Add custom/raw request/response support.

chain.go

@@ -7,7 +7,7 @@ package btcrpcclient
 import (
 	"bytes"
 	"encoding/hex"
-	"fmt"
+	"encoding/json"
 	"github.com/conformal/btcjson"
 	"github.com/conformal/btcutil"
 	"github.com/conformal/btcwire"
@@ -15,23 +15,22 @@ import (
 
 // FutureGetBestBlockHashResult is a future promise to deliver the result of a
 // GetBestBlockAsync RPC invocation (or an applicable error).
-type FutureGetBestBlockHashResult chan *futureResult
+type FutureGetBestBlockHashResult chan *response
 
 // Receive waits for the response promised by the future and returns the hash of
 // the best block in the longest block chain.
 func (r FutureGetBestBlockHashResult) Receive() (*btcwire.ShaHash, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return nil, err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmarshal result as a string.
-	txHashStr, ok := reply.(string)
+	var txHashStr string
-	if !ok {
+	err = json.Unmarshal(res, &txHashStr)
-		return nil, fmt.Errorf("unexpected response type for "+
+	if err != nil {
-			"getbestblockhash: %T\n", reply)
+		return nil, err
 	}
-
 	return btcwire.NewShaHashFromStr(txHashStr)
 }
 
@@ -58,21 +57,21 @@ func (c *Client) GetBestBlockHash() (*btcwire.ShaHash, error) {
 
 // FutureGetBlockResult is a future promise to deliver the result of a
 // GetBlockAsync RPC invocation (or an applicable error).
-type FutureGetBlockResult chan *futureResult
+type FutureGetBlockResult chan *response
 
 // Receive waits for the response promised by the future and returns the raw
 // block requested from the server given its hash.
 func (r FutureGetBlockResult) Receive() (*btcutil.Block, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return nil, err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmarshal result as a string.
-	blockHex, ok := reply.(string)
+	var blockHex string
-	if !ok {
+	err = json.Unmarshal(res, &blockHex)
-		return nil, fmt.Errorf("unexpected response type for "+
+	if err != nil {
-			"getblock (verbose=0): %T\n", reply)
+		return nil, err
 	}
 
 	// Decode the serialized block hex to raw bytes.
@@ -120,24 +119,23 @@ func (c *Client) GetBlock(blockHash *btcwire.ShaHash) (*btcutil.Block, error) {
 
 // FutureGetBlockVerboseResult is a future promise to deliver the result of a
 // GetBlockVerboseAsync RPC invocation (or an applicable error).
-type FutureGetBlockVerboseResult chan *futureResult
+type FutureGetBlockVerboseResult chan *response
 
 // Receive waits for the response promised by the future and returns the data
 // structure from the server with information about the requested block.
 func (r FutureGetBlockVerboseResult) Receive() (*btcjson.BlockResult, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return nil, err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmarshal the raw result into a BlockResult.
-	blockResult, ok := reply.(*btcjson.BlockResult)
+	var blockResult btcjson.BlockResult
-	if !ok {
+	err = json.Unmarshal(res, &blockResult)
-		return nil, fmt.Errorf("unexpected response type for "+
+	if err != nil {
-			"getblock (verbose=1): %T\n", reply)
+		return nil, err
 	}
-
+	return &blockResult, nil
-	return blockResult, nil
 }
 
 // GetBlockVerboseAsync returns an instance of a type that can be used to get
@@ -170,24 +168,23 @@ func (c *Client) GetBlockVerbose(blockHash *btcwire.ShaHash, verboseTx bool) (*b
 
 // FutureGetBlockCountResult is a future promise to deliver the result of a
 // GetBlockCountAsync RPC invocation (or an applicable error).
-type FutureGetBlockCountResult chan *futureResult
+type FutureGetBlockCountResult chan *response
 
 // Receive waits for the response promised by the future and returns the number
 // of blocks in the longest block chain.
 func (r FutureGetBlockCountResult) Receive() (int64, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return 0, err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmarshal the result as an int64.
-	count, ok := reply.(float64)
+	var count int64
-	if !ok {
+	err = json.Unmarshal(res, &count)
-		return 0, fmt.Errorf("unexpected response type for "+
+	if err != nil {
-			"getblockcount: %T\n", reply)
+		return 0, err
 	}
-
+	return count, nil
-	return int64(count), nil
 }
 
 // GetBlockCountAsync returns an instance of a type that can be used to get the
@@ -212,23 +209,22 @@ func (c *Client) GetBlockCount() (int64, error) {
 
 // FutureGetDifficultyResult is a future promise to deliver the result of a
 // GetDifficultyAsync RPC invocation (or an applicable error).
-type FutureGetDifficultyResult chan *futureResult
+type FutureGetDifficultyResult chan *response
 
 // Receive waits for the response promised by the future and returns the
 // proof-of-work difficulty as a multiple of the minimum difficulty.
 func (r FutureGetDifficultyResult) Receive() (float64, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return 0, err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmarshal the result as a float64.
-	difficulty, ok := reply.(float64)
+	var difficulty float64
-	if !ok {
+	err = json.Unmarshal(res, &difficulty)
-		return 0, fmt.Errorf("unexpected response type for "+
+	if err != nil {
-			"getdifficulty: %T\n", reply)
+		return 0, err
 	}
-
 	return difficulty, nil
 }
 
@@ -255,23 +251,22 @@ func (c *Client) GetDifficulty() (float64, error) {
 
 // FutureGetBlockHashResult is a future promise to deliver the result of a
 // GetBlockHashAsync RPC invocation (or an applicable error).
-type FutureGetBlockHashResult chan *futureResult
+type FutureGetBlockHashResult chan *response
 
 // Receive waits for the response promised by the future and returns the hash of
 // the block in the best block chain at the given height.
 func (r FutureGetBlockHashResult) Receive() (*btcwire.ShaHash, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return nil, err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmarshal the result as a string-encoded sha.
-	txHashStr, ok := reply.(string)
+	var txHashStr string
-	if !ok {
+	err = json.Unmarshal(res, &txHashStr)
-		return nil, fmt.Errorf("unexpected response type for "+
+	if err != nil {
-			"getblockhash: %T\n", reply)
+		return nil, err
 	}
-
 	return btcwire.NewShaHashFromStr(txHashStr)
 }
 
@@ -298,23 +293,24 @@ func (c *Client) GetBlockHash(blockHeight int64) (*btcwire.ShaHash, error) {
 
 // FutureGetRawMempoolResult is a future promise to deliver the result of a
 // GetRawMempoolAsync RPC invocation (or an applicable error).
-type FutureGetRawMempoolResult chan *futureResult
+type FutureGetRawMempoolResult chan *response
 
 // Receive waits for the response promised by the future and returns the hashes
 // of all transactions in the memory pool.
 func (r FutureGetRawMempoolResult) Receive() ([]*btcwire.ShaHash, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return nil, err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmarshal the result as an array of strings.
-	txHashStrs, ok := reply.([]string)
+	var txHashStrs []string
-	if !ok {
+	err = json.Unmarshal(res, &txHashStrs)
-		return nil, fmt.Errorf("unexpected response type for "+
+	if err != nil {
-			"getrawmempool (verbose=false): %T\n", reply)
+		return nil, err
 	}
 
+	// Create a slice of ShaHash arrays from the string slice.
 	txHashes := make([]*btcwire.ShaHash, 0, len(txHashStrs))
 	for _, hashStr := range txHashStrs {
 		txHash, err := btcwire.NewShaHashFromStr(hashStr)
@@ -352,24 +348,24 @@ func (c *Client) GetRawMempool() ([]*btcwire.ShaHash, error) {
 
 // FutureGetRawMempoolVerboseResult is a future promise to deliver the result of
 // a GetRawMempoolVerboseAsync RPC invocation (or an applicable error).
-type FutureGetRawMempoolVerboseResult chan *futureResult
+type FutureGetRawMempoolVerboseResult chan *response
 
 // Receive waits for the response promised by the future and returns a map of
 // transaction hashes to an associated data structure with information about the
 // transaction for all transactions in the memory pool.
 func (r FutureGetRawMempoolVerboseResult) Receive() (map[string]btcjson.GetRawMempoolResult, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return nil, err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmarshal the result as a map of strings (tx shas) to their detailed
-	mempoolItems, ok := reply.(map[string]btcjson.GetRawMempoolResult)
+	// results.
-	if !ok {
+	var mempoolItems map[string]btcjson.GetRawMempoolResult
-		return nil, fmt.Errorf("unexpected response type for "+
+	err = json.Unmarshal(res, &mempoolItems)
-			"getrawmempool (verbose=true): %T\n", reply)
+	if err != nil {
+		return nil, err
 	}
-
 	return mempoolItems, nil
 }
 
@@ -400,24 +396,23 @@ func (c *Client) GetRawMempoolVerbose() (map[string]btcjson.GetRawMempoolResult,
 // FutureVerifyChainResult is a future promise to deliver the result of a
 // VerifyChainAsync, VerifyChainLevelAsyncRPC, or VerifyChainBlocksAsync
 // invocation (or an applicable error).
-type FutureVerifyChainResult chan *futureResult
+type FutureVerifyChainResult chan *response
 
