snapshot of https://github.com/seaweedfs/seaweedfs.git (master, 2026-09-16; blobs > 131072B omitted)

weed/util/chunk_cache/on_disk_cache_layer.go

@@ -0,0 +1,92 @@
+package chunk_cache
+
+import (
+	"fmt"
+	"path"
+	"slices"
+
+	"github.com/seaweedfs/seaweedfs/weed/glog"
+	"github.com/seaweedfs/seaweedfs/weed/storage"
+	"github.com/seaweedfs/seaweedfs/weed/storage/types"
+)
+
+type OnDiskCacheLayer struct {
+	diskCaches []*ChunkCacheVolume
+}
+
+func NewOnDiskCacheLayer(dir, namePrefix string, diskSize int64, segmentCount int) *OnDiskCacheLayer {
+
+	volumeCount, volumeSize := int(diskSize/(30000*1024*1024)), int64(30000*1024*1024)
+	if volumeCount < segmentCount {
+		volumeCount, volumeSize = segmentCount, diskSize/int64(segmentCount)
+	}
+
+	c := &OnDiskCacheLayer{}
+	for i := 0; i < volumeCount; i++ {
+		fileName := path.Join(dir, fmt.Sprintf("%s_%d", namePrefix, i))
+		diskCache, err := LoadOrCreateChunkCacheVolume(fileName, volumeSize)
+		if err != nil {
+			glog.Errorf("failed to add cache %s : %v", fileName, err)
+		} else {
+			c.diskCaches = append(c.diskCaches, diskCache)
+		}
+	}
+
+	// keep newest cache to the front
+	slices.SortFunc(c.diskCaches, func(a, b *ChunkCacheVolume) int {
+		return b.lastModTime.Compare(a.lastModTime)
+	})
+	return c
+}
+
+func (c *OnDiskCacheLayer) setChunk(needleId types.NeedleId, data []byte) {
+
+	if len(c.diskCaches) == 0 {
+		return
+	}
+
+	if c.diskCaches[0].fileSize+int64(len(data)) > c.diskCaches[0].sizeLimit {
+		t, resetErr := c.diskCaches[len(c.diskCaches)-1].Reset()
+		if resetErr != nil {
+			glog.Errorf("failed to reset cache file %s", c.diskCaches[len(c.diskCaches)-1].fileName)
+			return
+		}
+		for i := len(c.diskCaches) - 1; i > 0; i-- {
+			c.diskCaches[i] = c.diskCaches[i-1]
+		}
+		c.diskCaches[0] = t
+	}
+
+	if err := c.diskCaches[0].WriteNeedle(needleId, data); err != nil {
+		glog.V(0).Infof("cache write %v size %d: %v", needleId, len(data), err)
+	}
+
+}
+
+func (c *OnDiskCacheLayer) readChunkAt(buffer []byte, needleId types.NeedleId, offset uint64) (n int, err error) {
+
+	for _, diskCache := range c.diskCaches {
+		n, err = diskCache.readNeedleSliceAt(buffer, needleId, offset)
+		if err == storage.ErrorNotFound {
+			continue
+		}
+		if err != nil {
+			glog.Warningf("failed to read cache file %s id %d: %v", diskCache.fileName, needleId, err)
+			continue
+		}
+		if n > 0 {
+			return
+		}
+	}
+
+	return
+
+}
+
+func (c *OnDiskCacheLayer) shutdown() {
+
+	for _, diskCache := range c.diskCaches {
+		diskCache.Shutdown()
+	}
+
+}