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 int32 // number of uploads in progress - atomic access required 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 := atomic.LoadInt32(&r.uploads) 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() { atomic.AddInt32(&r.uploads, 1) } // Stop should be called after finishing an upload func (r *Renew) Stop() { atomic.AddInt32(&r.uploads, -1) } // Invalidate invalidates the token source func (r *Renew) Invalidate() { r.ts.Invalidate() }