tabbyAPI-ollama/model.py
kingbri a14abfe21c Templates: Support bos_token and eos_token fields
These are commonly seen in huggingface provided chat templates and
aren't that difficult to add in.

For feature parity, honor the add_bos_token and ban_eos_token
parameters when constructing the prompt.

Signed-off-by: kingbri <bdashore3@proton.me>
2023-12-22 10:33:11 -05:00

567 lines
24 KiB
Python

import gc
import pathlib
import time
import torch
from exllamav2 import(
ExLlamaV2,
ExLlamaV2Config,
ExLlamaV2Cache,
ExLlamaV2Cache_8bit,
ExLlamaV2Tokenizer,
ExLlamaV2Lora
)
from exllamav2.generator import(
ExLlamaV2StreamingGenerator,
ExLlamaV2Sampler
)
from gen_logging import log_generation_params, log_prompt, log_response
from typing import List, Optional, Union
from templating import PromptTemplate, find_template_from_model, get_template_from_model_json, get_template_from_file
from utils import coalesce, unwrap
# Bytes to reserve on first device when loading with auto split
auto_split_reserve_bytes = 96 * 1024**2
class ModelContainer:
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
cache_fp8: bool = False
gpu_split_auto: bool = True
gpu_split: Optional[list] = None
active_loras: List[ExLlamaV2Lora] = []
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)
"""
self.quiet = quiet
self.cache_fp8 = "cache_mode" in kwargs and kwargs["cache_mode"] == "FP8"
self.gpu_split = kwargs.get("gpu_split")
self.gpu_split_auto = unwrap(kwargs.get("gpu_split_auto"), True)
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"), 1.0)
# Automatically calculate rope alpha
self.config.scale_alpha_value = unwrap(
kwargs.get("rope_alpha"),
self.calculate_rope_alpha(base_seq_len)
)
# Turn off flash attention?
self.config.no_flash_attn = 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()
"""
# Set prompt template override if provided
prompt_template_name = kwargs.get("prompt_template")
if prompt_template_name:
print(f"Attempting to load prompt template with name {prompt_template_name}")
# Read the template
self.prompt_template = get_template_from_file(prompt_template_name)
else:
# Then try finding the template from the tokenizer_config.json
self.prompt_template = get_template_from_model_json(
pathlib.Path(self.config.model_dir) / "tokenizer_config.json",
"chat_template",
"from_tokenizer_config"
)
# Try finding the chat template from the model's config.json
# TODO: This may not even be used with huggingface models, mark for removal.
if self.prompt_template is None:
self.prompt_template = get_template_from_model_json(
pathlib.Path(self.config.model_config),
"chat_template",
"from_model_config"
)
# If that fails, attempt fetching from model name
if self.prompt_template is None:
template_match = find_template_from_model(model_directory)
if template_match:
self.prompt_template = get_template_from_file(template_match)
# Catch all for template lookup errors
if self.prompt_template:
print(f"Using template {self.prompt_template.name} for chat completions.")
else:
print(
"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:
if hasattr(self.config, "num_experts_per_token"):
self.config.num_experts_per_token = num_experts_override
else:
print(" !! Warning: Currently installed ExLlamaV2 does not support overriding MoE experts")
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:
print("A draft config was found but a model name was not given. Please check your config.yml! Skipping draft load.")
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 calculate_rope_alpha(self, base_seq_len):
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
alpha = 1 if ratio <= 1.0 else -0.13436 + 0.80541 * ratio + 0.28833 * ratio ** 2
return alpha
def get_model_path(self, is_draft: bool = False):
model_path = pathlib.Path(self.draft_config.model_dir if is_draft else self.config.model_dir)
return model_path
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:
print("One of your loras does not have a name. Please check your config.yml! Skipping lora load.")
failure.append(lora_name)
continue
print(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))
print("Lora successfully loaded.")
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)
"""
# Load tokenizer
self.tokenizer = ExLlamaV2Tokenizer(self.config)
# Load draft model if a config is present
if self.draft_config:
self.draft_model = ExLlamaV2(self.draft_config)
if not self.quiet:
print("Loading draft model: " + self.draft_config.model_dir)
self.draft_cache = ExLlamaV2Cache(self.draft_model, lazy = True)
reserve = [auto_split_reserve_bytes] + [0] * 16
yield from self.draft_model.load_autosplit_gen(self.draft_cache, reserve_vram = 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)
# Load model
self.model = ExLlamaV2(self.config)
if not self.quiet:
print("Loading model: " + self.config.model_dir)
if not self.gpu_split_auto:
