idgenerator/Go/source/core/snowWorkerM1.go

/*
 * 版权属于：yitter(yitter@126.com)
 * 代码编辑：guoyahao
 * 代码修订：yitter
 * 开源地址：https://gitee.com/yitter/idgenerator
 */
package core

import (
	"math"
	"sync"
	"time"
	"yitidgen/contract"
)

type SnowWorkerM1 struct {
	BaseTime                int64  //基础时间
	WorkerId                uint16 //机器码
	WorkerIdBitLength       byte   //机器码位长
	SeqBitLength            byte   //自增序列数位长
	MaxSeqNumber            uint32 //最大序列数（含）
	MinSeqNumber            uint32 //最小序列数（含）
	TopOverCostCount        uint   //最大漂移次数
	_TimestampShift         byte
	_CurrentSeqNumber       uint32
	_LastTimeTick           int64
	_TurnBackTimeTick       int64
	_TurnBackIndex          byte
	_IsOverCost             bool
	_OverCostCountInOneTerm uint
	_GenCountInOneTerm      uint
	_TermIndex              uint
	sync.Mutex
}

func NewSnowWorkerM1(options *contract.IdGeneratorOptions) contract.ISnowWorker {
	var WorkerIdBitLength byte
	var SeqBitLength byte
	var MaxSeqNumber uint32

	var WorkerId = options.WorkerId

	if options.WorkerIdBitLength == 0 {
		WorkerIdBitLength = 6
	} else {
		WorkerIdBitLength = options.WorkerIdBitLength
	}
	if options.SeqBitLength == 0 {
		SeqBitLength = 6
	} else {
		SeqBitLength = options.SeqBitLength
	}
	if options.MaxSeqNumber > 0 {
		MaxSeqNumber = options.MaxSeqNumber
	} else {
		MaxSeqNumber = uint32(math.Pow(2, float64(options.SeqBitLength))) - 1
	}
	var MinSeqNumber = options.MinSeqNumber
	var TopOverCostCount = options.TopOverCostCount

	var BaseTime int64
	if options.BaseTime != 0 {
		BaseTime = options.BaseTime
	} else {
		BaseTime = 1582136402000
	}
	timestampShift := (byte)(options.WorkerIdBitLength + options.SeqBitLength)
	currentSeqNumber := options.MinSeqNumber
	return &SnowWorkerM1{
		BaseTime:          BaseTime,
		WorkerId:          WorkerId,
		WorkerIdBitLength: WorkerIdBitLength,
		SeqBitLength:      SeqBitLength,
		MaxSeqNumber:      MaxSeqNumber,
		MinSeqNumber:      MinSeqNumber,
		TopOverCostCount:  TopOverCostCount,
		_TimestampShift:   timestampShift,
		_CurrentSeqNumber: currentSeqNumber}
}

func (m1 *SnowWorkerM1) DoGenIdAction(arg *contract.OverCostActionArg) {

}

func (m1 *SnowWorkerM1) BeginOverCostAction(useTimeTick int64) {

}

func (m1 *SnowWorkerM1) EndOverCostAction(useTimeTick int64) {
	if m1._TermIndex > 10000 {
		m1._TermIndex = 0
	}
}