 // Receive waits for the response promised by the future and returns whether
 // or not the chain verified based on the check level and number of blocks
 // to verify specified in the original call.
 func (r FutureVerifyChainResult) Receive() (bool, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return false, err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmarshal the result as a boolean.
-	verified, ok := reply.(bool)
+	var verified bool
-	if !ok {
+	err = json.Unmarshal(res, &verified)
-		return false, fmt.Errorf("unexpected response type for "+
+	if err != nil {
-			"verifychain: %T\n", reply)
+		return false, err
 	}
-
 	return verified, nil
 }
 

extensions.go

@@ -6,6 +6,7 @@ package btcrpcclient
 
 import (
 	"encoding/base64"
+	"encoding/json"
 	"fmt"
 	"github.com/conformal/btcjson"
 	"github.com/conformal/btcutil"
@@ -15,24 +16,23 @@ import (
 
 // FutureDebugLevelResult is a future promise to deliver the result of a
 // DebugLevelAsync RPC invocation (or an applicable error).
-type FutureDebugLevelResult chan *futureResult
+type FutureDebugLevelResult chan *response
 
 // Receive waits for the response promised by the future and returns the result
 // of setting the debug logging level to the passed level specification or the
 // list of of the available subsystems for the special keyword 'show'.
 func (r FutureDebugLevelResult) Receive() (string, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return "", err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmashal the result as a string.
-	result, ok := reply.(string)
+	var result string
-	if !ok {
+	err = json.Unmarshal(res, &result)
-		return "", fmt.Errorf("unexpected response type for "+
+	if err != nil {
-			"debuglevel: %T\n", reply)
+		return "", err
 	}
-
 	return result, nil
 }
 
@@ -69,7 +69,7 @@ func (c *Client) DebugLevel(levelSpec string) (string, error) {
 
 // FutureCreateEncryptedWalletResult is a future promise to deliver the error
 // result of a CreateEncryptedWalletAsync RPC invocation.
-type FutureCreateEncryptedWalletResult chan *futureResult
+type FutureCreateEncryptedWalletResult chan *response
 
 // Receive waits for and returns the error response promised by the future.
 func (r FutureCreateEncryptedWalletResult) Receive() error {
@@ -104,28 +104,22 @@ func (c *Client) CreateEncryptedWallet(passphrase string) error {
 
 // FutureListAddressTransactionsResult is a future promise to deliver the result
 // of a ListAddressTransactionsAsync RPC invocation (or an applicable error).
-type FutureListAddressTransactionsResult chan *futureResult
+type FutureListAddressTransactionsResult chan *response
 
 // Receive waits for the response promised by the future and returns information
 // about all transactions associated with the provided addresses.
 func (r FutureListAddressTransactionsResult) Receive() ([]btcjson.ListTransactionsResult, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return nil, err
 	}
 
-	// No transactions.
+	// Unmarshal the result as an array of listtransactions objects.
-	if reply == nil {
+	var transactions []btcjson.ListTransactionsResult
-		return nil, nil
+	err = json.Unmarshal(res, &transactions)
+	if err != nil {
+		return nil, err
 	}
-
-	// Ensure the returned data is the expected type.
-	transactions, ok := reply.([]btcjson.ListTransactionsResult)
-	if !ok {
-		return nil, fmt.Errorf("unexpected response type for "+
-			"listaddresstransactions: %T\n", reply)
-	}
-
 	return transactions, nil
 }
 
@@ -161,30 +155,30 @@ func (c *Client) ListAddressTransactions(addresses []btcutil.Address, account st
 
 // FutureGetBestBlockResult is a future promise to deliver the result of a
 // GetBestBlockAsync RPC invocation (or an applicable error).
-type FutureGetBestBlockResult chan *futureResult
+type FutureGetBestBlockResult chan *response
 
 // Receive waits for the response promised by the future and returns the hash
 // and height of the block in the longest (best) chain.
 func (r FutureGetBestBlockResult) Receive() (*btcwire.ShaHash, int32, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return nil, 0, err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmarsal result as a getbestblock result object.
-	result, ok := reply.(*btcws.GetBestBlockResult)
+	var bestBlock btcws.GetBestBlockResult
-	if !ok {
+	err = json.Unmarshal(res, &bestBlock)
-		return nil, 0, fmt.Errorf("unexpected response type for "+
+	if err != nil {
-			"getbestblock: %T\n", reply)
+		return nil, 0, err
 	}
 
 	// Convert hash string.
-	hash, err := btcwire.NewShaHashFromStr(result.Hash)
+	hash, err := btcwire.NewShaHashFromStr(bestBlock.Hash)
 	if err != nil {
 		return nil, 0, err
 	}
 
-	return hash, result.Height, nil
+	return hash, bestBlock.Height, nil
 }
 
 // GetBestBlockAsync returns an instance of a type that can be used to get the
@@ -211,24 +205,24 @@ func (c *Client) GetBestBlock() (*btcwire.ShaHash, int32, error) {
 
 // FutureGetCurrentNetResult is a future promise to deliver the result of a
 // GetCurrentNetAsync RPC invocation (or an applicable error).
-type FutureGetCurrentNetResult chan *futureResult
+type FutureGetCurrentNetResult chan *response
 
 // Receive waits for the response promised by the future and returns the network
 // the server is running on.
 func (r FutureGetCurrentNetResult) Receive() (btcwire.BitcoinNet, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return 0, err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmarshal result as an int64.
-	fnet, ok := reply.(float64)
+	var net int64
-	if !ok {
+	err = json.Unmarshal(res, &net)
-		return 0, fmt.Errorf("unexpected response type for "+
+	if err != nil {
-			"getcurrentnet: %T\n", reply)
+		return 0, err
 	}
 
-	return btcwire.BitcoinNet(fnet), nil
+	return btcwire.BitcoinNet(net), nil
 }
 
 // GetCurrentNetAsync returns an instance of a type that can be used to get the
@@ -254,34 +248,35 @@ func (c *Client) GetCurrentNet() (btcwire.BitcoinNet, error) {
 
 // FutureExportWatchingWalletResult is a future promise to deliver the result of
 // an ExportWatchingWalletAsync RPC invocation (or an applicable error).
-type FutureExportWatchingWalletResult chan *futureResult
+type FutureExportWatchingWalletResult chan *response
 
 // Receive waits for the response promised by the future and returns the
 // exported wallet.
 func (r FutureExportWatchingWalletResult) Receive() ([]byte, []byte, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return nil, nil, err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmarshal result as a JSON object.
-	result, ok := reply.(map[string]interface{})
+	var obj map[string]interface{}
-	if !ok {
+	err = json.Unmarshal(res, &obj)
-		return nil, nil, fmt.Errorf("unexpected response type for "+
+	if err != nil {
-			"exportwatchingwallet: %T\n", reply)
+		return nil, nil, err
 	}
 
-	base64Wallet, ok := result["wallet"].(string)
+	// Check for the wallet and tx string fields in the object.
+	base64Wallet, ok := obj["wallet"].(string)
 	if !ok {
 		return nil, nil, fmt.Errorf("unexpected response type for "+
 			"exportwatchingwallet 'wallet' field: %T\n",
-			result["wallet"])
+			obj["wallet"])
 	}
-	base64TxStore, ok := result["tx"].(string)
+	base64TxStore, ok := obj["tx"].(string)
 	if !ok {
 		return nil, nil, fmt.Errorf("unexpected response type for "+
 			"exportwatchingwallet 'tx' field: %T\n",
-			result["tx"])
+			obj["tx"])
 	}
 
 	walletBytes, err := base64.StdEncoding.DecodeString(base64Wallet)

infrastructure.go

@@ -64,27 +64,20 @@ const (
 	connectionRetryInterval = time.Second * 5
 )
 
-// futureResult holds information about a future promise to deliver the result
-// of an asynchronous request.
-type futureResult struct {
-	reply *btcjson.Reply
-	err   error
-}
-
 // sendPostDetails houses an HTTP POST request to send to an RPC server as well
 // as the original JSON-RPC command and a channel to reply on when the server
 // responds with the result.
 type sendPostDetails struct {
 	command      btcjson.Cmd
 	request      *http.Request
-	responseChan chan *futureResult
+	responseChan chan *response
 }
 
 // jsonRequest holds information about a json request that is used to properly
 // detect, interpret, and deliver a reply to it.
 type jsonRequest struct {
 	cmd          btcjson.Cmd
-	responseChan chan *futureResult
+	responseChan chan *response
 }
 
 // Client represents a Bitcoin RPC client which allows easy access to the
@@ -231,70 +224,96 @@ func (c *Client) trackRegisteredNtfns(cmd btcjson.Cmd) {
 	}
 }
 
