chore: change CompareBytes to EqualBytes (CityOfZion/neo-storm#22)

* chore: change CompareBytes to EqualBytes

* chore: remove trailing spaces

* chore: rename EqualBytes to Equals

Imported from CityOfZion/neo-storm (da16e967d9631e132488731a42966bccb5ad7f30).

examples/token/nep5/nep5.go

@@ -4,6 +4,7 @@ import (
 	"github.com/CityOfZion/neo-storm/interop/engine"
 	"github.com/CityOfZion/neo-storm/interop/runtime"
 	"github.com/CityOfZion/neo-storm/interop/storage"
+	"github.com/CityOfZion/neo-storm/interop/util"
 )
 
 // Token holds all token info
@@ -85,28 +86,10 @@ func IsUsableAddress(addr []byte) bool {
 
 		// Check if a smart contract is calling scripthash
 		callingScriptHash := engine.GetCallingScriptHash()
-		if EqualAddresses(callingScriptHash, addr) {
+		if util.Equals(callingScriptHash, addr) {
 			return true
 		}
 	}
 
 	return false
 }
-
-// EqualAddresses compares two addresses if they're equal
-// also returns false if one of the two - or both - aren't actual addresses
-func EqualAddresses(a []byte, b []byte) bool {
-	aLen := len(a)
-	bLen := len(b)
-	if aLen != bLen || aLen != 20 || bLen != 20 {
-		return false
-	}
-
-	for i := 0; i < aLen; i++ {
-		if a[i] != b[i] {
-			return false
-		}
-	}
-
-	return true
-}

examples/token/token/token.go

@@ -1,97 +0,0 @@
-package token
-
-import (
-	"github.com/CityOfZion/neo-storm/interop/engine"
-	"github.com/CityOfZion/neo-storm/interop/runtime"
-	"github.com/CityOfZion/neo-storm/interop/storage"
-	"github.com/CityOfZion/neo-storm/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
-}
-
-// TODO: Transfer event
-// DoTransfer := action.RegisterAction("transfer", "from", "to", "amount")
-
-// 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)
-	// DoTransfer(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.CompareBytes(callingScriptHash, addr) {
-			return true
-		}
-	}
-
-	return false
-}

interop/util/util.go

@@ -5,8 +5,8 @@ func FromAddress(address string) []byte {
 	return nil
 }
 
-// CompareBytes compares a with b and will return true whether a and b
+// Equals compares a with b and will return true whether a and b
 // are equal.
-func CompareBytes(a, b []byte) bool {
+func Equals(a, b interface{}) bool {
 	return false
 }

pkg/vm/compiler/analysis.go

@@ -14,7 +14,7 @@ var (
 	builtinFuncs = []string{
 		"len", "append", "SHA256",
 		"SHA1", "Hash256", "Hash160",
-		"FromAddress", "CompareBytes",
+		"FromAddress", "Equals",
 	}
 )
 

pkg/vm/compiler/codegen.go

@@ -571,7 +571,7 @@ func (c *codegen) convertBuiltin(expr *ast.CallExpr) {
 		emitOpcode(c.prog, vm.HASH256)
 	case "Hash160":
 		emitOpcode(c.prog, vm.HASH160)
-	case "CompareBytes":
+	case "Equals":
 		emitOpcode(c.prog, vm.EQUAL)
 	case "FromAddress":
 		// We can be sure that this is a ast.BasicLit just containing a simple