边缘节点支持设置多个缓存目录

internal/caches/storage_file.go

@@ -93,7 +93,10 @@ type FileStorage struct {
 
 	openFileCache *OpenFileCache
 
-	diskIsFull bool
+	mainDir        string
+	mainDiskIsFull bool
+
+	subDirs []*FileDir
 }
 
 func NewFileStorage(policy *serverconfigs.HTTPCachePolicy) *FileStorage {
@@ -157,6 +160,16 @@ func (this *FileStorage) UpdatePolicy(newPolicy *serverconfigs.HTTPCachePolicy)
 		return
 	}
 
+	var subDirs = []*FileDir{}
+	for _, subDir := range newOptions.SubDirs {
+		subDirs = append(subDirs, &FileDir{
+			Path:     subDir.Path,
+			Capacity: subDir.Capacity,
+			IsFull:   false,
+		})
+	}
+	this.checkDiskSpace()
+
 	err = newOptions.Init()
 	if err != nil {
 		remotelogs.Error("CACHE", "update policy '"+types.String(this.policy.Id)+"' failed: init options failed: "+err.Error())
@@ -219,6 +232,19 @@ func (this *FileStorage) Init() error {
 	this.options.Dir = filepath.Clean(this.options.Dir)
 	var dir = this.options.Dir
 
+	var subDirs = []*FileDir{}
+	for _, subDir := range this.options.SubDirs {
+		subDirs = append(subDirs, &FileDir{
+			Path:     subDir.Path,
+			Capacity: subDir.Capacity,
+			IsFull:   false,
+		})
+	}
+	this.subDirs = subDirs
+	if len(subDirs) > 0 {
+		this.checkDiskSpace()
+	}
+
 	if len(dir) == 0 {
 		return errors.New("[CACHE]cache storage dir can not be empty")
 	}
@@ -321,7 +347,7 @@ func (this *FileStorage) openReader(key string, allowMemory bool, useStale bool,
 		}
 	}
 
-	hash, path := this.keyPath(key)
+	hash, path, _ := this.keyPath(key)
 
 	// 检查文件记录是否已过期
 	if !useStale {
@@ -404,11 +430,6 @@ func (this *FileStorage) openWriter(key string, expiredAt int64, status int, siz
 		return nil, ErrWritingUnavailable
 	}
 
-	// 当前磁盘可用容量是否严重不足
-	if this.diskIsFull {
-		return nil, NewCapacityError("the disk is full")
-	}
-
 	// 是否已忽略
 	if this.ignoreKeys.Has(key) {
 		return nil, ErrEntityTooLarge
@@ -475,8 +496,12 @@ func (this *FileStorage) openWriter(key string, expiredAt int64, status int, siz
 
 	var hash = stringutil.Md5(key)
 
+	dir, diskIsFull := this.subDir(hash)
+	if diskIsFull {
+		return nil, NewCapacityError("the disk is full")
+	}
+
 	// TODO 可以只stat一次
-	var dir = this.options.Dir + "/p" + strconv.FormatInt(this.policy.Id, 10) + "/" + hash[:2] + "/" + hash[2:4]
 	_, err = os.Stat(dir)
 	if err != nil {
 		if !os.IsNotExist(err) {
@@ -680,7 +705,7 @@ func (this *FileStorage) Delete(key string) error {
 		_ = memoryStorage.Delete(key)
 	})
 
-	hash, path := this.keyPath(key)
+	hash, path, _ := this.keyPath(key)
 	err := this.list.Remove(hash)
 	if err != nil {
 		return err
@@ -720,56 +745,67 @@ func (this *FileStorage) CleanAll() error {
 
 	// 删除缓存和目录
 	// 不能直接删除子目录，比较危险
-	dir := this.dir()
-	fp, err := os.Open(dir)
-	if err != nil {
-		return err
-	}
-	defer func() {
-		_ = fp.Close()
-	}()
 
-	stat, err := fp.Stat()
-	if err != nil {
-		return err
+	var rootDirs = []string{this.options.Dir}
+	var subDirs = this.subDirs // copy slice
+	if len(subDirs) > 0 {
+		for _, subDir := range subDirs {
+			rootDirs = append(rootDirs, subDir.Path)
+		}
 	}
 
