quick serve for empty files

cluster.go

@@ -125,6 +125,10 @@ func NewCluster(
 	return
 }
 
+func (cr *Cluster) usedOSS() bool {
+	return cr.ossList != nil
+}
+
 func (cr *Cluster) Connect(ctx context.Context) bool {
 	cr.mux.Lock()
 	defer cr.mux.Unlock()
@@ -455,14 +459,14 @@ func (cr *Cluster) SyncFiles(ctx context.Context, files0 []FileInfo) {
 		return
 	}
 
-	if cr.ossList == nil {
-		cr.syncFiles(ctx, cr.cacheDir, files0)
-	} else {
+	if cr.usedOSS() {
 		for _, item := range cr.ossList {
 			if err := cr.syncFiles(ctx, filepath.Join(item.FolderPath, "download"), files0); err != nil {
 				break
 			}
 		}
+	} else {
+		cr.syncFiles(ctx, cr.cacheDir, files0)
 	}
 
 	cr.issync.Store(false)
@@ -518,9 +522,14 @@ func (cr *Cluster) syncFiles(ctx context.Context, dir string, files0 []FileInfo)
 
 func (cr *Cluster) CheckFiles(dir string, files []FileInfo) (missing []FileInfo) {
 	logInfof("Start checking files at %q", dir)
+	usedOSS := cr.usedOSS()
 	for i, f := range files {
 		p := filepath.Join(dir, hashToFilename(f.Hash))
 		logDebugf("Checking file %s [%.2f%%]", p, (float32)(i+1)/(float32)(len(files))*100)
+		if usedOSS && f.Size == 0 {
+			logDebugf("Skipped empty file %s", p)
+			continue
+		}
 		stat, err := os.Stat(p)
 		if err == nil {
 			if sz := stat.Size(); sz != f.Size {

handler.go

@@ -19,6 +19,8 @@
 package main
 
 import (
+	"crypto"
+	"encoding/hex"
 	"errors"
 	"io"
 	"net"
@@ -143,6 +145,18 @@ func (cr *Cluster) GetHandler() (handler http.Handler) {
 	return
 }
 
+var emptyHashes = func() (hashes map[string]struct{}) {
+	hashMethods := []crypto.Hash{
+		crypto.MD5, crypto.SHA1,
+	}
+	hashes = make(map[string]struct{}, len(hashMethods))
+	for _, h := range hashMethods {
+		hs := hex.EncodeToString(h.New().Sum(nil))
+		hashes[hs] = struct{}{}
+	}
+	return
+}()
+
 func (cr *Cluster) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
 	method := req.Method
 	u := req.URL
@@ -161,6 +175,17 @@ func (cr *Cluster) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
 		}
 		name := req.Form.Get("name")
 
+		if _, ok := emptyHashes[hash]; ok {
+			rw.Header().Set("Cache-Control", "max-age=2592000") // 30 days
+			rw.Header().Set("Content-Type", "application/octet-stream")
+			rw.Header().Set("X-Bmclapi-Hash", hash)
+			rw.WriteHeader(http.StatusOK)
+			http.ServeContent(rw, req, name, time.Time{}, NullReader)
+			cr.hits.Add(1)
+			// cr.hbts.Add(0) // empty bytes
+			return
+		}
+
 		hashFilename := hashToFilename(hash)
 
 		// if use OSS redirect

util.go

@@ -24,6 +24,7 @@ import (
 	"crypto/x509"
 	"encoding/pem"
 	"fmt"
+	"io"
 	"math/rand"
 	"path/filepath"
 	"strings"
@@ -180,3 +181,16 @@ func forEachSliceFromRandomIndex(leng int, cb func(i int) (done bool)) (done boo
 	}
 	return false
 }
+
+type nullReader struct{}
+
+var (
+	NullReader = nullReader{}
+
+	_ io.ReaderAt   = NullReader
+	_ io.ReadSeeker = NullReader
+)
+
+func (nullReader) Read([]byte) (int, error)          { return 0, io.EOF }
+func (nullReader) ReadAt([]byte, int64) (int, error) { return 0, io.EOF }
+func (nullReader) Seek(int64, int) (int64, error)    { return 0, nil }