Merge pull request #100 from OpenBazaar/query

Limit Max inflight queries to blockbook.

client/blockbook/client.go

@@ -28,6 +28,8 @@ import (
 	"golang.org/x/net/proxy"
 )
 
+const maxInfightQueries = 25
+
 var Log = logging.MustGetLogger("client")
 
 type wsWatchdog struct {
@@ -350,14 +352,19 @@ func (i *BlockBookClient) GetTransactions(addrs []btcutil.Address) ([]model.Tran
 		Txs []model.Transaction
 		Err error
 	}
-	txChan := make(chan txsOrError)
+	var (
+		txChan    = make(chan txsOrError)
+		queryChan = make(chan struct{}, maxInfightQueries)
+		wg        sync.WaitGroup
+	)
+	wg.Add(len(addrs))
 	go func() {
-		var wg sync.WaitGroup
-		wg.Add(len(addrs))
 		for _, addr := range addrs {
+			queryChan <- struct{}{}
 			go func(a btcutil.Address) {
 				txs, err := i.getTransactions(maybeConvertCashAddress(a))
 				txChan <- txsOrError{txs, err}
+				<-queryChan
 				wg.Done()
 			}(addr)
 		}
@@ -439,13 +446,20 @@ func (i *BlockBookClient) GetUtxos(addrs []btcutil.Address) ([]model.Utxo, error
 		Utxo *model.Utxo
 		Err  error
 	}
-	utxoChan := make(chan utxoOrError)
-	var wg sync.WaitGroup
+	var (
+		wg        sync.WaitGroup
+		queryChan = make(chan struct{}, maxInfightQueries)
+		utxoChan  = make(chan utxoOrError)
+	)
 	wg.Add(len(addrs))
 	go func() {
 		for _, addr := range addrs {
+			queryChan <- struct{}{}
 			go func(addr btcutil.Address) {
 				defer wg.Done()
+				defer func() {
+					<-queryChan
+				}()
 				resp, err := i.RequestFunc("/utxo/"+maybeConvertCashAddress(addr), http.MethodGet, nil, nil)
 				if err != nil {
 					utxoChan <- utxoOrError{nil, err}

litecoin/address/address.go

@@ -160,26 +160,24 @@ func DecodeAddress(addr string, defaultNet *chaincfg.Params) (Address, error) {
 		prefix := addr[:oneIndex+1]
 		if IsBech32SegwitPrefix(prefix) {
 			witnessVer, witnessProg, err := decodeSegWitAddress(addr)
-			if err != nil {
-				return nil, err
-			}
-
-			// We currently only support P2WPKH and P2WSH, which is
-			// witness version 0.
-			if witnessVer != 0 {
-				return nil, UnsupportedWitnessVerError(witnessVer)
-			}
-
-			// The HRP is everything before the found '1'.
-			hrp := prefix[:len(prefix)-1]
-
-			switch len(witnessProg) {
-			case 20:
-				return newAddressWitnessPubKeyHash(hrp, witnessProg)
-			case 32:
-				return newAddressWitnessScriptHash(hrp, witnessProg)
-			default:
-				return nil, UnsupportedWitnessProgLenError(len(witnessProg))
+			if err == nil {
+				// We currently only support P2WPKH and P2WSH, which is
+				// witness version 0.
+				if witnessVer != 0 {
+					return nil, UnsupportedWitnessVerError(witnessVer)
+				}
+
+				// The HRP is everything before the found '1'.
+				hrp := prefix[:len(prefix)-1]
+
+				switch len(witnessProg) {
+				case 20:
+					return newAddressWitnessPubKeyHash(hrp, witnessProg)
+				case 32:
+					return newAddressWitnessScriptHash(hrp, witnessProg)
+				default:
+					return nil, UnsupportedWitnessProgLenError(len(witnessProg))
+				}
 			}
 		}
 	}