status-go/vendor/github.com/libp2p/go-libp2p-quic-transport/tracer.go

96 lines
2.6 KiB
Go

package libp2pquic
import (
"bufio"
"fmt"
"io"
"os"
"time"
"github.com/klauspost/compress/zstd"
"github.com/lucas-clemente/quic-go/logging"
"github.com/lucas-clemente/quic-go/qlog"
)
var tracer logging.Tracer
func init() {
tracers := []logging.Tracer{&metricsTracer{}}
if qlogDir := os.Getenv("QLOGDIR"); len(qlogDir) > 0 {
if qlogger := initQlogger(qlogDir); qlogger != nil {
tracers = append(tracers, qlogger)
}
}
tracer = logging.NewMultiplexedTracer(tracers...)
}
func initQlogger(qlogDir string) logging.Tracer {
return qlog.NewTracer(func(role logging.Perspective, connID []byte) io.WriteCloser {
// create the QLOGDIR, if it doesn't exist
if err := os.MkdirAll(qlogDir, 0777); err != nil {
log.Errorf("creating the QLOGDIR failed: %s", err)
return nil
}
return newQlogger(qlogDir, role, connID)
})
}
// The qlogger logs qlog events to a temporary file: .<name>.qlog.swp.
// When it is closed, it compresses the temporary file and saves it as <name>.qlog.zst.
// It is not possible to compress on the fly, as compression algorithms keep a lot of internal state,
// which can easily exhaust the host system's memory when running a few hundred QUIC connections in parallel.
type qlogger struct {
f *os.File // QLOGDIR/.log_xxx.qlog.swp
filename string // QLOGDIR/log_xxx.qlog.zst
*bufio.Writer // buffering the f
}
func newQlogger(qlogDir string, role logging.Perspective, connID []byte) io.WriteCloser {
t := time.Now().UTC().Format("2006-01-02T15-04-05.999999999UTC")
r := "server"
if role == logging.PerspectiveClient {
r = "client"
}
finalFilename := fmt.Sprintf("%s%clog_%s_%s_%x.qlog.zst", qlogDir, os.PathSeparator, t, r, connID)
filename := fmt.Sprintf("%s%c.log_%s_%s_%x.qlog.swp", qlogDir, os.PathSeparator, t, r, connID)
f, err := os.Create(filename)
if err != nil {
log.Errorf("unable to create qlog file %s: %s", filename, err)
return nil
}
return &qlogger{
f: f,
filename: finalFilename,
Writer: bufio.NewWriter(f),
}
}
func (l *qlogger) Close() error {
defer os.Remove(l.f.Name())
defer l.f.Close()
if err := l.Writer.Flush(); err != nil {
return err
}
if _, err := l.f.Seek(0, io.SeekStart); err != nil { // set the read position to the beginning of the file
return err
}
f, err := os.Create(l.filename)
if err != nil {
return err
}
defer f.Close()
buf := bufio.NewWriter(f)
c, err := zstd.NewWriter(buf, zstd.WithEncoderLevel(zstd.SpeedFastest), zstd.WithWindowSize(32*1024))
if err != nil {
return err
}
if _, err := io.Copy(c, l.f); err != nil {
return err
}
if err := c.Close(); err != nil {
return err
}
return buf.Flush()
}