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

weed/sftpd/sftp_file_reader.go

@@ -0,0 +1,99 @@
+package sftpd
+
+import (
+	"fmt"
+	"io"
+	"sync"
+
+	"github.com/seaweedfs/seaweedfs/weed/filer"
+	filer_pb "github.com/seaweedfs/seaweedfs/weed/pb/filer_pb"
+	"github.com/seaweedfs/seaweedfs/weed/sftpd/utils"
+)
+
+type SeaweedFileReaderAt struct {
+	fs         *SftpServer
+	entry      *filer_pb.Entry
+	reader     io.ReadSeeker
+	mu         sync.Mutex
+	bufferSize int
+	cache      *utils.LruCache
+	fileSize   int64
+}
+
+func NewSeaweedFileReaderAt(fs *SftpServer, entry *filer_pb.Entry) *SeaweedFileReaderAt {
+	return &SeaweedFileReaderAt{
+		fs:         fs,
+		entry:      entry,
+		bufferSize: 5 * 1024 * 1024,       // 5MB
+		cache:      utils.NewLRUCache(10), // Max 10 chunks = ~50MB
+		fileSize:   int64(entry.Attributes.FileSize),
+	}
+}
+
+func (ra *SeaweedFileReaderAt) ReadAt(p []byte, off int64) (n int, err error) {
+	ra.mu.Lock()
+	defer ra.mu.Unlock()
+
+	if off >= ra.fileSize {
+		return 0, io.EOF
+	}
+
+	remaining := len(p)
+	readOffset := off
+	totalRead := 0
+
+	for remaining > 0 && readOffset < ra.fileSize {
+		bufferKey := (readOffset / int64(ra.bufferSize)) * int64(ra.bufferSize)
+		bufferOffset := int(readOffset - bufferKey)
+
+		buffer, ok := ra.cache.Get(bufferKey)
+		if !ok {
+			readSize := ra.bufferSize
+			if bufferKey+int64(readSize) > ra.fileSize {
+				readSize = int(ra.fileSize - bufferKey)
+			}
+
+			if ra.reader == nil {
+				r := filer.NewFileReader(ra.fs, ra.entry)
+				if rs, ok := r.(io.ReadSeeker); ok {
+					ra.reader = rs
+				} else {
+					return 0, fmt.Errorf("reader is not seekable")
+				}
+			}
+
+			if _, err := ra.reader.Seek(bufferKey, io.SeekStart); err != nil {
+				return 0, fmt.Errorf("seek error: %w", err)
+			}
+
+			buffer = make([]byte, readSize)
+			readBytes, err := io.ReadFull(ra.reader, buffer)
+			if err != nil && err != io.ErrUnexpectedEOF {
+				return 0, fmt.Errorf("read error: %w", err)
+			}
+			buffer = buffer[:readBytes]
+			ra.cache.Put(bufferKey, buffer)
+		}
+
+		toCopy := len(buffer) - bufferOffset
+		if toCopy > remaining {
+			toCopy = remaining
+		}
+		if toCopy <= 0 {
+			break
+		}
+
+		copy(p[totalRead:], buffer[bufferOffset:bufferOffset+toCopy])
+		totalRead += toCopy
+		readOffset += int64(toCopy)
+		remaining -= toCopy
+	}
+
+	if totalRead == 0 {
+		return 0, io.EOF
+	}
+	if totalRead < len(p) {
+		return totalRead, io.EOF
+	}
+	return totalRead, nil
+}