xfy
8cc3fdef6f
- Add pathPrefixLen for zero-allocation path stripping - Precompute ETag in FileCache.Set, reuse on cache hits - Add MIME LRU cache with O(1) operations using container/list - Remove sharded cache (eager LRU was slower than single-lock) - Add FileInfo cache to reduce os.Stat calls (TTL-only strategy) - Adjust test expectations for normalized root path format Benchmark results: Lookup 12.7µs → 10.6µs (16% improvement) Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
139 lines
3.0 KiB
Go
139 lines
3.0 KiB
Go
// Package handler 提供 HTTP 请求处理器，包括路由、静态文件服务和零拷贝传输。
|
||
//
|
||
// 该文件实现 FileInfo 缓存，用于减少 os.Stat 调用。
|
||
// 替代原 fd 池设计，避免 fd 所有权问题。
|
||
//
|
||
// 设计说明：
|
||
// - 使用 TTL-only 新鲜度策略：缓存命中时不验证 ModTime
|
||
// - 理由：每次验证 ModTime 仍需 os.Stat 调用，违背缓存目的
|
||
// - 风险：TTL 内文件修改可能返回旧 FileInfo，但静态文件通常不频繁修改
|
||
//
|
||
// 作者：xfy
|
||
package handler
|
||
|
||
import (
|
||
"container/list"
|
||
"os"
|
||
"sync"
|
||
"time"
|
||
)
|
||
|
||
const (
|
||
fileInfoCacheMaxEntries = 2000
|
||
fileInfoCacheTTL = 10 * time.Second
|
||
)
|
||
|
||
// fileInfoEntry FileInfo 缓存条目
|
||
type fileInfoEntry struct {
|
||
path string
|
||
info os.FileInfo
|
||
cachedAt time.Time
|
||
element *list.Element
|
||
}
|
||
|
||
// FileInfoCache FileInfo 缓存（O(1) LRU）
|
||
type FileInfoCache struct {
|
||
entries map[string]*fileInfoEntry
|
||
lruList *list.List
|
||
mu sync.Mutex
|
||
}
|
||
|
||
// NewFileInfoCache 创建 FileInfo 缓存
|
||
func NewFileInfoCache() *FileInfoCache {
|
||
return &FileInfoCache{
|
||
entries: make(map[string]*fileInfoEntry, fileInfoCacheMaxEntries),
|
||
lruList: list.New(),
|
||
}
|
||
}
|
||
|
||
// Get 获取缓存的 FileInfo
|
||
func (c *FileInfoCache) Get(filePath string) (os.FileInfo, bool) {
|
||
c.mu.Lock()
|
||
defer c.mu.Unlock()
|
||
|
||
entry, ok := c.entries[filePath]
|
||
if !ok {
|
||
return nil, false
|
||
}
|
||
|
||
// 检查 TTL
|
||
if time.Since(entry.cachedAt) > fileInfoCacheTTL {
|
||
// 过期，删除并返回未命中
|
||
c.lruList.Remove(entry.element)
|
||
delete(c.entries, filePath)
|
||
return nil, false
|
||
}
|
||
|
||
// 命中，移动到 LRU 头部
|
||
c.lruList.MoveToFront(entry.element)
|
||
return entry.info, true
|
||
}
|
||
|
||
// Set 缓存 FileInfo
|
||
func (c *FileInfoCache) Set(filePath string, info os.FileInfo) {
|
||
c.mu.Lock()
|
||
defer c.mu.Unlock()
|
||
|
||
// 已存在，更新
|
||
if entry, ok := c.entries[filePath]; ok {
|
||
entry.info = info
|
||
entry.cachedAt = time.Now()
|
||
c.lruList.MoveToFront(entry.element)
|
||
return
|
||
}
|
||
|
||
// 淘汰最久未用的
|
||
if c.lruList.Len() >= fileInfoCacheMaxEntries {
|
||
if oldest := c.lruList.Back(); oldest != nil {
|
||
if entry, ok := oldest.Value.(*fileInfoEntry); ok {
|
||
delete(c.entries, entry.path)
|
||
}
|
||
c.lruList.Remove(oldest)
|
||
}
|
||
}
|
||
|
||
// 插入新条目
|
||
entry := &fileInfoEntry{
|
||
path: filePath,
|
||
info: info,
|
||
cachedAt: time.Now(),
|
||
}
|
||
entry.element = c.lruList.PushFront(entry)
|
||
c.entries[filePath] = entry
|
||
}
|
||
|
||
// Delete 删除缓存条目
|
||
func (c *FileInfoCache) Delete(filePath string) {
|
||
c.mu.Lock()
|
||
defer c.mu.Unlock()
|
||
|
||
if entry, ok := c.entries[filePath]; ok {
|
||
c.lruList.Remove(entry.element)
|
||
delete(c.entries, filePath)
|
||
}
|
||
}
|
||
|
||
// Clear 清空缓存
|
||
func (c *FileInfoCache) Clear() {
|
||
c.mu.Lock()
|
||
defer c.mu.Unlock()
|
||
|
||
c.entries = make(map[string]*fileInfoEntry, fileInfoCacheMaxEntries)
|
||
c.lruList = list.New()
|
||
}
|
||
|
||
// Stats 返回缓存统计
|
||
func (c *FileInfoCache) Stats() FileInfoCacheStats {
|
||
c.mu.Lock()
|
||
defer c.mu.Unlock()
|
||
|
||
return FileInfoCacheStats{
|
||
Entries: len(c.entries),
|
||
}
|
||
}
|
||
|
||
// FileInfoCacheStats FileInfo 缓存统计
|
||
type FileInfoCacheStats struct {
|
||
Entries int
|
||
}
|