-// handleMessage is the main handler for incoming requests.  It enforces
+type (
-// authentication, parses the incoming json, looks up and executes handlers
+	// inMessage is the first type that an incoming message is unmarshaled
-// (including pass through for standard RPC commands), sends the appropriate
+	// into. It supports both requests (for notification support) and
-// response.  It also detects commands which are marked as long-running and
+	// responses.  The partially-unmarshaled message is a notification if
-// sends them off to the asyncHander for processing.
+	// the embedded ID (from the response) is nil.  Otherwise, it is a
+	// response.
+	inMessage struct {
+		ID *uint64 `json:"id"`
+		*rawNotification
+		*rawResponse
+	}
+
+	// rawNotification is a partially-unmarshaled JSON-RPC notification.
+	rawNotification struct {
+		Method string            `json:"method"`
+		Params []json.RawMessage `json:"params"`
+	}
+
+	// rawResponse is a partially-unmarshaled JSON-RPC response.  For this
+	// to be valid (according to JSON-RPC 1.0 spec), ID may not be nil.
+	rawResponse struct {
+		Result json.RawMessage `json:"result"`
+		Error  *btcjson.Error  `json:"error"`
+	}
+)
+
+// response is the raw bytes of a JSON-RPC result, or the error if the response
+// error object was non-null.
+type response struct {
+	result []byte
+	err    error
+}
+
+// result checks whether the unmarshaled response contains a non-nil error,
+// returning an unmarshaled btcjson.Error (or an unmarshaling error) if so.
+// If the response is not an error, the raw bytes of the request are
+// returned for further unmashaling into specific result types.
+func (r rawResponse) result() (result []byte, err error) {
+	if r.Error != nil {
+		return nil, r.Error
+	}
+	return r.Result, nil
+}
+
+// handleMessage is the main handler for incoming notifications and responses.
 func (c *Client) handleMessage(msg []byte) {
-	// Attempt to unmarshal the message as a known JSON-RPC command.
+	// Attempt to unmarshal the message as either a notifiation or response.
-	if cmd, err := btcjson.ParseMarshaledCmd(msg); err == nil {
+	in := inMessage{}
-		// Commands that have an ID associated with them are not
+	err := json.Unmarshal(msg, &in)
-		// notifications.  Since this is a client, it should not
+	if err != nil {
-		// be receiving non-notifications.
+		log.Warnf("Remote server sent invalid message: %v", err)
-		if cmd.Id() != nil {
+		return
-			// Invalid response
+	}
-			log.Warnf("Remote server sent a non-notification "+
+
-				"JSON-RPC Request (Id: %v)", cmd.Id())
+	// JSON-RPC 1.0 notifications are requests with a null id.
+	if in.ID == nil {
+		ntfn := in.rawNotification
+		if ntfn == nil {
+			log.Warn("Malformed notification: missing " +
+				"method and parameters")
+			return
+		}
+		if ntfn.Method == "" {
+			log.Warn("Malformed notification: missing method")
+			return
+		}
+		// params are not optional: nil isn't valid (but len == 0 is)
+		if ntfn.Params == nil {
+			log.Warn("Malformed notification: missing params")
 			return
 		}
-
 		// Deliver the notification.
-		log.Tracef("Received notification [%s]", cmd.Method())
+		log.Tracef("Received notification [%s]", in.Method)
-		c.handleNotification(cmd)
+		c.handleNotification(in.rawNotification)
 		return
 	}
 
-	// The message was not a command/notification, so it should be a reply
+	if in.rawResponse == nil {
-	// to a previous request.
+		log.Warn("Malformed response: missing result and error")
-
-	var r btcjson.Reply
-	if err := json.Unmarshal([]byte(msg), &r); err != nil {
-		log.Warnf("Unable to unmarshal inbound message as " +
-			"notification or response")
 		return
 	}
 
-	// Ensure the reply has an id.
+	id := *in.ID
-	if r.Id == nil {
+	log.Tracef("Received response for id %d (result %s)", id, in.Result)
-		log.Warnf("Received response with no id")
-		return
-	}
-
-	// Ensure the id is the expected type.
-	fid, ok := (*r.Id).(float64)
-	if !ok {
-		log.Warnf("Received unexpected id type: %T (value %v)",
-			*r.Id, *r.Id)
-		return
-	}
-	id := uint64(fid)
-	log.Tracef("Received response for id %d (result %v)", id, r.Result)
 	request := c.removeRequest(id)
 
 	// Nothing more to do if there is no request associated with this reply.
 	if request == nil || request.responseChan == nil {
-		log.Warnf("Received unexpected reply: %s (id %d)", r.Result, id)
+		log.Warnf("Received unexpected reply: %s (id %d)", in.Result,
-		return
+			id)
-	}
-
-	// Unmarshal the reply into a concrete result if possible and deliver
-	// it to the associated channel.
-	reply, err := btcjson.ReadResultCmd(request.cmd.Method(), []byte(msg))
-	if err != nil {
-		log.Warnf("Failed to unmarshal reply to command [%s] "+
-			"(id %d): %v", request.cmd.Method(), id, err)
-		request.responseChan <- &futureResult{reply: nil, err: err}
 		return
 	}
 
@@ -303,8 +322,9 @@ func (c *Client) handleMessage(msg []byte) {
 	// can automatically be re-established on reconnect.
 	c.trackRegisteredNtfns(request.cmd)
 
-	// Deliver the reply.
+	// Deliver the response.
-	request.responseChan <- &futureResult{reply: &reply, err: nil}
+	result, err := in.rawResponse.result()
+	request.responseChan <- &response{result: result, err: err}
 }
 
 // wsInHandler handles all incoming messages for the websocket connection
@@ -576,24 +596,17 @@ func (c *Client) handleSendPostMessage(details *sendPostDetails) {
 	log.Tracef("Sending command [%s] with id %d", cmd.Method(), cmd.Id())
 	httpResponse, err := c.httpClient.Do(details.request)
 	if err != nil {
-		details.responseChan <- &futureResult{reply: nil, err: err}
+		details.responseChan <- &response{result: nil, err: err}
 		return
 	}
 
 	// Read the raw bytes and close the response.
-	respBytes, err := btcjson.GetRaw(httpResponse.Body)
+	resp, err := btcjson.GetRaw(httpResponse.Body)
 	if err != nil {
-		details.responseChan <- &futureResult{reply: nil, err: err}
+		details.responseChan <- &response{result: nil, err: err}
 		return
 	}
-
+	details.responseChan <- &response{result: resp, err: nil}
-	// Unmarshal the reply into a concrete result if possible.
-	reply, err := btcjson.ReadResultCmd(cmd.Method(), respBytes)
-	if err != nil {
-		details.responseChan <- &futureResult{reply: nil, err: err}
-		return
-	}
-	details.responseChan <- &futureResult{reply: &reply, err: nil}
 }
 
 // sendPostHandler handles all outgoing messages when the client is running
@@ -620,9 +633,9 @@ cleanup:
 	for {
 		select {
 		case details := <-c.sendPostChan:
-			details.responseChan <- &futureResult{
+			details.responseChan <- &response{
-				reply: nil,
+				result: nil,
-				err:   ErrClientShutdown,
+				err:    ErrClientShutdown,
 			}
 
 		default:
@@ -637,17 +650,17 @@ cleanup:
 // sendPostRequest sends the passed HTTP request to the RPC server using the
 // HTTP client associated with the client.  It is backed by a buffered channel,
 // so it will not block until the send channel is full.
-func (c *Client) sendPostRequest(req *http.Request, command btcjson.Cmd, responseChan chan *futureResult) {
+func (c *Client) sendPostRequest(req *http.Request, command btcjson.Cmd, responseChan chan *response) {
 	// Don't send the message if shutting down.
 	select {
 	case <-c.shutdown:
-		responseChan <- &futureResult{reply: nil, err: ErrClientShutdown}
+		responseChan <- &response{result: nil, err: ErrClientShutdown}
 	default:
 	}
 
 	c.sendPostChan <- &sendPostDetails{
-		request:      req,
 		command:      command,
+		request:      req,
 		responseChan: responseChan,
 	}
 }
@@ -655,9 +668,9 @@ func (c *Client) sendPostRequest(req *http.Request, command btcjson.Cmd, respons
 // newFutureError returns a new future result channel that already has the
 // passed error waitin on the channel with the reply set to nil.  This is useful
 // to easily return errors from the various Async functions.
-func newFutureError(err error) chan *futureResult {
+func newFutureError(err error) chan *response {
-	responseChan := make(chan *futureResult, 1)
+	responseChan := make(chan *response, 1)
-	responseChan <- &futureResult{err: err}
+	responseChan <- &response{err: err}
 	return responseChan
 }
 
