cosmos-sdk/x/bank/simulation/genesis.go
2024-09-19 07:20:41 +00:00

102 lines
4.4 KiB
Go

package simulation
import (
"math/rand"
sdkmath "cosmossdk.io/math"
"cosmossdk.io/x/bank/types"
sdk "github.com/cosmos/cosmos-sdk/types"
"github.com/cosmos/cosmos-sdk/types/module"
)
// KeyDefaultSendEnabled is store's key for the DefaultSendEnabled option
var KeyDefaultSendEnabled = []byte("DefaultSendEnabled")
// RandomGenesisDefaultSendEnabledParam computes randomized allow all send transfers param for the bank module
func RandomGenesisDefaultSendEnabledParam(r *rand.Rand) bool {
// 90% chance of transfers being enabled or P(a) = 0.9 for success
return r.Int63n(100) < 90
}
// RandomGenesisSendEnabled creates randomized values for the SendEnabled slice.
func RandomGenesisSendEnabled(r *rand.Rand, bondDenom string) []types.SendEnabled {
rv := make([]types.SendEnabled, 0, 2)
// 60% of the time, add a denom specific record.
if r.Int63n(100) < 60 {
// 75% of the those times, set send enabled to true.
bondEnabled := r.Int63n(100) < 75
rv = append(rv, types.SendEnabled{Denom: bondDenom, Enabled: bondEnabled})
}
// Probabilities:
// P(a) = 60.0% = There's SendEnable entry for the bond denom = .600
// P(a)' = 40.0% = There is NOT a SendEnable entry for the bond denom = 1 - P(a) = 1 - .600 = .400
// P(b) = 75.0% = The SendEnable entry is true (if there is such an entry) = .750
// P(b)' = 25.0% = The SendEnable entry is false (if there is such an entry) = 1 - P(b) = 1 - .750 = .250
// P(c) = 90.0% = The default send enabled is true (defined in RandomGenesisDefaultSendEnabledParam) = .900
// P(c)' = 10.0% = The default send enabled is false = 1 - P(c) = 1 - .900 = .100
//
// P(st) = 45.0% = There's a SendEnable entry that's true = P(a)*P(b) = .600*.750 = .450
// P(sf) = 15.0% = There's a SendEnable entry that's false = P(a)*P(b)' = .600*.250 = .150
//
// P(a'c) = 36.0% = No SendEnabled entry AND default is true = P(a)'*P(c) = .400*.900 = .360
// P(a'c') = 4.0% = No SendEnabled entry AND default is false = P(a)'*P(c)' = .400*.100 = .040
// P(stc) = 40.5% = SendEnabled entry is true AND default is true = P(st)*P(c) = .450*.900 = .405
// P(stc') = 4.5% = SendEnabled entry is true AND default is false = P(st)*P(c)' = .450*.100 = .045
// P(sfc) = 13.5% = SendEnabled entry is false AND default is true = P(sf)*P(c) = .150*.900 = .135
// P(sfc') = 1.5% = SendEnabled entry is false AND default is false = P(sf)*P(c)' = .150*.100 = .015
//
// P(set) = 42.0% = SendEnabled entry that equals the default = P(stc) + P(sfc') = .405 + .015 = .420
// P(sef) = 18.0% = SendEnabled entry that does not equal the default = P(stc') + P(sfc) = .045 + .135 = .180
//
// P(t) = 81.0% = Bond denom is sendable = P(a'c) + P(st) = .360 + .450 = .810
// P(f) = 19.0% = Bond denom is NOT sendable = P(a'c') + P(sf) = .040 + .150 = .190
return rv
}
// RandomGenesisBalances returns a slice of account balances. Each account has
// a balance of simState.InitialStake for simState.BondDenom.
func RandomGenesisBalances(simState *module.SimulationState) ([]types.Balance, error) {
genesisBalances := []types.Balance{}
for _, acc := range simState.Accounts {
addr, err := simState.AddressCodec.BytesToString(acc.Address)
if err != nil {
return nil, err
}
genesisBalances = append(genesisBalances, types.Balance{
Address: addr,
Coins: sdk.NewCoins(sdk.NewCoin(simState.BondDenom, simState.InitialStake)),
})
}
return genesisBalances, nil
}
// RandomizedGenState generates a random GenesisState for bank
func RandomizedGenState(simState *module.SimulationState) {
var defaultSendEnabledParam bool
simState.AppParams.GetOrGenerate(string(KeyDefaultSendEnabled), &defaultSendEnabledParam, simState.Rand, func(r *rand.Rand) { defaultSendEnabledParam = RandomGenesisDefaultSendEnabledParam(r) })
sendEnabled := RandomGenesisSendEnabled(simState.Rand, simState.BondDenom)
numAccs := int64(len(simState.Accounts))
totalSupply := simState.InitialStake.Mul(sdkmath.NewInt((numAccs + simState.NumBonded)))
supply := sdk.NewCoins(sdk.NewCoin(simState.BondDenom, totalSupply))
balances, err := RandomGenesisBalances(simState)
if err != nil {
panic(err)
}
bankGenesis := types.GenesisState{
Params: types.NewParams(defaultSendEnabledParam),
Balances: balances,
Supply: supply,
SendEnabled: sendEnabled,
}
simState.GenState[types.ModuleName] = simState.Cdc.MustMarshalJSON(&bankGenesis)
}