rclone/fs/pacer.go
Nick Craig-Wood 96438ff259 pacer: fix b2 deadlock by defaulting max connections to unlimited
Before this change, the maximum number of connections was set to 10.

This means that b2 could deadlock while uploading multipart uploads
due to a lock being held longer than it should have been.
2023-10-01 12:30:26 +01:00

95 lines
2.2 KiB
Go

// Pacer with logging and calculator
package fs
import (
"context"
"time"
"github.com/rclone/rclone/fs/fserrors"
"github.com/rclone/rclone/lib/pacer"
)
// Pacer is a simple wrapper around a pacer.Pacer with logging.
type Pacer struct {
*pacer.Pacer
}
type logCalculator struct {
pacer.Calculator
}
// NewPacer creates a Pacer for the given Fs and Calculator.
func NewPacer(ctx context.Context, c pacer.Calculator) *Pacer {
ci := GetConfig(ctx)
retries := ci.LowLevelRetries
if retries <= 0 {
retries = 1
}
p := &Pacer{
Pacer: pacer.New(
pacer.InvokerOption(pacerInvoker),
// pacer.MaxConnectionsOption(ci.Checkers+ci.Transfers),
pacer.RetriesOption(retries),
pacer.CalculatorOption(c),
),
}
p.SetCalculator(c)
return p
}
func (d *logCalculator) Calculate(state pacer.State) time.Duration {
oldSleepTime := state.SleepTime
newSleepTime := d.Calculator.Calculate(state)
if state.ConsecutiveRetries > 0 {
if newSleepTime != oldSleepTime {
Debugf("pacer", "Rate limited, increasing sleep to %v", newSleepTime)
}
} else {
if newSleepTime != oldSleepTime {
Debugf("pacer", "Reducing sleep to %v", newSleepTime)
}
}
return newSleepTime
}
// SetCalculator sets the pacing algorithm. Don't modify the Calculator object
// afterwards, use the ModifyCalculator method when needed.
//
// It will choose the default algorithm if nil is passed in.
func (p *Pacer) SetCalculator(c pacer.Calculator) {
switch c.(type) {
case *logCalculator:
Logf("pacer", "Invalid Calculator in fs.Pacer.SetCalculator")
case nil:
c = &logCalculator{pacer.NewDefault()}
default:
c = &logCalculator{c}
}
p.Pacer.SetCalculator(c)
}
// ModifyCalculator calls the given function with the currently configured
// Calculator and the Pacer lock held.
func (p *Pacer) ModifyCalculator(f func(pacer.Calculator)) {
p.Pacer.ModifyCalculator(func(c pacer.Calculator) {
switch _c := c.(type) {
case *logCalculator:
f(_c.Calculator)
default:
Logf("pacer", "Invalid Calculator in fs.Pacer: %t", c)
f(c)
}
})
}
func pacerInvoker(try, retries int, f pacer.Paced) (retry bool, err error) {
retry, err = f()
if retry {
Debugf("pacer", "low level retry %d/%d (error %v)", try, retries, err)
err = fserrors.RetryError(err)
}
return
}