@@ -665,27 +678,10 @@ func newFutureError(err error) chan *futureResult {
 // reply or any errors.  The examined errors include an error in the
 // futureResult and the error in the reply from the server.  This will block
 // until the result is available on the passed channel.
-func receiveFuture(responseChan chan *futureResult) (interface{}, error) {
+func receiveFuture(f chan *response) ([]byte, error) {
 	// Wait for a response on the returned channel.
-	response := <-responseChan
+	r := <-f
-	if response.err != nil {
+	return r.result, r.err
-		return nil, response.err
-	}
-
-	// At this point, the command was either sent to the server and
-	// there is a response from it, or it is intentionally a nil result
-	// used to bybass sends for cases such a requesting notifications when
-	// there are no handlers.
-	reply := response.reply
-	if reply == nil {
-		return nil, nil
-	}
-
-	if reply.Error != nil {
-		return nil, reply.Error
-	}
-
-	return reply.Result, nil
 }
 
 // marshalAndSendPost marshals the passed command to JSON-RPC and sends it to
@@ -694,10 +690,10 @@ func receiveFuture(responseChan chan *futureResult) (interface{}, error) {
 // and closed for each command when using this method, however, the underlying
 // HTTP client might coalesce multiple commands depending on several factors
 // including the remote server configuration.
-func (c *Client) marshalAndSendPost(cmd btcjson.Cmd, responseChan chan *futureResult) {
+func (c *Client) marshalAndSendPost(cmd btcjson.Cmd, responseChan chan *response) {
 	marshalledJSON, err := json.Marshal(cmd)
 	if err != nil {
-		responseChan <- &futureResult{reply: nil, err: err}
+		responseChan <- &response{result: nil, err: err}
 		return
 	}
 
@@ -709,7 +705,7 @@ func (c *Client) marshalAndSendPost(cmd btcjson.Cmd, responseChan chan *futureRe
 	url := protocol + "://" + c.config.Host
 	req, err := http.NewRequest("POST", url, bytes.NewReader(marshalledJSON))
 	if err != nil {
-		responseChan <- &futureResult{reply: nil, err: err}
+		responseChan <- &response{result: nil, err: err}
 		return
 	}
 	req.Close = true
@@ -724,10 +720,10 @@ func (c *Client) marshalAndSendPost(cmd btcjson.Cmd, responseChan chan *futureRe
 
 // marshalAndSend marshals the passed command to JSON-RPC and sends it to the
 // server.  It returns a response channel on which the reply will be delivered.
-func (c *Client) marshalAndSend(cmd btcjson.Cmd, responseChan chan *futureResult) {
+func (c *Client) marshalAndSend(cmd btcjson.Cmd, responseChan chan *response) {
-	marshalledJSON, err := json.Marshal(cmd)
+	marshalledJSON, err := cmd.MarshalJSON()
 	if err != nil {
-		responseChan <- &futureResult{reply: nil, err: err}
+		responseChan <- &response{result: nil, err: err}
 		return
 	}
 
@@ -739,12 +735,12 @@ func (c *Client) marshalAndSend(cmd btcjson.Cmd, responseChan chan *futureResult
 // response channel on which the reply will be deliver at some point in the
 // future.  It handles both websocket and HTTP POST mode depending on the
 // configuration of the client.
-func (c *Client) sendCmd(cmd btcjson.Cmd) chan *futureResult {
+func (c *Client) sendCmd(cmd btcjson.Cmd) chan *response {
 	// Choose which marshal and send function to use depending on whether
 	// the client running in HTTP POST mode or not.  When running in HTTP
 	// POST mode, the command is issued via an HTTP client.  Otherwise,
 	// the command is issued via the asynchronous websocket channels.
-	responseChan := make(chan *futureResult, 1)
+	responseChan := make(chan *response, 1)
 	if c.config.HttpPostMode {
 		c.marshalAndSendPost(cmd, responseChan)
 		return responseChan
@@ -804,9 +800,9 @@ func (c *Client) Disconnect() {
 		c.requestLock.Lock()
 		for e := c.requestList.Front(); e != nil; e = e.Next() {
 			req := e.Value.(*jsonRequest)
-			req.responseChan <- &futureResult{
+			req.responseChan <- &response{
-				reply: nil,
+				result: nil,
-				err:   ErrClientDisconnect,
+				err:    ErrClientDisconnect,
 			}
 		}
 		c.requestLock.Unlock()
@@ -834,9 +830,9 @@ func (c *Client) Shutdown() {
 	c.requestLock.Lock()
 	for e := c.requestList.Front(); e != nil; e = e.Next() {
 		req := e.Value.(*jsonRequest)
-		req.responseChan <- &futureResult{
+		req.responseChan <- &response{
-			reply: nil,
+			result: nil,
-			err:   ErrClientShutdown,
+			err:    ErrClientShutdown,
 		}
 	}
 	c.requestLock.Unlock()

mining.go

@@ -6,28 +6,28 @@ package btcrpcclient
 
 import (
 	"encoding/hex"
-	"fmt"
+	"encoding/json"
 	"github.com/conformal/btcjson"
 	"github.com/conformal/btcutil"
 )
 
 // FutureGetGenerateResult is a future promise to deliver the result of a
 // GetGenerateAsync RPC invocation (or an applicable error).
-type FutureGetGenerateResult chan *futureResult
+type FutureGetGenerateResult chan *response
 
 // Receive waits for the response promised by the future and returns true if the
 // server is set to mine, otherwise false.
 func (r FutureGetGenerateResult) Receive() (bool, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return false, err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmarshal result as a boolean.
-	result, ok := reply.(bool)
+	var result bool
-	if !ok {
+	err = json.Unmarshal(res, &result)
-		return false, fmt.Errorf("unexpected response type for "+
+	if err != nil {
-			"getgenerate: %T\n", reply)
+		return false, err
 	}
 
 	return result, nil
@@ -55,7 +55,7 @@ func (c *Client) GetGenerate() (bool, error) {
 
 // FutureSetGenerateResult is a future promise to deliver the result of a
 // SetGenerateAsync RPC invocation (or an applicable error).
-type FutureSetGenerateResult chan *futureResult
+type FutureSetGenerateResult chan *response
 
 // Receive waits for the response promised by the future and returns an error if
 // any occurred when setting the server to generate coins (mine) or not.
@@ -90,22 +90,22 @@ func (c *Client) SetGenerate(enable bool, numCPUs int) error {
 
 // FutureGetHashesPerSecResult is a future promise to deliver the result of a
 // GetHashesPerSecAsync RPC invocation (or an applicable error).
-type FutureGetHashesPerSecResult chan *futureResult
+type FutureGetHashesPerSecResult chan *response
 
 // Receive waits for the response promised by the future and returns a recent
 // hashes per second performance measurement while generating coins (mining).
 // Zero is returned if the server is not mining.
 func (r FutureGetHashesPerSecResult) Receive() (int64, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return -1, err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmarshal result as an int64.
-	result, ok := reply.(int64)
+	var result int64
-	if !ok {
+	err = json.Unmarshal(res, &result)
-		return -1, fmt.Errorf("unexpected response type for "+
+	if err != nil {
-			"getnetworkhashps: %T\n", reply)
+		return 0, err
 	}
 
 	return result, nil
@@ -135,24 +135,24 @@ func (c *Client) GetHashesPerSec() (int64, error) {
 
 // FutureGetMiningInfoResult is a future promise to deliver the result of a
 // GetMiningInfoAsync RPC invocation (or an applicable error).
-type FutureGetMiningInfoResult chan *futureResult
+type FutureGetMiningInfoResult chan *response
 
 // Receive waits for the response promised by the future and returns the mining
 // information.
 func (r FutureGetMiningInfoResult) Receive() (*btcjson.GetMiningInfoResult, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return nil, err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmarshal result as a getmininginfo result object.
-	result, ok := reply.(*btcjson.GetMiningInfoResult)
+	var infoResult btcjson.GetMiningInfoResult
-	if !ok {
+	err = json.Unmarshal(res, &infoResult)
-		return nil, fmt.Errorf("unexpected response type for "+
+	if err != nil {
-			"getmininginfo: %T\n", reply)
+		return nil, err
 	}
 
-	return result, nil
+	return &infoResult, nil
 }
 
 // GetMiningInfoAsync returns an instance of a type that can be used to get
@@ -177,22 +177,22 @@ func (c *Client) GetMiningInfo() (*btcjson.GetMiningInfoResult, error) {
 
 // FutureGetNetworkHashPS is a future promise to deliver the result of a
 // GetNetworkHashPSAsync RPC invocation (or an applicable error).
-type FutureGetNetworkHashPS chan *futureResult
+type FutureGetNetworkHashPS chan *response
 
 // Receive waits for the response promised by the future and returns the
 // estimated network hashes per second for the block heights provided by the
 // parameters.
 func (r FutureGetNetworkHashPS) Receive() (int64, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return -1, err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmarshal result as an int64.
-	result, ok := reply.(int64)
+	var result int64
-	if !ok {
+	err = json.Unmarshal(res, &result)
-		return -1, fmt.Errorf("unexpected response type for "+
+	if err != nil {
-			"getnetworkhashps: %T\n", reply)
+		return 0, err
 	}
 
 	return result, nil
@@ -275,24 +275,24 @@ func (c *Client) GetNetworkHashPS3(blocks, height int) (int64, error) {
 
