neoneo-go/pkg/vm/vm_ops_maths.go
2019-03-28 22:28:20 +00:00

315 lines
7.6 KiB
Go

package vm
import (
"math/big"
"github.com/CityOfZion/neo-go/pkg/vm/stack"
)
// Add adds two stack Items together.
// Returns an error if either items cannot be casted to an integer
// or if integers cannot be added together
func Add(op stack.Instruction, ctx *stack.Context, istack *stack.Invocation, rstack *stack.RandomAccess) (Vmstate, error) {
operandA, operandB, err := popTwoIntegers(ctx)
if err != nil {
return FAULT, err
}
res, err := operandA.Add(operandB)
if err != nil {
return FAULT, err
}
ctx.Estack.Push(res)
return NONE, nil
}
// Sub subtracts two stack Items.
// Returns an error if either items cannot be casted to an integer
// or if integers cannot be subtracted together
func Sub(op stack.Instruction, ctx *stack.Context, istack *stack.Invocation, rstack *stack.RandomAccess) (Vmstate, error) {
operandA, operandB, err := popTwoIntegers(ctx)
if err != nil {
return FAULT, err
}
res, err := operandB.Sub(operandA)
if err != nil {
return FAULT, err
}
ctx.Estack.Push(res)
return NONE, nil
}
// Inc increments the stack Item's value by 1.
// Returns an error if the item cannot be casted to an integer
// or if 1 cannot be added to the item.
func Inc(op stack.Instruction, ctx *stack.Context, istack *stack.Invocation, rstack *stack.RandomAccess) (Vmstate, error) {
i, err := ctx.Estack.PopInt()
if err != nil {
return FAULT, err
}
one, err := stack.NewInt(big.NewInt(1))
if err != nil {
return FAULT, err
}
res, err := i.Add(one)
if err != nil {
return FAULT, err
}
ctx.Estack.Push(res)
return NONE, nil
}
// Dec decrements the stack Item's value by 1.
// Returns an error if the item cannot be casted to an integer
// or if 1 cannot be subtracted to the item.
func Dec(op stack.Instruction, ctx *stack.Context, istack *stack.Invocation, rstack *stack.RandomAccess) (Vmstate, error) {
i, err := ctx.Estack.PopInt()
if err != nil {
return FAULT, err
}
one, err := stack.NewInt(big.NewInt(1))
if err != nil {
return FAULT, err
}
res, err := i.Sub(one)
if err != nil {
return FAULT, err
}
ctx.Estack.Push(res)
return NONE, nil
}
// Div divides one stack Item by an other.
// Returns an error if either items cannot be casted to an integer
// or if the division of the integers cannot be performed.
func Div(op stack.Instruction, ctx *stack.Context, istack *stack.Invocation, rstack *stack.RandomAccess) (Vmstate, error) {
operandA, operandB, err := popTwoIntegers(ctx)
if err != nil {
return FAULT, err
}
res, err := operandB.Div(operandA)
if err != nil {
return FAULT, err
}
ctx.Estack.Push(res)
return NONE, nil
}
// Mod returns the mod of two stack Items.
// Returns an error if either items cannot be casted to an integer
// or if the mode of the integers cannot be performed.
func Mod(op stack.Instruction, ctx *stack.Context, istack *stack.Invocation, rstack *stack.RandomAccess) (Vmstate, error) {
operandA, operandB, err := popTwoIntegers(ctx)
if err != nil {
return FAULT, err
}
res, err := operandB.Mod(operandA)
if err != nil {
return FAULT, err
}
ctx.Estack.Push(res)
return NONE, nil
}
// Nz pops an integer from the stack.
// Then pushes a boolean to the stack which evaluates to true
// iff the integer was not zero.
// Returns an error if the popped item cannot be casted to an integer
// or if we cannot create a boolean.
func Nz(op stack.Instruction, ctx *stack.Context, istack *stack.Invocation, rstack *stack.RandomAccess) (Vmstate, error) {
i, err := ctx.Estack.PopInt()
if err != nil {
return FAULT, err
}
b, err := i.Boolean()
if err != nil {
return FAULT, err
}
ctx.Estack.Push(b)
return NONE, nil
}
// Mul multiplies two stack Items together.
