go-ethereum/internal/flags/flags.go
Péter Szilágyi a1d049c1c4
internal/flags: remove low-use type TextMarshalerFlag (#30707)
Currently we have a custom TextMarshalerFlag. It's a nice idea, allowing
anything implementing text marshaller to be used as a flag. That said,
we only ever used it in one place because it's not that obvious how to
use and it needs some boilerplate on the type itself too, apart of the
heavy boilerplate got the custom flag.

All in all there's no *need* to drop this feature just now, but while
porting the cmds over to cli @v3, all other custom flags worker
perfectly, whereas this one started crashing deep inside the cli
package. The flag handling in v3 got rebuild on generics and there are a
number of new methods needed; and my guess is that maybe one of them
doesn't work like this flag currently is designed too.

We could definitely try and redesign this flag for cli v3... but all
that effort and boilerplate just to use it for 1 flag in 1 location,
seems not worth it. So for now I'm suggesting removing it and maybe
reconsider a similar feature in cli v3 with however it will work.
2024-10-31 19:52:39 +01:00

268 lines
6.8 KiB
Go

// Copyright 2015 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 flags
import (
"errors"
"flag"
"fmt"
"math/big"
"os"
"os/user"
"path/filepath"
"strings"
"syscall"
"github.com/ethereum/go-ethereum/common/math"
"github.com/urfave/cli/v2"
)
// DirectoryString is custom type which is registered in the flags library which cli uses for
// argument parsing. This allows us to expand Value to an absolute path when
// the argument is parsed
type DirectoryString string
func (s *DirectoryString) String() string {
return string(*s)
}
func (s *DirectoryString) Set(value string) error {
*s = DirectoryString(expandPath(value))
return nil
}
var (
_ cli.Flag = (*DirectoryFlag)(nil)
_ cli.RequiredFlag = (*DirectoryFlag)(nil)
_ cli.VisibleFlag = (*DirectoryFlag)(nil)
_ cli.DocGenerationFlag = (*DirectoryFlag)(nil)
_ cli.CategorizableFlag = (*DirectoryFlag)(nil)
)
// DirectoryFlag is custom cli.Flag type which expand the received string to an absolute path.
// e.g. ~/.ethereum -> /home/username/.ethereum
type DirectoryFlag struct {
Name string
Category string
DefaultText string
Usage string
Required bool
Hidden bool
HasBeenSet bool
Value DirectoryString
Aliases []string
EnvVars []string
}
// For cli.Flag:
func (f *DirectoryFlag) Names() []string { return append([]string{f.Name}, f.Aliases...) }
func (f *DirectoryFlag) IsSet() bool { return f.HasBeenSet }
func (f *DirectoryFlag) String() string { return cli.FlagStringer(f) }
// Apply called by cli library, grabs variable from environment (if in env)
// and adds variable to flag set for parsing.
func (f *DirectoryFlag) Apply(set *flag.FlagSet) error {
for _, envVar := range f.EnvVars {
envVar = strings.TrimSpace(envVar)
if value, found := syscall.Getenv(envVar); found {
f.Value.Set(value)
f.HasBeenSet = true
break
}
}
eachName(f, func(name string) {
set.Var(&f.Value, f.Name, f.Usage)
})
return nil
}
// For cli.RequiredFlag:
func (f *DirectoryFlag) IsRequired() bool { return f.Required }
// For cli.VisibleFlag:
func (f *DirectoryFlag) IsVisible() bool { return !f.Hidden }
// For cli.CategorizableFlag:
func (f *DirectoryFlag) GetCategory() string { return f.Category }
// For cli.DocGenerationFlag:
func (f *DirectoryFlag) TakesValue() bool { return true }
func (f *DirectoryFlag) GetUsage() string { return f.Usage }
func (f *DirectoryFlag) GetValue() string { return f.Value.String() }
