/
execution_context.go
73 lines (62 loc) · 2.03 KB
/
execution_context.go
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/*
* Copyright (C) 2018 The ontology Authors
* This file is part of The ontology library.
*
* The ontology is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* The ontology is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with The ontology. If not, see <http://www.gnu.org/licenses/>.
*/
package neovm
import (
"io"
"github.com/ontio/ontology/vm/neovm/utils"
)
type ExecutionContext struct {
Code []byte
OpReader *utils.VmReader
InstructionPointer int
vmFlags VmFeatureFlag
}
func NewExecutionContext(code []byte, flag VmFeatureFlag) *ExecutionContext {
var context ExecutionContext
context.Code = code
context.OpReader = utils.NewVmReader(code)
context.OpReader.AllowEOF = flag.AllowReaderEOF
context.vmFlags = flag
context.InstructionPointer = 0
return &context
}
func (ec *ExecutionContext) GetInstructionPointer() int {
return ec.OpReader.Position()
}
func (ec *ExecutionContext) SetInstructionPointer(offset int64) error {
_, err := ec.OpReader.Seek(offset, io.SeekStart)
return err
}
func (ec *ExecutionContext) NextInstruction() OpCode {
return OpCode(ec.Code[ec.OpReader.Position()])
}
func (self *ExecutionContext) ReadOpCode() (val OpCode, eof bool) {
code, err := self.OpReader.ReadByte()
if err != nil {
eof = true
return
}
val = OpCode(code)
return val, false
}
func (ec *ExecutionContext) Clone() *ExecutionContext {
context := NewExecutionContext(ec.Code, ec.vmFlags)
context.InstructionPointer = ec.InstructionPointer
_ = context.SetInstructionPointer(int64(ec.GetInstructionPointer()))
return context
}