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helper.go
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/
helper.go
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// Copyright 2020 The Swarm Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package test
import (
"fmt"
"math/rand"
"github.com/ethersphere/bee/pkg/swarm"
)
// RandomAddressAt generates a random address
// at proximity order prox relative to address.
func RandomAddressAt(self swarm.Address, prox int) swarm.Address {
addr := make([]byte, len(self.Bytes()))
copy(addr, self.Bytes())
pos := -1
if prox >= 0 {
pos = prox / 8
trans := prox % 8
transbytea := byte(0)
for j := 0; j <= trans; j++ {
transbytea |= 1 << uint8(7-j)
}
flipbyte := byte(1 << uint8(7-trans))
transbyteb := transbytea ^ byte(255)
randbyte := byte(rand.Intn(255))
addr[pos] = ((addr[pos] & transbytea) ^ flipbyte) | randbyte&transbyteb
}
for i := pos + 1; i < len(addr); i++ {
addr[i] = byte(rand.Intn(255))
}
a := swarm.NewAddress(addr)
if a.Equal(self) {
panic(fmt.Sprint(a.String(), self.String()))
}
return a
}
// RandomAddress generates a random address.
func RandomAddress() swarm.Address {
b := make([]byte, 32)
return RandomAddressAt(swarm.NewAddress(b), -1)
}