directory
)
# Load generation config overrides
generation_config_path = (
pathlib.Path(self.config.model_dir) / "generation_config.json"
)
if generation_config_path.exists():
try:
self.generation_config = GenerationConfig.from_file(
generation_config_path.parent
)
except Exception:
logger.error(traceback.format_exc())
logger.warning(
"Skipping generation config load because of an unexpected error."
)
# Catch all for template lookup errors
if self.prompt_template:
logger.info(
f'Using template "{self.prompt_template.name}" for chat completions.'
)
else:
logger.warning(
"Chat completions are disabled because a prompt "
"template wasn't provided or auto-detected."
)
# Set num of experts per token if provided
num_experts_override = kwargs.get("num_experts_per_token")
if num_experts_override:
self.config.num_experts_per_token = kwargs.get("num_experts_per_token")
# Make sure chunk size is >= 16 and <= max seq length
user_chunk_size = unwrap(kwargs.get("chunk_size"), 2048)
chunk_size = sorted((16, user_chunk_size, self.config.max_seq_len))[1]
self.config.max_input_len = chunk_size
self.config.max_attention_size = chunk_size**2
draft_args = unwrap(kwargs.get("draft"), {})
draft_model_name = draft_args.get("draft_model_name")
enable_draft = draft_args and draft_model_name
# Always disable draft if params are incorrectly configured
if draft_args and draft_model_name is None:
logger.warning(
"Draft model is disabled because a model name "
"wasn't provided. Please check your config.yml!"
)
enable_draft = False
if enable_draft:
self.draft_config = ExLlamaV2Config()
draft_model_path = pathlib.Path(
unwrap(draft_args.get("draft_model_dir"), "models")
)
draft_model_path = draft_model_path / draft_model_name
self.draft_config.model_dir = str(draft_model_path.resolve())
self.draft_config.prepare()
self.draft_config.scale_pos_emb = unwrap(
draft_args.get("draft_rope_scale"), 1.0
)
# Automatically calculate draft rope alpha
self.draft_config.scale_alpha_value = unwrap(
draft_args.get("draft_rope_alpha"),
self.calculate_rope_alpha(self.draft_config.max_seq_len),
)
self.draft_config.max_seq_len = self.config.max_seq_len
if chunk_size:
self.draft_config.max_input_len = chunk_size
self.draft_config.max_attention_size = chunk_size**2
def find_prompt_template(self, prompt_template_name, model_directory):
"""Tries to find a prompt template using various methods"""
logger.info("Attempting to load a prompt template if present.")
find_template_functions = [
lambda: PromptTemplate.from_model_json(
pathlib.Path(self.config.model_dir) / "tokenizer_config.json",
"chat_template",
),
lambda: PromptTemplate.from_file(find_template_from_model(model_directory)),
]
# Add lookup from prompt template name if provided
if prompt_template_name:
find_template_functions[:0] = [
lambda: PromptTemplate.from_file(prompt_template_name),
lambda: PromptTemplate.from_model_json(
pathlib.Path(self.config.model_dir) / "tokenizer_config.json",
"chat_template",
prompt_template_name,
),
]
# Continue on exception since functions are tried as they fail
for template_func in find_template_functions:
try:
prompt_template = template_func()
if prompt_template is not None:
return prompt_template
except TemplateLoadError as e:
logger.warning(f"TemplateLoadError: {str(e)}")
continue
except Exception:
logger.error(traceback.format_exc())
logger.warning(
"An unexpected error happened when trying to load the template. "
"Trying other methods."
