browserSpider/program/tun/roulette.go

// Proxy代理池时间轮盘切换
package main

import (
	"errors"
	"fmt"
	"sync"
	"sync/atomic"
	"time"
)

type (
	//IpItem
	IpItem struct {
		Ip       string   `json:"ip"`
		LifeTime int64    `json:"lifetime"`
		Ports    []string `json:"ports"`
		IpType   int      `json:"iptype"` //proxy 服务器类型
		Raw      string   //ip:port
		Index    int
	}
	//
	Roulette struct {
		Data   []*IpItem
		Length int32 //数据长度
		Cursor int32
		lock   *sync.RWMutex
	}
)

var (
	roulette = NewRoulette()
)

// NewRoulette
func NewRoulette() *Roulette {
	r := Roulette{lock: new(sync.RWMutex)}
	return &r
}

// Init
func (r *Roulette) Init(data []*IpItem) {
	r.lock.Lock()
	defer r.lock.Unlock()
	r.Data = data
	r.Length = int32(len(data))
	atomic.StoreInt32(&r.Cursor, 0)
}

func (r *Roulette) findOne() *IpItem {
	var pos int = 0
	if atomic.CompareAndSwapInt32(&r.Cursor, r.Length-1, 0) {
		pos = 0
	} else {
		pos = int(atomic.AddInt32(&r.Cursor, 1))
	}
	return r.Data[pos]
}

// 从时间轮中获取一个对象,不要近2分钟要过期的代理
func (r *Roulette) Get() (*IpItem, error) {
	for j := 0; j < 10000000; j++ {
		for i := 0; i < int(r.Length); i++ {
			if ip := r.findOne(); ip.LifeTime >= time.Now().Unix()+2*60 {
				return ip, nil
			} else {
				fmt.Print("O")
			}
		}
		fmt.Print("W")
		time.Sleep(20 * time.Second)
	}
	return nil, errors.New("找不到合适的代理")
}