 // FutureGetWork is a future promise to deliver the result of a
 // GetWorkAsync RPC invocation (or an applicable error).
-type FutureGetWork chan *futureResult
+type FutureGetWork chan *response
 
 // Receive waits for the response promised by the future and returns the hash
 // data to work on.
 func (r FutureGetWork) Receive() (*btcjson.GetWorkResult, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return nil, err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmarshal result as a getwork result object.
-	result, ok := reply.(*btcjson.GetWorkResult)
+	var result btcjson.GetWorkResult
-	if !ok {
+	err = json.Unmarshal(res, &result)
-		return nil, fmt.Errorf("unexpected response type for "+
+	if err != nil {
-			"getwork (request data): %T\n", reply)
+		return nil, err
 	}
 
-	return result, nil
+	return &result, nil
 }
 
 // GetWorkAsync returns an instance of a type that can be used to get the result
@@ -319,21 +319,21 @@ func (c *Client) GetWork() (*btcjson.GetWorkResult, error) {
 
 // FutureGetWorkSubmit is a future promise to deliver the result of a
 // GetWorkSubmitAsync RPC invocation (or an applicable error).
-type FutureGetWorkSubmit chan *futureResult
+type FutureGetWorkSubmit chan *response
 
 // Receive waits for the response promised by the future and returns whether
 // or not the submitted block header was accepted.
 func (r FutureGetWorkSubmit) Receive() (bool, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return false, err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmarshal result as a boolean.
-	accepted, ok := reply.(bool)
+	var accepted bool
-	if !ok {
+	err = json.Unmarshal(res, &accepted)
-		return false, fmt.Errorf("unexpected response type for "+
+	if err != nil {
-			"getwork (submit data): %T\n", reply)
+		return false, err
 	}
 
 	return accepted, nil
@@ -364,7 +364,7 @@ func (c *Client) GetWorkSubmit(data string) (bool, error) {
 
 // FutureSubmitBlockResult is a future promise to deliver the result of a
 // SubmitBlockAsync RPC invocation (or an applicable error).
-type FutureSubmitBlockResult chan *futureResult
+type FutureSubmitBlockResult chan *response
 
 // Receive waits for the response promised by the future and returns an error if
 // any occurred when submitting the block.

net.go

@@ -5,7 +5,7 @@
 package btcrpcclient
 
 import (
-	"fmt"
+	"encoding/json"
 	"github.com/conformal/btcjson"
 )
 
@@ -34,7 +34,7 @@ func (cmd AddNodeCommand) String() string {
 
 // FutureAddNodeResult is a future promise to deliver the result of an
 // AddNodeAsync RPC invocation (or an applicable error).
-type FutureAddNodeResult chan *futureResult
+type FutureAddNodeResult chan *response
 
 // Receive waits for the response promised by the future and returns an error if
 // any occurred when performing the specified command.
@@ -73,21 +73,21 @@ func (c *Client) AddNode(host string, command AddNodeCommand) error {
 
 // FutureGetAddedNodeInfoResult is a future promise to deliver the result of a
 // GetAddedNodeInfoAsync RPC invocation (or an applicable error).
-type FutureGetAddedNodeInfoResult chan *futureResult
+type FutureGetAddedNodeInfoResult chan *response
 
 // Receive waits for the response promised by the future and returns information
 // about manually added (persistent) peers.
 func (r FutureGetAddedNodeInfoResult) Receive() ([]btcjson.GetAddedNodeInfoResult, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return nil, err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmarshal as an array of getaddednodeinfo result objects.
-	nodeInfo, ok := reply.([]btcjson.GetAddedNodeInfoResult)
+	var nodeInfo []btcjson.GetAddedNodeInfoResult
-	if !ok {
+	err = json.Unmarshal(res, &nodeInfo)
-		return nil, fmt.Errorf("unexpected response type for "+
+	if err != nil {
-			"getaddednodeinfo (dns=true): %T\n", reply)
+		return nil, err
 	}
 
 	return nodeInfo, nil
@@ -118,21 +118,21 @@ func (c *Client) GetAddedNodeInfo(peer string) ([]btcjson.GetAddedNodeInfoResult
 
 // FutureGetAddedNodeInfoNoDNSResult is a future promise to deliver the result
 // of a GetAddedNodeInfoNoDNSAsync RPC invocation (or an applicable error).
-type FutureGetAddedNodeInfoNoDNSResult chan *futureResult
+type FutureGetAddedNodeInfoNoDNSResult chan *response
 
 // Receive waits for the response promised by the future and returns a list of
 // manually added (persistent) peers.
 func (r FutureGetAddedNodeInfoNoDNSResult) Receive() ([]string, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return nil, err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmarshal result as an array of strings.
-	nodes, ok := reply.([]string)
+	var nodes []string
-	if !ok {
+	err = json.Unmarshal(res, &nodes)
-		return nil, fmt.Errorf("unexpected response type for "+
+	if err != nil {
-			"getaddednodeinfo (dns=false): %T\n", reply)
+		return nil, err
 	}
 
 	return nodes, nil
@@ -164,24 +164,24 @@ func (c *Client) GetAddedNodeInfoNoDNS(peer string) ([]string, error) {
 
 // FutureGetConnectionCountResult is a future promise to deliver the result
 // of a GetConnectionCountAsync RPC invocation (or an applicable error).
-type FutureGetConnectionCountResult chan *futureResult
+type FutureGetConnectionCountResult chan *response
 
 // Receive waits for the response promised by the future and returns the number
 // of active connections to other peers.
 func (r FutureGetConnectionCountResult) Receive() (int64, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return 0, err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmarshal result as an int64.
-	fcount, ok := reply.(float64)
+	var count int64
-	if !ok {
+	err = json.Unmarshal(res, &count)
-		return 0, fmt.Errorf("unexpected response type for "+
+	if err != nil {
-			"getconnectioncount: %T\n", reply)
+		return 0, err
 	}
 
-	return int64(fcount), nil
+	return count, nil
 }
 
 // GetConnectionCountAsync returns an instance of a type that can be used to get
@@ -206,7 +206,7 @@ func (c *Client) GetConnectionCount() (int64, error) {
 
 // FuturePingResult is a future promise to deliver the result of a PingAsync RPC
 // invocation (or an applicable error).
-type FuturePingResult chan *futureResult
+type FuturePingResult chan *response
 
 // Receive waits for the response promised by the future and returns the result
 // of queueing a ping to be sent to each connected peer.
@@ -244,21 +244,21 @@ func (c *Client) Ping() error {
 
 // FutureGetPeerInfoResult is a future promise to deliver the result of a
 // GetPeerInfoAsync RPC invocation (or an applicable error).
-type FutureGetPeerInfoResult chan *futureResult
+type FutureGetPeerInfoResult chan *response
 
 // Receive waits for the response promised by the future and returns  data about
 // each connected network peer.
 func (r FutureGetPeerInfoResult) Receive() ([]btcjson.GetPeerInfoResult, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return nil, err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmarshal result as an array of getpeerinfo result objects.
-	peerInfo, ok := reply.([]btcjson.GetPeerInfoResult)
+	var peerInfo []btcjson.GetPeerInfoResult
-	if !ok {
+	err = json.Unmarshal(res, &peerInfo)
-		return nil, fmt.Errorf("unexpected response type for "+
+	if err != nil {
-			"getpeerinfo: %T\n", reply)
+		return nil, err
 	}
 
 	return peerInfo, nil
@@ -286,24 +286,24 @@ func (c *Client) GetPeerInfo() ([]btcjson.GetPeerInfoResult, error) {
 
 // FutureGetNetTotalsResult is a future promise to deliver the result of a
 // GetNetTotalsAsync RPC invocation (or an applicable error).
-type FutureGetNetTotalsResult chan *futureResult
+type FutureGetNetTotalsResult chan *response
 
 // Receive waits for the response promised by the future and returns network
 // traffic statistics.
 func (r FutureGetNetTotalsResult) Receive() (*btcjson.GetNetTotalsResult, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return nil, err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmarshal result as a getnettotals result object.
-	totals, ok := reply.(*btcjson.GetNetTotalsResult)
+	var totals btcjson.GetNetTotalsResult
-	if !ok {
+	err = json.Unmarshal(res, &totals)
-		return nil, fmt.Errorf("unexpected response type for "+
+	if err != nil {
-			"getnettotals: %T\n", reply)
+		return nil, err
 	}
 
-	return totals, nil
+	return &totals, nil
 }
 
 // GetNetTotalsAsync returns an instance of a type that can be used to get the

notify.go

@@ -7,7 +7,9 @@ package btcrpcclient
 import (
 	"bytes"
 	"encoding/hex"
+	"encoding/json"
 	"errors"
+	"fmt"
 	"github.com/conformal/btcjson"
 	"github.com/conformal/btcutil"
 	"github.com/conformal/btcwire"
@@ -68,9 +70,9 @@ func newNotificationState() *notificationState {
 // result waiting on the channel with the reply set to nil.  This is useful
 // to ignore things such as notifications when the caller didn't specify any
 // notification handlers.
-func newNilFutureResult() chan *futureResult {
+func newNilFutureResult() chan *response {
-	responseChan := make(chan *futureResult, 1)
+	responseChan := make(chan *response, 1)
-	responseChan <- &futureResult{reply: nil}
+	responseChan <- &response{result: nil, err: nil}
 	return responseChan
 }
 
