Bakalarska_praca/private_gpt/components/llm/custom/sagemaker.py

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2024-09-27 16:52:16 +00:00
# mypy: ignore-errors
from __future__ import annotations
import io
import json
import logging
from typing import TYPE_CHECKING, Any
import boto3 # type: ignore
from llama_index.core.base.llms.generic_utils import (
completion_response_to_chat_response,
stream_completion_response_to_chat_response,
)
from llama_index.core.bridge.pydantic import Field
from llama_index.core.llms import (
CompletionResponse,
CustomLLM,
LLMMetadata,
)
from llama_index.core.llms.callbacks import (
llm_chat_callback,
llm_completion_callback,
)
if TYPE_CHECKING:
from collections.abc import Sequence
from llama_index.callbacks import CallbackManager
from llama_index.llms import (
ChatMessage,
ChatResponse,
ChatResponseGen,
CompletionResponseGen,
)
logger = logging.getLogger(__name__)
class LineIterator:
r"""A helper class for parsing the byte stream input from TGI container.
The output of the model will be in the following format:
```
b'data:{"token": {"text": " a"}}\n\n'
b'data:{"token": {"text": " challenging"}}\n\n'
b'data:{"token": {"text": " problem"
b'}}'
...
```
While usually each PayloadPart event from the event stream will contain a byte array
with a full json, this is not guaranteed and some of the json objects may be split
across PayloadPart events. For example:
```
{'PayloadPart': {'Bytes': b'{"outputs": '}}
{'PayloadPart': {'Bytes': b'[" problem"]}\n'}}
```
This class accounts for this by concatenating bytes written via the 'write' function
and then exposing a method which will return lines (ending with a '\n' character)
within the buffer via the 'scan_lines' function. It maintains the position of the
last read position to ensure that previous bytes are not exposed again. It will
also save any pending lines that doe not end with a '\n' to make sure truncations
are concatinated
"""
def __init__(self, stream: Any) -> None:
"""Line iterator initializer."""
self.byte_iterator = iter(stream)
self.buffer = io.BytesIO()
self.read_pos = 0
def __iter__(self) -> Any:
"""Self iterator."""
return self
def __next__(self) -> Any:
"""Next element from iterator."""
while True:
self.buffer.seek(self.read_pos)
line = self.buffer.readline()
if line and line[-1] == ord("\n"):
self.read_pos += len(line)
return line[:-1]
try:
chunk = next(self.byte_iterator)
except StopIteration:
if self.read_pos < self.buffer.getbuffer().nbytes:
continue
raise
if "PayloadPart" not in chunk:
logger.warning("Unknown event type=%s", chunk)
continue
self.buffer.seek(0, io.SEEK_END)
self.buffer.write(chunk["PayloadPart"]["Bytes"])
class SagemakerLLM(CustomLLM):
"""Sagemaker Inference Endpoint models.
To use, you must supply the endpoint name from your deployed
Sagemaker model & the region where it is deployed.
To authenticate, the AWS client uses the following methods to
automatically load credentials:
https://boto3.amazonaws.com/v1/documentation/api/latest/guide/credentials.html
If a specific credential profile should be used, you must pass
the name of the profile from the ~/.aws/credentials file that is to be used.
Make sure the credentials / roles used have the required policies to
access the Sagemaker endpoint.
See: https://docs.aws.amazon.com/IAM/latest/UserGuide/access_policies.html
"""
endpoint_name: str = Field(description="")
temperature: float = Field(description="The temperature to use for sampling.")
max_new_tokens: int = Field(description="The maximum number of tokens to generate.")
context_window: int = Field(
description="The maximum number of context tokens for the model."
)
messages_to_prompt: Any = Field(
description="The function to convert messages to a prompt.", exclude=True
)
completion_to_prompt: Any = Field(
description="The function to convert a completion to a prompt.", exclude=True
)
generate_kwargs: dict[str, Any] = Field(
default_factory=dict, description="Kwargs used for generation."
)
model_kwargs: dict[str, Any] = Field(
default_factory=dict, description="Kwargs used for model initialization."
)
verbose: bool = Field(description="Whether to print verbose output.")
