Method Compress

pkg/context/compression_strategy.go:41–89

Compress 实现 CompressionStrategy 接口

(
	ctx context.Context,
	messages []Message,
	config WindowManagerConfig,
)

// Compress 实现 CompressionStrategy 接口
func (s *SlidingWindowStrategy) Compress(
	ctx context.Context,
	messages []Message,
	config WindowManagerConfig,
) ([]Message, error) {
	if len(messages) <= s.windowSize {
		// 不需要压缩
		return messages, nil
	}

	// 保留的消息索引
	keepIndices := make(map[int]bool)

	// 1. 始终保留 system 消息
	if config.AlwaysKeepSystem {
		for i, msg := range messages {
			if msg.Role == "system" {
				keepIndices[i] = true
			}
		}
	}

	// 2. 始终保留最近的 N 条消息
	recentCount := min(config.AlwaysKeepRecent, len(messages))
	for i := len(messages) - recentCount; i < len(messages); i++ {
		keepIndices[i] = true
	}

	// 3. 从剩余消息中选择最新的填充到窗口大小
	remainingSlots := s.windowSize - len(keepIndices)
	if remainingSlots > 0 {
		for i := len(messages) - 1; i >= 0 && remainingSlots > 0; i-- {
			if !keepIndices[i] {
				keepIndices[i] = true
				remainingSlots--
			}
		}
	}

	// 构建结果（保持原始顺序）
	result := []Message{}
	for i, msg := range messages {
		if keepIndices[i] {
			result = append(result, msg)
		}
	}

	return result, nil
}

// PriorityBasedStrategy 基于优先级的压缩策略
// 优先保留高优先级消息