feat: add LocalAI local embedding model support (#1021)

Co-authored-by: StyleZhang <jasonapring2015@outlook.com>

api/core/model_providers/models/llm/localai_model.py

@@ -0,0 +1,131 @@
+import logging
+from typing import List, Optional, Any
+
+import openai
+from langchain.callbacks.manager import Callbacks
+from langchain.schema import LLMResult, get_buffer_string
+
+from core.model_providers.error import LLMBadRequestError, LLMAPIConnectionError, LLMAPIUnavailableError, \
+    LLMRateLimitError, LLMAuthorizationError
+from core.model_providers.providers.base import BaseModelProvider
+from core.third_party.langchain.llms.chat_open_ai import EnhanceChatOpenAI
+from core.third_party.langchain.llms.open_ai import EnhanceOpenAI
+from core.model_providers.models.llm.base import BaseLLM
+from core.model_providers.models.entity.message import PromptMessage
+from core.model_providers.models.entity.model_params import ModelMode, ModelKwargs
+
+
+class LocalAIModel(BaseLLM):
+    def __init__(self, model_provider: BaseModelProvider,
+                 name: str,
+                 model_kwargs: ModelKwargs,
+                 streaming: bool = False,
+                 callbacks: Callbacks = None):
+        credentials = model_provider.get_model_credentials(
+            model_name=name,
+            model_type=self.type
+        )
+
+        if credentials['completion_type'] == 'chat_completion':
+            self.model_mode = ModelMode.CHAT
+        else:
+            self.model_mode = ModelMode.COMPLETION
+
+        super().__init__(model_provider, name, model_kwargs, streaming, callbacks)
+
+    def _init_client(self) -> Any:
+        provider_model_kwargs = self._to_model_kwargs_input(self.model_rules, self.model_kwargs)
+        if self.model_mode == ModelMode.COMPLETION:
+            client = EnhanceOpenAI(
+                model_name=self.name,
+                streaming=self.streaming,
+                callbacks=self.callbacks,
+                request_timeout=60,
+                openai_api_key="1",
+                openai_api_base=self.credentials['server_url'] + '/v1',
+                **provider_model_kwargs
+            )
+        else:
+            extra_model_kwargs = {
+                'top_p': provider_model_kwargs.get('top_p')
+            }
+
+            client = EnhanceChatOpenAI(
+                model_name=self.name,
+                temperature=provider_model_kwargs.get('temperature'),
+                max_tokens=provider_model_kwargs.get('max_tokens'),
+                model_kwargs=extra_model_kwargs,
+                streaming=self.streaming,
+                callbacks=self.callbacks,
+                request_timeout=60,
+                openai_api_key="1",
+                openai_api_base=self.credentials['server_url'] + '/v1'
+            )
+
+        return client
+
+    def _run(self, messages: List[PromptMessage],
+             stop: Optional[List[str]] = None,
+             callbacks: Callbacks = None,
+             **kwargs) -> LLMResult:
+        """
+        run predict by prompt messages and stop words.
+
+        :param messages:
+        :param stop:
+        :param callbacks:
+        :return:
+        """
+        prompts = self._get_prompt_from_messages(messages)
+        return self._client.generate([prompts], stop, callbacks)
+
+    def get_num_tokens(self, messages: List[PromptMessage]) -> int:
+        """
+        get num tokens of prompt messages.
+
+        :param messages:
+        :return:
+        """
+        prompts = self._get_prompt_from_messages(messages)
+        if isinstance(prompts, str):
+            return self._client.get_num_tokens(prompts)
+        else:
+            return max(sum([self._client.get_num_tokens(get_buffer_string([m])) for m in prompts]) - len(prompts), 0)
+
+    def _set_model_kwargs(self, model_kwargs: ModelKwargs):
+        provider_model_kwargs = self._to_model_kwargs_input(self.model_rules, model_kwargs)
+        if self.model_mode == ModelMode.COMPLETION:
+            for k, v in provider_model_kwargs.items():
+                if hasattr(self.client, k):
+                    setattr(self.client, k, v)
+        else:
+            extra_model_kwargs = {
+                'top_p': provider_model_kwargs.get('top_p')
+            }
+
+            self.client.temperature = provider_model_kwargs.get('temperature')
+            self.client.max_tokens = provider_model_kwargs.get('max_tokens')
+            self.client.model_kwargs = extra_model_kwargs
+
+    def handle_exceptions(self, ex: Exception) -> Exception:
+        if isinstance(ex, openai.error.InvalidRequestError):
+            logging.warning("Invalid request to LocalAI API.")
+            return LLMBadRequestError(str(ex))
+        elif isinstance(ex, openai.error.APIConnectionError):
+            logging.warning("Failed to connect to LocalAI API.")
+            return LLMAPIConnectionError(ex.__class__.__name__ + ":" + str(ex))
+        elif isinstance(ex, (openai.error.APIError, openai.error.ServiceUnavailableError, openai.error.Timeout)):
+            logging.warning("LocalAI service unavailable.")
+            return LLMAPIUnavailableError(ex.__class__.__name__ + ":" + str(ex))
+        elif isinstance(ex, openai.error.RateLimitError):
+            return LLMRateLimitError(str(ex))
+        elif isinstance(ex, openai.error.AuthenticationError):
+            return LLMAuthorizationError(str(ex))
+        elif isinstance(ex, openai.error.OpenAIError):
+            return LLMBadRequestError(ex.__class__.__name__ + ":" + str(ex))
+        else:
+            return ex
+
+    @classmethod
+    def support_streaming(cls):
+        return True