core: allow to create hard-fork

pkg/config/hardfork.go

@@ -0,0 +1,31 @@
+package config
+
+//go:generate stringer -type=Hardfork -linecomment
+
+// Hardfork represents the application hard-fork identifier.
+type Hardfork byte
+
+const (
+	// HF2712FixSyscallFees represents hard-fork introduced in #2469 (ported from
+	// https://github.com/neo-project/neo/pull/2712) changing the prices of
+	// System.Contract.CreateStandardAccount and
+	// System.Contract.CreateMultisigAccount interops.
+	HF2712FixSyscallFees Hardfork = 1 << iota // HF_2712_FixSyscallFees
+)
+
+// hardforks holds a map of Hardfork string representation to its type.
+var hardforks map[string]Hardfork
+
+func init() {
+	hardforks = make(map[string]Hardfork)
+	for _, hf := range []Hardfork{HF2712FixSyscallFees} {
+		hardforks[hf.String()] = hf
+	}
+}
+
+// IsHardforkValid denotes whether the provided string represents a valid
+// Hardfork name.
+func IsHardforkValid(s string) bool {
+	_, ok := hardforks[s]
+	return ok
+}

pkg/config/hardfork_string.go

@@ -0,0 +1,24 @@
+// Code generated by "stringer -type Hardfork -linecomment ./pkg/config/hardfork.go"; DO NOT EDIT.
+
+package config
+
+import "strconv"
+
+func _() {
+	// An "invalid array index" compiler error signifies that the constant values have changed.
+	// Re-run the stringer command to generate them again.
+	var x [1]struct{}
+	_ = x[HF2712FixSyscallFees-1]
+}
+
+const _Hardfork_name = "HF_2712_FixSyscallFees"
+
+var _Hardfork_index = [...]uint8{0, 22}
+
+func (i Hardfork) String() string {
+	i -= 1
+	if i >= Hardfork(len(_Hardfork_index)-1) {
+		return "Hardfork(" + strconv.FormatInt(int64(i+1), 10) + ")"
+	}
+	return _Hardfork_name[_Hardfork_index[i]:_Hardfork_index[i+1]]
+}

pkg/config/protocol_config.go

@@ -23,6 +23,9 @@ type (
 		Magic       netmode.Magic `yaml:"Magic"`
 		MemPoolSize int           `yaml:"MemPoolSize"`
 
+		// Hardforks is a map of hardfork names that enables version-specific application
+		// logic dependent on the specified height.
+		Hardforks map[string]uint32 `yaml:"Hardforks"`
 		// InitialGASSupply is the amount of GAS generated in the genesis block.
 		InitialGASSupply fixedn.Fixed8 `yaml:"InitialGASSupply"`
 		// P2PNotaryRequestPayloadPoolSize specifies the memory pool size for P2PNotaryRequestPayloads.
@@ -94,6 +97,11 @@ func (p *ProtocolConfiguration) Validate() error {
 			return fmt.Errorf("NativeActivations configuration section contains unexpected native contract name: %s", name)
 		}
 	}
+	for name := range p.Hardforks {
+		if !IsHardforkValid(name) {
+			return fmt.Errorf("Hardforks configuration section contains unexpected hardfork: %s", name)
+		}
+	}
 	if p.ValidatorsCount != 0 && len(p.ValidatorsHistory) != 0 {
 		return errors.New("configuration should either have ValidatorsCount or ValidatorsHistory, not both")
 	}

pkg/config/protocol_config_test.go

@@ -100,6 +100,12 @@ func TestProtocolConfigurationValidation(t *testing.T) {
 		ValidatorsHistory: map[uint32]int{0: 4, 100: 4},
 	}
 	require.Error(t, p.Validate())
+	p = &ProtocolConfiguration{
+		Hardforks: map[string]uint32{
+			"HF_Unknown": 123, // Unknown hard-fork.
+		},
+	}
+	require.Error(t, p.Validate())
 	p = &ProtocolConfiguration{
 		StandbyCommittee: []string{
 			"02b3622bf4017bdfe317c58aed5f4c753f206b7db896046fa7d774bbc4bf7f8dc2",

pkg/core/blockchain.go

@@ -259,6 +259,10 @@ func NewBlockchain(s storage.Store, cfg config.ProtocolConfiguration, log *zap.L
 		cfg.NativeUpdateHistories = map[string][]uint32{}
 		log.Info("NativeActivations are not set, using default values")
 	}
+	if cfg.Hardforks == nil {
+		cfg.Hardforks = map[string]uint32{}
+		log.Info("Hardforks are not set, using default value")
+	}
 	bc := &Blockchain{
 		config:      cfg,
 		dao:         dao.NewSimple(s, cfg.StateRootInHeader, cfg.P2PSigExtensions),

pkg/core/interop/context.go

@@ -48,6 +48,7 @@ type Context struct {
 	Chain          Ledger
 	Container      hash.Hashable
 	Network        uint32
+	Hardforks      map[string]uint32
 	Natives        []Contract
 	Trigger        trigger.Type
 	Block          *block.Block
@@ -71,9 +72,11 @@ func NewContext(trigger trigger.Type, bc Ledger, d *dao.Simple, baseExecFee, bas
 	getContract func(*dao.Simple, util.Uint160) (*state.Contract, error), natives []Contract,
 	block *block.Block, tx *transaction.Transaction, log *zap.Logger) *Context {
 	dao := d.GetPrivate()
+	cfg := bc.GetConfig()
 	return &Context{
 		Chain:          bc,
-		Network:        uint32(bc.GetConfig().Magic),
+		Network:        uint32(cfg.Magic),
+		Hardforks:      cfg.Hardforks,
 		Natives:        natives,
 		Trigger:        trigger,
 		Block:          block,
@@ -368,3 +371,12 @@ func (ic *Context) GetBlock(hash util.Uint256) (*block.Block, error) {
 	}
 	return block, nil
 }
+
+// IsHardforkEnabled tells whether specified hard-fork enabled at the current context height.
+func (ic *Context) IsHardforkEnabled(hf config.Hardfork) bool {
+	height, ok := ic.Hardforks[hf.String()]
+	if ok {
+		return ic.BlockHeight() >= height
+	}
+	return len(ic.Hardforks) == 0 // Enable each hard-fork by default.
+}