modernize some code

analyzer/analyzer.go

@@ -157,7 +157,7 @@ func Analyze(ctx context.Context, client *containerd.Client, ref string, opts ..
 
 	// Create the container and the task
 	var container containerd.Container
-	for i := 0; i < 3; i++ {
+	for range 3 {
 		id := xid.New().String()
 		var s runtimespec.Spec
 		container, err = client.NewContainer(ctx, id,
@@ -221,8 +221,8 @@ func Analyze(ctx context.Context, client *containerd.Client, ref string, opts ..
 		prePaths := preMonitor.GetPaths()
 		for _, path := range prePaths {
 			cleanPath := path
-			if strings.HasPrefix(path, target) {
-				cleanPath = strings.TrimPrefix(path, target)
+			if after, ok := strings.CutPrefix(path, target); ok {
+				cleanPath = after
 			}
 			if err := rc.Record(cleanPath); err != nil {
 				log.G(ctx).WithError(err).Debugf("failed to record pre-container path %q", cleanPath)

analyzer/recorder/recorder.go

@@ -80,7 +80,6 @@ func imageRecorderFromManifest(ctx context.Context, cs content.Store, manifestDe
 	var eg errgroup.Group
 	filesMap := make([]map[string]struct{}, len(manifest.Layers))
 	for i, desc := range manifest.Layers {
-		i, desc := i, desc
 		filesMap[i] = make(map[string]struct{})
 
 		// Create the index from the layer blob.

analyzer/recorder/recorder_test.go

@@ -217,7 +217,6 @@ func TestNodeIndex(t *testing.T) {
 	ctx := context.Background()
 	for _, tt := range tests {
 		for _, prefix := range allowedPrefix {
-			prefix := prefix
 			for mediatype, cWrapper := range compressWrappers {
 				t.Run(tt.name+":"+mediatype+",prefix="+prefix, func(t *testing.T) {
 					var layers []ocispec.Descriptor

cache/cache.go

@@ -134,7 +134,7 @@ func NewDirectoryCache(directory string, config DirectoryCacheConfig) (BlobCache
 	bufPool := config.BufPool
 	if bufPool == nil {
 		bufPool = &sync.Pool{
-			New: func() interface{} {
+			New: func() any {
 				return new(bytes.Buffer)
 			},
 		}
@@ -146,7 +146,7 @@ func NewDirectoryCache(directory string, config DirectoryCacheConfig) (BlobCache
 			maxEntry = defaultMaxLRUCacheEntry
 		}
 		dataCache = cacheutil.NewLRUCache(maxEntry)
-		dataCache.OnEvicted = func(key string, value interface{}) {
+		dataCache.OnEvicted = func(key string, value any) {
 			value.(*bytes.Buffer).Reset()
 			bufPool.Put(value)
 		}
@@ -158,7 +158,7 @@ func NewDirectoryCache(directory string, config DirectoryCacheConfig) (BlobCache
 			maxEntry = defaultMaxCacheFds
 		}
 		fdCache = cacheutil.NewLRUCache(maxEntry)
-		fdCache.OnEvicted = func(key string, value interface{}) {
+		fdCache.OnEvicted = func(key string, value any) {
 			value.(*os.File).Close()
 		}
 	}

cmd/containerd-stargz-grpc/db/reader.go

@@ -221,7 +221,7 @@ func (r *reader) init(decompressedR io.Reader, rOpts metadata.Options) (retErr e
 
