Merge PR #3621: module inter-dependency cleanup

types/invariant.go

@@ -0,0 +1,10 @@
+package types
+
+// An Invariant is a function which tests a particular invariant.
+// If the invariant has been broken, it should return an error
+// containing a descriptive message about what happened.
+// The simulator will then halt and print the logs.
+type Invariant func(ctx Context) error
+
+// group of Invarient
+type Invariants []Invariant

types/stake.go

@@ -1,6 +1,8 @@
 package types
 
 import (
+	"math/big"
+
 	abci "github.com/tendermint/tendermint/abci/types"
 	"github.com/tendermint/tendermint/crypto"
 )
@@ -8,11 +10,21 @@ import (
 // status of a validator
 type BondStatus byte
 
-// nolint
+// staking constants
 const (
 	Unbonded  BondStatus = 0x00
 	Unbonding BondStatus = 0x01
 	Bonded    BondStatus = 0x02
+
+	// default bond denomination
+	DefaultBondDenom = "stake"
+
+	// Delay, in blocks, between when validator updates are returned to Tendermint and when they are applied.
+	// For example, if this is 0, the validator set at the end of a block will sign the next block, or
+	// if this is 1, the validator set at the end of a block will sign the block after the next.
+	// Constant as this should not change without a hard fork.
+	// TODO: Link to some Tendermint docs, this is very unobvious.
+	ValidatorUpdateDelay int64 = 1
 )
 
 //BondStatusToString for pretty prints of Bond Status
@@ -29,6 +41,19 @@ func BondStatusToString(b BondStatus) string {
 	}
 }
 
+// PowerReduction is the amount of staking tokens required for 1 unit of Tendermint power
+var PowerReduction = NewIntFromBigInt(new(big.Int).Exp(big.NewInt(10), big.NewInt(6), nil))
+
+// TokensToTendermintPower - convert input tokens to potential tendermint power
+func TokensToTendermintPower(tokens Int) int64 {
+	return (tokens.Div(PowerReduction)).Int64()
+}
+
+// TokensFromTendermintPower - convert input power to tokens
+func TokensFromTendermintPower(power int64) Int {
+	return NewInt(power).Mul(PowerReduction)
+}
+
 // nolint
 func (b BondStatus) Equal(b2 BondStatus) bool {
 	return byte(b) == byte(b2)