tabbyAPI-ollama/backends/exllamav2/model.py
kingbri 1ec8eb9620 Tree: Format
Signed-off-by: kingbri <bdashore3@proton.me>
2024-03-13 00:02:55 -04:00

1003 lines
37 KiB
Python

"""The model container class for ExLlamaV2 models."""
import gc
from itertools import zip_longest
import pathlib
import time
import torch
from exllamav2 import (
ExLlamaV2,
ExLlamaV2Config,
ExLlamaV2Cache,
ExLlamaV2Cache_8bit,
ExLlamaV2Cache_Q4,
ExLlamaV2Tokenizer,
ExLlamaV2Lora,
)
from exllamav2.generator import ExLlamaV2StreamingGenerator, ExLlamaV2Sampler
from loguru import logger
from typing import List, Optional, Union
from backends.exllamav2.grammar import ExLlamaV2Grammar
from common.gen_logging import log_generation_params, log_prompt, log_response
from common.templating import (
PromptTemplate,
find_template_from_model,
get_template_from_model_json,
get_template_from_file,
)
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
# 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: 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 2038
self.config.max_seq_len = 4096
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)
)
# low_mem is currently broken in exllamav2. Don't use it until it's
# fixed.
"""
if "low_mem" in kwargs and kwargs["low_mem"]:
self.config.set_low_mem()
"""
# Try to set prompt template
self.prompt_template = self.find_prompt_template(
kwargs.get("prompt_template"), model_directory
)
# 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")
chunk_size = min(
unwrap(kwargs.get("chunk_size"), 2048), self.config.max_seq_len
)
self.config.max_input_len = chunk_size
self.config.max_attn_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" in kwargs:
self.draft_config.max_input_len = kwargs["chunk_size"]
self.draft_config.max_attn_size = kwargs["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: get_template_from_model_json(
pathlib.Path(self.config.model_dir) / "tokenizer_config.json",
"chat_template",
"from_tokenizer_config",
),
lambda: get_template_from_file(find_template_from_model(model_directory)),
]
# Add lookup from prompt template name if provided
if prompt_template_name:
find_template_functions.insert(
0, lambda: get_template_from_file(prompt_template_name)
)
for func in find_template_functions:
try:
prompt_template = func()
if prompt_template is not None:
return prompt_template
except (FileNotFoundError, LookupError):
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,
"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
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)
"""
for _ in self.load_gen(progress_callback):
pass
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
# FIXME(alpin): Does self.model need to be passed here?
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}
def load_gen(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)
"""
# Notify that the model is being loaded
self.model_is_loading = True
# Load tokenizer
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)
yield from self.draft_model.load_autosplit_gen(
self.draft_cache,
reserve_vram=autosplit_reserve,
last_id_only=True,
callback_gen=progress_callback,
)
# 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,
)
# Always return logprobs and logits
self.generator.return_probabilities = True
self.generator.return_logits = True
# 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]
def get_special_tokens(self, add_bos_token: bool, ban_eos_token: bool):
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))
def generate(self, prompt: str, **kwargs):
"""Generate a response to a prompt"""
generations = list(self.generate_gen(prompt, **kwargs))
joined_generation = {
"text": "",
"prompt_tokens": 0,
"generation_tokens": 0,
"offset": [],
"token_probs": {},
"logprobs": [],
}
if generations:
for generation in generations:
joined_generation["text"] += unwrap(generation.get("text"), "")
joined_generation["offset"].append(unwrap(generation.get("offset"), []))
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!"""
pass
# pylint: disable=too-many-locals,too-many-branches,too-many-statements
def generate_gen(self, prompt: str, **kwargs):
"""
Create generator function for prompt completion
Args:
prompt (str): Input prompt
**kwargs:
'token_healing' (bool): Use token healing (default: False)
'temperature' (float): Sampling temperature (default: 1.0)
'temperature_last' (bool): Apply temperature after all other
samplers (default: False)
'top_k' (int): Sampling top-K (default: 0)
'top_p' (float): Sampling top-P (default: 1.0)
'min_p' (float): Sampling min-P (default: 0.0)
'tfs' (float): Tail-free sampling (default: 0.0)
'typical' (float): Sampling typical (default: 0.0)
'mirostat' (bool): Use Mirostat (default: False)
'mirostat_tau' (float) Mirostat tau parameter (default: 1.5)
'mirostat_eta' (float) Mirostat eta parameter (default: 0.1)
'frequency_penalty' (float): Token frequency penalty (default: 0.0)
'presence_penalty' (float): Token presence penalty (default: 0.0)
'repetition_penalty' (float): Token repetition penalty
(default: 1.15)
'penalty_range' (int): Penalty range
(default: whole context)
'repetition_decay' (int): Repetition penalty range
(default: same as range)
'stop' (List[Union[str, int]]): List of stop strings/tokens to
end response (default: [EOS])
'max_tokens' (int): Max no. tokens in response (default: 150)
'add_bos_token' (bool): Adds the BOS token to the start of the
prompt (default: True)
'ban_eos_token' (bool): Bans the EOS token from generation
(default: False)
'logit_bias' (Dict[int, float]): Biases specific tokens to
either show up more or less (default: None)
'stream_interval' (float): Interval in seconds between each
output chunk (default: immediate)
'generate_window' (int): Space to reserve at the end of the
model's context when generating. Rolls context window by
the same amount if context length is exceeded to allow
generating pastthe models max_seq_len.
"""
token_healing = unwrap(kwargs.get("token_healing"), False)
max_tokens = unwrap(kwargs.get("max_tokens"), 150)
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
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)
self.generator.return_top_tokens = request_logprobs
# 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
# Log generation options to console
# Some options are too large, so log the args instead
log_generation_params(
max_tokens=max_tokens,
**vars(gen_settings),
token_healing=token_healing,
auto_scale_penalty_range=auto_scale_penalty_range,
generate_window=generate_window,
add_bos_token=add_bos_token,
ban_eos_token=ban_eos_token,
logprobs=request_logprobs,
stop_conditions=stop_conditions,
logit_bias=logit_bias,
)
# Log prompt to console
log_prompt(prompt, negative_prompt)
# 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
)
# 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, [self.tokenizer.eos_token_id])
else:
stop_conditions.append(self.tokenizer.eos_token_id)
# 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]
# 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]
# Split for exllama versions that have CFG
if self.use_cfg:
self.generator.begin_stream(
active_ids,
gen_settings,
token_healing=token_healing,
loras=self.active_loras,
input_mask=mask,
position_offsets=offsets,
)
else:
self.generator.begin_stream(
active_ids,
gen_settings,
token_healing=token_healing,
loras=self.active_loras,
)
# 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
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:
break
# Print response
log_response(full_response)
elapsed_time = last_chunk_time - start_time
initial_response = (
f"Metrics: {generated_tokens} tokens generated in "
f"{round(elapsed_time, 2)} seconds"
)
itemization = []
extra_parts = []
# Add tokens per second
tokens_per_second = (
"Indeterminate"
if elapsed_time == 0
else round(generated_tokens / elapsed_time, 2)
)
itemization.append(f"{tokens_per_second} T/s")
# Add context (original token count)
if ids is not None:
itemization.append(f"context {context_len} tokens")
if context_len > self.config.max_seq_len:
extra_parts.append("<-- Not accurate (truncated)")
# Print output
logger.info(
initial_response
+ " ("
+ ", ".join(itemization)
+ ") "
+ " ".join(extra_parts)
)