@@ -161,183 +163,192 @@ type NotificationHandlers struct {
 	// for this package needs to be updated for a new notification type or
 	// the caller is using a custom notification this package does not know
 	// about.
-	OnUnknownNotification func(ntfn interface{})
+	OnUnknownNotification func(method string, params []json.RawMessage)
 }
 
 // handleNotification examines the passed notification type, performs
 // conversions to get the raw notification types into higher level types and
 // delivers the notification to the appropriate On<X> handler registered with
 // the client.
-func (c *Client) handleNotification(cmd btcjson.Cmd) {
+func (c *Client) handleNotification(ntfn *rawNotification) {
 	// Ignore the notification if the client is not interested in any
 	// notifications.
 	if c.ntfnHandlers == nil {
 		return
 	}
 
-	switch ntfn := cmd.(type) {
+	switch ntfn.Method {
 	// OnBlockConnected
-	case *btcws.BlockConnectedNtfn:
+	case btcws.BlockConnectedNtfnMethod:
 		// Ignore the notification is the client is not interested in
 		// it.
 		if c.ntfnHandlers.OnBlockConnected == nil {
 			return
 		}
 
-		hash, err := btcwire.NewShaHashFromStr(ntfn.Hash)
+		blockSha, blockHeight, err := parseChainNtfnParams(ntfn.Params)
 		if err != nil {
-			log.Warnf("Received block connected notification with "+
+			log.Warnf("Received invalid block connected "+
-				"invalid hash string: %q", ntfn.Hash)
+				"notification: %v", err)
 			return
 		}
 
-		c.ntfnHandlers.OnBlockConnected(hash, ntfn.Height)
+		c.ntfnHandlers.OnBlockConnected(blockSha, blockHeight)
 
 	// OnBlockDisconnected
-	case *btcws.BlockDisconnectedNtfn:
+	case btcws.BlockDisconnectedNtfnMethod:
 		// Ignore the notification is the client is not interested in
 		// it.
 		if c.ntfnHandlers.OnBlockDisconnected == nil {
 			return
 		}
 
-		hash, err := btcwire.NewShaHashFromStr(ntfn.Hash)
+		blockSha, blockHeight, err := parseChainNtfnParams(ntfn.Params)
 		if err != nil {
-			log.Warnf("Received block disconnected notification "+
+			log.Warnf("Received invalid block connected "+
-				"with invalid hash string: %q", ntfn.Hash)
+				"notification: %v", err)
 			return
 		}
 
-		c.ntfnHandlers.OnBlockDisconnected(hash, ntfn.Height)
+		c.ntfnHandlers.OnBlockDisconnected(blockSha, blockHeight)
 
 	// OnRecvTx
-	case *btcws.RecvTxNtfn:
+	case btcws.RecvTxNtfnMethod:
 		// Ignore the notification is the client is not interested in
 		// it.
 		if c.ntfnHandlers.OnRecvTx == nil {
 			return
 		}
 
-		// Decode the serialized transaction hex to raw bytes.
+		tx, block, err := parseChainTxNtfnParams(ntfn.Params)
-		serializedTx, err := hex.DecodeString(ntfn.HexTx)
 		if err != nil {
-			log.Warnf("Received recvtx notification with invalid "+
+			log.Warnf("Received invalid recvtx notification: %v",
-				"transaction hex '%q': %v", ntfn.HexTx, err)
-		}
-
-		// Deserialize the transaction.
-		var msgTx btcwire.MsgTx
-		err = msgTx.Deserialize(bytes.NewReader(serializedTx))
-		if err != nil {
-			log.Warnf("Received recvtx notification with "+
-				"transaction that failed to deserialize: %v",
 				err)
+			return
 		}
 
-		c.ntfnHandlers.OnRecvTx(btcutil.NewTx(&msgTx), ntfn.Block)
+		c.ntfnHandlers.OnRecvTx(tx, block)
 
 	// OnRedeemingTx
-	case *btcws.RedeemingTxNtfn:
+	case btcws.RedeemingTxNtfnMethod:
 		// Ignore the notification is the client is not interested in
 		// it.
 		if c.ntfnHandlers.OnRedeemingTx == nil {
 			return
 		}
 
-		// Decode the serialized transaction hex to raw bytes.
+		tx, block, err := parseChainTxNtfnParams(ntfn.Params)
-		serializedTx, err := hex.DecodeString(ntfn.HexTx)
 		if err != nil {
-			log.Warnf("Received redeemingtx notification with "+
+			log.Warnf("Received invalid redeemingtx "+
-				"invalid transaction hex '%q': %v", ntfn.HexTx,
+				"notification: %v", err)
-				err)
+			return
 		}
 
-		// Deserialize the transaction.
+		c.ntfnHandlers.OnRedeemingTx(tx, block)
-		var msgTx btcwire.MsgTx
-		err = msgTx.Deserialize(bytes.NewReader(serializedTx))
-		if err != nil {
-			log.Warnf("Received redeemingtx notification with "+
-				"transaction that failed to deserialize: %v",
-				err)
-		}
-
-		c.ntfnHandlers.OnRedeemingTx(btcutil.NewTx(&msgTx), ntfn.Block)
 
 	// OnRescanProgress
-	case *btcws.RescanProgressNtfn:
+	case btcws.RescanProgressNtfnMethod:
 		// Ignore the notification is the client is not interested in
 		// it.
 		if c.ntfnHandlers.OnRescanProgress == nil {
 			return
 		}
 
-		c.ntfnHandlers.OnRescanProgress(ntfn.LastProcessed)
+		lastProcessed, err := parseRescanProgressNtfnParams(ntfn.Params)
+		if err != nil {
+			log.Warnf("Received invalid rescanprogress "+
+				"notification: %v", err)
+			return
+		}
+
+		c.ntfnHandlers.OnRescanProgress(lastProcessed)
 
 	// OnTxAccepted
-	case *btcws.TxAcceptedNtfn:
+	case btcws.TxAcceptedNtfnMethod:
 		// Ignore the notification is the client is not interested in
 		// it.
 		if c.ntfnHandlers.OnTxAccepted == nil {
 			return
 		}
 
-		hash, err := btcwire.NewShaHashFromStr(ntfn.TxID)
+		hash, amt, err := parseTxAcceptedNtfnParams(ntfn.Params)
 		if err != nil {
-			log.Warnf("Received tx accepted notification with "+
+			log.Warnf("Received invalid tx accepted "+
-				"invalid hash string: %q", ntfn.TxID)
+				"notification: %v", err)
 			return
 		}
 
-		c.ntfnHandlers.OnTxAccepted(hash, btcutil.Amount(ntfn.Amount))
+		c.ntfnHandlers.OnTxAccepted(hash, amt)
 
 	// OnTxAcceptedVerbose
-	case *btcws.TxAcceptedVerboseNtfn:
+	case btcws.TxAcceptedVerboseNtfnMethod:
 		// Ignore the notification is the client is not interested in
 		// it.
 		if c.ntfnHandlers.OnTxAcceptedVerbose == nil {
 			return
 		}
 
-		c.ntfnHandlers.OnTxAcceptedVerbose(ntfn.RawTx)
+		rawTx, err := parseTxAcceptedVerboseNtfnParams(ntfn.Params)
+		if err != nil {
+			log.Warnf("Received invalid tx accepted verbose "+
+				"notification: %v", err)
+			return
+		}
+
+		c.ntfnHandlers.OnTxAcceptedVerbose(rawTx)
 
 	// OnBtcdConnected
-	case *btcws.BtcdConnectedNtfn:
+	case btcws.BtcdConnectedNtfnMethod:
 		// Ignore the notification is the client is not interested in
 		// it.
 		if c.ntfnHandlers.OnBtcdConnected == nil {
 			return
 		}
 
-		c.ntfnHandlers.OnBtcdConnected(ntfn.Connected)
+		connected, err := parseBtcdConnectedNtfnParams(ntfn.Params)
+		if err != nil {
+			log.Warnf("Received invalid btcd connected "+
+				"notification: %v", err)
+			return
+		}
+
+		c.ntfnHandlers.OnBtcdConnected(connected)
 
 	// OnAccountBalance
-	case *btcws.AccountBalanceNtfn:
+	case btcws.AccountBalanceNtfnMethod:
 		// Ignore the notification is the client is not interested in
 		// it.
 		if c.ntfnHandlers.OnAccountBalance == nil {
 			return
 		}
 
