neo-go/pkg/vm/stack/bytearray.go

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VM: Add basic vm (#166) * VM:Add abstract stack item * VM: Add stackItems; Array, Boolean, Int and ByteArray * VM: Add tests for stack item * VM: first pass at Random Access Stack object * VM: Add Sub, Mul, Mod LSH, RSH * VM: moved test helper functions into separate file * VM: removed helper functions from stack_test.go * Add conversions for bytearray and Int stack items * Add instructions file for vm * - Add guide to stack readme - Add testReadInt64 * Add Builder * Refactor Int, Boolean, ByteArray conversion * Add Context stack Item * Add Invocation stack - convenience RAS * rename testhelper to test_helper * Move opcode file * - Add `Add` OpCode - Add Opcode Function map * - Add test for math `Add` opcode - basic opcode execution * Add popTwoIntegers convenience func * Add `SUB` Opcode * Export Context Read methods - Return errors where failable * - Add `Op` to handleOP func signature - Add PushNBytes OPcode * remove error on NewBoolean - Expose underlying with Getter on Boolean StackItem - Add Equals method for ByteArray * Make Next() method on Context failable, refactor peekContext and Peek * Add ExecuteOp, Step and Run methods on the VM * Add Equal Opcode * Add THROWIFNOT Opcode * Add RET Opcode * Refactor PushNBytes Opcode * refactor Add, Sub to return VMSTATE add popTwoByteArrays helper function * Add basic tests for vm * clarify vm states * Add astack * [VM] Pass ResultStack to the opcode handlers * [VM] refactor handlers to have rstack as argument * [Stack] - Change RemoveCurrentContext for PopCurrentContext - Add CopTo method to stack * [VM] Add Result stack Len check in simple run test * [VM] fix typo * [Peer/Stall] Change seconds to milliseconds in test
2019-03-18 21:40:21 +00:00
package stack
import (
"bytes"
"errors"
"math/big"
"strconv"
)
// ByteArray represents a slice of bytes on the stack
type ByteArray struct {
*abstractItem
val []byte
}
//NewByteArray returns a ByteArray stack item
// given a byte slice
func NewByteArray(val []byte) *ByteArray {
return &ByteArray{
&abstractItem{},
val,
}
}
//ByteArray overrides the default abstractItem Bytes array method
func (ba *ByteArray) ByteArray() (*ByteArray, error) {
return ba, nil
}
//Equals returns true, if two bytearrays are equal
func (ba *ByteArray) Equals(other *ByteArray) *Boolean {
// If either are nil, return false
if ba == nil || other == nil {
return NewBoolean(false)
}
return NewBoolean(bytes.Equal(ba.val, other.val))
}
//Integer overrides the default Integer method to convert an
// ByteArray Into an integer
func (ba *ByteArray) Integer() (*Int, error) {
dest := reverse(ba.val)
integerVal := new(big.Int).SetBytes(dest)
return NewInt(integerVal)
}
// Boolean will convert a byte array into a boolean stack item
func (ba *ByteArray) Boolean() (*Boolean, error) {
boolean, err := strconv.ParseBool(string(ba.val))
if err != nil {
return nil, errors.New("cannot convert byte array to a boolean")
}
return NewBoolean(boolean), nil
}
// XXX: move this into a pkg/util/slice folder
// Go mod not working
func reverse(b []byte) []byte {
if len(b) < 2 {
return b
}
dest := make([]byte, len(b))
for i, j := 0, len(b)-1; i < j+1; i, j = i+1, j-1 {
dest[i], dest[j] = b[j], b[i]
}
return dest
}