mirror of
https://github.com/nspcc-dev/neo-go.git
synced 2024-12-11 15:30:07 +00:00
a1e3655560
neo-storm has developed more wrappers for syscall APIs, so they can and should be used as a drop-in replacement for pkg/vm/api. Moving it out of vm, as it's not exactly related to the VM itself.
95 lines
2.2 KiB
Go
95 lines
2.2 KiB
Go
package nep5
|
|
|
|
import (
|
|
"github.com/CityOfZion/neo-go/pkg/interop/engine"
|
|
"github.com/CityOfZion/neo-go/pkg/interop/runtime"
|
|
"github.com/CityOfZion/neo-go/pkg/interop/storage"
|
|
"github.com/CityOfZion/neo-go/pkg/interop/util"
|
|
)
|
|
|
|
// Token holds all token info
|
|
type Token struct {
|
|
// Token name
|
|
Name string
|
|
// Ticker symbol
|
|
Symbol string
|
|
// Amount of decimals
|
|
Decimals int
|
|
// Token owner address
|
|
Owner []byte
|
|
// Total tokens * multiplier
|
|
TotalSupply int
|
|
// Storage key for circulation value
|
|
CirculationKey string
|
|
}
|
|
|
|
// GetSupply gets the token totalSupply value from VM storage
|
|
func (t Token) GetSupply(ctx storage.Context) interface{} {
|
|
return storage.Get(ctx, t.CirculationKey)
|
|
}
|
|
|
|
// BalanceOf gets the token balance of a specific address
|
|
func (t Token) BalanceOf(ctx storage.Context, hodler []byte) interface{} {
|
|
return storage.Get(ctx, hodler)
|
|
}
|
|
|
|
// Transfer token from one user to another
|
|
func (t Token) Transfer(ctx storage.Context, from []byte, to []byte, amount int) bool {
|
|
amountFrom := t.CanTransfer(ctx, from, to, amount)
|
|
if amountFrom == -1 {
|
|
return false
|
|
}
|
|
|
|
if amountFrom == 0 {
|
|
storage.Delete(ctx, from)
|
|
}
|
|
|
|
if amountFrom > 0 {
|
|
diff := amountFrom - amount
|
|
storage.Put(ctx, from, diff)
|
|
}
|
|
|
|
amountTo := storage.Get(ctx, to).(int)
|
|
totalAmountTo := amountTo + amount
|
|
storage.Put(ctx, to, totalAmountTo)
|
|
runtime.Notify("transfer", from, to, amount)
|
|
return true
|
|
}
|
|
|
|
// CanTransfer returns the amount it can transfer
|
|
func (t Token) CanTransfer(ctx storage.Context, from []byte, to []byte, amount int) int {
|
|
if len(to) != 20 && !IsUsableAddress(from) {
|
|
return -1
|
|
}
|
|
|
|
amountFrom := storage.Get(ctx, from).(int)
|
|
if amountFrom < amount {
|
|
return -1
|
|
}
|
|
|
|
// Tell Transfer the result is equal - special case since it uses Delete
|
|
if amountFrom == amount {
|
|
return 0
|
|
}
|
|
|
|
// return amountFrom value back to Transfer, reduces extra Get
|
|
return amountFrom
|
|
}
|
|
|
|
// IsUsableAddress checks if the sender is either the correct NEO address or SC address
|
|
func IsUsableAddress(addr []byte) bool {
|
|
if len(addr) == 20 {
|
|
|
|
if runtime.CheckWitness(addr) {
|
|
return true
|
|
}
|
|
|
|
// Check if a smart contract is calling scripthash
|
|
callingScriptHash := engine.GetCallingScriptHash()
|
|
if util.Equals(callingScriptHash, addr) {
|
|
return true
|
|
}
|
|
}
|
|
|
|
return false
|
|
}
|