上一篇中实现了延迟触发器，开发过程中还有另外一种按照日期触发的需求，例如：
注意：
需要用到上一篇文章中的Job接口
1、每天晚上8点开始某个活动
2、每整点执行某些操作等
首先我们要用到cron格式解析，对应git地址
https://github.com/rfyiamcool/cronlib
下面是直接搬家的cronlib源代码
package timer
//
// crontab parser import from https://github.com/robfig/cron/blob/master/parser.go
//
import (
"fmt"
"math"
"strconv"
"strings"
"time"
)
// ConstantDelaySchedule represents a simple recurring duty cycle, e.g. "Every 5 minutes".
// It does not support jobs more frequent than once a second.
type ConstantDelaySchedule struct {
Delay time.Duration
}
// Every returns a crontab Schedule that activates once every duration.
// Delays of less than a second are not supported (will round up to 1 second).
// Any fields less than a Second are truncated.
//@return ConstantDelaySchedule{}
func Every(duration time.Duration) ConstantDelaySchedule {
if duration < time.Second {
duration = time.Second
}
return ConstantDelaySchedule{
Delay: duration - time.Duration(duration.Nanoseconds())%time.Second,
}
}
// Next returns the next time this should be run.
// This rounds so that the next activation time will be on the second.
//@return time.Now()
func (schedule ConstantDelaySchedule) Next(t time.Time) time.Time {
return t.Add(schedule.Delay - time.Duration(t.Nanosecond())*time.Nanosecond)
}
// The Schedule describes a job's duty cycle.
type TimeRunner interface {
// Return the next activation time, later than the given time.
// Next is invoked initially, and then each time the job is run.
Next(time.Time) time.Time
}
// SpecSchedule specifies a duty cycle (to the second granularity), based on a
// traditional crontab specification. It is computed initially and stored as bit sets.
type SpecSchedule struct {
Second, Minute, Hour, Dom, Month, Dow uint64
}
// bounds provides a range of acceptable values (plus a map of name to value).
type bounds struct {
min, max uint
names map[string]uint
}
// The bounds for each field.
var (
seconds = bounds{0, 59, nil}
minutes = bounds{0, 59, nil}
hours = bounds{0, 23, nil}
dom = bounds{1, 31, nil}
months = bounds{1, 12, map[string]uint{
"jan": 1,
"feb": 2,
"mar": 3,
"apr": 4,
"may": 5,
"jun": 6,
"jul": 7,
"aug": 8,
"sep": 9,
"oct": 10,
"nov": 11,
"dec": 12,
}}
dow = bounds{0, 6, map[string]uint{
"sun": 0,
"mon": 1,
"tue": 2,
"wed": 3,
"thu": 4,
"fri": 5,
"sat": 6,
}}
)
const (
// Set the top bit if a star was included in the expression.
starBit = 1 << 63
)
// Next returns the next time this schedule is activated, greater than the given
// time. If no time can be found to satisfy the schedule, return the zero time.
//@return time.Now()
func (s *SpecSchedule) Next(t time.Time) time.Time {
// General approach:
// For Month, Day, Hour, Minute, Second:
// Check if the time value matches. If yes, continue to the next field.
// If the field doesn't match the schedule, then increment the field until it matches.
// While incrementing the field, a wrap-around brings it back to the beginning
// of the field list (since it is necessary to re-verify previous field
// values)
// Start at the earliest possible time (the upcoming second).
t = t.Add(1*time.Second - time.Duration(t.Nanosecond())*time.Nanosecond)
// This flag indicates whether a field has been incremented.
added := false
// If no time is found within five years, return zero.
yearLimit := t.Year() + 5
WRAP:
if t.Year() > yearLimit {
return time.Time{}
}
// Find the first applicable month.