-		balance, err := btcjson.JSONToAmount(ntfn.Balance)
+		account, bal, conf, err := parseAccountBalanceNtfnParams(ntfn.Params)
 		if err != nil {
-			log.Warnf("Received account balance notification with "+
+			log.Warnf("Received invalid account balance "+
-				"an amount that does not parse: %v",
+				"notification: %v", err)
-				ntfn.Balance)
 			return
 		}
 
-		c.ntfnHandlers.OnAccountBalance(ntfn.Account,
+		c.ntfnHandlers.OnAccountBalance(account, bal, conf)
-			btcutil.Amount(balance), ntfn.Confirmed)
 
 	// OnWalletLockState
-	case *btcws.WalletLockStateNtfn:
+	case btcws.WalletLockStateNtfnMethod:
 		// Ignore the notification is the client is not interested in
 		// it.
 		if c.ntfnHandlers.OnWalletLockState == nil {
 			return
 		}
 
-		c.ntfnHandlers.OnWalletLockState(ntfn.Locked)
+		// The account name is not notified, so the return value is
+		// discarded.
+		_, locked, err := parseWalletLockStateNtfnParams(ntfn.Params)
+		if err != nil {
+			log.Warnf("Received invalid wallet lock state "+
+				"notification: %v", err)
+			return
+		}
+
+		c.ntfnHandlers.OnWalletLockState(locked)
 
 	// OnUnknownNotification
 	default:
@@ -345,13 +356,250 @@ func (c *Client) handleNotification(cmd btcjson.Cmd) {
 			return
 		}
 
-		c.ntfnHandlers.OnUnknownNotification(ntfn)
+		c.ntfnHandlers.OnUnknownNotification(ntfn.Method, ntfn.Params)
 	}
 }
 
+// wrongNumParams is an error type describing an unparseable JSON-RPC
+// notificiation due to an incorrect number of parameters for the
+// expected notification type.  The value is the number of parameters
+// of the invalid notification.
+type wrongNumParams int
+
+// Error satisifies the builtin error interface.
+func (e wrongNumParams) Error() string {
+	return fmt.Sprintf("wrong number of parameters (%d)", e)
+}
+
+// parseChainNtfnParams parses out the block hash and height from the parameters
+// of blockconnected and blockdisconnected notifications.
+func parseChainNtfnParams(params []json.RawMessage) (*btcwire.ShaHash,
+	int32, error) {
+
+	if len(params) != 2 {
+		return nil, 0, wrongNumParams(len(params))
+	}
+
+	// Unmarshal first parameter as a string.
+	var blockShaStr string
+	err := json.Unmarshal(params[0], &blockShaStr)
+	if err != nil {
+		return nil, 0, err
+	}
+
+	// Unmarshal second parameter as an integer.
+	var blockHeight int32
+	err = json.Unmarshal(params[1], &blockHeight)
+	if err != nil {
+		return nil, 0, err
+	}
+
+	// Create ShaHash from block sha string.
+	blockSha, err := btcwire.NewShaHashFromStr(blockShaStr)
+	if err != nil {
+		return nil, 0, err
+	}
+
+	return blockSha, blockHeight, nil
+}
+
+// parseChainTxNtfnParams parses out the transaction and optional details about
+// the block it's mined in from the parameters of recvtx and redeemingtx
+// notifications.
+func parseChainTxNtfnParams(params []json.RawMessage) (*btcutil.Tx,
+	*btcws.BlockDetails, error) {
+
+	if len(params) == 0 || len(params) > 2 {
+		return nil, nil, wrongNumParams(len(params))
+	}
+
+	// Unmarshal first parameter as a string.
+	var txHex string
+	err := json.Unmarshal(params[0], &txHex)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	// If present, unmarshal second optional parameter as the block details
+	// JSON object.
+	var block *btcws.BlockDetails
+	if len(params) > 1 {
+		err = json.Unmarshal(params[1], &block)
+		if err != nil {
+			return nil, nil, err
+		}
+	}
+
+	// Hex decode and deserialize the transaction.
+	serializedTx, err := hex.DecodeString(txHex)
+	if err != nil {
+		return nil, nil, err
+	}
+	var msgTx btcwire.MsgTx
+	err = msgTx.Deserialize(bytes.NewReader(serializedTx))
+	if err != nil {
+		return nil, nil, err
+	}
+
+	// TODO: Change recvtx and redeemingtx callback signatures to use
+	// nicer types for details about the block (block sha as a
+	// btcwire.ShaHash, block time as a time.Time, etc.).
+	return btcutil.NewTx(&msgTx), block, nil
+}
+
+// parseRescanProgressNtfnParams parses out the height of the last rescanned
+// from the parameters of a rescanprogress notification.
+func parseRescanProgressNtfnParams(params []json.RawMessage) (int32, error) {
+	if len(params) != 1 {
+		return 0, wrongNumParams(len(params))
+	}
+
+	// Unmarshal first parameter as an integer.
+	var height int32
+	err := json.Unmarshal(params[0], &height)
+	if err != nil {
+		return 0, err
+	}
+
+	return height, nil
+}
+
+// parseTxAcceptedNtfnParams parses out the transaction hash and total amount
+// from the parameters of a txaccepted notification.
+func parseTxAcceptedNtfnParams(params []json.RawMessage) (*btcwire.ShaHash,
+	btcutil.Amount, error) {
+
+	if len(params) != 2 {
+		return nil, 0, wrongNumParams(len(params))
+	}
+
+	// Unmarshal first parameter as a string.
+	var txShaStr string
+	err := json.Unmarshal(params[0], &txShaStr)
+	if err != nil {
+		return nil, 0, err
+	}
+
+	// Unmarshal second parameter as an integer.
+	var amt int64
+	err = json.Unmarshal(params[1], &amt)
+	if err != nil {
+		return nil, 0, err
+	}
+
+	// Decode string encoding of transaction sha.
+	txSha, err := btcwire.NewShaHashFromStr(txShaStr)
+	if err != nil {
+		return nil, 0, err
+	}
+
+	return txSha, btcutil.Amount(amt), nil
+}
+
+// parseTxAcceptedVerboseNtfnParams parses out details about a raw transaction
+// from the parameters of a txacceptedverbose notification.
+func parseTxAcceptedVerboseNtfnParams(params []json.RawMessage) (*btcjson.TxRawResult,
+	error) {
+
+	if len(params) != 1 {
+		return nil, wrongNumParams(len(params))
+	}
+
+	// Unmarshal first parameter as a raw transaction result object.
+	var rawTx btcjson.TxRawResult
+	err := json.Unmarshal(params[0], &rawTx)
+	if err != nil {
+		return nil, err
+	}
+
+	// TODO: change txacceptedverbose notifiation callbacks to use nicer
+	// types for all details about the transaction (i.e. decoding hashes
+	// from their string encoding).
+	return &rawTx, nil
+}
+
+// parseBtcdConnectedNtfnParams parses out the connection status of btcd
+// and btcwallet from the parameters of a btcdconnected notification.
+func parseBtcdConnectedNtfnParams(params []json.RawMessage) (bool, error) {
+	if len(params) != 1 {
+		return false, wrongNumParams(len(params))
+	}
+
+	// Unmarshal first parameter as a boolean.
+	var connected bool
+	err := json.Unmarshal(params[0], &connected)
+	if err != nil {
+		return false, err
+	}
+
+	return connected, nil
+}
+
+// parseAccountBalanceNtfnParams parses out the account name, total balance,
+// and whether or not the balance is confirmed or unconfirmed from the
+// parameters of an accountbalance notification.
+func parseAccountBalanceNtfnParams(params []json.RawMessage) (account string,
+	balance btcutil.Amount, confirmed bool, err error) {
+
+	if len(params) != 3 {
+		return "", 0, false, wrongNumParams(len(params))
+	}
+
+	// Unmarshal first parameter as a string.
+	err = json.Unmarshal(params[0], &account)
+	if err != nil {
+		return "", 0, false, err
+	}
+
+	// Unmarshal second parameter as a floating point number.
+	var fbal float64
+	err = json.Unmarshal(params[1], &fbal)
+	if err != nil {
+		return "", 0, false, err
+	}
+
+	// Unmarshal third parameter as a boolean.
+	err = json.Unmarshal(params[2], &confirmed)
+	if err != nil {
+		return "", 0, false, err
+	}
+
+	// Bounds check amount.
+	bal, err := btcjson.JSONToAmount(fbal)
+	if err != nil {
+		return "", 0, false, err
+	}
+
+	return account, btcutil.Amount(bal), confirmed, nil
+}
+
+// parseWalletLockStateNtfnParams parses out the account name and locked
+// state of an account from the parameters of a walletlockstate notification.
+func parseWalletLockStateNtfnParams(params []json.RawMessage) (account string,
+	locked bool, err error) {
+
+	if len(params) != 2 {
+		return "", false, wrongNumParams(len(params))
+	}
+
+	// Unmarshal first parameter as a string.
+	err = json.Unmarshal(params[0], &account)
+	if err != nil {
+		return "", false, err
+	}
+
+	// Unmarshal second parameter as a boolean.
+	err = json.Unmarshal(params[1], &locked)
+	if err != nil {
+		return "", false, err
+	}
+
+	return account, locked, nil
+}
+
 // FutureNotifyBlocksResult is a future promise to deliver the result of a
 // NotifyBlocksAsync RPC invocation (or an applicable error).
-type FutureNotifyBlocksResult chan *futureResult
+type FutureNotifyBlocksResult chan *response
 
