Use closures for data connections
Breaks the API, but avoids common pitfalls like unclosed connections.
This commit is contained in:
Julian Kornberger
parent
988909ab28
commit
619c7c29e5
@ -3,6 +3,7 @@ package ftp
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import (
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"bytes"
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"io/ioutil"
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"net"
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"net/textproto"
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"testing"
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"time"
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@ -67,25 +68,22 @@ func testConn(t *testing.T, disableEPSV bool) {
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t.Error(err)
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}
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r, err := c.Retr("tset")
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if err != nil {
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t.Error(err)
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} else {
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buf, err := ioutil.ReadAll(r)
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err = c.Retr("tset", func(conn net.Conn) error {
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buf, err := ioutil.ReadAll(conn)
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if err != nil {
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t.Error(err)
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}
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if string(buf) != testData {
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t.Errorf("'%s'", buf)
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}
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r.Close()
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}
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r, err = c.RetrFrom("tset", 5)
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return nil
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})
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if err != nil {
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t.Error(err)
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} else {
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buf, err := ioutil.ReadAll(r)
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}
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err = c.RetrFrom("tset", 5, func(conn net.Conn) error {
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buf, err := ioutil.ReadAll(conn)
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if err != nil {
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t.Error(err)
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}
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@ -93,7 +91,10 @@ func testConn(t *testing.T, disableEPSV bool) {
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if string(buf) != expected {
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t.Errorf("read %q, expected %q", buf, expected)
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}
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r.Close()
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return nil
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})
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if err != nil {
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t.Error(err)
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}
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err = c.Delete("tset")
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133
ftp.go
133
ftp.go
@ -39,11 +39,7 @@ type Entry struct {
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Time time.Time
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}
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// response represent a data-connection
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type response struct {
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conn net.Conn
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c *ServerConn
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}
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type connHandler func(net.Conn) error
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// Connect is an alias to Dial, for backward compatibility
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func Connect(addr string) (*ServerConn, error) {
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@ -258,37 +254,44 @@ func (c *ServerConn) cmd(expected int, format string, args ...interface{}) (int,
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// cmdDataConnFrom executes a command which require a FTP data connection.
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// Issues a REST FTP command to specify the number of bytes to skip for the transfer.
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func (c *ServerConn) cmdDataConnFrom(offset uint64, format string, args ...interface{}) (net.Conn, error) {
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func (c *ServerConn) cmdDataConnFrom(offset uint64, format string, arg interface{}, h connHandler) error {
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conn, err := c.openDataConn()
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if err != nil {
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return nil, err
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return err
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}
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if offset != 0 {
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_, _, err := c.cmd(StatusRequestFilePending, "REST %d", offset)
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if err != nil {
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if _, _, err := c.cmd(StatusRequestFilePending, "REST %d", offset); err != nil {
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conn.Close()
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return nil, err
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return err
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}
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}
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_, err = c.conn.Cmd(format, args...)
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if err != nil {
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if _, err := c.conn.Cmd(format, arg); err != nil {
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conn.Close()
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return nil, err
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return err
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}
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code, msg, err := c.conn.ReadResponse(-1)
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if err != nil {
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if code, msg, err := c.conn.ReadResponse(-1); err != nil {
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conn.Close()
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return nil, err
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}
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if code != StatusAlreadyOpen && code != StatusAboutToSend {
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return err
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} else if code != StatusAlreadyOpen && code != StatusAboutToSend {
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conn.Close()
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return nil, &textproto.Error{Code: code, Msg: msg}
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return &textproto.Error{Code: code, Msg: msg}
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}
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return conn, nil
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// Execute handler
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if err = h(conn); err != nil {
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conn.Close()
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return err
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}
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err = conn.Close()
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_, _, err2 := c.conn.ReadResponse(StatusClosingDataConnection)
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if err2 != nil {
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err = err2
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}
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return err
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}
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var errUnsupportedListLine = errors.New("Unsupported LIST line")
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@ -508,45 +511,30 @@ func (e *Entry) setTime(fields []string) (err error) {
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// NameList issues an NLST FTP command.
