package querylog import ( "bytes" "encoding/json" "fmt" "os" "time" "github.com/AdguardTeam/golibs/errors" "github.com/AdguardTeam/golibs/log" ) // flushLogBuffer flushes the current buffer to file and resets the current // buffer. func (l *queryLog) flushLogBuffer() (err error) { l.fileFlushLock.Lock() defer l.fileFlushLock.Unlock() var flushBuffer []*logEntry func() { l.bufferLock.Lock() defer l.bufferLock.Unlock() flushBuffer = l.buffer l.buffer = nil l.flushPending = false }() err = l.flushToFile(flushBuffer) return errors.Annotate(err, "writing to file: %w") } // flushToFile saves the specified log entries to the query log file func (l *queryLog) flushToFile(buffer []*logEntry) (err error) { if len(buffer) == 0 { log.Debug("querylog: nothing to write to a file") return nil } start := time.Now() var b bytes.Buffer e := json.NewEncoder(&b) for _, entry := range buffer { err = e.Encode(entry) if err != nil { log.Error("Failed to marshal entry: %s", err) return err } } elapsed := time.Since(start) log.Debug("%d elements serialized via json in %v: %d kB, %v/entry, %v/entry", len(buffer), elapsed, b.Len()/1024, float64(b.Len())/float64(len(buffer)), elapsed/time.Duration(len(buffer))) var zb bytes.Buffer filename := l.logFile zb = b l.fileWriteLock.Lock() defer l.fileWriteLock.Unlock() f, err := os.OpenFile(filename, os.O_WRONLY|os.O_CREATE|os.O_APPEND, 0o644) if err != nil { log.Error("failed to create file \"%s\": %s", filename, err) return err } defer func() { err = errors.WithDeferred(err, f.Close()) }() n, err := f.Write(zb.Bytes()) if err != nil { log.Error("Couldn't write to file: %s", err) return err } log.Debug("querylog: ok \"%s\": %v bytes written", filename, n) return nil } func (l *queryLog) rotate() error { from := l.logFile to := l.logFile + ".1" err := os.Rename(from, to) if err != nil { if errors.Is(err, os.ErrNotExist) { log.Debug("querylog: no log to rotate") return nil } return fmt.Errorf("failed to rename old file: %w", err) } log.Debug("querylog: renamed %s into %s", from, to) return nil } func (l *queryLog) readFileFirstTimeValue() (first time.Time, err error) { var f *os.File f, err = os.Open(l.logFile) if err != nil { return time.Time{}, err } defer func() { err = errors.WithDeferred(err, f.Close()) }() buf := make([]byte, 512) var r int r, err = f.Read(buf) if err != nil { return time.Time{}, err } val := readJSONValue(string(buf[:r]), `"T":"`) t, err := time.Parse(time.RFC3339Nano, val) if err != nil { return time.Time{}, err } log.Debug("querylog: the oldest log entry: %s", val) return t, nil } func (l *queryLog) periodicRotate() { defer log.OnPanic("querylog: rotating") l.checkAndRotate() // rotationCheckIvl is the period of time between checking the need for // rotating log files. It's smaller of any available rotation interval to // increase time accuracy. // // See https://github.com/AdguardTeam/AdGuardHome/issues/3823. const rotationCheckIvl = 1 * time.Hour rotations := time.NewTicker(rotationCheckIvl) defer rotations.Stop() for range rotations.C { l.checkAndRotate() } } // checkAndRotate rotates log files if those are older than the specified // rotation interval. func (l *queryLog) checkAndRotate() { var rotationIvl time.Duration func() { l.confMu.RLock() defer l.confMu.RUnlock() rotationIvl = l.conf.RotationIvl }() oldest, err := l.readFileFirstTimeValue() if err != nil && !errors.Is(err, os.ErrNotExist) { log.Error("querylog: reading oldest record for rotation: %s", err) return } if rotTime, now := oldest.Add(rotationIvl), time.Now(); rotTime.After(now) { log.Debug( "querylog: %s <= %s, not rotating", now.Format(time.RFC3339), rotTime.Format(time.RFC3339), ) return } err = l.rotate() if err != nil { log.Error("querylog: rotating: %s", err) return } log.Debug("querylog: rotated successfully") }