mirror of https://github.com/prometheus/prometheus
134 lines
3.3 KiB
Go
134 lines
3.3 KiB
Go
// Copyright 2019 The Prometheus Authors
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
//
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
package logging
|
|
|
|
import (
|
|
"context"
|
|
"log/slog"
|
|
"sync"
|
|
"time"
|
|
)
|
|
|
|
const (
|
|
garbageCollectEvery = 10 * time.Second
|
|
expireEntriesAfter = 1 * time.Minute
|
|
maxEntries = 1024
|
|
)
|
|
|
|
var _ slog.Handler = (*Deduper)(nil)
|
|
|
|
// Deduper implements *slog.Handler, dedupes log lines based on a time duration.
|
|
type Deduper struct {
|
|
next *slog.Logger
|
|
repeat time.Duration
|
|
quit chan struct{}
|
|
mtx sync.RWMutex
|
|
seen map[string]time.Time
|
|
}
|
|
|
|
// Dedupe log lines to next, only repeating every repeat duration.
|
|
func Dedupe(next *slog.Logger, repeat time.Duration) *Deduper {
|
|
d := &Deduper{
|
|
next: next,
|
|
repeat: repeat,
|
|
quit: make(chan struct{}),
|
|
seen: map[string]time.Time{},
|
|
}
|
|
go d.run()
|
|
return d
|
|
}
|
|
|
|
// Enabled returns true if the Deduper's internal slog.Logger is enabled at the
|
|
// provided context and log level, and returns false otherwise. It implements
|
|
// slog.Handler.
|
|
func (d *Deduper) Enabled(ctx context.Context, level slog.Level) bool {
|
|
return d.next.Enabled(ctx, level)
|
|
}
|
|
|
|
// Handle uses the provided context and slog.Record to deduplicate messages
|
|
// every 1m. Log records received within the interval are not acted on, and
|
|
// thus dropped. Log records that pass deduplication and need action invoke the
|
|
// Handle() method on the Deduper's internal slog.Logger's handler, effectively
|
|
// chaining log calls to the internal slog.Logger.
|
|
func (d *Deduper) Handle(ctx context.Context, r slog.Record) error {
|
|
line := r.Message
|
|
d.mtx.RLock()
|
|
last, ok := d.seen[line]
|
|
d.mtx.RUnlock()
|
|
|
|
if ok && time.Since(last) < d.repeat {
|
|
return nil
|
|
}
|
|
|
|
d.mtx.Lock()
|
|
if len(d.seen) < maxEntries {
|
|
d.seen[line] = time.Now()
|
|
}
|
|
d.mtx.Unlock()
|
|
|
|
return d.next.Handler().Handle(ctx, r.Clone())
|
|
}
|
|
|
|
// WithAttrs adds the provided attributes to the Deduper's internal
|
|
// slog.Logger. It implements slog.Handler.
|
|
func (d *Deduper) WithAttrs(attrs []slog.Attr) slog.Handler {
|
|
return &Deduper{
|
|
next: slog.New(d.next.Handler().WithAttrs(attrs)),
|
|
repeat: d.repeat,
|
|
quit: d.quit,
|
|
seen: d.seen,
|
|
}
|
|
}
|
|
|
|
// WithGroup adds the provided group name to the Deduper's internal
|
|
// slog.Logger. It implements slog.Handler.
|
|
func (d *Deduper) WithGroup(name string) slog.Handler {
|
|
if name == "" {
|
|
return d
|
|
}
|
|
|
|
return &Deduper{
|
|
next: slog.New(d.next.Handler().WithGroup(name)),
|
|
repeat: d.repeat,
|
|
quit: d.quit,
|
|
seen: d.seen,
|
|
}
|
|
}
|
|
|
|
// Stop the Deduper.
|
|
func (d *Deduper) Stop() {
|
|
close(d.quit)
|
|
}
|
|
|
|
func (d *Deduper) run() {
|
|
ticker := time.NewTicker(garbageCollectEvery)
|
|
defer ticker.Stop()
|
|
|
|
for {
|
|
select {
|
|
case <-ticker.C:
|
|
d.mtx.Lock()
|
|
now := time.Now()
|
|
for line, seen := range d.seen {
|
|
if now.Sub(seen) > expireEntriesAfter {
|
|
delete(d.seen, line)
|
|
}
|
|
}
|
|
d.mtx.Unlock()
|
|
case <-d.quit:
|
|
return
|
|
}
|
|
}
|
|
}
|