github.com/aigarnetwork/aigar@v0.0.0-20191115204914-d59a6eb70f8e/les/flowcontrol/logger.go (about)

     1  //  Copyright 2018 The go-ethereum Authors
     2  //  Copyright 2019 The go-aigar Authors
     3  //  This file is part of the go-aigar library.
     4  //
     5  //  The go-aigar library is free software: you can redistribute it and/or modify
     6  //  it under the terms of the GNU Lesser General Public License as published by
     7  //  the Free Software Foundation, either version 3 of the License, or
     8  //  (at your option) any later version.
     9  //
    10  //  The go-aigar library is distributed in the hope that it will be useful,
    11  //  but WITHOUT ANY WARRANTY; without even the implied warranty of
    12  //  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    13  //  GNU Lesser General Public License for more details.
    14  //
    15  //  You should have received a copy of the GNU Lesser General Public License
    16  //  along with the go-aigar library. If not, see <http://www.gnu.org/licenses/>.
    17  
    18  package flowcontrol
    19  
    20  import (
    21  	"fmt"
    22  	"time"
    23  
    24  	"github.com/AigarNetwork/aigar/common/mclock"
    25  )
    26  
    27  // logger collects events in string format and discards events older than the
    28  // "keep" parameter
    29  type logger struct {
    30  	events           map[uint64]logEvent
    31  	writePtr, delPtr uint64
    32  	keep             time.Duration
    33  }
    34  
    35  // logEvent describes a single event
    36  type logEvent struct {
    37  	time  mclock.AbsTime
    38  	event string
    39  }
    40  
    41  // newLogger creates a new logger
    42  func newLogger(keep time.Duration) *logger {
    43  	return &logger{
    44  		events: make(map[uint64]logEvent),
    45  		keep:   keep,
    46  	}
    47  }
    48  
    49  // add adds a new event and discards old events if possible
    50  func (l *logger) add(now mclock.AbsTime, event string) {
    51  	keepAfter := now - mclock.AbsTime(l.keep)
    52  	for l.delPtr < l.writePtr && l.events[l.delPtr].time <= keepAfter {
    53  		delete(l.events, l.delPtr)
    54  		l.delPtr++
    55  	}
    56  	l.events[l.writePtr] = logEvent{now, event}
    57  	l.writePtr++
    58  }
    59  
    60  // dump prints all stored events
    61  func (l *logger) dump(now mclock.AbsTime) {
    62  	for i := l.delPtr; i < l.writePtr; i++ {
    63  		e := l.events[i]
    64  		fmt.Println(time.Duration(e.time-now), e.event)
    65  	}
    66  }