params: new param system

params/chainparam.go

@@ -9,79 +9,40 @@ import (
 )
 
 // ChainID
-type ChainID big.Int
-
-func NewChainID(input string) *ChainID {
-	b, ok := new(big.Int).SetString(input, 0)
-	if !ok {
-		panic("invalid chainID: " + input)
-	}
-	return (*ChainID)(b)
-}
-
-func (v *ChainID) MarshalText() ([]byte, error) {
-	return (*big.Int)(v).MarshalText()
-}
-
-func (v *ChainID) UnmarshalText(input []byte) error {
-	return (*big.Int)(v).UnmarshalText(input)
-}
-
-func (v *ChainID) BigInt() *big.Int {
-	return (*big.Int)(v)
-}
-
-func (v *ChainID) Validate(cfg *Config2) error {
-	b := (*big.Int)(v)
-	if b.Sign() <= 0 {
-		return fmt.Errorf("invalid chainID value %v", b)
-	}
-	return nil
-}
+var ChainID = Define(T[*big.Int]{
+	Name: "chainId",
+	Validate: func(v *big.Int, cfg *Config2) error {
+		if v.Sign() <= 0 {
+			return fmt.Errorf("invalid chainID value %v", v)
+		}
+		return nil
+	},
+})
 
 // TerminalTotalDifficulty (TTD) is the total difficulty value where
-type TerminalTotalDifficulty big.Int
-
-func NewTerminalTotalDifficulty(input string) *TerminalTotalDifficulty {
-	b, ok := new(big.Int).SetString(input, 0)
-	if !ok {
-		panic("invalid terminal total difficulty: " + input)
-	}
-	return (*TerminalTotalDifficulty)(b)
-}
-
-func (v *TerminalTotalDifficulty) MarshalText() ([]byte, error) {
-	return (*big.Int)(v).MarshalText()
-}
-
-func (v *TerminalTotalDifficulty) UnmarshalText(input []byte) error {
-	return (*big.Int)(v).UnmarshalText(input)
-}
-
-func (v *TerminalTotalDifficulty) BigInt() *big.Int {
-	return (*big.Int)(v)
-}
-
-func (v *TerminalTotalDifficulty) Validate(cfg *Config2) error {
-	return nil
-}
+var TerminalTotalDifficulty = Define(T[*big.Int]{
+	Name:     "terminalTotalDifficulty",
+	Optional: true,
+})
 
 // DepositContractAddress configures the location of the deposit contract.
-type DepositContractAddress common.Address
-
-func (v DepositContractAddress) Validate(cfg *Config2) error {
-	return nil
-}
+var DepositContractAddress = Define(T[common.Address]{
+	Name:     "depositContractAddress",
+	Optional: true,
+})
 
 // This configures the EIP-4844 parameters across forks.
 // There must be an entry for each fork
-type BlobSchedule map[forks.Fork]BlobConfig
+var BlobSchedule = Define(T[map[forks.Fork]BlobConfig]{
+	Name:     "blobSchedule",
+	Optional: true,
+	Validate: validateBlobSchedule,
+})
 
-// Validate checks that all forks with blobs explicitly define the blob schedule configuration.
-func (v BlobSchedule) Validate(cfg *Config2) error {
+func validateBlobSchedule(schedule map[forks.Fork]BlobConfig, cfg *Config2) error {
+	// Check that all forks with blobs explicitly define the blob schedule configuration.
 	for _, f := range forks.CanonOrder {
 		if f.HasBlobs() {
-			schedule := Get[BlobSchedule](cfg)
 			bcfg, defined := schedule[f]
 			if cfg.Scheduled(f) && !defined {
 				return fmt.Errorf("invalid chain configuration: missing entry for fork %q in blobSchedule", f)
@@ -99,32 +60,7 @@ func (v BlobSchedule) Validate(cfg *Config2) error {
 // DAOForkSupport is the chain parameter that configures the DAO fork.
 // true=supports or false=opposes the fork.
 // The default value is true.
-type DAOForkSupport bool
-
-func (v DAOForkSupport) Validate(cfg *Config2) error {
-	return nil
-}
-
-func init() {
-	Define(Parameter[*ChainID]{
-		Name:     "chainId",
-		Optional: false,
-	})
-	Define(Parameter[*TerminalTotalDifficulty]{
-		Name:     "terminalTotalDifficulty",
-		Optional: false,
-	})
-	Define(Parameter[DAOForkSupport]{
-		Name:     "daoForkSupport",
-		Optional: true,
-		Default:  true,
-	})
-	Define(Parameter[BlobSchedule]{
-		Name:     "blobSchedule",
-		Optional: true,
-	})
-	Define(Parameter[DepositContractAddress]{
-		Name:     "depositContractAddress",
-		Optional: true,
-	})
-}
+var DAOForkSupport = Define(T[bool]{
+	Optional: true,
+	Default:  true,
+})

