chore(btcclient): reduce rpc calls (#51)

Reduces the number of RPC calls in methods by combining them.

[References issue](babylonchain/vigilante#218)

btcclient/interface.go

@@ -14,7 +14,7 @@ import (
 type BTCClient interface {
 	Stop()
 	WaitForShutdown()
-	GetBestBlock() (*chainhash.Hash, uint64, error)
+	GetBestBlock() (uint64, error)
 	GetBlockByHash(blockHash *chainhash.Hash) (*types.IndexedBlock, *wire.MsgBlock, error)
 	FindTailBlocksByHeight(height uint64) ([]*types.IndexedBlock, error)
 	GetBlockByHeight(height uint64) (*types.IndexedBlock, *wire.MsgBlock, error)

btcclient/query.go

@@ -12,20 +12,14 @@ import (
 	"github.com/babylonlabs-io/vigilante/types"
 )
 
-// GetBestBlock provides similar functionality with the btcd.rpcclient.GetBestBlock function
-// We implement this, because this function is only provided by btcd.
-// TODO: replace two rpc calls with only one c.GetBlockCount
-func (c *Client) GetBestBlock() (*chainhash.Hash, uint64, error) {
-	btcLatestBlockHash, err := c.getBestBlockHashWithRetry()
+// GetBestBlock returns the height of the best block
+func (c *Client) GetBestBlock() (uint64, error) {
+	height, err := c.getBlockCountWithRetry()
 	if err != nil {
-		return nil, 0, err
+		return 0, err
 	}
-	btcLatestBlock, err := c.getBlockVerboseWithRetry(btcLatestBlockHash)
-	if err != nil {
-		return nil, 0, err
-	}
-	btcLatestBlockHeight := uint64(btcLatestBlock.Height)
-	return btcLatestBlockHash, btcLatestBlockHeight, nil
+
+	return uint64(height), nil
 }
 
 func (c *Client) GetBlockByHash(blockHash *chainhash.Hash) (*types.IndexedBlock, *wire.MsgBlock, error) {
@@ -213,3 +207,26 @@ func (c *Client) FindTailBlocksByHeight(baseHeight uint64) ([]*types.IndexedBloc
 
 	return c.getChainBlocks(baseHeight, tipIb)
 }
+
+func (c *Client) getBlockCountWithRetry() (int64, error) {
+	var (
+		height int64
+		err    error
+	)
+
+	if err = retry.Do(func() error {
+		height, err = c.GetBlockCount()
+		if err != nil {
+			return err
+		}
+		return nil
+	},
+		retry.Delay(c.retrySleepTime),
+		retry.MaxDelay(c.maxRetrySleepTime),
+		retry.Attempts(c.maxRetryTimes),
+	); err != nil {
+		c.logger.Debug("failed to query get block count", zap.Error(err))
+	}
+
+	return height, nil
+}

monitor/btcscanner/btc_scanner.go

@@ -152,7 +152,7 @@ func (bs *BtcScanner) Bootstrap() {
 	// clear all the blocks in the cache to avoid forks
 	bs.unconfirmedBlockCache.RemoveAll()
 
-	_, bestHeight, err := bs.btcClient.GetBestBlock()
+	bestHeight, err := bs.btcClient.GetBestBlock()
 	if err != nil {
 		panic(fmt.Errorf("cannot get the best BTC block %w", err))
 	}

monitor/btcscanner/btc_scanner_test.go

@@ -30,7 +30,7 @@ func FuzzBootStrap(f *testing.F) {
 		defer ctl.Finish()
 		mockBtcClient := mocks.NewMockBTCClient(ctl)
 		confirmedBlocks := chainIndexedBlocks[:numBlocks-k]
-		mockBtcClient.EXPECT().GetBestBlock().Return(nil, uint64(bestHeight), nil)
+		mockBtcClient.EXPECT().GetBestBlock().Return(uint64(bestHeight), nil)
 		for i := 0; i < int(numBlocks); i++ {
 			mockBtcClient.EXPECT().GetBlockByHeight(gomock.Eq(uint64(chainIndexedBlocks[i].Height))).
 				Return(chainIndexedBlocks[i], nil, nil).AnyTimes()

reporter/bootstrapping.go

@@ -233,7 +233,7 @@ func (r *Reporter) waitUntilBTCSync() error {
 	)
 
 	// Retrieve hash/height of the latest block in BTC
-	btcLatestBlockHash, btcLatestBlockHeight, err = r.btcClient.GetBestBlock()
+	btcLatestBlockHeight, err = r.btcClient.GetBestBlock()
 	if err != nil {
 		return err
 	}
@@ -264,7 +264,7 @@ func (r *Reporter) waitUntilBTCSync() error {
 		// When BTC catches up, break and continue the bootstrapping process
 		ticker := time.NewTicker(5 * time.Second) // TODO: parameterise the polling interval
 		for range ticker.C {
-			_, btcLatestBlockHeight, err = r.btcClient.GetBestBlock()
+			btcLatestBlockHeight, err = r.btcClient.GetBestBlock()
 			if err != nil {
 				return err
 			}