From e77532852307b4f86e8ed09038c4dfc717173db4 Mon Sep 17 00:00:00 2001
From: Nick Craig-Wood <nick@craig-wood.com>
Date: Wed, 6 Jan 2021 12:19:23 +0000
Subject: [PATCH] ftp,sftp: Make --tpslimit apply - fixes #4906

---
 backend/ftp/ftp.go   |  2 ++
 backend/sftp/sftp.go |  2 ++
 docs/content/docs.md | 15 ++++++++++++---
 3 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/backend/ftp/ftp.go b/backend/ftp/ftp.go
index a27fd267b..387ef1f78 100644
--- a/backend/ftp/ftp.go
+++ b/backend/ftp/ftp.go
@@ -15,6 +15,7 @@ import (
 	"github.com/jlaffaye/ftp"
 	"github.com/pkg/errors"
 	"github.com/rclone/rclone/fs"
+	"github.com/rclone/rclone/fs/accounting"
 	"github.com/rclone/rclone/fs/config"
 	"github.com/rclone/rclone/fs/config/configmap"
 	"github.com/rclone/rclone/fs/config/configstruct"
@@ -258,6 +259,7 @@ func (f *Fs) getFtpConnection(ctx context.Context) (c *ftp.ServerConn, err error
 	if f.opt.Concurrency > 0 {
 		f.tokens.Get()
 	}
+	accounting.LimitTPS(ctx)
 	f.poolMu.Lock()
 	if len(f.pool) > 0 {
 		c = f.pool[0]
diff --git a/backend/sftp/sftp.go b/backend/sftp/sftp.go
index 60be731b2..e7c93c775 100644
--- a/backend/sftp/sftp.go
+++ b/backend/sftp/sftp.go
@@ -21,6 +21,7 @@ import (
 	"github.com/pkg/errors"
 	"github.com/pkg/sftp"
 	"github.com/rclone/rclone/fs"
+	"github.com/rclone/rclone/fs/accounting"
 	"github.com/rclone/rclone/fs/config"
 	"github.com/rclone/rclone/fs/config/configmap"
 	"github.com/rclone/rclone/fs/config/configstruct"
@@ -349,6 +350,7 @@ func (f *Fs) newSftpClient(conn *ssh.Client, opts ...sftp.ClientOption) (*sftp.C
 
 // Get an SFTP connection from the pool, or open a new one
 func (f *Fs) getSftpConnection(ctx context.Context) (c *conn, err error) {
+	accounting.LimitTPS(ctx)
 	f.poolMu.Lock()
 	for len(f.pool) > 0 {
 		c = f.pool[0]
diff --git a/docs/content/docs.md b/docs/content/docs.md
index 4590a26c4..2de1c664f 100644
--- a/docs/content/docs.md
+++ b/docs/content/docs.md
@@ -1297,10 +1297,15 @@ facility is `DAEMON`.
 
 ### --tpslimit float ###
 
-Limit HTTP transactions per second to this. Default is 0 which is used
-to mean unlimited transactions per second.
+Limit transactions per second to this number. Default is 0 which is
+used to mean unlimited transactions per second.
 
-For example to limit rclone to 10 HTTP transactions per second use
+A transaction is roughly defined as an API call; its exact meaning
+will depend on the backend. For HTTP based backends it is an HTTP
+PUT/GET/POST/etc and its response. For FTP/SFTP it is a round trip
+transaction over TCP.
+
+For example to limit rclone to 10 transactions per second use
 `--tpslimit 10`, or to 1 transaction every 2 seconds use `--tpslimit
 0.5`.
 
@@ -1311,6 +1316,10 @@ banned or rate limited).
 This can be very useful for `rclone mount` to control the behaviour of
 applications using it.
 
+This limit applies to all HTTP based backends and to the FTP and SFTP
+backends. It does not apply to the local backend or the Tardigrade
+backend.
+
 See also `--tpslimit-burst`.
 
 ### --tpslimit-burst int ###