 	// Initialize root node
 	var ok bool
-	for i := 0; i < 100; i++ {
+	for range 100 {
 		fsID := xid.New().String()
 		if err := r.initRootNode(fsID); err != nil {
 			if errors.Is(err, errbolt.ErrBucketExists) {
@@ -930,10 +930,7 @@ func (fr *fileReader) ReadAt(p []byte, off int64) (n int, err error) {
 	}
 
 	compressedBytesRemain := fr.nextOffset - ent.offset
-	bufSize := int(2 << 20)
-	if bufSize > int(compressedBytesRemain) {
-		bufSize = int(compressedBytesRemain)
-	}
+	bufSize := min(int(2<<20), int(compressedBytesRemain))
 
 	br := bufio.NewReaderSize(io.NewSectionReader(fr.r.sr, ent.offset, compressedBytesRemain), bufSize)
 	if _, err := br.Peek(bufSize); err != nil {

cmd/containerd-stargz-grpc/ipfs/resolvehandler.go

@@ -74,6 +74,6 @@ func (f *fetcher) Check() error {
 }
 
 func (f *fetcher) GenID(off int64, size int64) string {
-	sum := sha256.Sum256([]byte(fmt.Sprintf("%s-%d-%d", f.cid, off, size)))
+	sum := sha256.Sum256(fmt.Appendf(nil, "%s-%d-%d", f.cid, off, size))
 	return fmt.Sprintf("%x", sum)
 }

cmd/stargz-store/main.go

@@ -25,6 +25,7 @@ import (
 	"fmt"
 	"io"
 	golog "log"
+	"maps"
 	"math/rand"
 	"net"
 	"os"
@@ -250,9 +251,7 @@ func (sk *storeKeychain) add(data []byte) error {
 	if sk.config == nil {
 		sk.config = make(map[string]authConfig)
 	}
-	for k, c := range conf {
-		sk.config[k] = c
-	}
+	maps.Copy(sk.config, conf)
 	sk.configMu.Unlock()
 	return nil
 }

estargz/build.go

@@ -238,7 +238,6 @@ func Build(tarBlob *io.SectionReader, opt ...Option) (_ *Blob, rErr error) {
 	var mu sync.Mutex
 	var eg errgroup.Group
 	for i, parts := range tarParts {
-		i, parts := i, parts
 		// builds verifiable stargz sub-blobs
 		eg.Go(func() error {
 			esgzFile, err := layerFiles.TempFile("", "esgzdata")

estargz/build_test.go

@@ -354,11 +354,8 @@ func TestSort(t *testing.T) {
 	}
 	for _, tt := range tests {
 		for _, srcCompression := range srcCompressions {
-			srcCompression := srcCompression
 			for _, logprefix := range allowedPrefix {
-				logprefix := logprefix
 				for _, tarprefix := range allowedPrefix {
-					tarprefix := tarprefix
 					t.Run(fmt.Sprintf("%s-logprefix=%q-tarprefix=%q-src=%d", tt.name, logprefix, tarprefix, srcCompression), func(t *testing.T) {
 						// Sort tar file
 						var pfiles []string

estargz/estargz_test.go

@@ -101,10 +101,7 @@ func regularFileReader(name string, size int64, chunkSize int64) (*TOCEntry, *Re
 	var written int64
 	for written < size {
 		remain := size - written
-		cs := chunkSize
-		if remain < cs {
-			cs = remain
-		}
+		cs := min(remain, chunkSize)
 		ent.ChunkSize = cs
 		ent.ChunkOffset = written
 		chunks = append(chunks, ent)

estargz/gzip_test.go

@@ -121,7 +121,7 @@ func checkLegacyFooter(t *testing.T, off int64) {
 func legacyFooterBytes(tocOff int64) []byte {
 	buf := bytes.NewBuffer(make([]byte, 0, legacyFooterSize))
 	gz, _ := gzip.NewWriterLevel(buf, gzip.NoCompression)
-	gz.Extra = []byte(fmt.Sprintf("%016xSTARGZ", tocOff))
+	gz.Extra = fmt.Appendf(nil, "%016xSTARGZ", tocOff)
 	gz.Close()
 	if buf.Len() != legacyFooterSize {
 		panic(fmt.Sprintf("footer buffer = %d, not %d", buf.Len(), legacyFooterSize))

