native: make HF-specific MD cache less lazy

Initialize all necessary HF-specific contract descriptors once during
contract construction.

Signed-off-by: Anna Shaleva <shaleva.ann@nspcc.ru>

pkg/config/hardfork.go

@@ -5,6 +5,13 @@ package config
 // Hardfork represents the application hard-fork identifier.
 type Hardfork byte
 
+// HFDefault is a default value of Hardfork enum. It's a special constant
+// aimed to denote the node code enabled by default starting from the
+// genesis block. HFDefault is not a hard-fork, but this constant can be used for
+// convenient hard-forks comparison and to refer to the default hard-fork-less
+// node behaviour.
+const HFDefault Hardfork = 0 // Default
+
 const (
 	// HFAspidochelone represents hard-fork introduced in #2469 (ported from
 	// https://github.com/neo-project/neo/pull/2712) and #2519 (ported from
@@ -52,6 +59,14 @@ func (hf Hardfork) Cmp(other Hardfork) int {
 	}
 }
 
+// Prev returns the previous hardfork for the given one. Calling Prev for the default hardfork is a no-op.
+func (hf Hardfork) Prev() Hardfork {
+	if hf == HFDefault {
+		panic("unexpected call to Prev for the default hardfork")
+	}
+	return hf >> 1
+}
+
 // IsHardforkValid denotes whether the provided string represents a valid
 // Hardfork name.
 func IsHardforkValid(s string) bool {

pkg/config/hardfork_string.go

@@ -8,24 +8,24 @@ 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[HFDefault-0]
 	_ = x[HFAspidochelone-1]
 	_ = x[HFBasilisk-2]
 	_ = x[hfLast-4]
 }
 
 const (
-	_Hardfork_name_0 = "AspidocheloneBasilisk"
+	_Hardfork_name_0 = "DefaultAspidocheloneBasilisk"
 	_Hardfork_name_1 = "hfLast"
 )
 
 var (
-	_Hardfork_index_0 = [...]uint8{0, 13, 21}
+	_Hardfork_index_0 = [...]uint8{0, 7, 20, 28}
 )
 
 func (i Hardfork) String() string {
 	switch {
-	case 1 <= i && i <= 2:
-		i -= 1
+	case i <= 2:
 		return _Hardfork_name_0[_Hardfork_index_0[i]:_Hardfork_index_0[i+1]]
 	case i == 4:
 		return _Hardfork_name_1

pkg/core/interop/context.go

@@ -7,7 +7,6 @@ import (
 	"fmt"
 	"sort"
 	"strings"
-	"sync"
 
 	"github.com/nspcc-dev/neo-go/pkg/config"
 	"github.com/nspcc-dev/neo-go/pkg/core/block"
@@ -204,10 +203,9 @@ type ContractMD struct {
 	// by mutex.
 	ActiveHFs map[config.Hardfork]struct{}
 
-	// mdCache contains hardfork-specific ready-to-use contract descriptors. This cache is lazy and thus, protected by
-	// mdCacheLock.
-	mdCacheLock sync.RWMutex
-	mdCache     map[config.Hardfork]*HFSpecificContractMD
+	// mdCache contains hardfork-specific ready-to-use contract descriptors. This cache is initialized in the native
+	// contracts constructors, and acts as read-only during the whole node lifetime, thus not protected by mutex.
+	mdCache map[config.Hardfork]*HFSpecificContractMD
 
 	// onManifestConstruction is a callback for manifest finalization.
 	onManifestConstruction func(*manifest.Manifest)
@@ -238,26 +236,50 @@ func NewContractMD(name string, id int32, onManifestConstruction ...func(*manife
 
 // HFSpecificContractMD returns hardfork-specific native contract metadata, i.e. with methods, events and script
 // corresponding to the specified hardfork. If hardfork is not specified, then default metadata will be returned
-// (methods, events and script that are always active).
+// (methods, events and script that are always active). Calling this method for hardforks older than the contract
+// activation hardfork is a no-op.
 func (c *ContractMD) HFSpecificContractMD(hf *config.Hardfork) *HFSpecificContractMD {
 	var key config.Hardfork
 	if hf != nil {
 		key = *hf
 	}
-	c.mdCacheLock.RLock()
-	if md, ok := c.mdCache[key]; ok {
-		c.mdCacheLock.RUnlock()
-		return md
+	md, ok := c.mdCache[key]
+	if !ok {
+		panic(fmt.Errorf("native contract descriptor cache is not initialized: contract %s, hardfork %s", c.Hash.StringLE(), key))
+	}
+	if md == nil {
+		panic(fmt.Errorf("native contract descriptor cache is nil: contract %s, hardfork %s", c.Hash.StringLE(), key))
 	}
-	c.mdCacheLock.RUnlock()
-
-	md := c.buildHFSpecificMD(hf)
 	return md
 }
 