func (m1 *SnowWorkerM1) BeginTurnBackAction(useTimeTick int64) {

}

func (m1 *SnowWorkerM1) EndTurnBackAction(useTimeTick int64) {

}

func (m1 *SnowWorkerM1) NextOverCostId() uint64 {
	currentTimeTick := m1.GetCurrentTimeTick()
	if currentTimeTick > m1._LastTimeTick {
		m1.EndOverCostAction(currentTimeTick)
		m1._LastTimeTick = currentTimeTick
		m1._CurrentSeqNumber = m1.MinSeqNumber
		m1._IsOverCost = false
		m1._OverCostCountInOneTerm = 0
		m1._GenCountInOneTerm = 0
		return m1.CalcId(m1._LastTimeTick)
	}
	if m1._OverCostCountInOneTerm >= m1.TopOverCostCount {
		m1.EndOverCostAction(currentTimeTick)
		m1._LastTimeTick = m1.GetNextTimeTick()
		m1._CurrentSeqNumber = m1.MinSeqNumber
		m1._IsOverCost = false
		m1._OverCostCountInOneTerm = 0
		m1._GenCountInOneTerm = 0
		return m1.CalcId(m1._LastTimeTick)
	}
	if m1._CurrentSeqNumber > m1.MaxSeqNumber {
		m1._LastTimeTick++
		m1._CurrentSeqNumber = m1.MinSeqNumber
		m1._IsOverCost = true
		m1._OverCostCountInOneTerm++
		m1._GenCountInOneTerm++

		return m1.CalcId(m1._LastTimeTick)
	}
	m1._GenCountInOneTerm++
	return m1.CalcId(m1._LastTimeTick)
}

func (m1 *SnowWorkerM1) NextNormalId() uint64 {
	currentTimeTick := m1.GetCurrentTimeTick()
	if currentTimeTick < m1._LastTimeTick {
		if m1._TurnBackTimeTick < 1 {
			m1._TurnBackTimeTick = m1._LastTimeTick - 1
			m1._TurnBackIndex++
			// 每毫秒序列数的前5位是预留位，0用于手工新值，1-4是时间回拨次序
			// 最多4次回拨（防止回拨重叠）
			if m1._TurnBackIndex > 4 {
				m1._TurnBackIndex = 1
			}
			m1.BeginTurnBackAction(m1._TurnBackTimeTick)
		}
		time.Sleep(time.Duration(10) * time.Millisecond)
		return m1.CalcTurnBackId(m1._TurnBackTimeTick)
	}
	// 时间追平时，_TurnBackTimeTick清零
	if m1._TurnBackTimeTick > 0 {
		m1.EndTurnBackAction(m1._TurnBackTimeTick)
		m1._TurnBackTimeTick = 0
	}
	if currentTimeTick > m1._LastTimeTick {
		m1._LastTimeTick = currentTimeTick
		m1._CurrentSeqNumber = m1.MinSeqNumber
		return m1.CalcId(m1._LastTimeTick)
	}
	if m1._CurrentSeqNumber > m1.MaxSeqNumber {
		m1.BeginOverCostAction(currentTimeTick)
		m1._TermIndex++
		m1._LastTimeTick++
		m1._CurrentSeqNumber = m1.MinSeqNumber
		m1._IsOverCost = true
		m1._OverCostCountInOneTerm = 1
		m1._GenCountInOneTerm = 1

		return m1.CalcId(m1._LastTimeTick)
	}
	return m1.CalcId(m1._LastTimeTick)
}

func (m1 *SnowWorkerM1) CalcId(useTimeTick int64) uint64 {
	result := uint64(useTimeTick<<m1._TimestampShift) + uint64(m1.WorkerId<<m1.SeqBitLength) + uint64(m1._CurrentSeqNumber)
	m1._CurrentSeqNumber++
	return result
}

func (m1 *SnowWorkerM1) CalcTurnBackId(useTimeTick int64) uint64 {
	result := uint64(useTimeTick<<m1._TimestampShift) + uint64(m1.WorkerId<<m1.SeqBitLength) + uint64(m1._TurnBackIndex)
	m1._TurnBackTimeTick--
	return result
}

func (m1 *SnowWorkerM1) GetCurrentTimeTick() int64 {
	var millis = time.Now().UnixNano() / 1e6
	return millis - m1.BaseTime
}

func (m1 *SnowWorkerM1) GetNextTimeTick() int64 {
	tempTimeTicker := m1.GetCurrentTimeTick()
	for tempTimeTicker <= m1._LastTimeTick {
		tempTimeTicker = m1.GetCurrentTimeTick()
	}
	return tempTimeTicker
}

func (m1 *SnowWorkerM1) NextId() uint64 {
	m1.Lock()
	defer m1.Unlock()
	if m1._IsOverCost {
		return m1.NextOverCostId()
	} else {
		return m1.NextNormalId()
	}
}