estargz/testutil.go

@@ -187,15 +187,10 @@ func testBuild(t *TestRunner, controllers ...TestingControllerFactory) {
 			tt.minChunkSize = []int{0}
 		}
 		for _, srcCompression := range srcCompressions {
-			srcCompression := srcCompression
 			for _, newCL := range controllers {
-				newCL := newCL
 				for _, srcTarFormat := range []tar.Format{tar.FormatUSTAR, tar.FormatPAX, tar.FormatGNU} {
-					srcTarFormat := srcTarFormat
 					for _, prefix := range allowedPrefix {
-						prefix := prefix
 						for _, minChunkSize := range tt.minChunkSize {
-							minChunkSize := minChunkSize
 							t.Run(tt.name+"-"+fmt.Sprintf("compression=%v,prefix=%q,src=%d,format=%s,minChunkSize=%d", newCL(), prefix, srcCompression, srcTarFormat, minChunkSize), func(t *TestRunner) {
 								tarBlob := buildTar(t, tt.in, prefix, srcTarFormat)
 								// Test divideEntries()
@@ -675,15 +670,10 @@ func testDigestAndVerify(t *TestRunner, controllers ...TestingControllerFactory)
 			tt.minChunkSize = []int{0}
 		}
 		for _, srcCompression := range srcCompressions {
-			srcCompression := srcCompression
 			for _, newCL := range controllers {
-				newCL := newCL
 				for _, prefix := range allowedPrefix {
-					prefix := prefix
 					for _, srcTarFormat := range []tar.Format{tar.FormatUSTAR, tar.FormatPAX, tar.FormatGNU} {
-						srcTarFormat := srcTarFormat
 						for _, minChunkSize := range tt.minChunkSize {
-							minChunkSize := minChunkSize
 							t.Run(tt.name+"-"+fmt.Sprintf("compression=%v,prefix=%q,format=%s,minChunkSize=%d", newCL(), prefix, srcTarFormat, minChunkSize), func(t *TestRunner) {
 								// Get original tar file and chunk digests
 								dgstMap := make(map[string]digest.Digest)
@@ -1488,11 +1478,8 @@ func testWriteAndOpen(t *TestRunner, controllers ...TestingControllerFactory) {
 
 	for _, tt := range tests {
 		for _, newCL := range controllers {
-			newCL := newCL
 			for _, prefix := range allowedPrefix {
-				prefix := prefix
 				for _, srcTarFormat := range []tar.Format{tar.FormatUSTAR, tar.FormatPAX, tar.FormatGNU} {
-					srcTarFormat := srcTarFormat
 					for _, lossless := range []bool{true, false} {
 						t.Run(tt.name+"-"+fmt.Sprintf("compression=%v,prefix=%q,lossless=%v,format=%s", newCL(), prefix, lossless, srcTarFormat), func(t *TestRunner) {
 							var tr io.Reader = buildTar(t, tt.in, prefix, srcTarFormat)
@@ -2072,7 +2059,7 @@ func (f tarEntryFunc) appendTar(tw *tar.Writer, prefix string, format tar.Format
 	return f(tw, prefix, format)
 }
 
-func buildTar(t TestingT, ents []tarEntry, prefix string, opts ...interface{}) *io.SectionReader {
+func buildTar(t TestingT, ents []tarEntry, prefix string, opts ...any) *io.SectionReader {
 	format := tar.FormatUnknown
 	for _, opt := range opts {
 		switch v := opt.(type) {
@@ -2096,7 +2083,7 @@ func buildTar(t TestingT, ents []tarEntry, prefix string, opts ...interface{}) *
 	return io.NewSectionReader(bytes.NewReader(data), 0, int64(len(data)))
 }
 
-func dir(name string, opts ...interface{}) tarEntry {
+func dir(name string, opts ...any) tarEntry {
 	return tarEntryFunc(func(tw *tar.Writer, prefix string, format tar.Format) error {
 		var o owner
 		mode := os.FileMode(0755)
@@ -2137,7 +2124,7 @@ type owner struct {
 	gid int
 }
 