+// BuildHFSpecificMD generates and caches contract's descriptor for every known hardfork.
+func (c *ContractMD) BuildHFSpecificMD(activeIn *config.Hardfork) {
+	var start config.Hardfork
+	if activeIn != nil {
+		start = *activeIn
+	}
+
+	for _, hf := range append([]config.Hardfork{config.HFDefault}, config.Hardforks...) {
+		switch {
+		case hf.Cmp(start) < 0:
+			continue
+		case hf.Cmp(start) == 0:
+			c.buildHFSpecificMD(hf)
+		default:
+			if _, ok := c.ActiveHFs[hf]; !ok {
+				// Intentionally omit HFSpecificContractMD structure copying since mdCache is read-only.
+				c.mdCache[hf] = c.mdCache[hf.Prev()]
+				continue
+			}
+			c.buildHFSpecificMD(hf)
+		}
+	}
+}
+
 // buildHFSpecificMD builds hardfork-specific contract descriptor that includes methods and events active starting from
-// the specified hardfork or older.
-func (c *ContractMD) buildHFSpecificMD(hf *config.Hardfork) *HFSpecificContractMD {
+// the specified hardfork or older. It also updates cache with the received value.
+func (c *ContractMD) buildHFSpecificMD(hf config.Hardfork) {
 	var (
 		abiMethods = make([]manifest.Method, 0, len(c.methods))
 		methods    = make([]HFSpecificMethodAndPrice, 0, len(c.methods))
@@ -267,7 +289,7 @@ func (c *ContractMD) buildHFSpecificMD(hf *config.Hardfork) *HFSpecificContractM
 	w := io.NewBufBinWriter()
 	for i := range c.methods {
 		m := c.methods[i]
-		if !(m.ActiveFrom == nil || (hf != nil && (*m.ActiveFrom).Cmp(*hf) >= 0)) {
+		if !(m.ActiveFrom == nil || (hf != config.HFDefault && (*m.ActiveFrom).Cmp(hf) >= 0)) {
 			continue
 		}
 
@@ -289,7 +311,7 @@ func (c *ContractMD) buildHFSpecificMD(hf *config.Hardfork) *HFSpecificContractM
 	}
 	for i := range c.events {
 		e := c.events[i]
-		if !(e.ActiveFrom == nil || (hf != nil && (*e.ActiveFrom).Cmp(*hf) >= 0)) {
+		if !(e.ActiveFrom == nil || (hf != config.HFDefault && (*e.ActiveFrom).Cmp(hf) >= 0)) {
 			continue
 		}
 
@@ -314,10 +336,6 @@ func (c *ContractMD) buildHFSpecificMD(hf *config.Hardfork) *HFSpecificContractM
 	if c.onManifestConstruction != nil {
 		c.onManifestConstruction(m)
 	}
-	var key config.Hardfork
-	if hf != nil {
-		key = *hf
-	}
 	md := &HFSpecificContractMD{
 		ContractBase: state.ContractBase{
 			ID:       c.ID,
@@ -329,10 +347,7 @@ func (c *ContractMD) buildHFSpecificMD(hf *config.Hardfork) *HFSpecificContractM
 		Events:  events,
 	}
 
-	c.mdCacheLock.Lock()
-	c.mdCache[key] = md
-	c.mdCacheLock.Unlock()
-	return md
+	c.mdCache[hf] = md
 }
 
 // AddMethod adds a new method to a native contract.

