61 lines
1.6 KiB
Go
61 lines
1.6 KiB
Go
package mock
|
|
|
|
import (
|
|
"math/big"
|
|
"math/rand"
|
|
|
|
sdk "github.com/cosmos/cosmos-sdk/types"
|
|
)
|
|
|
|
// BigInterval is a representation of the interval [lo, hi), where
|
|
// lo and hi are both of type sdk.Int
|
|
type BigInterval struct {
|
|
lo sdk.Int
|
|
hi sdk.Int
|
|
}
|
|
|
|
// RandFromBigInterval chooses an interval uniformly from the provided list of
|
|
// BigIntervals, and then chooses an element from an interval uniformly at random.
|
|
func RandFromBigInterval(r *rand.Rand, intervals []BigInterval) sdk.Int {
|
|
if len(intervals) == 0 {
|
|
return sdk.ZeroInt()
|
|
}
|
|
|
|
interval := intervals[r.Intn(len(intervals))]
|
|
|
|
lo := interval.lo
|
|
hi := interval.hi
|
|
|
|
diff := hi.Sub(lo)
|
|
result := sdk.NewIntFromBigInt(new(big.Int).Rand(r, diff.BigInt()))
|
|
result = result.Add(lo)
|
|
|
|
return result
|
|
}
|
|
|
|
// shamelessly copied from https://stackoverflow.com/questions/22892120/how-to-generate-a-random-string-of-a-fixed-length-in-golang#31832326
|
|
|
|
const letterBytes = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
|
|
const (
|
|
letterIdxBits = 6 // 6 bits to represent a letter index
|
|
letterIdxMask = 1<<letterIdxBits - 1 // All 1-bits, as many as letterIdxBits
|
|
letterIdxMax = 63 / letterIdxBits // # of letter indices fitting in 63 bits
|
|
)
|
|
|
|
func RandStringOfLength(r *rand.Rand, n int) string {
|
|
b := make([]byte, n)
|
|
// A src.Int63() generates 63 random bits, enough for letterIdxMax characters!
|
|
for i, cache, remain := n-1, r.Int63(), letterIdxMax; i >= 0; {
|
|
if remain == 0 {
|
|
cache, remain = r.Int63(), letterIdxMax
|
|
}
|
|
if idx := int(cache & letterIdxMask); idx < len(letterBytes) {
|
|
b[i] = letterBytes[idx]
|
|
i--
|
|
}
|
|
cache >>= letterIdxBits
|
|
remain--
|
|
}
|
|
return string(b)
|
|
}
|