)
continue
def calculate_rope_alpha(self, base_seq_len):
"""Calculate the rope alpha value for a given sequence length."""
ratio = self.config.max_seq_len / base_seq_len
# Default to a 1 alpha if the sequence length is ever less
# than or equal to 1
if ratio <= 1.0:
alpha = 1
else:
alpha = -0.13436 + 0.80541 * ratio + 0.28833 * ratio**2
return alpha
def get_model_path(self, is_draft: bool = False):
"""Get the path for this model."""
model_path = pathlib.Path(
self.draft_config.model_dir if is_draft else self.config.model_dir
)
return model_path
def get_model_parameters(self):
model_params = {
"name": self.get_model_path().name,
"rope_scale": self.config.scale_pos_emb,
"rope_alpha": self.config.scale_alpha_value,
"max_seq_len": self.config.max_seq_len,
"cache_mode": self.cache_mode,
"chunk_size": self.config.max_input_len,
"num_experts_per_token": self.config.num_experts_per_token,
"use_cfg": self.use_cfg,
"prompt_template": self.prompt_template.name
if self.prompt_template
else None,
}
if self.draft_config:
draft_model_params = {
"name": self.get_model_path(is_draft=True).name,
"rope_scale": self.draft_config.scale_pos_emb,
"rope_alpha": self.draft_config.scale_alpha_value,
"max_seq_len": self.draft_config.max_seq_len,
}
model_params["draft"] = draft_model_params
return model_params
async def load(self, progress_callback=None):
"""
Load model
Args:
progress_callback (function, optional): A function to call for each
module loaded. Prototype:
def progress(loaded_modules: int, total_modules: int)
"""
async for _ in self.load_gen(progress_callback):
pass
async def load_loras(self, lora_directory: pathlib.Path, **kwargs):
"""
Load loras
"""
loras = unwrap(kwargs.get("loras"), [])
success: List[str] = []
failure: List[str] = []
for lora in loras:
lora_name = lora.get("name")
lora_scaling = unwrap(lora.get("scaling"), 1.0)
if lora_name is None:
logger.warning(
"One of your loras does not have a name. Please check your "
"config.yml! Skipping lora load."
)
failure.append(lora_name)
continue
logger.info(f"Loading lora: {lora_name} at scaling {lora_scaling}")
lora_path = lora_directory / lora_name
self.active_loras.append(
ExLlamaV2Lora.from_directory(self.model, lora_path, lora_scaling)
)
logger.info(f"Lora successfully loaded: {lora_name}")
success.append(lora_name)
# Return success and failure names
return {"success": success, "failure": failure}
async def load_gen(self, progress_callback=None):
"""Basic async wrapper around the loading generator"""
load_generator = self.load_gen_sync(progress_callback)
async for value in iterate_in_threadpool(load_generator):
yield value
@torch.inference_mode()
def load_gen_sync(self, progress_callback=None):
"""
Load model, generator function
Args:
progress_callback (function, optional): A function to call for each
module loaded. Prototype:
def progress(loaded_modules: int, total_modules: int)
Runs under a shared inference mode context.
"""
# Notify that the model is being loaded
self.model_is_loading = True
# Reset tokenizer namespace vars and create a tokenizer
ExLlamaV2Tokenizer.unspecial_piece_to_id = {}
ExLlamaV2Tokenizer.unspecial_id_to_piece = {}
ExLlamaV2Tokenizer.extended_id_to_piece = {}
ExLlamaV2Tokenizer.extended_piece_to_id = {}
self.tokenizer = ExLlamaV2Tokenizer(self.config)
# Calculate autosplit reserve for all GPUs
gpu_count = torch.cuda.device_count()
autosplit_reserve = self.autosplit_reserve + [0] * (
gpu_count - len(self.autosplit_reserve)
)
# Load draft model if a config is present
if self.draft_config:
self.draft_model = ExLlamaV2(self.draft_config)
if not self.quiet:
logger.info("Loading draft model: " + self.draft_config.model_dir)
self.draft_cache = ExLlamaV2Cache(self.draft_model, lazy=True)
for value in self.draft_model.load_autosplit_gen(