for value in self.model.load_gen(self.gpu_split, callback_gen = progress_callback):
if isinstance(value, str):
yield value
if self.cache_fp8:
self.cache = ExLlamaV2Cache_8bit(self.model, lazy = self.gpu_split_auto)
else:
self.cache = ExLlamaV2Cache(self.model, lazy = self.gpu_split_auto)
if self.gpu_split_auto:
reserve = [auto_split_reserve_bytes] + [0] * 16
yield from self.model.load_autosplit_gen(self.cache, reserve_vram = 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.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)
print("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
gc.collect()
torch.cuda.empty_cache()
# Common function for token operations
def get_tokens(self, text: Optional[str], ids: Optional[List[int]], **kwargs):
if text:
# Assume token encoding
return self.tokenizer.encode(
text,
add_bos = unwrap(kwargs.get("add_bos_token"), True),
encode_special_tokens = unwrap(kwargs.get("encode_special_tokens"), True)
)
if ids:
# Assume token decoding
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 generate(self, prompt: str, **kwargs):
generation = list(self.generate_gen(prompt, **kwargs))
if generation:
response = "".join(map(lambda chunk: chunk[0], generation))
return response, generation[-1][1], generation[-1][2]
else:
return "", 0, 0
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)
'repetition_penalty' (float): Token repetition/presence penalty (default: 1.15)
'repetition_range' (int): Repetition 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 past
the 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 = min(unwrap(kwargs.get("generate_window"), 512), max_tokens)
# Sampler settings
gen_settings = ExLlamaV2Sampler.Settings()
# Warn of unsupported settings if the setting is enabled
if (unwrap(kwargs.get("mirostat"), False)) and not hasattr(gen_settings, "mirostat"):
print(" !! Warning: Currently installed ExLlamaV2 does not support Mirostat sampling")
if (unwrap(kwargs.get("min_p"), 0.0)) not in [0.0, 1.0] and not hasattr(gen_settings, "min_p"):
print(" !! Warning: Currently installed ExLlamaV2 does not support min-P sampling")
if (unwrap(kwargs.get("tfs"), 0.0)) not in [0.0, 1.0] and not hasattr(gen_settings, "tfs"):
print(" !! Warning: Currently installed ExLlamaV2 does not support tail-free sampling (TFS)")
if (unwrap(kwargs.get("temperature_last"), False)) and not hasattr(gen_settings, "temperature_last"):
print(" !! Warning: Currently installed ExLlamaV2 does not support temperature_last")
# Apply settings
gen_settings.temperature = unwrap(kwargs.get("temperature"), 1.0)
gen_settings.temperature_last = unwrap(kwargs.get("temperature_last"), False)
gen_settings.top_k = unwrap(kwargs.get("top_k"), 0)
gen_settings.top_p = unwrap(kwargs.get("top_p"), 1.0)
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)
# 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)
gen_settings.token_repetition_penalty = unwrap(kwargs.get("repetition_penalty"), 1.0)
gen_settings.token_repetition_range = unwrap(kwargs.get("repetition_range"), self.config.max_seq_len)
# 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
fallback_decay = 0 if gen_settings.token_repetition_range <= 0 else 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")
# 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,
add_bos_token = add_bos_token,
ban_eos_token = ban_eos_token,
stop_conditions = stop_conditions,
logit_bias = logit_bias
)
# Log prompt to console
log_prompt(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, bias in logit_bias.items():
gen_settings.token_bias[token] = bias
# 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 = self.tokenizer.encode(
prompt,
add_bos = add_bos_token,
encode_special_tokens = True
)
context_len = len(ids[0])
if context_len > self.config.max_seq_len:
print(
f"WARNING: The context length {context_len} is greater than the max_seq_len {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((1, 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((1, 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]
self.generator.begin_stream(active_ids, gen_settings, token_healing = token_healing, loras = self.active_loras)
# Generate
chunk, eos, tokens = self.generator.stream()
if token_healing:
ids[:, -1] = self.generator.sequence_ids[:, -2] # Extract healed token
token_healing = False
save_tokens = torch.cat((save_tokens, tokens), 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):
yield chunk_buffer, prompt_tokens, generated_tokens
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 {round(elapsed_time, 2)} seconds"
itemization = []
extra_parts = []
# Add tokens per second
itemization.append(f"{'Indeterminate' if elapsed_time == 0 else round(generated_tokens / elapsed_time, 2)} 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
print(initial_response + " (" + ", ".join(itemization) + ") " + " ".join(extra_parts))