// If it's this month, then do nothing.
for 1<<uint(t.Month())&s.Month == 0 {
// If we have to add a month, reset the other parts to 0.
if !added {
added = true
// Otherwise, set the date at the beginning (since the current time is irrelevant).
t = time.Date(t.Year(), t.Month(), 1, 0, 0, 0, 0, t.Location())
}
t = t.AddDate(0, 1, 0)
// Wrapped around.
if t.Month() == time.January {
goto WRAP
}
}
// Now get a day in that month.
for !dayMatches(s, t) {
if !added {
added = true
t = time.Date(t.Year(), t.Month(), t.Day(), 0, 0, 0, 0, t.Location())
}
t = t.AddDate(0, 0, 1)
if t.Day() == 1 {
goto WRAP
}
}
for 1<<uint(t.Hour())&s.Hour == 0 {
if !added {
added = true
t = time.Date(t.Year(), t.Month(), t.Day(), t.Hour(), 0, 0, 0, t.Location())
}
t = t.Add(1 * time.Hour)
if t.Hour() == 0 {
goto WRAP
}
}
for 1<<uint(t.Minute())&s.Minute == 0 {
if !added {
added = true
t = t.Truncate(time.Minute)
}
t = t.Add(1 * time.Minute)
if t.Minute() == 0 {
goto WRAP
}
}
for 1<<uint(t.Second())&s.Second == 0 {
if !added {
added = true
t = t.Truncate(time.Second)
}
t = t.Add(1 * time.Second)
if t.Second() == 0 {
goto WRAP
}
}
return t
}
// dayMatches returns true if the schedule's day-of-week and day-of-month
// restrictions are satisfied by the given time.
//@return false
func dayMatches(s *SpecSchedule, t time.Time) bool {
var (
domMatch bool = 1<<uint(t.Day())&s.Dom > 0
dowMatch bool = 1<<uint(t.Weekday())&s.Dow > 0
)
if s.Dom&starBit > 0 || s.Dow&starBit > 0 {
return domMatch && dowMatch
}
return domMatch || dowMatch
}
// Configuration options for creating a parser. Most options specify which
// fields should be included, while others enable features. If a field is not
// included the parser will assume a default value. These options do not change
// the order fields are parse in.
type ParseOption int
const (
Second ParseOption = 1 << iota // Seconds field, default 0
Minute // Minutes field, default 0
Hour // Hours field, default 0
Dom // Day of month field, default *
Month // Month field, default *
Dow // Day of week field, default *
DowOptional // Optional day of week field, default *
Descriptor // Allow descriptors such as @monthly, @weekly, etc.
)
var places = []ParseOption{
Second,
Minute,
Hour,
Dom,
Month,
Dow,
}
var defaults = []string{
"0",
"0",
"0",
"*",
"*",
"*",
}
// A custom Parser that can be configured.
type Parser struct {
options ParseOption
optionals int
}
// Creates a custom Parser with custom options.
//
// // Standard parser without descriptors
// specParser := NewParser(Minute | Hour | Dom | Month | Dow)
// sched, err := specParser.Parse("0 0 15 */3 *")
//
// // Same as above, just excludes time fields
// subsParser := NewParser(Dom | Month | Dow)
// sched, err := specParser.Parse("15 */3 *")
//
// // Same as above, just makes Dow optional
// subsParser := NewParser(Dom | Month | DowOptional)
// sched, err := specParser.Parse("15 */3")
//
//@return Parser{}
func NewParser(options ParseOption) Parser {
optionals := 0
if options&DowOptional > 0 {
options |= Dow
optionals++
}
return Parser{options, optionals}
}
// Parse returns a new crontab schedule representing the given spec.
// It returns a descriptive error if the spec is not valid.
// It accepts crontab specs and features configured by NewParser.
//@return nil,nil
func (p Parser) Parse(spec string) (TimeRunner, error) {
if len(spec) == 0 {
return nil, fmt.Errorf("Empty spec string")
}
if spec[0] == '@' && p.options&Descriptor > 0 {
return parseDescriptor(spec)
}
// Figure out how many fields we need
max := 0
for _, place := range places {
if p.options&place > 0 {
max++
}
}
min := max - p.optionals
// Split fields on whitespace
fields := strings.Fields(spec)
// Validate number of fields
if count := len(fields); count < min || count > max {
if min == max {
return nil, fmt.Errorf("Expected exactly %d fields, found %d: %s", min, count, spec)
}
return nil, fmt.Errorf("Expected %d to %d fields, found %d: %s", min, max, count, spec)
}
// Fill in missing fields
fields = expandFields(fields, p.options)
var err error
field := func(field string, r bounds) uint64 {
if err != nil {
return 0
}
var bits uint64
bits, err = getField(field, r)
return bits
}
var (
second = field(fields[0], seconds)
minute = field(fields[1], minutes)
hour = field(fields[2], hours)
dayofmonth = field(fields[3], dom)
month = field(fields[4], months)
dayofweek = field(fields[5], dow)
)
if err != nil {
return nil, err
}
return &SpecSchedule{
Second: second,
Minute: minute,
Hour: hour,
Dom: dayofmonth,
Month: month,
Dow: dayofweek,
}, nil
}
//@return nil
func expandFields(fields []string, options ParseOption) []string {
n := 0
count := len(fields)
expFields := make([]string, len(places))
copy(expFields, defaults)
for i, place := range places {
if options&place > 0 {
expFields[i] = fields[n]
n++
}
if n == count {
break
}
}
return expFields
}
var standardParser = NewParser(
Minute | Hour | Dom | Month | Dow | Descriptor,
)
// ParseStandard returns a new crontab schedule representing the given standardSpec
// (https://en.wikipedia.org/wiki/Cron). It differs from Parse requiring to always
// pass 5 entries representing: minute, hour, day of month, month and day of week,
// in that order. It returns a descriptive error if the spec is not valid.