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func (c *ServerConn) NameList(path string) (entries []string, err error) {
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conn, err := c.cmdDataConnFrom(0, "NLST %s", path)
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if err != nil {
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return
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}
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err = c.cmdDataConnFrom(0, "NLST %s", path, func(conn net.Conn) error {
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r := &response{conn, c}
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defer r.Close()
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scanner := bufio.NewScanner(r)
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for scanner.Scan() {
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entries = append(entries, scanner.Text())
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}
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if err = scanner.Err(); err != nil {
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return entries, err
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}
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scanner := bufio.NewScanner(conn)
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for scanner.Scan() {
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entries = append(entries, scanner.Text())
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}
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return scanner.Err()
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})
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return
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}
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// List issues a LIST FTP command.
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func (c *ServerConn) List(path string) (entries []*Entry, err error) {
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conn, err := c.cmdDataConnFrom(0, "LIST %s", path)
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if err != nil {
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return
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}
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err = c.cmdDataConnFrom(0, "LIST %s", path, func(conn net.Conn) error {
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r := &response{conn, c}
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defer r.Close()
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scanner := bufio.NewScanner(r)
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for scanner.Scan() {
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line := scanner.Text()
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entry, err := parseListLine(line)
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if err == nil {
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entries = append(entries, entry)
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scanner := bufio.NewScanner(conn)
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for scanner.Scan() {
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line := scanner.Text()
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if entry, err := parseListLine(line); err == nil {
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entries = append(entries, entry)
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}
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}
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}
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if err := scanner.Err(); err != nil {
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return nil, err
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}
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return scanner.Err()
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})
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return
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}
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@ -587,21 +575,16 @@ func (c *ServerConn) CurrentDir() (string, error) {
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// FTP server.
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//
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// The returned ReadCloser must be closed to cleanup the FTP data connection.
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func (c *ServerConn) Retr(path string) (io.ReadCloser, error) {
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return c.RetrFrom(path, 0)
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func (c *ServerConn) Retr(path string, h connHandler) error {
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return c.RetrFrom(path, 0, h)
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}
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// RetrFrom issues a RETR FTP command to fetch the specified file from the remote
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// FTP server, the server will not send the offset first bytes of the file.
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//
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// The returned ReadCloser must be closed to cleanup the FTP data connection.
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func (c *ServerConn) RetrFrom(path string, offset uint64) (io.ReadCloser, error) {
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conn, err := c.cmdDataConnFrom(offset, "RETR %s", path)
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if err != nil {
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return nil, err
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}
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return &response{conn, c}, nil
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func (c *ServerConn) RetrFrom(path string, offset uint64, h connHandler) error {
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return c.cmdDataConnFrom(offset, "RETR %s", path, h)
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}
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// Stor issues a STOR FTP command to store a file to the remote FTP server.
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@ -618,19 +601,10 @@ func (c *ServerConn) Stor(path string, r io.Reader) error {
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//
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// Hint: io.Pipe() can be used if an io.Writer is required.
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func (c *ServerConn) StorFrom(path string, r io.Reader, offset uint64) error {
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conn, err := c.cmdDataConnFrom(offset, "STOR %s", path)
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if err != nil {
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return c.cmdDataConnFrom(offset, "STOR %s", path, func(conn net.Conn) error {
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_, err := io.Copy(conn, r)
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return err
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}
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_, err = io.Copy(conn, r)
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conn.Close()
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if err != nil {
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return err
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}
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_, _, err = c.conn.ReadResponse(StatusClosingDataConnection)
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return err
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})
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}
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// Rename renames a file on the remote FTP server.
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@ -685,18 +659,3 @@ func (c *ServerConn) Quit() error {
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c.conn.Cmd("QUIT")
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return c.conn.Close()
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}
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// Read implements the io.Reader interface on a FTP data connection.
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func (r *response) Read(buf []byte) (int, error) {
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return r.conn.Read(buf)
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}
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// Close implements the io.Closer interface on a FTP data connection.
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func (r *response) Close() error {
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err := r.conn.Close()
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_, _, err2 := r.c.conn.ReadResponse(StatusClosingDataConnection)
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if err2 != nil {
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err = err2
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}
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return err
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}
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