Activate and use OpenAI streaming API.

chatmastermind/ais/openai.py

@@ -2,7 +2,8 @@
 Implements the OpenAI client classes and functions.
 """
 import openai
-from typing import Optional, Union
+import tiktoken
+from typing import Optional, Union, Generator
 from ..tags import Tag
 from ..message import Message, Answer
 from ..chat import Chat
@@ -12,6 +13,52 @@ from ..configuration import OpenAIConfig
 ChatType = list[dict[str, str]]
 
 
+class OpenAIAnswer:
+    def __init__(self,
+                 idx: int,
+                 streams: dict[int, 'OpenAIAnswer'],
+                 response: openai.ChatCompletion,
+                 tokens: Tokens,
+                 encoding: tiktoken.core.Encoding) -> None:
+        self.idx = idx
+        self.streams = streams
+        self.response = response
+        self.position: int = 0
+        self.encoding = encoding
+        self.data: list[str] = []
+        self.finished: bool = False
+        self.tokens = tokens
+
+    def stream(self) -> Generator[str, None, None]:
+        while True:
+            if not self.next():
+                continue
+            if len(self.data) <= self.position:
+                break
+            yield self.data[self.position]
+            self.position += 1
+
+    def next(self) -> bool:
+        if self.finished:
+            return True
+        try:
+            chunk = next(self.response)
+        except StopIteration:
+            self.finished = True
+        if not self.finished:
+            found_choice = False
+            for choice in chunk['choices']:
+                if not choice['finish_reason']:
+                    self.streams[choice['index']].data.append(choice['delta']['content'])
+                    self.tokens.completion += len(self.encoding.encode(choice['delta']['content']))
+                    self.tokens.total = self.tokens.prompt + self.tokens.completion
+                if choice['index'] == self.idx:
+                    found_choice = True
+            if not found_choice:
+                return False
+        return True
+
+
 class OpenAI(AI):
     """
     The OpenAI AI client.
@@ -21,7 +68,6 @@ class OpenAI(AI):
         self.ID = config.ID
         self.name = config.name
         self.config = config
-        openai.api_key = config.api_key
 
     def request(self,
                 question: Message,
@@ -33,7 +79,10 @@ class OpenAI(AI):
         chat history. The nr. of requested answers corresponds to the
         nr. of messages in the 'AIResponse'.
         """
-        oai_chat = self.openai_chat(chat, self.config.system, question)
+        self.encoding = tiktoken.encoding_for_model(self.config.model)
+        openai.api_key = self.config.api_key
+        oai_chat, prompt_tokens = self.openai_chat(chat, self.config.system, question)
+        tokens: Tokens = Tokens(prompt_tokens, 0, prompt_tokens)
         response = openai.ChatCompletion.create(
             model=self.config.model,
             messages=oai_chat,
@@ -41,22 +90,24 @@ class OpenAI(AI):
             max_tokens=self.config.max_tokens,
             top_p=self.config.top_p,
             n=num_answers,
+            stream=True,
             frequency_penalty=self.config.frequency_penalty,
             presence_penalty=self.config.presence_penalty)
-        question.answer = Answer(response['choices'][0]['message']['content'])
+        streams: dict[int, OpenAIAnswer] = {}
+        for n in range(num_answers):
+            streams[n] = OpenAIAnswer(n, streams, response, tokens, self.encoding)
+        question.answer = Answer(streams[0].stream())
         question.tags = set(otags) if otags is not None else None
         question.ai = self.ID
         question.model = self.config.model
         answers: list[Message] = [question]
-        for choice in response['choices'][1:]:  # type: ignore
+        for idx in range(1, num_answers):
             answers.append(Message(question=question.question,
-                                   answer=Answer(choice['message']['content']),
+                                   answer=Answer(streams[idx].stream()),
                                    tags=otags,
                                    ai=self.ID,
                                    model=self.config.model))
-        return AIResponse(answers, Tokens(response['usage']['prompt_tokens'],
-                                          response['usage']['completion_tokens'],
-                                          response['usage']['total_tokens']))
+        return AIResponse(answers, tokens)
 
     def models(self) -> list[str]:
         """
@@ -83,24 +134,26 @@ class OpenAI(AI):
             print('\nNot ready: ' + ', '.join(not_ready))
 
     def openai_chat(self, chat: Chat, system: str,
-                    question: Optional[Message] = None) -> ChatType:
+                    question: Optional[Message] = None) -> tuple[ChatType, int]:
         """
         Create a chat history with system message in OpenAI format.
         Optionally append a new question.
         """
         oai_chat: ChatType = []
+        prompt_tokens: int = 0
 
-        def append(role: str, content: str) -> None:
+        def append(role: str, content: str) -> int:
             oai_chat.append({'role': role, 'content': content.replace("''", "'")})
+            return len(self.encoding.encode(', '.join(['role:', oai_chat[-1]['role'], 'content:', oai_chat[-1]['content']])))
 
-        append('system', system)
+        prompt_tokens += append('system', system)
         for message in chat.messages:
             if message.answer:
-                append('user', message.question)
-                append('assistant', message.answer)
+                prompt_tokens += append('user', message.question)
+                prompt_tokens += append('assistant', message.answer)
         if question:
-            append('user', question.question)
-        return oai_chat
+            prompt_tokens += append('user', question.question)
+        return oai_chat, prompt_tokens
 
     def tokens(self, data: Union[Message, Chat]) -> int:
         raise NotImplementedError