self.draft_cache,
reserve_vram=autosplit_reserve,
last_id_only=True,
callback_gen=progress_callback,
):
if value:
yield value
# Test VRAM allocation with a full-length forward pass
input_ids = torch.zeros((1, self.config.max_input_len), dtype=torch.long)
self.draft_model.forward(input_ids, cache=self.cache, preprocess_only=True)
self.model = ExLlamaV2(self.config)
if not self.quiet:
logger.info("Loading model: " + self.config.model_dir)
# Load model with manual split
# Entrypoint for single GPU users
if not self.gpu_split_auto:
logger.info("Loading with a manual GPU split (or a one GPU setup)")
for value in self.model.load_gen(
self.gpu_split,
callback_gen=progress_callback,
):
if value:
yield value
batch_size = 2 if self.use_cfg else 1
if self.cache_mode == "Q4":
self.cache = ExLlamaV2Cache_Q4(
self.model, lazy=self.gpu_split_auto, batch_size=batch_size
)
elif self.cache_mode == "FP8":
self.cache = ExLlamaV2Cache_8bit(
self.model, lazy=self.gpu_split_auto, batch_size=batch_size
)
else:
self.cache = ExLlamaV2Cache(
self.model, lazy=self.gpu_split_auto, batch_size=batch_size
)
# Load model with autosplit
if self.gpu_split_auto:
logger.info("Loading with autosplit")
for value in self.model.load_autosplit_gen(
self.cache,
reserve_vram=autosplit_reserve,
last_id_only=True,
callback_gen=progress_callback,
):
if value:
yield value
# Test VRAM allocation with a full-length forward pass
input_ids = torch.zeros((1, self.config.max_input_len), dtype=torch.long)
self.model.forward(input_ids, cache=self.cache, preprocess_only=True)
# Create generator
self.generator = ExLlamaV2StreamingGenerator(
self.model,
self.cache,
self.tokenizer,
self.draft_model,
self.draft_cache,
)
# Clean up any extra vram usage from torch and cuda
# (Helps reduce VRAM bottlenecking on Windows)
gc.collect()
torch.cuda.empty_cache()
# Update model load state
self.model_is_loading = False
self.model_loaded = True
logger.info("Model successfully loaded.")
def unload(self, loras_only: bool = False):
"""
Free all VRAM resources used by this model
"""
for lora in self.active_loras:
lora.unload()
self.active_loras = []
# Unload the entire model if not just unloading loras
if not loras_only:
if self.model:
self.model.unload()
self.model = None
if self.draft_model:
self.draft_model.unload()
self.draft_model = None
self.config = None
self.cache = None
self.tokenizer = None
self.generator = None
# Set all model state variables to False
self.model_is_loading = False
self.model_loaded = False
gc.collect()
torch.cuda.empty_cache()
logger.info("Loras unloaded." if loras_only else "Model unloaded.")
def encode_tokens(self, text: str, **kwargs):
"""Wrapper to encode tokens from a text string"""
return (
self.tokenizer.encode(
text,
add_bos=unwrap(kwargs.get("add_bos_token"), True),
encode_special_tokens=unwrap(kwargs.get("encode_special_tokens"), True),
)
.flatten()
.tolist()
)
def decode_tokens(self, ids: List[int], **kwargs):
"""Wrapper to decode tokens from a list of IDs"""
ids = torch.tensor([ids])
return self.tokenizer.decode(
ids,
decode_special_tokens=unwrap(kwargs.get("decode_special_tokens"), True),
)[0]
# TODO: Maybe support generation_config for eos_token
def get_special_tokens(
self, add_bos_token: bool = True, ban_eos_token: bool = False
):
return {
"bos_token": self.tokenizer.bos_token if add_bos_token else "",
"eos_token": self.tokenizer.eos_token if not ban_eos_token else "",
"pad_token": self.tokenizer.pad_token,
"unk_token": self.tokenizer.unk_token,
}
def get_logprobs(self, token_ids: torch.Tensor, token_probs: torch.Tensor):
top_tokens = list(
map(
lambda index: self.tokenizer.extended_id_to_piece.get(
index, self.tokenizer.id_to_piece[index]
),
token_ids.flatten().tolist(),
)
)