-	if !stat.IsDir() {
-		return nil
-	}
-
-	// 改成待删除
-	subDirs, err := fp.Readdir(-1)
-	if err != nil {
-		return err
-	}
-	for _, info := range subDirs {
-		subDir := info.Name()
-
-		// 检查目录名
-		ok, err := regexp.MatchString(`^[0-9a-f]{2}$`, subDir)
+	for _, rootDir := range rootDirs {
+		var dir = rootDir + "/p" + types.String(this.policy.Id)
+		fp, err := os.Open(dir)
 		if err != nil {
 			return err
 		}
-		if !ok {
-			continue
-		}
+		defer func() {
+			_ = fp.Close()
+		}()
 
-		// 修改目录名
-		tmpDir := dir + "/" + subDir + "-deleted"
-		err = os.Rename(dir+"/"+subDir, tmpDir)
+		stat, err := fp.Stat()
 		if err != nil {
 			return err
 		}
-	}
 
-	// 重新遍历待删除
-	goman.New(func() {
-		err = this.cleanDeletedDirs(dir)
-		if err != nil {
-			remotelogs.Warn("CACHE", "delete '*-deleted' dirs failed: "+err.Error())
+		if !stat.IsDir() {
+			return nil
 		}
-	})
+
+		// 改成待删除
+		subDirs, err := fp.Readdir(-1)
+		if err != nil {
+			return err
+		}
+		for _, info := range subDirs {
+			subDir := info.Name()
+
+			// 检查目录名
+			ok, err := regexp.MatchString(`^[0-9a-f]{2}$`, subDir)
+			if err != nil {
+				return err
+			}
+			if !ok {
+				continue
+			}
+
+			// 修改目录名
+			tmpDir := dir + "/" + subDir + "-deleted"
+			err = os.Rename(dir+"/"+subDir, tmpDir)
+			if err != nil {
+				return err
+			}
+		}
+
+		// 重新遍历待删除
+		goman.New(func() {
+			err = this.cleanDeletedDirs(dir)
+			if err != nil {
+				remotelogs.Warn("CACHE", "delete '*-deleted' dirs failed: "+err.Error())
+			}
+		})
+	}
 
 	return nil
 }
@@ -802,7 +838,7 @@ func (this *FileStorage) Purge(keys []string, urlType string) error {
 
 	// URL
 	for _, key := range keys {
-		hash, path := this.keyPath(key)
+		hash, path, _ := this.keyPath(key)
 		err := this.removeCacheFile(path)
 		if err != nil && !os.IsNotExist(err) {
 			return err
@@ -873,25 +909,22 @@ func (this *FileStorage) CanSendfile() bool {
 	return this.options.EnableSendfile
 }
 
-// 绝对路径
-func (this *FileStorage) dir() string {
-	return this.options.Dir + "/p" + strconv.FormatInt(this.policy.Id, 10) + "/"
-}
-
 // 获取Key对应的文件路径
-func (this *FileStorage) keyPath(key string) (hash string, path string) {
+func (this *FileStorage) keyPath(key string) (hash string, path string, diskIsFull bool) {
 	hash = stringutil.Md5(key)
-	dir := this.options.Dir + "/p" + strconv.FormatInt(this.policy.Id, 10) + "/" + hash[:2] + "/" + hash[2:4]
+	var dir string
+	dir, diskIsFull = this.subDir(hash)
 	path = dir + "/" + hash + ".cache"
 	return
 }
 
 // 获取Hash对应的文件路径
-func (this *FileStorage) hashPath(hash string) (path string) {
+func (this *FileStorage) hashPath(hash string) (path string, diskIsFull bool) {
 	if len(hash) != 32 {
-		return ""
+		return "", false
 	}
-	dir := this.options.Dir + "/p" + strconv.FormatInt(this.policy.Id, 10) + "/" + hash[:2] + "/" + hash[2:4]
+	var dir string
+	dir, diskIsFull = this.subDir(hash)
 	path = dir + "/" + hash + ".cache"
 	return
 }
@@ -949,6 +982,7 @@ func (this *FileStorage) initList() error {
 }
 
