From 101a3ff39c858b80f8cb1e98533332a03b17e626 Mon Sep 17 00:00:00 2001
From: Tony Blyler <tony@blyler.cc>
Date: Sat, 14 May 2016 11:24:44 -0400
Subject: [PATCH] Add resume support to downloads
---
easysftp.go | 37 ++++++++++++++++++++++++++++++++-----
1 file changed, 32 insertions(+), 5 deletions(-)
diff --git a/easysftp.go b/easysftp.go
index 19f7045..2488069 100644
--- a/easysftp.go
+++ b/easysftp.go
@@ -99,8 +99,8 @@ func (c *Client) Lstat(path string) (os.FileInfo, error) {
return sftpClient.Lstat(path)
}
-// Download a file from the given path to the output writer
-func (c *Client) Download(path string, output io.Writer) error {
+// Download a file from the given path to the output writer with the given offset of the remote file
+func (c *Client) Download(path string, output io.Writer, offset int64) error {
sftpClient, err := c.newSftpClient()
if err != nil {
return err
@@ -124,12 +124,18 @@ func (c *Client) Download(path string, output io.Writer) error {
defer remote.Close()
+ _, err = remote.Seek(offset, 0)
+ if err != nil {
+ return err
+ }
+
_, err = io.Copy(output, remote)
return err
}
// Mirror downloads an entire folder (recursively) or file underneath the given localParentPath
-func (c *Client) Mirror(path string, localParentPath string) error {
+// resume will continue downloading interrupted files
+func (c *Client) Mirror(path string, localParentPath string, resume bool) error {
sftpClient, err := c.newSftpClient()
if err != nil {
return err
@@ -154,9 +160,19 @@ func (c *Client) Mirror(path string, localParentPath string) error {
}
}
+ flags := os.O_RDWR | os.O_CREATE
+
+ if resume {
+ // append to the end of the file
+ flags |= os.O_APPEND
+ } else {
+ // truncate the file
+ flags |= os.O_TRUNC
+ }
+
file, err := os.OpenFile(
localPath,
- os.O_RDWR|os.O_CREATE|os.O_TRUNC,
+ flags,
c.config.FileMode,
)
if err != nil {
@@ -165,7 +181,18 @@ func (c *Client) Mirror(path string, localParentPath string) error {
defer file.Close()
- return c.Download(path, file)
+ var offset int64
+ if resume {
+ info, err := file.Stat()
+ if err != nil {
+ return err
+ }
+
+ // we assume that the size of the file is the resume point
+ offset = info.Size()
+ }
+
+ return c.Download(path, file, offset)
}
// download the whole directory recursively