go-ethereum/core/vm/stack.go
Nick Johnson 781915f183 core/vm: Refactor tracing to make Tracer the main interface
This CL makes several refactors:
 - Define a Tracer interface, implementing the `CaptureState` method
 - Add the VM environment as the first argument of
   `Tracer.CaptureState`
 - Rename existing functionality `StructLogger` an make it an
   implementation of `Tracer`
 - Delete `StructLogCollector` and make `StructLogger` collect the logs
   directly
 - Change all callers to use the new `StructLogger` where necessary and
   extract logs from that.
 - Deletes the apparently obsolete and likely nonfunctional 'TraceCall'
   from the eth API.

Callers that only wish accumulated logs can use the `StructLogger`
implementation straightforwardly. Callers that wish to efficiently
capture VM traces and operate on them without excessive copying can now
implement the `Tracer` interface to receive VM state at each step and
do with it as they wish.

This CL also removes the accumulation of logs from the vm.Environment;
this was necessary as part of the refactor, but also simplifies it by
removing a responsibility that doesn't directly belong to the
Environment.
2016-08-22 09:26:15 +01:00

89 lines
2.2 KiB
Go

// Copyright 2014 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library 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 go-ethereum library 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 go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package vm
import (
"fmt"
"math/big"
)
// stack is an object for basic stack operations. Items popped to the stack are
// expected to be changed and modified. stack does not take care of adding newly
// initialised objects.
type Stack struct {
data []*big.Int
}
func newstack() *Stack {
return &Stack{}
}
func (st *Stack) Data() []*big.Int {
return st.data
}
func (st *Stack) push(d *big.Int) {
// NOTE push limit (1024) is checked in baseCheck
//stackItem := new(big.Int).Set(d)
//st.data = append(st.data, stackItem)
st.data = append(st.data, d)
}
func (st *Stack) pushN(ds ...*big.Int) {
st.data = append(st.data, ds...)
}
func (st *Stack) pop() (ret *big.Int) {
ret = st.data[len(st.data)-1]
st.data = st.data[:len(st.data)-1]
return
}
func (st *Stack) len() int {
return len(st.data)
}
func (st *Stack) swap(n int) {
st.data[st.len()-n], st.data[st.len()-1] = st.data[st.len()-1], st.data[st.len()-n]
}
func (st *Stack) dup(n int) {
st.push(new(big.Int).Set(st.data[st.len()-n]))
}
func (st *Stack) peek() *big.Int {
return st.data[st.len()-1]
}
func (st *Stack) require(n int) error {
if st.len() < n {
return fmt.Errorf("stack underflow (%d <=> %d)", len(st.data), n)
}
return nil
}
func (st *Stack) Print() {
fmt.Println("### stack ###")
if len(st.data) > 0 {
for i, val := range st.data {
fmt.Printf("%-3d %v\n", i, val)
}
} else {
fmt.Println("-- empty --")
}
fmt.Println("#############")
}