def truncate()

in agents/utils/history_util.py [0:0]
37 lines of code
8 McCabe index (conditional complexity)

    def truncate(self) -> None:
        """Remove oldest messages when context window limit is exceeded."""
        if self.total_tokens <= self.context_window_tokens:
            return

        TRUNCATION_NOTICE_TOKENS = 25
        TRUNCATION_MESSAGE = {
            "role": "user",
            "content": [
                {
                    "type": "text",
                    "text": "[Earlier history has been truncated.]",
                }
            ],
        }

        def remove_message_pair():
            self.messages.pop(0)
            self.messages.pop(0)

            if self.message_tokens:
                input_tokens, output_tokens = self.message_tokens.pop(0)
                self.total_tokens -= input_tokens + output_tokens

        while (
            self.message_tokens
            and len(self.messages) >= 2
            and self.total_tokens > self.context_window_tokens
        ):
            remove_message_pair()

            if self.messages and self.message_tokens:
                original_input_tokens, original_output_tokens = (
                    self.message_tokens[0]
                )
                self.messages[0] = TRUNCATION_MESSAGE
                self.message_tokens[0] = (
                    TRUNCATION_NOTICE_TOKENS,
                    original_output_tokens,
                )
                self.total_tokens += (
                    TRUNCATION_NOTICE_TOKENS - original_input_tokens
                )