tabbyAPI-ollama/endpoints/OAI/utils/chat_completion.py
kingbri c8371e0f50 OAI: Copy gen params for "n"
For multiple generations in the same request, nested arrays kept their
original reference, resulting in duplications. This will occur with
any collection type.

For optimization purposes, a deepcopy isn't run for the first iteration
since original references are created.

This is not the most elegant solution, but it works for the described
cases.

Signed-off-by: kingbri <bdashore3@proton.me>
2024-05-28 00:52:30 -04:00

275 lines
8.7 KiB
Python

"""Chat completion utilities for OAI server."""
import asyncio
import pathlib
from asyncio import CancelledError
from copy import deepcopy
from typing import List, Optional
from uuid import uuid4
from fastapi import HTTPException, Request
from jinja2 import TemplateError
from loguru import logger
from common import model
from common.networking import (
get_generator_error,
handle_request_disconnect,
handle_request_error,
request_disconnect_loop,
)
from common.utils import unwrap
from endpoints.OAI.types.chat_completion import (
ChatCompletionLogprobs,
ChatCompletionLogprob,
ChatCompletionMessage,
ChatCompletionRequest,
ChatCompletionRespChoice,
ChatCompletionStreamChunk,
ChatCompletionResponse,
ChatCompletionStreamChoice,
)
from endpoints.OAI.types.common import UsageStats
def _create_response(generations: List[dict], model_name: Optional[str]):
"""Create a chat completion response from the provided text."""
prompt_tokens = unwrap(generations[-1].get("prompt_tokens"), 0)
completion_tokens = unwrap(generations[-1].get("generated_tokens"), 0)
choices = []
for index, generation in enumerate(generations):
message = ChatCompletionMessage(
role="assistant", content=unwrap(generation.get("text"), "")
)
logprob_response = None
token_probs = unwrap(generation.get("token_probs"), {})
if token_probs:
logprobs = unwrap(generation.get("logprobs"), [])
collected_token_probs = []
for index, token in enumerate(token_probs.keys()):
top_logprobs = [
ChatCompletionLogprob(token=token, logprob=logprob)
for token, logprob in logprobs[index].items()
]
collected_token_probs.append(
ChatCompletionLogprob(
token=token,
logprob=token_probs[token],
top_logprobs=top_logprobs,
)
)
logprob_response = ChatCompletionLogprobs(content=collected_token_probs)
choice = ChatCompletionRespChoice(
index=index,
finish_reason=generation.get("finish_reason"),
message=message,
logprobs=logprob_response,
)
choices.append(choice)
response = ChatCompletionResponse(
choices=choices,
model=unwrap(model_name, ""),
usage=UsageStats(
prompt_tokens=prompt_tokens,
completion_tokens=completion_tokens,
total_tokens=prompt_tokens + completion_tokens,
),
)
return response
def _create_stream_chunk(
const_id: str,
generation: Optional[dict] = None,
model_name: Optional[str] = None,
):
"""Create a chat completion stream chunk from the provided text."""
logprob_response = None
if "finish_reason" in generation:
choice = ChatCompletionStreamChoice(
finish_reason=generation.get("finish_reason")
)
else:
message = ChatCompletionMessage(
role="assistant", content=unwrap(generation.get("text"), "")
)
token_probs = unwrap(generation.get("token_probs"), {})
if token_probs:
logprobs = unwrap(generation.get("logprobs"), {})
top_logprobs = [
ChatCompletionLogprob(token=token, logprob=logprob)
for token, logprob in logprobs.items()
]
generated_token = next(iter(token_probs))
token_prob_response = ChatCompletionLogprob(
token=generated_token,
logprob=token_probs[generated_token],
top_logprobs=top_logprobs,
)
logprob_response = ChatCompletionLogprobs(content=[token_prob_response])
choice = ChatCompletionStreamChoice(
delta=message,
logprobs=logprob_response,
)
chunk = ChatCompletionStreamChunk(
id=const_id, choices=[choice], model=unwrap(model_name, "")
)
return chunk
def format_prompt_with_template(data: ChatCompletionRequest):
"""
Compile the prompt and get any additional stop strings from the template.
Template stop strings can be overriden by sampler overrides if force is true.
"""
try:
special_tokens_dict = model.container.get_special_tokens(
unwrap(data.add_bos_token, True),
unwrap(data.ban_eos_token, False),
)
# Overwrite any protected vars with their values
data.template_vars.update(
{
"messages": data.messages,
"add_generation_prompt": data.add_generation_prompt,
**special_tokens_dict,
}
)
prompt, template_stop_strings = model.container.prompt_template.render(
data.template_vars
)
# Append response prefix if present
if data.response_prefix:
if data.add_generation_prompt:
prompt += data.response_prefix
else:
logger.warning(
"Could not add response prefix because "
"add_generation_prompt is False"
)
# Removes the starting BOS token if present
# This is to prevent add_bos_token from adding multiple bos tokens
bos_token = special_tokens_dict.get("bos_token")
if bos_token and prompt.startswith(bos_token):
prompt = prompt.removeprefix(bos_token)
# Append template stop strings
if isinstance(data.stop, str):
data.stop = [data.stop] + template_stop_strings
else:
data.stop += template_stop_strings
return prompt
except KeyError as exc:
error_message = handle_request_error(
"Could not find a Conversation from prompt template "
f"'{model.container.prompt_template.name}'. "
"Check your spelling?",
).error.message
raise HTTPException(400, error_message) from exc
except TemplateError as exc:
error_message = handle_request_error(f"TemplateError: {str(exc)}").error.message
raise HTTPException(400, error_message) from exc
async def stream_generate_chat_completion(
prompt: str, data: ChatCompletionRequest, request: Request, model_path: pathlib.Path
):
"""Generator for the generation process."""
abort_event = asyncio.Event()
try:
const_id = f"chatcmpl-{uuid4().hex}"
new_generation = model.container.generate_gen(
prompt, abort_event, **data.to_gen_params()
)
# Create a background task to avoid blocking the loop
disconnect_task = asyncio.create_task(request_disconnect_loop(request))
async for generation in new_generation:
# Sometimes this fires, and sometimes a CancelledError will fire
# Keep both implementations in to avoid the headache
if disconnect_task.done():
abort_event.set()
handle_request_disconnect("Completion generation cancelled by user.")
response = _create_stream_chunk(const_id, generation, model_path.name)
yield response.model_dump_json()
# Break if the generation is finished
if "finish_reason" in generation:
break
except CancelledError:
# Get out if the request gets disconnected
abort_event.set()
handle_request_disconnect("Chat completion generation cancelled by user.")
except Exception:
yield get_generator_error(
"Chat completion aborted. Please check the server console."
)
async def generate_chat_completion(
prompt: str, data: ChatCompletionRequest, model_path: pathlib.Path
):
gen_tasks: List[asyncio.Task] = []
gen_params = data.to_gen_params()
try:
for n in range(0, data.n):
# Deepcopy gen params above the first index
# to ensure nested structures aren't shared
if n > 0:
task_gen_params = deepcopy(gen_params)
else:
task_gen_params = gen_params
gen_tasks.append(
asyncio.create_task(
model.container.generate(prompt, **task_gen_params)
)
)
generations = await asyncio.gather(*gen_tasks)
response = _create_response(generations, model_path.name)
return response
except Exception as exc:
error_message = handle_request_error(
"Chat completion aborted. Maybe the model was unloaded? "
"Please check the server console."
).error.message
# Server error if there's a generation exception
raise HTTPException(503, error_message) from exc