top_values = torch.log(token_probs).flatten().tolist()
# Cannot return -inf in JSON
cleaned_values = list(
map(lambda value: -1000 if value == float("-inf") else value, top_values)
)
return dict(zip_longest(top_tokens, cleaned_values))
async def generate(self, prompt: str, **kwargs):
"""Generate a response to a prompt"""
generations = []
async for generation in self.generate_gen(prompt, **kwargs):
generations.append(generation)
joined_generation = {
"text": "",
"prompt_tokens": 0,
"generation_tokens": 0,
"offset": [],
"token_probs": {},
"logprobs": [],
}
if generations:
# Get finish_reason first and then shift where -1 points to
if "finish_reason" in generations[-1]:
finish_reason_gen = generations.pop()
joined_generation["finish_reason"] = finish_reason_gen.get(
"finish_reason"
)
else:
joined_generation["finish_reason"] = "stop"
if len(generations) > 0:
for generation in generations:
joined_generation["text"] += unwrap(generation.get("text"), "")
joined_generation["offset"].append(unwrap(generation.get("offset"), -1))
joined_generation["token_probs"].update(
unwrap(generation.get("token_probs"), {})
)
# Include empty logprob dicts for index preservation
joined_generation["logprobs"].append(
unwrap(generation.get("logprobs"), {})
)
joined_generation["prompt_tokens"] = unwrap(
generations[-1].get("prompt_tokens"), 0
)
joined_generation["generation_tokens"] = unwrap(
generations[-1].get("generated_tokens"), 0
)
return joined_generation
def check_unsupported_settings(self, **kwargs):
"""Check and warn the user if a sampler is unsupported. Meant for dev wheels!"""
return kwargs
async def generate_gen(
self, prompt: str, abort_event: Optional[threading.Event] = None, **kwargs
):
"""Basic async wrapper for completion generator"""
sync_generator = self.generate_gen_sync(prompt, abort_event, **kwargs)
async for value in iterate_in_threadpool(sync_generator):
yield value
@torch.inference_mode()
def generate_gen_sync(
self, prompt: str, abort_event: Optional[threading.Event] = None, **kwargs
):
"""
Create generator function for prompt completion.
for kwargs, check common/sampling.py
"""
token_healing = unwrap(kwargs.get("token_healing"), False)
stream_interval = unwrap(kwargs.get("stream_interval"), 0)
generate_window = max(
unwrap(kwargs.get("generate_window"), 512), self.config.max_seq_len // 8
)
# Sampler settings
gen_settings = ExLlamaV2Sampler.Settings()
# Check unsupported settings for dev wheels
kwargs = self.check_unsupported_settings(**kwargs)
# Apply settings
gen_settings.temperature = unwrap(kwargs.get("temperature"), 1.0)
gen_settings.temperature_last = unwrap(kwargs.get("temperature_last"), False)
gen_settings.smoothing_factor = unwrap(kwargs.get("smoothing_factor"), 0.0)
gen_settings.top_k = unwrap(kwargs.get("top_k"), 0)
gen_settings.top_p = unwrap(kwargs.get("top_p"), 1.0)
gen_settings.top_a = unwrap(kwargs.get("top_a"), 0.0)
gen_settings.min_p = unwrap(kwargs.get("min_p"), 0.0)
gen_settings.tfs = unwrap(kwargs.get("tfs"), 1.0)
gen_settings.typical = unwrap(kwargs.get("typical"), 1.0)
gen_settings.mirostat = unwrap(kwargs.get("mirostat"), False)
# DynaTemp settings
max_temp = unwrap(kwargs.get("max_temp"), 1.0)
min_temp = unwrap(kwargs.get("min_temp"), 1.0)
if max_temp > min_temp:
gen_settings.max_temp = max_temp
gen_settings.min_temp = min_temp
gen_settings.temp_exponent = unwrap(kwargs.get("temp_exponent"), 1.0)
else:
# Force to default values
gen_settings.max_temp = 1.0
gen_settings.min_temp = 1.0
gen_settings.temp_exponent = 1.0
# Warn if max/min temp values are > 0
# and if they're less than or equal to each other
if max_temp < min_temp or (
1 not in {min_temp, max_temp} and max_temp == min_temp
):
logger.warning(
"Max temp is less than or equal to min temp, skipping DynaTemp."
