blob: 245802231ea985e3b4343d9b381bd9f6f95fa883 [file] [log] [blame]
// Copyright 2019 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package export
import (
"context"
"fmt"
"io"
"golang.org/x/tools/internal/telemetry/event"
)
// LogWriter returns an Exporter that logs events to the supplied writer.
// If onlyErrors is true it does not log any event that did not have an
// associated error.
// It ignores all telemetry other than log events.
func LogWriter(w io.Writer, onlyErrors bool) event.Exporter {
lw := &logWriter{writer: w, onlyErrors: onlyErrors}
return lw.ProcessEvent
}
type logWriter struct {
writer io.Writer
onlyErrors bool
}
func (w *logWriter) ProcessEvent(ctx context.Context, ev event.Event, tagMap event.TagMap) context.Context {
switch {
case ev.IsLog():
if w.onlyErrors && event.Err.Get(tagMap) == nil {
return ctx
}
fmt.Fprintf(w.writer, "%v\n", ev)
case ev.IsStartSpan():
if span := GetSpan(ctx); span != nil {
fmt.Fprintf(w.writer, "start: %v %v", span.Name, span.ID)
if span.ParentID.IsValid() {
fmt.Fprintf(w.writer, "[%v]", span.ParentID)
}
}
case ev.IsEndSpan():
if span := GetSpan(ctx); span != nil {
fmt.Fprintf(w.writer, "finish: %v %v", span.Name, span.ID)
}
}
return ctx
}