Function compact_session

tutorials/07_auto_compaction.py:294–340

执行压缩。 算法很简单： 1. 判断是否需要压缩 → 不需要就直接返回 2. 把消息分成两组：旧的（要压缩的）和新的（要保留的） 3. 旧消息 → 生成摘要 4. 新 Session = [摘要消息] + [保留的消息] 对应源码: compact.rs:75-111

(session: Session, config: CompactionConfig)

def compact_session(session: Session, config: CompactionConfig) -> CompactionResult:
    """
    执行压缩。

    算法很简单：
    1. 判断是否需要压缩 → 不需要就直接返回
    2. 把消息分成两组：旧的（要压缩的）和新的（要保留的）
    3. 旧消息 → 生成摘要
    4. 新 Session = [摘要消息] + [保留的消息]

    对应源码: compact.rs:75-111
    """
    if not should_compact(session, config):
        return CompactionResult(
            summary="",
            compacted_session=session,
            removed_message_count=0,
        )

    # 分割点：保留最后 N 条消息
    keep_from = max(0, len(session.messages) - config.preserve_recent_messages)
    removed_messages = session.messages[:keep_from]
    preserved_messages = session.messages[keep_from:]

    # 生成摘要
    summary = summarize_messages(removed_messages)

    # 构造"续接消息"—— 告诉 AI "之前的对话被压缩了，以下是摘要"
    continuation = (
        "This session is being continued from a previous conversation "
        "that ran out of context. The summary below covers the earlier "
        "portion of the conversation.\n\n"
        f"{summary}\n\n"
        "Recent messages are preserved verbatim.\n"
        "Continue the conversation from where it left off without asking "
        "the user any further questions."
    )

    # 新的消息列表：[系统摘要] + [保留的消息]
    new_messages = [ConversationMessage.system_text(continuation)]
    new_messages.extend(preserved_messages)

    return CompactionResult(
        summary=summary,
        compacted_session=Session(version=session.version, messages=new_messages),
        removed_message_count=len(removed_messages),
    )


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