)
# Default tau and eta fallbacks don't matter if mirostat is off
gen_settings.mirostat_tau = unwrap(kwargs.get("mirostat_tau"), 1.5)
gen_settings.mirostat_eta = unwrap(kwargs.get("mirostat_eta"), 0.1)
# Set CFG scale and negative prompt
cfg_scale = unwrap(kwargs.get("cfg_scale"), 1.0)
negative_prompt = None
if cfg_scale not in [None, 1.0]:
if self.use_cfg:
gen_settings.cfg_scale = cfg_scale
# If the negative prompt is empty, use the BOS token
negative_prompt = unwrap(
kwargs.get("negative_prompt"), self.tokenizer.bos_token
)
else:
logger.warning(
"CFG is currently disabled. "
"Please reload your model with use_cfg = True.",
)
gen_settings.token_repetition_penalty = unwrap(
kwargs.get("repetition_penalty"), 1.0
)
gen_settings.token_frequency_penalty = unwrap(
kwargs.get("frequency_penalty"), 0.0
)
gen_settings.token_presence_penalty = unwrap(
kwargs.get("presence_penalty"), 0.0
)
# Applies for all penalties despite being called token_repetition_range
gen_settings.token_repetition_range = unwrap(
kwargs.get("penalty_range"), self.config.max_seq_len
)
# Dynamically scale penalty range to output tokens
# Only do this if freq/pres pen is enabled
# and the repetition range is -1
auto_scale_penalty_range = (
gen_settings.token_frequency_penalty != 0
or gen_settings.token_presence_penalty != 0
) and gen_settings.token_repetition_range == -1
# Always make sure the fallback is 0 if range < 0
# It's technically fine to use -1, but this just validates the passed
# fallback
# Always default to 0 if something goes wrong
if gen_settings.token_repetition_range < 0:
fallback_decay = 0
else:
fallback_decay = gen_settings.token_repetition_range
gen_settings.token_repetition_decay = coalesce(
kwargs.get("repetition_decay"), fallback_decay, 0
)
stop_conditions: List[Union[str, int]] = unwrap(kwargs.get("stop"), [])
add_bos_token = unwrap(kwargs.get("add_bos_token"), True)
ban_eos_token = unwrap(kwargs.get("ban_eos_token"), False)
logit_bias = kwargs.get("logit_bias")
# Logprobs
request_logprobs = unwrap(kwargs.get("logprobs"), 0)
# Speculative Ngram
self.generator.speculative_ngram = unwrap(
kwargs.get("speculative_ngram"), False
)
# Override sampler settings for temp = 0
if gen_settings.temperature == 0:
gen_settings.temperature = 1.0
gen_settings.top_k = 1
gen_settings.top_p = 0
gen_settings.typical = 0
# Store the gen settings for logging purposes
gen_settings_log_dict = vars(gen_settings)
# Set banned tokens
banned_tokens = unwrap(kwargs.get("banned_tokens"), [])
if banned_tokens:
gen_settings.disallow_tokens(self.tokenizer, banned_tokens)
# Set logit bias
if logit_bias:
# Create a vocab tensor if it doesn't exist for token biasing
if gen_settings.token_bias is None:
padding = -self.tokenizer.config.vocab_size % 32
gen_settings.token_bias = torch.zeros(
(self.tokenizer.config.vocab_size + padding,),
dtype=torch.float,
)
# Map logits to the tensor with their biases
for token_id, bias in logit_bias.items():
if 0 <= token_id < len(self.tokenizer.id_to_piece):
gen_settings.token_bias[token_id] = bias
else:
logger.warning(
f"Logit bias: Token {token_id} not present "
"in the model's vocab. Skipping."
