rclone/lib/oauthutil/renew.go
2023-08-22 12:52:13 +01:00

74 lines
1.9 KiB
Go

package oauthutil
import (
"sync/atomic"
"github.com/rclone/rclone/fs"
)
// Renew allows tokens to be renewed on expiry if uploads are in progress.
type Renew struct {
name string // name to use in logs
ts *TokenSource // token source that needs renewing
uploads atomic.Int32 // number of uploads in progress
run func() error // a transaction to run to renew the token on
}
// NewRenew creates a new Renew struct and starts a background process
// which renews the token whenever it expires. It uses the run() call
// to run a transaction to do this.
//
// It will only renew the token if the number of uploads > 0
func NewRenew(name string, ts *TokenSource, run func() error) *Renew {
r := &Renew{
name: name,
ts: ts,
run: run,
}
go r.renewOnExpiry()
return r
}
// renewOnExpiry renews the token whenever it expires. Useful when there
// are lots of uploads in progress and the token doesn't get renewed.
// Amazon seem to cancel your uploads if you don't renew your token
// for 2hrs.
func (r *Renew) renewOnExpiry() {
expiry := r.ts.OnExpiry()
for {
<-expiry
uploads := r.uploads.Load()
if uploads != 0 {
fs.Debugf(r.name, "Token expired - %d uploads in progress - refreshing", uploads)
// Do a transaction
err := r.run()
if err == nil {
fs.Debugf(r.name, "Token refresh successful")
} else {
fs.Errorf(r.name, "Token refresh failed: %v", err)
}
} else {
fs.Debugf(r.name, "Token expired but no uploads in progress - doing nothing")
}
}
}
// Start should be called before starting an upload
func (r *Renew) Start() {
r.uploads.Add(1)
}
// Stop should be called after finishing an upload
func (r *Renew) Stop() {
r.uploads.Add(-1)
}
// Invalidate invalidates the token source
func (r *Renew) Invalidate() {
r.ts.Invalidate()
}
// Expire expires the token source
func (r *Renew) Expire() error {
return r.ts.Expire()
}