go实现路由表操作

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//源代码package comroutingimport (    "fmt"    "strconv"    "strings")type CRoute_S struct {    routeTable map[int]map[int]bool}func CreateCRouter() *CRoute_S {    var route CRoute_S    route.routeTable = make(map[int]map[int]bool)    var maskLen int = 0    for maskLen = 0; maskLen <= 32; maskLen++ {        route.routeTable[maskLen] = make(map[int]bool)    }    return &route}func AddCRouteItem(cr *CRoute_S, prefix string, maskLen int) bool {    if nil == cr || nil == cr.routeTable {        return false    }    rtVal := ipStr2Val(prefix)    if 0 > rtVal {        return false    }    if maskLen < 0 {        maskLen = 0    } else if maskLen > 32 {        maskLen = 32    }    rtVal = ipValMasked(rtVal, maskLen)    cr.routeTable[maskLen][rtVal] = true    return true}func DelCRouteItem(cr *CRoute_S, prefix string, maskLen int) bool {    if nil == cr || nil == cr.routeTable {        return false    }    rtVal := ipStr2Val(prefix)    if 0 > rtVal {        return false    }    if maskLen < 0 {        maskLen = 0    } else if maskLen > 32 {        maskLen = 32    }    rtVal = ipValMasked(rtVal, maskLen)    if _, bExist := cr.routeTable[maskLen][rtVal]; false == bExist {        return true    }    delete(cr.routeTable[maskLen], rtVal)    return true}func SearchCRoute(cr *CRoute_S, ip string) bool {    if nil == cr || nil == cr.routeTable {        return false    }    rtVal := ipStr2Val(ip)    if 0 > rtVal {        return false    }    var maskLen int = 0    for maskLen = 32; maskLen >= 0; maskLen-- {        tmpVal := ipValMasked(rtVal, maskLen)        if _, bExist := cr.routeTable[maskLen][tmpVal]; bExist {            fmt.Printf("SearchCRoute ip=%s match Item %s\n", ip, ipVal2Str(tmpVal))            return true        }    }    fmt.Printf("SearchCRoute ip=%s match Item fail\n", ip)    return false}func PrintCRoute(cr *CRoute_S) {    if nil == cr || nil == cr.routeTable {        return    }    var maskLen int = 0    for maskLen = 32; maskLen >= 0; maskLen-- {        if 0 == len(cr.routeTable[maskLen]) {            continue        }        fmt.Printf("maskLen=%d List As:\n", maskLen)        itemSeq := 1        for ipVal, _ := range cr.routeTable[maskLen] {            fmt.Printf("%d: %s\n", itemSeq, ipVal2Str(ipVal))            itemSeq++        }    }}func ipStr2Val(ip string) int {    segs := strings.Split(strings.TrimSpace(ip), ".")    if 4 != len(segs) {        return -1    }    ret := make([]int, 0)    for _, segx := range segs {        val, err := strconv.Atoi(segx)        if nil != err {            return -1        }        ret = append(ret, val)    }    rtVal := ret[0]<<24 + ret[1]<<16 + ret[2]<<8 + ret[3]    return rtVal}func ipVal2Str(ipVal int) string {    s1 := (ipVal & 0xff000000) >> 24    s2 := (ipVal & 0xff0000) >> 16    s3 := (ipVal & 0xff00) >> 8    s4 := (ipVal & 0xff)    return fmt.Sprintf("%d.%d.%d.%d", s1, s2, s3, s4)}func ipValMasked(ipVal int, maskLen int) int {    rtVal := (ipVal >> uint(32-maskLen)) & 0xffffffff    rtVal = rtVal << uint(32-maskLen)    return rtVal}

//测试代码package mainimport (    "common/comrouting"    "fmt")func main() {    router := comrouting.CreateCRouter()    comrouting.AddCRouteItem(router, "192.168.0.0", 16)    comrouting.AddCRouteItem(router, "192.168.1.0", 24)    comrouting.PrintCRoute(router)    ret := comrouting.SearchCRoute(router, "192.168.1.0")    fmt.Printf("ret=%v\n\n", ret)    comrouting.DelCRouteItem(router, "192.168.1.0", 24)    comrouting.PrintCRoute(router)    ret = comrouting.SearchCRoute(router, "192.168.1.0")    fmt.Printf("ret=%v\n", ret)}

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