go-ethereum/eth/tracers/native/tracer.go
Felix Lange b628d72766
build: upgrade to go 1.19 (#25726)
This changes the CI / release builds to use the latest Go version. It also
upgrades golangci-lint to a newer version compatible with Go 1.19.

In Go 1.19, godoc has gained official support for links and lists. The
syntax for code blocks in doc comments has changed and now requires a
leading tab character. gofmt adapts comments to the new syntax
automatically, so there are a lot of comment re-formatting changes in this
PR. We need to apply the new format in order to pass the CI lint stage with
Go 1.19.

With the linter upgrade, I have decided to disable 'gosec' - it produces
too many false-positive warnings. The 'deadcode' and 'varcheck' linters
have also been removed because golangci-lint warns about them being
unmaintained. 'unused' provides similar coverage and we already have it
enabled, so we don't lose much with this change.
2022-09-10 13:25:40 +02:00

80 lines
2.6 KiB
Go

// Copyright 2021 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 native is a collection of tracers written in go.
//
// In order to add a native tracer and have it compiled into the binary, a new
// file needs to be added to this folder, containing an implementation of the
// `eth.tracers.Tracer` interface.
//
// Aside from implementing the tracer, it also needs to register itself, using the
// `register` method -- and this needs to be done in the package initialization.
//
// Example:
//
// func init() {
// register("noopTracerNative", newNoopTracer)
// }
package native
import (
"encoding/json"
"errors"
"github.com/ethereum/go-ethereum/eth/tracers"
)
// init registers itself this packages as a lookup for tracers.
func init() {
tracers.RegisterLookup(false, lookup)
}
// ctorFn is the constructor signature of a native tracer.
type ctorFn = func(*tracers.Context, json.RawMessage) (tracers.Tracer, error)
/*
ctors is a map of package-local tracer constructors.
We cannot be certain about the order of init-functions within a package,
The go spec (https://golang.org/ref/spec#Package_initialization) says
> To ensure reproducible initialization behavior, build systems
> are encouraged to present multiple files belonging to the same
> package in lexical file name order to a compiler.
Hence, we cannot make the map in init, but must make it upon first use.
*/
var ctors map[string]ctorFn
// register is used by native tracers to register their presence.
func register(name string, ctor ctorFn) {
if ctors == nil {
ctors = make(map[string]ctorFn)
}
ctors[name] = ctor
}
// lookup returns a tracer, if one can be matched to the given name.
func lookup(name string, ctx *tracers.Context, cfg json.RawMessage) (tracers.Tracer, error) {
if ctors == nil {
ctors = make(map[string]ctorFn)
}
if ctor, ok := ctors[name]; ok {
return ctor(ctx, cfg)
}
return nil, errors.New("no tracer found")
}