)
# Initialize grammar handler
grammar_handler = ExLlamaV2Grammar()
gen_settings.filters = []
# Add JSON schema filter if it exists
json_schema = unwrap(kwargs.get("json_schema"))
if json_schema:
grammar_handler.add_json_schema_filter(
json_schema, gen_settings, self.model, self.tokenizer
)
# Add EBNF filter if it exists
grammar_string = unwrap(kwargs.get("grammar_string"))
if grammar_string:
grammar_handler.add_ebnf_filter(
grammar_string, gen_settings, self.model, self.tokenizer
)
# Fetch EOS tokens from generation_config if they exist
eos_tokens = (
self.generation_config.eos_tokens()
if self.generation_config
else [self.tokenizer.eos_token_id]
)
# Ban the EOS token if specified. If not, append to stop conditions
# as well.
# Set this below logging to avoid polluting the stop strings array
if ban_eos_token:
gen_settings.disallow_tokens(self.tokenizer, eos_tokens)
else:
stop_conditions += eos_tokens
# Stop conditions
self.generator.set_stop_conditions(stop_conditions)
# Tokenized context
ids, offsets = self.tokenizer.encode(
[prompt, negative_prompt]
if negative_prompt and gen_settings.cfg_scale not in [None, 1.0]
else prompt,
add_bos=add_bos_token,
encode_special_tokens=True,
return_offsets=True,
)
mask = (
self.tokenizer.padding_mask(ids)
if self.use_cfg and gen_settings.cfg_scale not in [None, 1.0]
else None
)
context_len = len(ids[0])
if context_len > self.config.max_seq_len:
logger.warning(
f"Context length {context_len} is greater than max_seq_len "
f"{self.config.max_seq_len}. Generation is truncated and "
"metrics may not be accurate."
)
prompt_tokens = ids.shape[-1]
# Automatically set max_tokens to fill up the context
# This should be an OK default, but may be changed in the future
max_tokens = unwrap(
kwargs.get("max_tokens"), self.config.max_seq_len - prompt_tokens
)
# Set min_tokens to generate while keeping EOS banned
min_tokens = unwrap(kwargs.get("min_tokens"), 0)
# This is an inverse of skip_special_tokens
decode_special_tokens = unwrap(not kwargs.get("skip_special_tokens"), False)
begin_stream_args = {
"token_healing": token_healing,
"loras": self.active_loras,
"return_probabilities": request_logprobs > 0,
"return_top_tokens": request_logprobs,
"return_logits": request_logprobs > 0,
"abort_event": abort_event,
}
if self.use_cfg:
begin_stream_args.update(
{
"input_mask": mask,
"position_offsets": offsets,
}
)
# Check if decode_special_tokens is supported
# TODO: Remove when a new version of ExllamaV2 is released
if decode_special_tokens:
begin_stream_signature = signature(self.generator.begin_stream_ex)
try:
_bound_vars = begin_stream_signature.bind_partial(
decode_special_tokens=True
)
begin_stream_args["decode_special_tokens"] = decode_special_tokens
except TypeError:
logger.warning(
"skip_special_tokens is not supported by the currently "
"installed ExLlamaV2 version."
)
# Check if temporary token bans are supported
# TODO: Remove when a new version of ExllamaV2 is released
if min_tokens:
stream_signature = signature(self.generator.stream_ex)
try:
_bound_vars = stream_signature.bind_partial(
ban_tokens=[]
)
except TypeError:
logger.warning(
"min_tokens is not supported by the currently "
"installed ExLlamaV2 version."
