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