go-ethereum/eth/tracers/internal/util.go
Sina M 064f37d6f6
eth/tracers: live chain tracing with hooks (#29189)
Here we add a Go API for running tracing plugins within the main block import process. 

As an advanced user of geth, you can now create a Go file in eth/tracers/live/, and within
that file register your custom tracer implementation. Then recompile geth and select your tracer
on the command line. Hooks defined in the tracer will run whenever a block is processed.

The hook system is defined in package core/tracing. It uses a struct with callbacks, instead of 
requiring an interface, for several reasons:

- We plan to keep this API stable long-term. The core/tracing hook API does not depend on
  on deep geth internals.
- There are a lot of hooks, and tracers will only need some of them. Using a struct allows you
   to implement only the hooks you want to actually use.

All existing tracers in eth/tracers/native have been rewritten to use the new hook system.

This change breaks compatibility with the vm.EVMLogger interface that we used to have.
If you are a user of vm.EVMLogger, please migrate to core/tracing, and sorry for breaking
your stuff. But we just couldn't have both the old and new tracing APIs coexist in the EVM.

---------

Co-authored-by: Matthieu Vachon <matthieu.o.vachon@gmail.com>
Co-authored-by: Delweng <delweng@gmail.com>
Co-authored-by: Martin HS <martin@swende.se>
2024-03-22 18:53:53 +01:00

81 lines
2.1 KiB
Go

// Copyright 2023 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 internal
import (
"errors"
"fmt"
"github.com/holiman/uint256"
)
const (
memoryPadLimit = 1024 * 1024
)
// GetMemoryCopyPadded returns offset + size as a new slice.
// It zero-pads the slice if it extends beyond memory bounds.
func GetMemoryCopyPadded(m []byte, offset, size int64) ([]byte, error) {
if offset < 0 || size < 0 {
return nil, errors.New("offset or size must not be negative")
}
length := int64(len(m))
if offset+size < length { // slice fully inside memory
return memoryCopy(m, offset, size), nil
}
paddingNeeded := offset + size - length
if paddingNeeded > memoryPadLimit {
return nil, fmt.Errorf("reached limit for padding memory slice: %d", paddingNeeded)
}
cpy := make([]byte, size)
if overlap := length - offset; overlap > 0 {
copy(cpy, MemoryPtr(m, offset, overlap))
}
return cpy, nil
}
func memoryCopy(m []byte, offset, size int64) (cpy []byte) {
if size == 0 {
return nil
}
if len(m) > int(offset) {
cpy = make([]byte, size)
copy(cpy, m[offset:offset+size])
return
}
return
}
// MemoryPtr returns a pointer to a slice of memory.
func MemoryPtr(m []byte, offset, size int64) []byte {
if size == 0 {
return nil
}
if len(m) > int(offset) {
return m[offset : offset+size]
}
return nil
}
// Back returns the n'th item in stack
func StackBack(st []uint256.Int, n int) *uint256.Int {
return &st[len(st)-n-1]
}