)
min_tokens = 0
# Log generation options to console
# Some options are too large, so log the args instead
log_generation_params(
max_tokens=max_tokens,
min_tokens=min_tokens,
stream=kwargs.get("stream"),
**gen_settings_log_dict,
token_healing=token_healing,
auto_scale_penalty_range=auto_scale_penalty_range,
generate_window=generate_window,
bos_token_id=self.tokenizer.bos_token_id,
eos_token_id=eos_tokens,
add_bos_token=add_bos_token,
ban_eos_token=ban_eos_token,
skip_special_tokens=not decode_special_tokens,
speculative_ngram=self.generator.speculative_ngram,
logprobs=request_logprobs,
stop_conditions=stop_conditions,
banned_tokens=banned_tokens,
logit_bias=logit_bias,
)
# Log prompt to console
log_prompt(prompt, negative_prompt)
# Begin
generated_tokens = 0
full_response = ""
start_time = time.time()
last_chunk_time = start_time
save_tokens = torch.empty((ids.shape[0], 0), dtype=torch.bool)
chunk_buffer = ""
chunk_tokens = 0
while True:
# Ingest prompt
if chunk_tokens == 0:
ids = torch.cat((ids, save_tokens), dim=-1)
save_tokens = torch.empty((ids.shape[0], 0), dtype=torch.bool)
overflow = ids.shape[-1] + generate_window - self.config.max_seq_len
active_ids = ids[:, max(0, overflow) :]
chunk_tokens = self.config.max_seq_len - active_ids.shape[-1]
# Kick off the streaming generation
self.generator.begin_stream_ex(
active_ids, gen_settings, **begin_stream_args
)
# Reset offsets for subsequent passes if the context is truncated
offsets = None
if auto_scale_penalty_range:
gen_settings.token_repetition_range = generated_tokens
# Run dict generation
# Guarantees return of chunk, eos, and chunk_token_ids
if generated_tokens < min_tokens:
raw_generation = self.generator.stream_ex(ban_tokens=eos_tokens)
else:
raw_generation = self.generator.stream_ex()
if token_healing:
# Extract healed token
ids[:, -1] = self.generator.sequence_ids[:, -2]
token_healing = False
# Get parameters that will always exist
chunk = raw_generation["chunk"]
eos = raw_generation["eos"]
tokens = raw_generation["chunk_token_ids"]
save_tokens = torch.cat(
(save_tokens, tokens.expand(save_tokens.shape[0], -1)), dim=-1
)
chunk_buffer += chunk
generated_tokens += 1
chunk_tokens -= 1
# Yield output
now = time.time()
elapsed = now - last_chunk_time
if chunk_buffer != "" and (
elapsed > stream_interval or eos or generated_tokens == max_tokens
):
generation = {
"text": chunk_buffer,
"prompt_tokens": prompt_tokens,
"generated_tokens": generated_tokens,
"offset": len(full_response),
}
if request_logprobs > 0:
# Get top tokens and probs
top_tokens = unwrap(
raw_generation.get("top_tokens"),
torch.empty((1, 0, 1), dtype=torch.long),
)
top_probs = unwrap(
raw_generation.get("top_probs"),
torch.empty((1, 0, 1), dtype=torch.float),
)
if top_tokens.numel() > 0 and top_probs.numel() > 0:
logprobs = self.get_logprobs(top_tokens, top_probs)
generation["logprobs"] = logprobs
# The first logprob is the selected token prob
generation["token_probs"] = {
token: logprobs[token]
for token in list(logprobs.keys())[:1]
}
yield generation
full_response += chunk_buffer
chunk_buffer = ""
last_chunk_time = now
if eos or generated_tokens == max_tokens:
# Print response
log_response(full_response)
# Print metrics
elapsed_time = last_chunk_time - start_time
context_len = None if ids is None else context_len
log_metrics(
generated_tokens, elapsed_time, context_len, self.config.max_seq_len
)
finish_reason = "length" if generated_tokens == max_tokens else "stop"
generation = {"finish_reason": finish_reason}
yield generation
break