-func file(name, contents string, opts ...interface{}) tarEntry {
+func file(name, contents string, opts ...any) tarEntry {
 	return tarEntryFunc(func(tw *tar.Writer, prefix string, format tar.Format) error {
 		var xattrs xAttr
 		var o owner
@@ -2349,7 +2336,7 @@ func (f fileInfoOnlyMode) Size() int64        { return 0 }
 func (f fileInfoOnlyMode) Mode() os.FileMode  { return os.FileMode(f) }
 func (f fileInfoOnlyMode) ModTime() time.Time { return time.Now() }
 func (f fileInfoOnlyMode) IsDir() bool        { return os.FileMode(f).IsDir() }
-func (f fileInfoOnlyMode) Sys() interface{}   { return nil }
+func (f fileInfoOnlyMode) Sys() any           { return nil }
 
 func CheckGzipHasStreams(t TestingT, b []byte, streams []int64) {
 	if len(streams) == 0 {

estargz/types.go

@@ -246,7 +246,7 @@ func (fi fileInfo) Name() string       { return path.Base(fi.e.Name) }
 func (fi fileInfo) IsDir() bool        { return fi.e.Type == "dir" }
 func (fi fileInfo) Size() int64        { return fi.e.Size }
 func (fi fileInfo) ModTime() time.Time { return fi.e.ModTime() }
-func (fi fileInfo) Sys() interface{}   { return fi.e }
+func (fi fileInfo) Sys() any           { return fi.e }
 func (fi fileInfo) Mode() (m os.FileMode) {
 	// TOCEntry.Mode is tar.Header.Mode so we can understand the these bits using `tar` pkg.
 	m = (&tar.Header{Mode: fi.e.Mode}).FileInfo().Mode() &

estargz/zstdchunked/zstdchunked_test.go

@@ -21,7 +21,7 @@ import (
 	"crypto/sha256"
 	"fmt"
 	"io"
-	"sort"
+	"slices"
 	"testing"
 
 	"github.com/containerd/stargz-snapshotter/estargz"
@@ -79,9 +79,7 @@ func (zc *zstdController) TestStreams(t estargz.TestingT, b []byte, streams []in
 
 	// We expect the last offset is footer offset.
 	// 8 is the size of the zstd skippable frame header + the frame size (see WriteTOCAndFooter)
-	sort.Slice(streams, func(i, j int) bool {
-		return streams[i] < streams[j]
-	})
+	slices.Sort(streams)
 	streams[len(streams)-1] = streams[len(streams)-1] - 8
 	wants := map[int64]struct{}{}
 	for _, s := range streams {
@@ -127,7 +125,7 @@ func (zc *zstdController) TestStreams(t estargz.TestingT, b []byte, streams []in
 }
 
 func nextIndex(s1, sub []byte) int {
-	for i := 0; i < len(s1); i++ {
+	for i := range s1 {
 		if len(s1)-i < len(sub) {
 			return -1
 		} else if bytes.Equal(s1[i:i+len(sub)], sub) {

fs/fs.go

@@ -262,7 +262,6 @@ func (fs *filesystem) Mount(ctx context.Context, mountpoint string, labels map[s
 	// Also resolve and cache other layers in parallel
 	preResolve := src[0] // TODO: should we pre-resolve blobs in other sources as well?
 	for _, desc := range neighboringLayers(preResolve.Manifest, preResolve.Target) {
-		desc := desc
 		go func() {
 			// Avoids to get canceled by client.
 			ctx := log.WithLogger(context.Background(), log.G(ctx).WithField("mountpoint", mountpoint))
@@ -416,7 +415,7 @@ func (fs *filesystem) check(ctx context.Context, l layer.Layer, labels map[strin
 		retrynum = 1
 		rErr     = fmt.Errorf("failed to refresh connection")
 	)
-	for retry := 0; retry < retrynum; retry++ {
+	for retry := range retrynum {
 		log.G(ctx).Warnf("refreshing(%d)...", retry)
 		for _, s := range src {
 			err := l.Refresh(ctx, s.Hosts, s.Name, s.Target)