func (f *DirectoryFlag) GetEnvVars() []string { return f.EnvVars }
func (f *DirectoryFlag) GetDefaultText() string {
if f.DefaultText != "" {
return f.DefaultText
}
return f.GetValue()
}
var (
_ cli.Flag = (*BigFlag)(nil)
_ cli.RequiredFlag = (*BigFlag)(nil)
_ cli.VisibleFlag = (*BigFlag)(nil)
_ cli.DocGenerationFlag = (*BigFlag)(nil)
_ cli.CategorizableFlag = (*BigFlag)(nil)
)
// BigFlag is a command line flag that accepts 256 bit big integers in decimal or
// hexadecimal syntax.
type BigFlag struct {
Name string
Category string
DefaultText string
Usage string
Required bool
Hidden bool
HasBeenSet bool
Value *big.Int
defaultValue *big.Int
Aliases []string
EnvVars []string
}
// For cli.Flag:
func (f *BigFlag) Names() []string { return append([]string{f.Name}, f.Aliases...) }
func (f *BigFlag) IsSet() bool { return f.HasBeenSet }
func (f *BigFlag) String() string { return cli.FlagStringer(f) }
func (f *BigFlag) Apply(set *flag.FlagSet) error {
// Set default value so that environment wont be able to overwrite it
if f.Value != nil {
f.defaultValue = new(big.Int).Set(f.Value)
}
for _, envVar := range f.EnvVars {
envVar = strings.TrimSpace(envVar)
if value, found := syscall.Getenv(envVar); found {
if _, ok := f.Value.SetString(value, 10); !ok {
return fmt.Errorf("could not parse %q from environment variable %q for flag %s", value, envVar, f.Name)
}
f.HasBeenSet = true
break
}
}
eachName(f, func(name string) {
f.Value = new(big.Int)
set.Var((*bigValue)(f.Value), f.Name, f.Usage)
})
return nil
}
// For cli.RequiredFlag:
func (f *BigFlag) IsRequired() bool { return f.Required }
// For cli.VisibleFlag:
func (f *BigFlag) IsVisible() bool { return !f.Hidden }
// For cli.CategorizableFlag:
func (f *BigFlag) GetCategory() string { return f.Category }
// For cli.DocGenerationFlag:
func (f *BigFlag) TakesValue() bool { return true }
func (f *BigFlag) GetUsage() string { return f.Usage }
func (f *BigFlag) GetValue() string { return f.Value.String() }
func (f *BigFlag) GetEnvVars() []string { return f.EnvVars }
func (f *BigFlag) GetDefaultText() string {
if f.DefaultText != "" {
return f.DefaultText
}
return f.defaultValue.String()
}
// bigValue turns *big.Int into a flag.Value
type bigValue big.Int
func (b *bigValue) String() string {
if b == nil {
return ""
}
return (*big.Int)(b).String()
}
func (b *bigValue) Set(s string) error {
intVal, ok := math.ParseBig256(s)
if !ok {
return errors.New("invalid integer syntax")
}
*b = (bigValue)(*intVal)
return nil
}
// GlobalBig returns the value of a BigFlag from the global flag set.
func GlobalBig(ctx *cli.Context, name string) *big.Int {
val := ctx.Generic(name)
if val == nil {
return nil
}
return (*big.Int)(val.(*bigValue))
}
// Expands a file path
// 1. replace tilde with users home dir
// 2. expands embedded environment variables
// 3. cleans the path, e.g. /a/b/../c -> /a/c
// Note, it has limitations, e.g. ~someuser/tmp will not be expanded
func expandPath(p string) string {
// Named pipes are not file paths on windows, ignore
if strings.HasPrefix(p, `\\.\pipe`) {
return p
}
if strings.HasPrefix(p, "~/") || strings.HasPrefix(p, "~\\") {
if home := HomeDir(); home != "" {
p = home + p[1:]
}
}
return filepath.Clean(os.ExpandEnv(p))
}
func HomeDir() string {
if home := os.Getenv("HOME"); home != "" {
return home
}
if usr, err := user.Current(); err == nil {
return usr.HomeDir
}
return ""
}
func eachName(f cli.Flag, fn func(string)) {
for _, name := range f.Names() {
name = strings.Trim(name, " ")
fn(name)
}
}