 // 清理任务
+// TODO purge每个分区
 func (this *FileStorage) purgeLoop() {
 	// 检查磁盘剩余空间
 	this.checkDiskSpace()
@@ -960,7 +994,19 @@ func (this *FileStorage) purgeLoop() {
 	if lfuFreePercent <= 0 {
 		lfuFreePercent = 5
 	}
-	if this.diskIsFull {
+
+	var hasFullDisk = this.mainDiskIsFull
+	if !hasFullDisk {
+		var subDirs = this.subDirs // copy slice
+		for _, subDir := range subDirs {
+			if subDir.IsFull {
+				hasFullDisk = true
+				break
+			}
+		}
+	}
+
+	if hasFullDisk {
 		startLFU = true
 	} else {
 		var usedPercent = float32(this.TotalDiskSize()*100) / float32(capacityBytes)
@@ -993,7 +1039,7 @@ func (this *FileStorage) purgeLoop() {
 		}
 		for i := 0; i < times; i++ {
 			countFound, err := this.list.Purge(purgeCount, func(hash string) error {
-				path := this.hashPath(hash)
+				path, _ := this.hashPath(hash)
 				err := this.removeCacheFile(path)
 				if err != nil && !os.IsNotExist(err) {
 					remotelogs.Error("CACHE", "purge '"+path+"' error: "+err.Error())
@@ -1027,7 +1073,7 @@ func (this *FileStorage) purgeLoop() {
 
 				remotelogs.Println("CACHE", "LFU purge policy '"+this.policy.Name+"' id: "+types.String(this.policy.Id)+", count: "+types.String(count))
 				err := this.list.PurgeLFU(count, func(hash string) error {
-					path := this.hashPath(hash)
+					path, _ := this.hashPath(hash)
 					err := this.removeCacheFile(path)
 					if err != nil && !os.IsNotExist(err) {
 						remotelogs.Error("CACHE", "purge '"+path+"' error: "+err.Error())
@@ -1354,7 +1400,55 @@ func (this *FileStorage) checkDiskSpace() {
 		err := unix.Statfs(this.options.Dir, &stat)
 		if err == nil {
 			var availableBytes = stat.Bavail * uint64(stat.Bsize)
-			this.diskIsFull = availableBytes < MinDiskSpace
+			this.mainDiskIsFull = availableBytes < MinDiskSpace
+		}
+	}
+	var subDirs = this.subDirs // copy slice
+	for _, subDir := range subDirs {
+		var stat unix.Statfs_t
+		err := unix.Statfs(subDir.Path, &stat)
+		if err == nil {
+			var availableBytes = stat.Bavail * uint64(stat.Bsize)
+			subDir.IsFull = availableBytes < MinDiskSpace
 		}
 	}
 }
+
+// 获取目录
+func (this *FileStorage) subDir(hash string) (dirPath string, dirIsFull bool) {
+	var suffix = "/p" + types.String(this.policy.Id) + "/" + hash[:2] + "/" + hash[2:4]
+
+	if len(hash) < 4 {
+		return this.options.Dir + suffix, this.mainDiskIsFull
+	}
+
+	var subDirs = this.subDirs // copy slice
+	var countSubDirs = len(subDirs)
+	if countSubDirs == 0 {
+		return this.options.Dir + suffix, this.mainDiskIsFull
+	}
+
+	countSubDirs++ // add main dir
+
+	// 最多只支持16个目录
+	if countSubDirs > 16 {
+		countSubDirs = 16
+	}
+
+	var dirIndex = this.charCode(hash[0]) % uint8(countSubDirs)
+	if dirIndex == 0 {
+		return this.options.Dir + suffix, this.mainDiskIsFull
+	}
+	var subDir = subDirs[dirIndex-1]
+	return subDir.Path + suffix, subDir.IsFull
+}
+
+func (this *FileStorage) charCode(r byte) uint8 {
+	if r >= '0' && r <= '9' {
+		return r - '0'
+	}
+	if r >= 'a' && r <= 'z' {
+		return r - 'a' + 10
+	}
+	return 0
+}