[#905] morph/client: Fetch NNS hash once on init

NNS contract hash is taken from the contract with ID=1.
Because morph client is expected to work with the same chain,
and because contract hash doesn't change on update, there is no need to
fetch it from each new endpoint.

Change-Id: Ic6dc18283789da076d6a0b3701139b97037714cc
Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>

pkg/morph/client/client.go

@@ -60,6 +60,7 @@ type Client struct {
 	rpcActor *actor.Actor        // neo-go RPC actor
 	gasToken *nep17.Token        // neo-go GAS token wrapper
 	rolemgmt *rolemgmt.Contract  // neo-go Designation contract wrapper
+	nnsHash  util.Uint160        // NNS contract hash
 
 	acc     *wallet.Account // neo account
 	accAddr util.Uint160    // account's address
@@ -94,27 +95,12 @@ type Client struct {
 type cache struct {
 	m sync.RWMutex
 
-	nnsHash   *util.Uint160
 	gKey      *keys.PublicKey
 	txHeights *lru.Cache[util.Uint256, uint32]
 
 	metrics metrics.MorphCacheMetrics
 }
 
-func (c *cache) nns() *util.Uint160 {
-	c.m.RLock()
-	defer c.m.RUnlock()
-
-	return c.nnsHash
-}
-
-func (c *cache) setNNSHash(nnsHash util.Uint160) {
-	c.m.Lock()
-	defer c.m.Unlock()
-
-	c.nnsHash = &nnsHash
-}
-
 func (c *cache) groupKey() *keys.PublicKey {
 	c.m.RLock()
 	defer c.m.RUnlock()
@@ -133,7 +119,6 @@ func (c *cache) invalidate() {
 	c.m.Lock()
 	defer c.m.Unlock()
 
-	c.nnsHash = nil
 	c.gKey = nil
 	c.txHeights.Purge()
 }

pkg/morph/client/constructor.go

@@ -145,6 +145,11 @@ func New(ctx context.Context, key *keys.PrivateKey, opts ...Option) (*Client, er
 	if cli.client == nil {
 		return nil, ErrNoHealthyEndpoint
 	}
+	cs, err := cli.client.GetContractStateByID(nnsContractID)
+	if err != nil {
+		return nil, fmt.Errorf("resolve nns hash: %w", err)
+	}
+	cli.nnsHash = cs.Hash
 	cli.setActor(act)
 
 	go cli.closeWaiter(ctx)

pkg/morph/client/nns.go

@@ -61,11 +61,7 @@ func (c *Client) NNSContractAddress(name string) (sh util.Uint160, err error) {
 		return util.Uint160{}, ErrConnectionLost
 	}
 
-	nnsHash, err := c.NNSHash()
-	if err != nil {
-		return util.Uint160{}, err
-	}
-
+	nnsHash := c.NNSHash()
 	sh, err = nnsResolve(c.client, nnsHash, name)
 	if err != nil {
 		return sh, fmt.Errorf("NNS.resolve: %w", err)
@@ -74,34 +70,8 @@ func (c *Client) NNSContractAddress(name string) (sh util.Uint160, err error) {
 }
 
 // NNSHash returns NNS contract hash.
-func (c *Client) NNSHash() (util.Uint160, error) {
-	c.switchLock.RLock()
-	defer c.switchLock.RUnlock()
-
-	if c.inactive {
-		return util.Uint160{}, ErrConnectionLost
-	}
-
-	success := false
-	startedAt := time.Now()
-
-	defer func() {
-		c.cache.metrics.AddMethodDuration("NNSContractHash", success, time.Since(startedAt))
-	}()
-
-	nnsHash := c.cache.nns()
-
-	if nnsHash == nil {
-		cs, err := c.client.GetContractStateByID(nnsContractID)
-		if err != nil {
-			return util.Uint160{}, fmt.Errorf("NNS contract state: %w", err)
-		}
-
-		c.cache.setNNSHash(cs.Hash)
-		nnsHash = &cs.Hash
-	}
-	success = true
-	return *nnsHash, nil
+func (c *Client) NNSHash() util.Uint160 {
+	return c.nnsHash
 }
 
 func nnsResolveItem(c *rpcclient.WSClient, nnsHash util.Uint160, domain string) (stackitem.Item, error) {
@@ -241,11 +211,7 @@ func (c *Client) contractGroupKey() (*keys.PublicKey, error) {
 		return gKey, nil
 	}
 
-	nnsHash, err := c.NNSHash()
-	if err != nil {
-		return nil, err
-	}
-
+	nnsHash := c.NNSHash()
 	item, err := nnsResolveItem(c.client, nnsHash, NNSGroupKeyName)
 	if err != nil {
 		return nil, err