Method Compress

pkg/context/compression_strategy.go:118–178

Compress 实现 CompressionStrategy 接口

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

// Compress 实现 CompressionStrategy 接口
func (s *PriorityBasedStrategy) Compress(
	ctx context.Context,
	messages []Message,
	config WindowManagerConfig,
) ([]Message, error) {
	if len(messages) <= s.targetSize {
		return messages, nil
	}

	// 计算所有消息的优先级
	withPriority := CalculateMessagePriorities(ctx, messages, s.priorityCalculator)

	// 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. 按优先级排序，选择最高优先级的消息
	SortMessagesByPriority(withPriority, true) // 降序排序

	remainingSlots := s.targetSize - len(keepIndices)
	for _, msgWithPri := range withPriority {
		if remainingSlots <= 0 {
			break
		}

		// 找到该消息的原始索引
		for i, msg := range messages {
			if msg.Role == msgWithPri.Message.Role && msg.Content == msgWithPri.Message.Content {
				if !keepIndices[i] {
					keepIndices[i] = true
					remainingSlots--
					break
				}
			}
		}
	}

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