docker/distribution/utils/progress.go

45 строки
1.2 KiB
Go

package utils
import (
"io"
"net"
"os"
"syscall"
"github.com/Sirupsen/logrus"
"github.com/docker/docker/pkg/progress"
"github.com/docker/docker/pkg/streamformatter"
)
// WriteDistributionProgress is a helper for writing progress from chan to JSON
// stream with an optional cancel function.
func WriteDistributionProgress(cancelFunc func(), outStream io.Writer, progressChan <-chan progress.Progress) {
progressOutput := streamformatter.NewJSONStreamFormatter().NewProgressOutput(outStream, false)
operationCancelled := false
for prog := range progressChan {
if err := progressOutput.WriteProgress(prog); err != nil && !operationCancelled {
// don't log broken pipe errors as this is the normal case when a client aborts
if isBrokenPipe(err) {
logrus.Info("Pull session cancelled")
} else {
logrus.Errorf("error writing progress to client: %v", err)
}
cancelFunc()
operationCancelled = true
// Don't return, because we need to continue draining
// progressChan until it's closed to avoid a deadlock.
}
}
}
func isBrokenPipe(e error) bool {
if netErr, ok := e.(*net.OpError); ok {
e = netErr.Err
if sysErr, ok := netErr.Err.(*os.SyscallError); ok {
e = sysErr.Err
}
}
return e == syscall.EPIPE
}