//
// It accepts
// - Standard crontab specs, e.g. "* * * * ?"
// - Descriptors, e.g. "@midnight", "@every 1h30m"
//@return nil,nil
func ParseStandard(standardSpec string) (TimeRunner, error) {
return standardParser.Parse(standardSpec)
}
var defaultParser = NewParser(
Second | Minute | Hour | Dom | Month | DowOptional | Descriptor,
)
// Parse returns a new crontab schedule representing the given spec.
// It returns a descriptive error if the spec is not valid.
//
// It accepts
// - Full crontab specs, e.g. "* * * * * ?"
// - Descriptors, e.g. "@midnight", "@every 1h30m"
//@return nil,nil
func Parse(spec string) (TimeRunner, error) {
return defaultParser.Parse(spec)
}
// getField returns an Int with the bits set representing all of the times that
// the field represents or error parsing field value. A "field" is a comma-separated
// list of "ranges".
//@return 0,nil
func getField(field string, r bounds) (uint64, error) {
var bits uint64
ranges := strings.FieldsFunc(field, func(r rune) bool { return r == ',' })
for _, expr := range ranges {
bit, err := getRange(expr, r)
if err != nil {
return bits, err
}
bits |= bit
}
return bits, nil
}
// getRange returns the bits indicated by the given expression:
// number | number "-" number [ "/" number ]
// or error parsing range.
//@return 0,nil
func getRange(expr string, r bounds) (uint64, error) {
var (
start, end, step uint
rangeAndStep = strings.Split(expr, "/")
lowAndHigh = strings.Split(rangeAndStep[0], "-")
singleDigit = len(lowAndHigh) == 1
err error
)
var extra uint64
if lowAndHigh[0] == "*" || lowAndHigh[0] == "?" {
start = r.min
end = r.max
extra = starBit
} else {
start, err = parseIntOrName(lowAndHigh[0], r.names)
if err != nil {
return 0, err
}
switch len(lowAndHigh) {
case 1:
end = start
case 2:
end, err = parseIntOrName(lowAndHigh[1], r.names)
if err != nil {
return 0, err
}
default:
return 0, fmt.Errorf("Too many hyphens: %s", expr)
}
}
switch len(rangeAndStep) {
case 1:
step = 1
case 2:
step, err = mustParseInt(rangeAndStep[1])
if err != nil {
return 0, err
}
// Special handling: "N/step" means "N-max/step".
if singleDigit {
end = r.max
}
default:
return 0, fmt.Errorf("Too many slashes: %s", expr)
}
if start < r.min {
return 0, fmt.Errorf("Beginning of range (%d) below minimum (%d): %s", start, r.min, expr)
}
if end > r.max {
return 0, fmt.Errorf("End of range (%d) above maximum (%d): %s", end, r.max, expr)
}
if start > end {
return 0, fmt.Errorf("Beginning of range (%d) beyond end of range (%d): %s", start, end, expr)
}
if step == 0 {
return 0, fmt.Errorf("Step of range should be a positive number: %s", expr)
}
return getBits(start, end, step) | extra, nil
}
// parseIntOrName returns the (possibly-named) integer contained in expr.
//@return 0,nil
func parseIntOrName(expr string, names map[string]uint) (uint, error) {
if names != nil {
if namedInt, ok := names[strings.ToLower(expr)]; ok {
return namedInt, nil
}
}
return mustParseInt(expr)
}
// mustParseInt parses the given expression as an int or returns an error.