fs/layer/layer.go

@@ -158,7 +158,7 @@ func NewResolver(root string, backgroundTaskManager *task.BackgroundTaskManager,
 	// the filesystem resolves and caches all layers in an image (not only queried one) in parallel,
 	// before they are actually queried.
 	layerCache := cacheutil.NewTTLCache(resolveResultEntryTTL)
-	layerCache.OnEvicted = func(key string, value interface{}) {
+	layerCache.OnEvicted = func(key string, value any) {
 		if err := value.(*layer).close(); err != nil {
 			log.L.WithField("key", key).WithError(err).Warnf("failed to clean up layer")
 			return
@@ -169,7 +169,7 @@ func NewResolver(root string, backgroundTaskManager *task.BackgroundTaskManager,
 	// blobCache caches resolved blobs for futural use. This is especially useful when a layer
 	// isn't eStargz/stargz (the *layer object won't be created/cached in this case).
 	blobCache := cacheutil.NewTTLCache(resolveResultEntryTTL)
-	blobCache.OnEvicted = func(key string, value interface{}) {
+	blobCache.OnEvicted = func(key string, value any) {
 		if err := value.(remote.Blob).Close(); err != nil {
 			log.L.WithField("key", key).WithError(err).Warnf("failed to clean up blob")
 			return
@@ -212,16 +212,16 @@ func newCache(root string, cacheType string, cfg config.Config) (cache.BlobCache
 	}
 
 	bufPool := &sync.Pool{
-		New: func() interface{} {
+		New: func() any {
 			return new(bytes.Buffer)
 		},
 	}
 	dCache, fCache := cacheutil.NewLRUCache(maxDataEntry), cacheutil.NewLRUCache(maxFdEntry)
-	dCache.OnEvicted = func(key string, value interface{}) {
+	dCache.OnEvicted = func(key string, value any) {
 		value.(*bytes.Buffer).Reset()
 		bufPool.Put(value)
 	}
-	fCache.OnEvicted = func(key string, value interface{}) {
+	fCache.OnEvicted = func(key string, value any) {
 		value.(*os.File).Close()
 	}
 	// create a cache on an unique directory

fs/layer/testutil.go

@@ -252,10 +252,7 @@ func testPrefetch(t *TestRunner, factory metadata.Store, lc layerConfig) {
 				if tt.chunkSize > 0 {
 					chunkSize = tt.chunkSize
 				}
-				minChunkSize := 0
-				if tt.minChunkSize > 0 {
-					minChunkSize = tt.minChunkSize
-				}
+				minChunkSize := max(tt.minChunkSize, 0)
 				sr, dgst, err := tutil.BuildEStargz(tt.in,
 					tutil.WithEStargzOptions(
 						estargz.WithChunkSize(chunkSize),
@@ -1127,7 +1124,7 @@ func getDirentAndNode(t TestingT, root *node, path string) (ent fuse.DirEntry, n
 	// get the target's parent directory.
 	var eo fuse.EntryOut
 	d := root
-	for _, name := range strings.Split(dir, "/") {
+	for name := range strings.SplitSeq(dir, "/") {
 		if len(name) == 0 {
 			continue
 		}
@@ -1169,7 +1166,7 @@ func getDirent(t TestingT, root *node, path string) (ent fuse.DirEntry, err erro
 	// get the target's parent directory.
 	var eo fuse.EntryOut
 	d := root
-	for _, name := range strings.Split(dir, "/") {
+	for name := range strings.SplitSeq(dir, "/") {
 		if len(name) == 0 {
 			continue
 		}

fs/metrics/layer/metrics.go

@@ -55,14 +55,11 @@ func (c *Controller) Collect(ch chan<- prometheus.Metric) {
 	c.layerMu.RLock()
 	wg := &sync.WaitGroup{}
 	for mp, l := range c.layer {
-		mp, l := mp, l
-		wg.Add(1)
-		go func() {
-			defer wg.Done()
+		wg.Go(func() {
 			for _, e := range c.metrics {
 				e.collect(mp, l, c.ns, ch)
 			}
-		}()
+		})
 	}
 	c.layerMu.RUnlock()
 	wg.Wait()