sftpgo/sftpd/transfer.go
2019-09-07 23:27:37 +02:00

121 lines
3.7 KiB
Go

package sftpd
import (
"os"
"time"
"github.com/drakkan/sftpgo/dataprovider"
"github.com/drakkan/sftpgo/logger"
)
const (
transferUpload = iota
transferDownload
)
const (
uploadModeStandard = iota
uploadModeAtomic
)
// Transfer contains the transfer details for an upload or a download.
// It implements the io Reader and Writer interface to handle files downloads and uploads
type Transfer struct {
file *os.File
path string
start time.Time
bytesSent int64
bytesReceived int64
user dataprovider.User
connectionID string
transferType int
lastActivity time.Time
isNewFile bool
protocol string
transferError error
isFinished bool
}
// TransferError is called if there is an unexpected error.
// For example network or client issues
func (t *Transfer) TransferError(err error) {
t.transferError = err
logger.Warn(logSender, t.connectionID, "Unexpected error for transfer, path: %#v, error: %#v bytes sent: %v, "+
"bytes received: %v", t.path, t.transferError, t.bytesSent, t.bytesReceived)
}
// ReadAt reads len(p) bytes from the File to download starting at byte offset off and updates the bytes sent.
// It handles download bandwidth throttling too
func (t *Transfer) ReadAt(p []byte, off int64) (n int, err error) {
t.lastActivity = time.Now()
readed, e := t.file.ReadAt(p, off)
t.bytesSent += int64(readed)
t.handleThrottle()
return readed, e
}
// WriteAt writes len(p) bytes to the uploaded file starting at byte offset off and updates the bytes received.
// It handles upload bandwidth throttling too
func (t *Transfer) WriteAt(p []byte, off int64) (n int, err error) {
t.lastActivity = time.Now()
written, e := t.file.WriteAt(p, off)
t.bytesReceived += int64(written)
t.handleThrottle()
return written, e
}
// Close it is called when the transfer is completed.
// It closes the underlying file, log the transfer info, update the user quota, for uploads, and execute any defined actions.
func (t *Transfer) Close() error {
err := t.file.Close()
if t.isFinished {
return err
}
if t.transferType == transferUpload && t.file.Name() != t.path {
err = os.Rename(t.file.Name(), t.path)
logger.Debug(logSender, t.connectionID, "atomic upload completed, rename: %#v -> %#v, error: %v",
t.file.Name(), t.path, err)
}
elapsed := time.Since(t.start).Nanoseconds() / 1000000
if t.transferError == nil {
if t.transferType == transferDownload {
logger.TransferLog(downloadLogSender, t.path, elapsed, t.bytesSent, t.user.Username, t.connectionID, t.protocol)
executeAction(operationDownload, t.user.Username, t.path, "")
} else {
logger.TransferLog(uploadLogSender, t.path, elapsed, t.bytesReceived, t.user.Username, t.connectionID, t.protocol)
executeAction(operationUpload, t.user.Username, t.path, "")
}
}
removeTransfer(t)
if t.transferType == transferUpload {
numFiles := 0
if t.isNewFile {
numFiles = 1
}
dataprovider.UpdateUserQuota(dataProvider, t.user, numFiles, t.bytesReceived, false)
}
t.isFinished = true
return err
}
func (t *Transfer) handleThrottle() {
var wantedBandwidth int64
var trasferredBytes int64
if t.transferType == transferDownload {
wantedBandwidth = t.user.DownloadBandwidth
trasferredBytes = t.bytesSent
} else {
wantedBandwidth = t.user.UploadBandwidth
trasferredBytes = t.bytesReceived
}
if wantedBandwidth > 0 {
// real and wanted elapsed as milliseconds, bytes as kilobytes
realElapsed := time.Since(t.start).Nanoseconds() / 1000000
// trasferredBytes / 1000 = KB/s, we multiply for 1000 to get milliseconds
wantedElapsed := 1000 * (trasferredBytes / 1000) / wantedBandwidth
if wantedElapsed > realElapsed {
toSleep := time.Duration(wantedElapsed - realElapsed)
time.Sleep(toSleep * time.Millisecond)
}
}
}