pkg/core/native/crypto.go

@@ -41,6 +41,7 @@ const cryptoContractID = -3
 
 func newCrypto() *Crypto {
 	c := &Crypto{ContractMD: *interop.NewContractMD(nativenames.CryptoLib, cryptoContractID)}
+	defer c.BuildHFSpecificMD(c.ActiveIn())
 
 	desc := newDescriptor("sha256", smartcontract.ByteArrayType,
 		manifest.NewParameter("data", smartcontract.ByteArrayType))

pkg/core/native/designate.go

@@ -104,6 +104,8 @@ func (s *Designate) isValidRole(r noderoles.Role) bool {
 
 func newDesignate(p2pSigExtensionsEnabled bool, initialNodeRoles map[noderoles.Role]keys.PublicKeys) *Designate {
 	s := &Designate{ContractMD: *interop.NewContractMD(nativenames.Designation, designateContractID)}
+	defer s.BuildHFSpecificMD(s.ActiveIn())
+
 	s.p2pSigExtensionsEnabled = p2pSigExtensionsEnabled
 	s.initialNodeRoles = initialNodeRoles
 

pkg/core/native/ledger.go

@@ -31,6 +31,7 @@ func newLedger() *Ledger {
 	var l = &Ledger{
 		ContractMD: *interop.NewContractMD(nativenames.Ledger, ledgerContractID),
 	}
+	defer l.BuildHFSpecificMD(l.ActiveIn())
 
 	desc := newDescriptor("currentHash", smartcontract.Hash256Type)
 	md := newMethodAndPrice(l.currentHash, 1<<15, callflag.ReadStates)

pkg/core/native/management.go

@@ -101,6 +101,7 @@ func newManagement() *Management {
 	var m = &Management{
 		ContractMD: *interop.NewContractMD(nativenames.Management, ManagementContractID),
 	}
+	defer m.BuildHFSpecificMD(m.ActiveIn())
 
 	desc := newDescriptor("getContract", smartcontract.ArrayType,
 		manifest.NewParameter("hash", smartcontract.Hash160Type))

pkg/core/native/native_gas.go

@@ -37,6 +37,7 @@ func newGAS(init int64, p2pSigExtensionsEnabled bool) *GAS {
 		initialSupply:           init,
 		p2pSigExtensionsEnabled: p2pSigExtensionsEnabled,
 	}
+	defer g.BuildHFSpecificMD(g.ActiveIn())
 
 	nep17 := newNEP17Native(nativenames.Gas, gasContractID)
 	nep17.symbol = "GAS"

pkg/core/native/native_neo.go

@@ -172,6 +172,7 @@ func makeValidatorKey(key *keys.PublicKey) []byte {
 // newNEO returns NEO native contract.
 func newNEO(cfg config.ProtocolConfiguration) *NEO {
 	n := &NEO{}
+	defer n.BuildHFSpecificMD(n.ActiveIn())
 
 	nep17 := newNEP17Native(nativenames.Neo, neoContractID)
 	nep17.symbol = "NEO"

pkg/core/native/notary.go

@@ -73,6 +73,7 @@ func copyNotaryCache(src, dst *NotaryCache) {
 // newNotary returns Notary native contract.
 func newNotary() *Notary {
 	n := &Notary{ContractMD: *interop.NewContractMD(nativenames.Notary, notaryContractID)}
+	defer n.BuildHFSpecificMD(n.ActiveIn())
 
 	desc := newDescriptor("onNEP17Payment", smartcontract.VoidType,
 		manifest.NewParameter("from", smartcontract.Hash160Type),

pkg/core/native/oracle.go

@@ -118,6 +118,7 @@ func newOracle() *Oracle {
 		ContractMD:  *interop.NewContractMD(nativenames.Oracle, oracleContractID),
 		newRequests: make(map[uint64]*state.OracleRequest),
 	}
+	defer o.BuildHFSpecificMD(o.ActiveIn())
 
 	o.oracleScript = CreateOracleResponseScript(o.Hash)
 

pkg/core/native/policy.go

@@ -105,6 +105,7 @@ func newPolicy(p2pSigExtensionsEnabled bool) *Policy {
 		ContractMD:              *interop.NewContractMD(nativenames.Policy, policyContractID),
 		p2pSigExtensionsEnabled: p2pSigExtensionsEnabled,
 	}
+	defer p.BuildHFSpecificMD(p.ActiveIn())
 
 	desc := newDescriptor("getFeePerByte", smartcontract.IntegerType)
 	md := newMethodAndPrice(p.getFeePerByte, 1<<15, callflag.ReadStates)

pkg/core/native/std.go

@@ -46,6 +46,7 @@ var (
 
 func newStd() *Std {
 	s := &Std{ContractMD: *interop.NewContractMD(nativenames.StdLib, stdContractID)}
+	defer s.BuildHFSpecificMD(s.ActiveIn())
 
 	desc := newDescriptor("serialize", smartcontract.ByteArrayType,
 		manifest.NewParameter("item", smartcontract.AnyType))