les/flowcontrol/logger.go


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65

// Copyright 2019 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.

package flowcontrol

import (
    "fmt"
    "time"

    "github.com/ethereum/go-ethereum/common/mclock"
)

// logger collects events in string format and discards events older than the
// "keep" parameter
type logger struct {
    events           map[uint64]logEvent
    writePtr, delPtr uint64
    keep             time.Duration
}

// logEvent describes a single event
type logEvent struct {
    time  mclock.AbsTime
    event string
}

// newLogger creates a new logger
func newLogger(keep time.Duration) *logger {
    return &logger{
        events: make(map[uint64]logEvent),
        keep:   keep,
    }
}

// add adds a new event and discards old events if possible
func (l *logger) add(now mclock.AbsTime, event string) {
    keepAfter := now - mclock.AbsTime(l.keep)
    for l.delPtr < l.writePtr && l.events[l.delPtr].time <= keepAfter {
        delete(l.events, l.delPtr)
        l.delPtr++
    }
    l.events[l.writePtr] = logEvent{now, event}
    l.writePtr++
}

// dump prints all stored events
func (l *logger) dump(now mclock.AbsTime) {
    for i := l.delPtr; i < l.writePtr; i++ {
        e := l.events[i]
        fmt.Println(time.Duration(e.time-now), e.event)
    }
}