//@return 0,nil
func mustParseInt(expr string) (uint, error) {
num, err := strconv.Atoi(expr)
if err != nil {
return 0, fmt.Errorf("Failed to parse int from %s: %s", expr, err)
}
if num < 0 {
return 0, fmt.Errorf("Negative number (%d) not allowed: %s", num, expr)
}
return uint(num), nil
}
// getBits sets all bits in the range [min, max], modulo the given step size.
//@return 0
func getBits(min, max, step uint) uint64 {
var bits uint64
// If step is 1, use shifts.
if step == 1 {
return ^(math.MaxUint64 << (max + 1)) & (math.MaxUint64 << min)
}
// Else, use a simple loop.
for i := min; i <= max; i += step {
bits |= 1 << i
}
return bits
}
// all returns all bits within the given bounds. (plus the star bit)
//@return 0
func all(r bounds) uint64 {
return getBits(r.min, r.max, 1) | starBit
}
// parseDescriptor returns a predefined schedule for the expression, or error if none matches.
//@return nil,nil
func parseDescriptor(descriptor string) (TimeRunner, error) {
switch descriptor {
case "@yearly", "@annually":
return &SpecSchedule{
Second: 1 << seconds.min,
Minute: 1 << minutes.min,
Hour: 1 << hours.min,
Dom: 1 << dom.min,
Month: 1 << months.min,
Dow: all(dow),
}, nil
case "@monthly":
return &SpecSchedule{
Second: 1 << seconds.min,
Minute: 1 << minutes.min,
Hour: 1 << hours.min,
Dom: 1 << dom.min,
Month: all(months),
Dow: all(dow),
}, nil
case "@weekly":
return &SpecSchedule{
Second: 1 << seconds.min,
Minute: 1 << minutes.min,
Hour: 1 << hours.min,
Dom: all(dom),
Month: all(months),
Dow: 1 << dow.min,
}, nil
case "@daily", "@midnight":
return &SpecSchedule{
Second: 1 << seconds.min,
Minute: 1 << minutes.min,
Hour: 1 << hours.min,
Dom: all(dom),
Month: all(months),
Dow: all(dow),
}, nil
case "@hourly":
return &SpecSchedule{
Second: 1 << seconds.min,
Minute: 1 << minutes.min,
Hour: all(hours),
Dom: all(dom),
Month: all(months),
Dow: all(dow),
}, nil
}
const every = "@every "
if strings.HasPrefix(descriptor, every) {
duration, err := time.ParseDuration(descriptor[len(every):])
if err != nil {
return nil, fmt.Errorf("Failed to parse duration %s: %s", descriptor, err)
}
return Every(duration), nil
}
return nil, fmt.Errorf("Unrecognized descriptor: %s", descriptor)
}
下面是根据解析类进行的工具封装，同样我们以new_jobTimerLink创建管理器，通过Add函数添加任务。最终达到的效果：
//前6个字段分别表示：
// 秒钟：0-59
// 分钟：0-59
// 小时：1-23
// 日期：1-31
// 月份：1-12
// 星期：0-6（0 表示周日）
//还可以用一些特殊符号：
// *： 表示任何时刻
// ,： 表示分割，如第三段里：2,4，表示 2 点和 4 点执行
// －：表示一个段，如第三端里： 1-5，就表示 1 到 5 点
// /n : 表示每个n的单位执行一次，如第三段里，*/1, 就表示每隔 1 个小时执行一次命令。也可以写成1-23/1.