params/config2.go

@@ -22,7 +22,6 @@ import (
 	"fmt"
 	"maps"
 	"math/big"
-	"reflect"
 	"slices"
 	"strings"
 
@@ -35,21 +34,17 @@ type Activations map[forks.Fork]uint64
 // Config2 represents the chain configuration.
 type Config2 struct {
 	activation Activations
-	param      map[reflect.Type]ParameterType
+	param      map[int]any
 }
 
-func NewConfig2(activations Activations, param ...ParameterType) *Config2 {
+func NewConfig2(activations Activations, param ...ParamValue) *Config2 {
 	cfg := &Config2{
 		activation: maps.Clone(activations),
-		param:      make(map[reflect.Type]ParameterType, len(param)),
+		param:      make(map[int]any, len(param)),
 	}
 	cfg.activation[forks.Frontier] = 0
 	for _, pv := range param {
-		info, ok := findParam(pv)
-		if !ok {
-			panic(fmt.Sprintf("undefined chain parameter type %T", pv))
-		}
-		cfg.param[info.rtype] = pv
+		cfg.param[pv.id] = pv.value
 	}
 	return cfg
 }
@@ -109,12 +104,12 @@ func (cfg *Config2) LatestFork(time uint64) forks.Fork {
 func (cfg *Config2) MarshalJSON() ([]byte, error) {
 	m := make(map[string]any)
 	// params
-	for _, p := range cfg.param {
-		info, ok := findParam(p)
+	for id, value := range cfg.param {
+		info, ok := paramRegistry[id]
 		if !ok {
-			panic(fmt.Sprintf("unknown chain parameter %T", p))
+			panic(fmt.Sprintf("unknown chain parameter id %v", id))
 		}
-		m[info.name] = p
+		m[info.name] = value
 	}
 	// forks
 	for f, act := range cfg.activation {
@@ -187,15 +182,15 @@ func (cfg *Config2) decodeActivation(key string, dec *json.Decoder) error {
 }
 
 func (cfg *Config2) decodeParameter(key string, dec *json.Decoder) error {
-	info, ok := paramRegistryByName[key]
+	id, ok := paramRegistryByName[key]
 	if !ok {
 		return fmt.Errorf("unknown chain parameter %q", key)
 	}
-	v := reflect.New(info.rtype).Interface()
+	v := paramRegistry[id].new()
 	if err := dec.Decode(v); err != nil {
 		return err
 	}
-	cfg.param[info.rtype] = v.(ParameterType)
+	cfg.param[id] = v
 	return nil
 }
 
@@ -235,15 +230,15 @@ func (cfg *Config2) Validate() error {
 	}
 
 	// Check parameters.
-	for rtype, info := range paramRegistry {
-		v, isSet := cfg.param[rtype]
+	for id, info := range paramRegistry {
+		v, isSet := cfg.param[id]
 		if !isSet {
 			if !info.optional {
 				return fmt.Errorf("required chain parameter %s is not set", info.name)
 			}
-			v = info.defaultVal
+			v = info.defaultValue
 		}
-		if err := v.Validate(cfg); err != nil {
+		if err := info.validate(v, cfg); err != nil {
 			return fmt.Errorf("invalid %s: %w", info.name, err)
 		}
 	}
@@ -296,12 +291,10 @@ func (cfg *Config2) checkCompatible(newcfg *Config2, num uint64, time uint64) *C
 		}
 	}
 
