go-pulse/les/csvlogger/csvlogger.go

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// 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 csvlogger
import (
"fmt"
"os"
"sync"
"time"
"github.com/ethereum/go-ethereum/common/mclock"
"github.com/ethereum/go-ethereum/log"
)
// Logger is a metrics/events logger that writes logged values and events into a comma separated file
type Logger struct {
file *os.File
started mclock.AbsTime
channels []*Channel
period time.Duration
stopCh, stopped chan struct{}
storeCh chan string
eventHeader string
}
// NewLogger creates a new Logger
func NewLogger(fileName string, updatePeriod time.Duration, eventHeader string) *Logger {
if fileName == "" {
return nil
}
f, err := os.Create(fileName)
if err != nil {
log.Error("Error creating log file", "name", fileName, "error", err)
return nil
}
return &Logger{
file: f,
period: updatePeriod,
stopCh: make(chan struct{}),
storeCh: make(chan string, 1),
eventHeader: eventHeader,
}
}
// NewChannel creates a new value logger channel that writes values in a single
// column. If the relative change of the value is bigger than the given threshold
// then a new line is added immediately (threshold can also be 0).
func (l *Logger) NewChannel(name string, threshold float64) *Channel {
if l == nil {
return nil
}
c := &Channel{
logger: l,
name: name,
threshold: threshold,
}
l.channels = append(l.channels, c)
return c
}
// NewMinMaxChannel creates a new value logger channel that writes the minimum and
// maximum of the tracked value in two columns. It never triggers adding a new line.
// If zeroDefault is true then 0 is written to both min and max columns if no update
// was given during the last period. If it is false then the last update will appear
// in both columns.
func (l *Logger) NewMinMaxChannel(name string, zeroDefault bool) *Channel {
if l == nil {
return nil
}
c := &Channel{
logger: l,
name: name,
minmax: true,
mmZeroDefault: zeroDefault,
}
l.channels = append(l.channels, c)
return c
}
func (l *Logger) store(event string) {
s := fmt.Sprintf("%g", float64(mclock.Now()-l.started)/1000000000)
for _, ch := range l.channels {
s += ", " + ch.store()
}
if event != "" {
s += ", " + event
}
l.file.WriteString(s + "\n")
}
// Start writes the header line and starts the logger
func (l *Logger) Start() {
if l == nil {
return
}
l.started = mclock.Now()
s := "Time"
for _, ch := range l.channels {
s += ", " + ch.header()
}
if l.eventHeader != "" {
s += ", " + l.eventHeader
}
l.file.WriteString(s + "\n")
go func() {
timer := time.NewTimer(l.period)
for {
select {
case <-timer.C:
l.store("")
timer.Reset(l.period)
case event := <-l.storeCh:
l.store(event)
if !timer.Stop() {
<-timer.C
}
timer.Reset(l.period)
case <-l.stopCh:
close(l.stopped)
return
}
}
}()
}
// Stop stops the logger and closes the file
func (l *Logger) Stop() {
if l == nil {
return
}
l.stopped = make(chan struct{})
close(l.stopCh)
<-l.stopped
l.file.Close()
}
// Event immediately adds a new line and adds the given event string in the last column
func (l *Logger) Event(event string) {
if l == nil {
return
}
select {
case l.storeCh <- event:
case <-l.stopCh:
}
}
// Channel represents a logger channel tracking a single value
type Channel struct {
logger *Logger
lock sync.Mutex
name string
threshold, storeMin, storeMax, lastValue, min, max float64
minmax, mmSet, mmZeroDefault bool
}
// Update updates the tracked value
func (lc *Channel) Update(value float64) {
if lc == nil {
return
}
lc.lock.Lock()
defer lc.lock.Unlock()
lc.lastValue = value
if lc.minmax {
if value > lc.max || !lc.mmSet {
lc.max = value
}
if value < lc.min || !lc.mmSet {
lc.min = value
}
lc.mmSet = true
} else {
if value < lc.storeMin || value > lc.storeMax {
select {
case lc.logger.storeCh <- "":
default:
}
}
}
}
func (lc *Channel) store() (s string) {
lc.lock.Lock()
defer lc.lock.Unlock()
if lc.minmax {
s = fmt.Sprintf("%g, %g", lc.min, lc.max)
lc.mmSet = false
if lc.mmZeroDefault {
lc.min = 0
} else {
lc.min = lc.lastValue
}
lc.max = lc.min
} else {
s = fmt.Sprintf("%g", lc.lastValue)
lc.storeMin = lc.lastValue * (1 - lc.threshold)
lc.storeMax = lc.lastValue * (1 + lc.threshold)
if lc.lastValue < 0 {
lc.storeMin, lc.storeMax = lc.storeMax, lc.storeMin
}
}
return
}
func (lc *Channel) header() string {
if lc.minmax {
return lc.name + " (min), " + lc.name + " (max)"
}
return lc.name
}