Go/GoLang check IP address in range

Question

In Go/GoLang, what is the fastest way to check if an IP address is in a specific range?

For example, given range 216.14.49.184 to 216.14.49.191

Answer 1

I ported over the code from a C# example found here: https://stackoverflow.com/a/2138724/1655418

And for some reason it ends up being 1ms faster than Nick's solution.

My question was for the "fastest" way, so I figured I'd post mine and see what the community thinks.

package iptesting

import (
    "fmt"
    "testing"
    "net"
    "time"
    "bytes"
)

func TestIPRangeTime(t *testing.T) {
    lowerBytes := net.ParseIP("216.14.49.184").To4()
    upperBytes := net.ParseIP("216.14.49.191").To4()
    inputBytes := net.ParseIP("216.14.49.184").To4()

    startTime := time.Now()
    for i := 0; i < 27000; i++ {
        IsInRange(inputBytes, lowerBytes, upperBytes)
    }
    endTime := time.Now()

    fmt.Println("ELAPSED time port: ", endTime.Sub(startTime))

    lower := net.ParseIP("216.14.49.184")
    upper := net.ParseIP("216.14.49.191")
    trial := net.ParseIP("216.14.49.184")

    startTime = time.Now()
    for i := 0; i < 27000; i++ {
        IsInRange2(trial, lower, upper)
    }
    endTime = time.Now()

    fmt.Println("ELAPSED time bytescompare: ", endTime.Sub(startTime))
}

func IsInRange2(trial net.IP, lower net.IP, upper net.IP) bool {
    if bytes.Compare(trial, lower) >= 0 && bytes.Compare(trial, upper) <= 0 {
        return true
    }
    return false
}

func IsInRange(ip []byte, lower []byte, upper []byte) bool {
    //fmt.Printf("given ip len: %d\n", len(ip))
    lowerBoundary := true
    upperBoundary := true
    for i := 0; i < len(lower) && (lowerBoundary || upperBoundary); i++ {
        if lowerBoundary && ip[i] < lower[i] || upperBoundary && ip[i] > upper[i] {
            return false
        }

        if ip[i] == lower[i] {
            if lowerBoundary {
                lowerBoundary = true
            } else {
                lowerBoundary = false
            }
            //lowerBoundary &= true
        } else {
            lowerBoundary = false
            //lowerBoundary &= false
        }

        if ip[i] == upper[i] {
            //fmt.Printf("matched upper\n")
            if upperBoundary {
                upperBoundary = true
            } else {
                upperBoundary = false
            }
            //upperBoundary &= true
        } else {
            upperBoundary = false
            //upperBoundary &= false
        }
    }
    return true
}

My results:

=== RUN TestIPRangeTime
ELAPSED time port:  1.0001ms
ELAPSED time bytescompare:  2.0001ms
--- PASS: TestIPRangeTime (0.00 seconds)

=== RUN TestIPRangeTime
ELAPSED time port:  1ms
ELAPSED time bytescompare:  2.0002ms
--- PASS: TestIPRangeTime (0.00 seconds)

=== RUN TestIPRangeTime
ELAPSED time port:  1.0001ms
ELAPSED time bytescompare:  2.0001ms
--- PASS: TestIPRangeTime (0.00 seconds)

=== RUN TestIPRangeTime
ELAPSED time port:  1.0001ms
ELAPSED time bytescompare:  2.0001ms
--- PASS: TestIPRangeTime (0.00 seconds)