// Returns an error if either items cannot be casted to an integer
// or if integers cannot be multiplied together.
func Mul(op stack.Instruction, ctx *stack.Context, istack *stack.Invocation, rstack *stack.RandomAccess) (Vmstate, error) {
operandA, operandB, err := popTwoIntegers(ctx)
if err != nil {
return FAULT, err
}
res, err := operandA.Mul(operandB)
if err != nil {
return FAULT, err
}
ctx.Estack.Push(res)
return NONE, nil
}
// Abs pops an integer off of the stack and pushes its absolute value onto the stack.
// Returns an error if the popped value is not an integer or if the absolute value cannot be taken
func Abs(op stack.Instruction, ctx *stack.Context, istack *stack.Invocation, rstack *stack.RandomAccess) (Vmstate, error) {
i, err := ctx.Estack.PopInt()
if err != nil {
return FAULT, err
}
a, err := i.Abs()
if err != nil {
return FAULT, err
}
ctx.Estack.Push(a)
return NONE, nil
}
// Not flips the stack Item's value.
// If the value is True, it is flipped to False and viceversa.
func Not(op stack.Instruction, ctx *stack.Context, istack *stack.Invocation, rstack *stack.RandomAccess) (Vmstate, error) {
b, err := ctx.Estack.PopBoolean()
if err != nil {
return FAULT, err
}
ctx.Estack.Push(b.Not())
return NONE, nil
}
// Sign puts the sign of the top stack Item on top of the stack.
// If value is negative, put -1;
// If positive, put 1;
// If value is zero, put 0.
func Sign(op stack.Instruction, ctx *stack.Context, istack *stack.Invocation, rstack *stack.RandomAccess) (Vmstate, error) {
i, err := ctx.Estack.PopInt()
if err != nil {
return FAULT, err
}
s := int64(i.Value().Sign())
sign, err := stack.NewInt(big.NewInt(s))
if err != nil {
return FAULT, err
}
ctx.Estack.Push(sign)
return NONE, nil
}
// Negate flips the sign of the stack Item.
func Negate(op stack.Instruction, ctx *stack.Context, istack *stack.Invocation, rstack *stack.RandomAccess) (Vmstate, error) {
i, err := ctx.Estack.PopInt()
if err != nil {
return FAULT, err
}
a := big.NewInt(0).Neg(i.Value())
b, err := stack.NewInt(a)
if err != nil {
return FAULT, err
}
ctx.Estack.Push(b)
return NONE, nil
}
func popTwoIntegers(ctx *stack.Context) (*stack.Int, *stack.Int, error) {
operandA, err := ctx.Estack.PopInt()
if err != nil {
return nil, nil, err
}
operandB, err := ctx.Estack.PopInt()
if err != nil {
return nil, nil, err
}
return operandA, operandB, nil
}
// Shl pops two integers, a and b, off of the stack and pushes an integer to the stack
// whose value is the b's value shift to the left by a's value bits.
// Returns an error if either items cannot be casted to an integer
// or if the left shift operation cannot per performed with the two integer's value.
func Shl(op stack.Instruction, ctx *stack.Context, istack *stack.Invocation, rstack *stack.RandomAccess) (Vmstate, error) {
a, b, err := popTwoIntegers(ctx)
if err != nil {
return FAULT, err
}
res, err := b.Lsh(a)
if err != nil {
return FAULT, err
}
ctx.Estack.Push(res)
return NONE, nil
}
// Shr pops two integers, a and b, off of the stack and pushes an integer to the stack
// whose value is the b's value shift to the right by a's value bits.
// Returns an error if either items cannot be casted to an integer
// or if the right shift operation cannot per performed with the two integer's value.
func Shr(op stack.Instruction, ctx *stack.Context, istack *stack.Invocation, rstack *stack.RandomAccess) (Vmstate, error) {
a, b, err := popTwoIntegers(ctx)
if err != nil {
return FAULT, err
}
res, err := b.Rsh(a)
if err != nil {
return FAULT, err
}
ctx.Estack.Push(res)
return NONE, nil
}
func popTwoByteArrays(ctx *stack.Context) (*stack.ByteArray, *stack.ByteArray, error) {
// Pop first stack item and cast as byte array
ba1, err := ctx.Estack.PopByteArray()
if err != nil {
return nil, nil, err
}
// Pop second stack item and cast as byte array
ba2, err := ctx.Estack.PopByteArray()
if err != nil {
return nil, nil, err
}
return ba1, ba2, nil
}