/////////////////////////////////////////////////////////
// 0/30 * * * * * 每 30 秒
// 0,30 * * * * * 每 30 秒
// 0 43 21 * * * 21:43 执行每天
// 0 15 05 * * * 05:15 执行
// 0 0 17 * * * 17:00 执行
// 0 0 17 * * 1 每周一的 17:00 执行
// 0 0,10 17 * * 0,2,3 每周日,周二,周三的 17:00和 17:10 执行
// 0 0-10 17 1 * * 毎月1日从 17:00 到 7:10 毎隔 1 分钟 执行
// 0 0 0 1,15 * 1 毎月1日和 15 日和 一日的 0:00 执行
// 0 42 4 1 * * 毎月1日的 4:42 分 执行
// 0 0 21 * * 1-6 周一到周六 21:00 执行
// 0 0,10,20,30,40,50 * * * * 每隔 10 分 执行
// 0 */10 * * * * 每隔 10 分 执行
// 0 * 1 * * * 从 1:0 到 1:59 每隔 1 分钟 执行
// 0 0 1 * * * 1:00 执行
// 0 0 */1 * * * 毎时 0 分 每隔 1 小时 执行
// 0 0 * * * * 毎时 0 分 每隔 1 小时 执行
// 0 2 8-20/3 * * * 8:02,11:02,14:02,17:02,20:02 执行
// 0 30 5 1,15 * * 1 日 和 15 日的 5:30 执行实现如下：
package timer
import (
"sync"
"sync/atomic"
"time"
)
//https://github.com/rfyiamcool/cronlib
type JobTimer struct {
Id uint64 //自己的id
Times int //次数 <=0无限循环
target TimeJob //任务
st int64 //执行时的服务器时间
pre *JobTimer //上一个
next *JobTimer //下一个
group *jobTimerLink //所属定时器
remain int //剩余次数
runner TimeRunner //时序
}
/*
时刻任务队列
辅助一系列时刻任务
每一个link有自己所属的自增id
*/
type jobTimerLink struct {
idInc uint64
stopChan chan bool //关闭用的定时器
sync.Mutex //同步锁
Head *JobTimer //头
Tail *JobTimer //尾
}
//@return nil
func new_jobTimerLink() *jobTimerLink {
link := &jobTimerLink{}
link.stopChan = make(chan bool)
link.run()
return link
}
//添加一个任务
//@return nil
func (this *jobTimerLink) Add(timeParams string, job TimeJob, ts int) *JobTimer {
cron, err := Parse(timeParams)
if err != nil {
return nil
}
tick := &JobTimer{
Id: atomic.AddUint64(&this.idInc, 1),
Times: ts,
target: job,
group: this,
runner: cron,
}
if tick.Times <= 0 {
tick.remain = -1
} else {
tick.remain = tick.Times
}
tick.st = tick.runner.Next(time.Now()).UnixNano()
this.Lock()
if this.insert(tick) {
this.Unlock()
this.restart()
return tick
}
this.Unlock()
return tick
}
//添加一个定时器
//@return false
func (this *jobTimerLink) insert(t *JobTimer) bool {
t.pre, t.next = nil, nil
if this.Tail == nil { //空队列
this.Tail = t
this.Head = t
return true
}
now := this.Tail
for now != nil && now.st > t.st {
now = now.pre
}
if now == nil { //插入到表头
this.Head.pre = t
t.next = this.Head
this.Head = t
return true
} else {
if now == this.Tail { //插入到尾
t.pre = now
now.next = t
this.Tail = t
} else { //插入到中间
next := now.next
t.pre = now
t.next = next
next.pre = t
now.next = t
}
}
return false
}
//删除一个定时器
func (this *jobTimerLink) remove(t *JobTimer) {
//TODO
}
//移除一个头
//@return nil
func (this *jobTimerLink) shift() *JobTimer {
if this.Head == nil {
return nil
}
h := this.Head
this.Head = this.Head.next
if this.Head != nil {
this.Head.pre = nil
} else {
this.Tail = nil
}
return h
}
//停止当前得
func (this *jobTimerLink) restart() {
this.stopChan <- false
}
//重启定时器
func (this *jobTimerLink) run() {
go func() {
for {
now := time.Now()
nowTime := now.UnixNano()
watiTime := nowTime
this.Lock()
if this.Head != nil {
watiTime = this.Head.st - nowTime
for watiTime <= 0 { //如果已经超时
tc := this.shift()
if tc.remain < 0 {
tc.st = tc.runner.Next(now).UnixNano()
this.insert(tc)
} else {
tc.remain--
if tc.remain > 0 {
tc.st = tc.runner.Next(now).UnixNano()
this.insert(tc)
}
}
go tc.target.RunTimeJob()
if this.Head != nil {
watiTime = this.Head.st - nowTime
} else {
break
}
}
}
if this.Head == nil {
watiTime = nowTime
}
this.Unlock()
ticker := time.NewTicker(time.Duration(watiTime))
select {
case <-ticker.C:
ticker.Stop()
ticker = nil
case flag := <-this.stopChan:
ticker.Stop()
ticker = nil
if flag {
return
}
}
}
}()
}