-	if cfg.Active(forks.DAO, num, time) && Get[DAOForkSupport](cfg) != Get[DAOForkSupport](newcfg) {
+	if cfg.Active(forks.DAO, num, time) && DAOForkSupport.Get(cfg) != DAOForkSupport.Get(newcfg) {
 		return newBlockCompatError2("DAO fork support flag", forks.DAO, cfg, newcfg)
 	}
-	chainID := (*big.Int)(Get[*ChainID](cfg))
-	newChainID := (*big.Int)(Get[*ChainID](newcfg))
-	if cfg.Active(forks.TangerineWhistle, num, time) && !configBlockEqual(chainID, newChainID) {
+	if cfg.Active(forks.TangerineWhistle, num, time) && !configBlockEqual(ChainID.Get(cfg), ChainID.Get(newcfg)) {
 		return newBlockCompatError2("EIP158 chain ID", forks.TangerineWhistle, cfg, newcfg)
 	}
 

params/registry.go

@@ -18,72 +18,78 @@ package params
 
 import (
 	"fmt"
-	"reflect"
 )
 
-type ParameterType interface{
-	Validate(*Config2) error
+type Parameter[V any] struct{
+	info regInfo
 }
 
-type paramInfo struct {
-	rtype      reflect.Type
-	name       string
-	optional   bool
-	defaultVal ParameterType
+func (p Parameter[V]) Get(cfg *Config2) V {
+	v, ok := cfg.param[p.info.id]
+	if ok {
+		return v.(V)
+	}
+	return p.info.defaultValue.(V)
+}
+
+func (p Parameter[V]) V(v V) ParamValue {
+	return ParamValue{p.info.id, v}
+}
+
+type ParamValue struct{
+	id int
+	value any
 }
 
 var (
-	paramRegistry = map[reflect.Type]*paramInfo{}
-	paramRegistryByName = map[string]*paramInfo{}
+	paramCounter int
+	paramRegistry = map[int]regInfo{}
+	paramRegistryByName = map[string]int{}
 )
 
-// Get retrieves the value of a chain parameter.
-func Get[T ParameterType](cfg *Config2) T {
-	for _, p := range cfg.param {
-		if v, ok := p.(T); ok {
-			return v
-		}
-	}
-	// get default
-	var z T
-	info, ok := findParam(z)
-	if !ok {
-		panic(fmt.Sprintf("unknown parameter type %T", z))
-	}
-	return info.defaultVal.(T)
+type T[V any] struct{
+	Name string
+	Optional bool
+	Default V
+	Validate func(v V, cfg *Config2) error
 }
 
-// Parameter is the definition of a chain parameter.
-type Parameter[T ParameterType] struct {
-	Name     string
-	Optional bool
-	Default  T
+type regInfo struct{
+	id int
+	name string
+	optional bool
+	defaultValue any
+	new func() any
+	validate func(any, *Config2) error
 }
 
 // Define creates a chain parameter in the registry.
-func Define[T ParameterType](def Parameter[T]) {
-	var z T
-	info, defined := paramRegistryByName[def.Name]
-	if defined {
-		panic(fmt.Sprintf("chain parameter %q already registered with type %v", info.name, info.rtype))
+func Define[V any](def T[V]) Parameter[V] {
+	if id, defined := paramRegistryByName[def.Name]; defined {
+		info := paramRegistry[id]
+		panic(fmt.Sprintf("chain parameter %q already registered with type %T", def.Name, info.defaultValue))
 	}
-	rtype := reflect.TypeOf(z)
-	info, defined = paramRegistry[rtype]
-	if defined {
-		panic(fmt.Sprintf("chain parameter of type %v already registered with name %q", rtype, info.name))
-	}
-	info = &paramInfo{
-		rtype:      rtype,
-		name:       def.Name,
-		optional:   def.Optional,
-		defaultVal: def.Default,
-	}
-	paramRegistry[rtype] = info
-	paramRegistryByName[def.Name] = info
-}
 
-func findParam(v any) (*paramInfo, bool) {
-	rtype := reflect.TypeOf(v)
-	info, ok := paramRegistry[rtype]
-	return info, ok
+	id := paramCounter
+	paramCounter++
+
+	regInfo := regInfo{
+		id: id,
+		name: def.Name,
+		optional: def.Optional,
+		defaultValue: def.Default,
+		new: func() any {
+			var z V
+			return z
+		},
+		validate: func(v any, cfg *Config2) error {
+			if def.Validate == nil {
+				return nil
+			}
+			return def.Validate(v.(V), cfg)
+		},
+	}
+	paramRegistry[id] = regInfo
+	paramRegistryByName[def.Name] = id
+	return Parameter[V]{info: regInfo}
 }