class TrimmedInMemorySaver(InMemorySaver):
    """帶自動(dòng)裁剪功能的 InMemorySaver（LangGraph v0.2+ 兼容）"""
    def __init__(self, max_tokens=3000, strategy="last", *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.max_tokens = max_tokens
        self.strategy = strategy
    def put(
        self,
        config: RunnableConfig,
        checkpoint: Checkpoint,
        metadata: CheckpointMetadata,
        new_versions: ChannelVersions,
    ) -> RunnableConfig:
        thread_id = config.get("configurable", {}).get("thread_id")
        if not thread_id:
            return super().put(config, checkpoint, metadata, new_versions)
        # 嘗試從 checkpoint 中提取 messages（根據(jù)你項(xiàng)目 checkpoint 結(jié)構(gòu)調(diào)整）
        messages = None
        if isinstance(checkpoint, dict) and "channel_values" in checkpoint:
            messages = checkpoint["channel_values"].get("messages")
        elif isinstance(checkpoint, dict) and "messages" in checkpoint:
            messages = checkpoint["messages"]
        logger.info(f"InMemorySaver中的messages: {messages}")
        # logger.info(f"InMemorySaver中的messages過濾之后的messages: {messages}")
        """ list 類型 BaseMessage messages.type """
        if messages:
            fliter_messages = [
                message
                for message in messages
                if not isinstance(message, ToolMessage)
            ]
            logger.info(f"記憶去除toolmessage: {fliter_messages}")
            # 關(guān)鍵：傳入 token_counter（這里用近似計(jì)數(shù)器）
            trimmed_messages = trim_messages(
                fliter_messages,
                max_tokens=self.max_tokens,
                strategy=self.strategy,
                token_counter=count_tokens_approximately,
                # 可選：保證以 human 開始并以 human/tool 結(jié)束以確保消息序列有效
                # start_notallow="human",
                # end_notallow=("human", "tool"),
                include_system=True,
            )
            logger.info(f"trimmed_messages之后 記憶去除think標(biāo)簽和toolmessage: {trimmed_messages}")
            # 寫回裁剪后的 messages（視 checkpoint 具體結(jié)構(gòu)）
            if "channel_values" in checkpoint:
                checkpoint["channel_values"]["messages"] = trimmed_messages
            else:
                checkpoint["messages"] = trimmed_messages
        # 繼續(xù)調(diào)用父類的 put 執(zhí)行真正保存
        return super().put(config, checkpoint, metadata, new_versions)