_boto_client: Any = boto3.client(
"sagemaker-runtime",
) # TODO make it an optional field
def __init__(
self,
endpoint_name: str | None = "",
temperature: float = 0.1,
max_new_tokens: int = 512, # to review defaults
context_window: int = 2048, # to review defaults
messages_to_prompt: Any = None,
completion_to_prompt: Any = None,
callback_manager: CallbackManager | None = None,
generate_kwargs: dict[str, Any] | None = None,
model_kwargs: dict[str, Any] | None = None,
verbose: bool = True,
) -> None:
"""SagemakerLLM initializer."""
model_kwargs = model_kwargs or {}
model_kwargs.update({"n_ctx": context_window, "verbose": verbose})
messages_to_prompt = messages_to_prompt or {}
completion_to_prompt = completion_to_prompt or {}
generate_kwargs = generate_kwargs or {}
generate_kwargs.update(
{"temperature": temperature, "max_tokens": max_new_tokens}
)
super().__init__(
endpoint_name=endpoint_name,
temperature=temperature,
context_window=context_window,
max_new_tokens=max_new_tokens,
messages_to_prompt=messages_to_prompt,
completion_to_prompt=completion_to_prompt,
callback_manager=callback_manager,
generate_kwargs=generate_kwargs,
model_kwargs=model_kwargs,
verbose=verbose,
)
@property
def inference_params(self):
# TODO expose the rest of params
return {
"do_sample": True,
"top_p": 0.7,
"temperature": self.temperature,
"top_k": 50,
"max_new_tokens": self.max_new_tokens,
}
@property
def metadata(self) -> LLMMetadata:
"""Get LLM metadata."""
return LLMMetadata(
context_window=self.context_window,
num_output=self.max_new_tokens,
model_name="Sagemaker LLama 2",
)
@llm_completion_callback()
def complete(self, prompt: str, **kwargs: Any) -> CompletionResponse:
self.generate_kwargs.update({"stream": False})
is_formatted = kwargs.pop("formatted", False)
if not is_formatted:
prompt = self.completion_to_prompt(prompt)
request_params = {
"inputs": prompt,
"stream": False,
"parameters": self.inference_params,
}
resp = self._boto_client.invoke_endpoint(
EndpointName=self.endpoint_name,
Body=json.dumps(request_params),
ContentType="application/json",
)
response_body = resp["Body"]
response_str = response_body.read().decode("utf-8")
response_dict = json.loads(response_str)
return CompletionResponse(
text=response_dict[0]["generated_text"][len(prompt) :], raw=resp
)
@llm_completion_callback()
def stream_complete(self, prompt: str, **kwargs: Any) -> CompletionResponseGen:
def get_stream():
text = ""
request_params = {
"inputs": prompt,
"stream": True,
"parameters": self.inference_params,
}
resp = self._boto_client.invoke_endpoint_with_response_stream(
EndpointName=self.endpoint_name,
Body=json.dumps(request_params),
ContentType="application/json",
)
event_stream = resp["Body"]
start_json = b"{"
stop_token = "<|endoftext|>"
first_token = True
for line in LineIterator(event_stream):
if line != b"" and start_json in line:
data = json.loads(line[line.find(start_json) :].decode("utf-8"))
special = data["token"]["special"]
stop = data["token"]["text"] == stop_token
if not special and not stop:
delta = data["token"]["text"]
# trim the leading space for the first token if present
if first_token:
delta = delta.lstrip()
first_token = False
text += delta
yield CompletionResponse(delta=delta, text=text, raw=data)
return get_stream()
@llm_chat_callback()
def chat(self, messages: Sequence[ChatMessage], **kwargs: Any) -> ChatResponse:
prompt = self.messages_to_prompt(messages)
completion_response = self.complete(prompt, formatted=True, **kwargs)
return completion_response_to_chat_response(completion_response)
@llm_chat_callback()
def stream_chat(
self, messages: Sequence[ChatMessage], **kwargs: Any
) -> ChatResponseGen:
prompt = self.messages_to_prompt(messages)
completion_response = self.stream_complete(prompt, formatted=True, **kwargs)
return stream_completion_response_to_chat_response(completion_response)