xfy
8b382606df
Conflict: sendfile.go (!linux build tag) was incorrectly modified to include linuxSendfile and getSocketFd functions which already exist in sendfile_linux.go. Resolution: Keep HEAD version (simple fallback returning ENOTSUP) as Linux implementation is properly separated in sendfile_linux.go. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
95 lines
2.2 KiB
Go
95 lines
2.2 KiB
Go
// Package resolver 提供 DNS 解析功能，支持缓存和后台刷新。
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//
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// 该文件包含 DNS 缓存相关的实现。
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//
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// 作者：xfy
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package resolver
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import (
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"sync"
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"time"
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)
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// CacheStats 返回缓存统计信息。
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type CacheStats struct {
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Hits int64 // 缓存命中次数
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Misses int64 // 缓存未命中次数
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Entries int // 当前缓存条目数
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Expired int // 过期条目数
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}
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// GetCacheStats 返回当前缓存统计信息。
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// 这是一个辅助函数，用于测试和监控。
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func (r *DNSResolver) GetCacheStats() CacheStats {
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hits := r.hits.Load()
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misses := r.misses.Load()
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// 统计缓存条目
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var entries, expired int
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now := time.Now()
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r.cache.Range(func(_ interface{}, value interface{}) bool {
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entries++
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entry := value.(*DNSCacheEntry) //nolint:errcheck
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entry.mu.RLock()
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if now.After(entry.ExpiresAt) {
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expired++
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}
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entry.mu.RUnlock()
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return true
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})
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return CacheStats{
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Hits: hits,
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Misses: misses,
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Entries: entries,
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Expired: expired,
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}
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}
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// GetCacheEntry 获取指定主机的缓存条目（用于测试）。
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func (r *DNSResolver) GetCacheEntry(host string) (*DNSCacheEntry, bool) {
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if entry, ok := r.cache.Load(host); ok {
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return entry.(*DNSCacheEntry), true //nolint:errcheck
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}
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return nil, false
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}
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// DeleteCacheEntry 删除指定主机的缓存条目。
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func (r *DNSResolver) DeleteCacheEntry(host string) {
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r.cache.Delete(host)
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r.mu.Lock()
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delete(r.refreshHosts, host)
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r.mu.Unlock()
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}
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// ClearCache 清空所有缓存。
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func (r *DNSResolver) ClearCache() {
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r.cache = sync.Map{}
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r.mu.Lock()
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r.refreshHosts = make(map[string]struct{})
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r.mu.Unlock()
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}
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// GetHitRate 返回缓存命中率。
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func (r *DNSResolver) GetHitRate() float64 {
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hits := r.hits.Load()
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misses := r.misses.Load()
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total := hits + misses
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if total == 0 {
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return 0
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}
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return float64(hits) / float64(total)
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}
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// IsCached 检查指定主机是否在缓存中且未过期。
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func (r *DNSResolver) IsCached(host string) bool {
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if entry, ok := r.cache.Load(host); ok {
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cacheEntry := entry.(*DNSCacheEntry) //nolint:errcheck
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cacheEntry.mu.RLock()
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expiresAt := cacheEntry.ExpiresAt
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cacheEntry.mu.RUnlock()
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return time.Now().Before(expiresAt)
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}
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return false
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}
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