 // Receive waits for the response promised by the future and returns an error
 // if the registration was not successful.
@@ -405,7 +653,7 @@ func (c *Client) NotifyBlocks() error {
 
 // FutureNotifySpentResult is a future promise to deliver the result of a
 // NotifySpentAsync RPC invocation (or an applicable error).
-type FutureNotifySpentResult chan *futureResult
+type FutureNotifySpentResult chan *response
 
 // Receive waits for the response promised by the future and returns an error
 // if the registration was not successful.
@@ -484,7 +732,7 @@ func (c *Client) NotifySpent(outpoints []*btcwire.OutPoint) error {
 
 // FutureNotifyNewTransactionsResult is a future promise to deliver the result
 // of a NotifyNewTransactionsAsync RPC invocation (or an applicable error).
-type FutureNotifyNewTransactionsResult chan *futureResult
+type FutureNotifyNewTransactionsResult chan *response
 
 // Receive waits for the response promised by the future and returns an error
 // if the registration was not successful.
@@ -542,7 +790,7 @@ func (c *Client) NotifyNewTransactions(verbose bool) error {
 
 // FutureNotifyReceivedResult is a future promise to deliver the result of a
 // NotifyReceivedAsync RPC invocation (or an applicable error).
-type FutureNotifyReceivedResult chan *futureResult
+type FutureNotifyReceivedResult chan *response
 
 // Receive waits for the response promised by the future and returns an error
 // if the registration was not successful.
@@ -630,7 +878,7 @@ func (c *Client) NotifyReceived(addresses []btcutil.Address) error {
 
 // FutureRescanResult is a future promise to deliver the result of a RescanAsync
 // or RescanEndHeightAsync RPC invocation (or an applicable error).
-type FutureRescanResult chan *futureResult
+type FutureRescanResult chan *response
 
 // Receive waits for the response promised by the future and returns an error
 // if the rescan was not successful.

rawrequest.go

@@ -0,0 +1,90 @@
+// Copyright (c) 2014 Conformal Systems LLC.
+// Use of this source code is governed by an ISC
+// license that can be found in the LICENSE file.
+
+package btcrpcclient
+
+import (
+	"encoding/json"
+	"errors"
+	"github.com/conformal/btcjson"
+)
+
+// rawRequest satisifies the btcjson.Cmd interface for btcjson raw commands.
+// This type exists here rather than making btcjson.RawCmd satisify the Cmd
+// interface due to conflict between the Id and Method field names vs method
+// names.
+type rawRequest struct {
+	btcjson.RawCmd
+}
+
+// Enforce that rawRequest is a btcjson.Cmd.
+var _ btcjson.Cmd = &rawRequest{}
+
+// Id returns the JSON-RPC id of the request.
+func (r *rawRequest) Id() interface{} {
+	return r.RawCmd.Id
+}
+
+// Method returns the method string of the request.
+func (r *rawRequest) Method() string {
+	return r.RawCmd.Method
+}
+
+// MarshalJSON marshals the raw request as a JSON-RPC 1.0 object.
+func (r *rawRequest) MarshalJSON() ([]byte, error) {
+	return json.Marshal(r.RawCmd)
+}
+
+// UnmarshalJSON unmarshals a JSON-RPC 1.0 object into the raw request.
+func (r *rawRequest) UnmarshalJSON(b []byte) error {
+	return json.Unmarshal(b, &r.RawCmd)
+}
+
+// FutureRawResult is a future promise to deliver the result of a RawRequest RPC
+// invocation (or an applicable error).
+type FutureRawResult chan *response
+
+// Receive waits for the response promised by the future and returns the raw
+// response, or an error if the request was unsuccessful.
+func (r FutureRawResult) Receive() (json.RawMessage, error) {
+	return receiveFuture(r)
+}
+
+// RawRequestAsync returns an instance of a type that can be used to get the
+// result of a custom RPC request at some future time by invoking the Receive
+// function on the returned instance.
+//
+// See RawRequest for the blocking version and more details.
+func (c *Client) RawRequestAsync(method string, params []json.RawMessage) FutureRawResult {
+	// Method may not be empty.
+	if method == "" {
+		return newFutureError(errors.New("no method"))
+	}
+
+	// Marshal parameters as "[]" instead of "null" when no parameters
+	// are passed.
+	if params == nil {
+		params = []json.RawMessage{}
+	}
+
+	cmd := &rawRequest{
+		RawCmd: btcjson.RawCmd{
+			Jsonrpc: "1.0",
+			Id:      c.NextID(),
+			Method:  method,
+			Params:  params,
+		},
+	}
+
+	return c.sendCmd(cmd)
+}
+
+// RawRequest allows the caller to send a raw or custom request to the server.
+// This method may be used to send and receive requests and responses for
+// requests that are not handled by this client package, or to proxy partially
+// unmarshaled requests to another JSON-RPC server if a request cannot be
+// handled directly.
+func (c *Client) RawRequest(method string, params []json.RawMessage) (json.RawMessage, error) {
+	return c.RawRequestAsync(method, params).Receive()
+}

rawtransactions.go

@@ -7,7 +7,7 @@ package btcrpcclient
 import (
 	"bytes"
 	"encoding/hex"
-	"fmt"
+	"encoding/json"
 	"github.com/conformal/btcjson"
 	"github.com/conformal/btcutil"
 	"github.com/conformal/btcwire"
@@ -58,21 +58,21 @@ func (s SigHashType) String() string {
 
 // FutureGetRawTransactionResult is a future promise to deliver the result of a
 // GetRawTransactionAsync RPC invocation (or an applicable error).
-type FutureGetRawTransactionResult chan *futureResult
+type FutureGetRawTransactionResult chan *response
 
 // Receive waits for the response promised by the future and returns a
 // transaction given its hash.
 func (r FutureGetRawTransactionResult) Receive() (*btcutil.Tx, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return nil, err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmarshal result as a string.
-	txHex, ok := reply.(string)
+	var txHex string
-	if !ok {
+	err = json.Unmarshal(res, &txHex)
-		return nil, fmt.Errorf("unexpected response type for "+
+	if err != nil {
-			"getrawtransaction (verbose=0): %T\n", reply)
+		return nil, err
 	}
 
 	// Decode the serialized transaction hex to raw bytes.
@@ -120,24 +120,24 @@ func (c *Client) GetRawTransaction(txHash *btcwire.ShaHash) (*btcutil.Tx, error)
 // FutureGetRawTransactionVerboseResult is a future promise to deliver the
 // result of a GetRawTransactionVerboseAsync RPC invocation (or an applicable
 // error).
-type FutureGetRawTransactionVerboseResult chan *futureResult
+type FutureGetRawTransactionVerboseResult chan *response
 
 // Receive waits for the response promised by the future and returns information
 // about a transaction given its hash.
 func (r FutureGetRawTransactionVerboseResult) Receive() (*btcjson.TxRawResult, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return nil, err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmarshal result as a gettrawtransaction result object.
-	result, ok := reply.(*btcjson.TxRawResult)
+	var rawTxResult btcjson.TxRawResult
-	if !ok {
+	err = json.Unmarshal(res, &rawTxResult)
-		return nil, fmt.Errorf("unexpected response type for "+
+	if err != nil {
-			"getrawtransaction (verbose=1): %T\n", reply)
+		return nil, err
 	}
 
-	return result, nil
+	return &rawTxResult, nil
 }
 
 // GetRawTransactionVerboseAsync returns an instance of a type that can be used
@@ -170,24 +170,24 @@ func (c *Client) GetRawTransactionVerbose(txHash *btcwire.ShaHash) (*btcjson.TxR
 
 // FutureDecodeRawTransactionResult is a future promise to deliver the result
 // of a DecodeRawTransactionAsync RPC invocation (or an applicable error).
-type FutureDecodeRawTransactionResult chan *futureResult
+type FutureDecodeRawTransactionResult chan *response
 
 // Receive waits for the response promised by the future and returns information
 // about a transaction given its serialized bytes.
 func (r FutureDecodeRawTransactionResult) Receive() (*btcjson.TxRawResult, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return nil, err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmarshal result as a decoderawtransaction result object.
-	result, ok := reply.(*btcjson.TxRawResult)
+	var rawTxResult btcjson.TxRawResult
-	if !ok {
+	err = json.Unmarshal(res, &rawTxResult)
-		return nil, fmt.Errorf("unexpected response type for "+
+	if err != nil {
-			"decoderawtransaction: %T\n", reply)
+		return nil, err
 	}
 
-	return result, nil
+	return &rawTxResult, nil
 }
 
 // DecodeRawTransactionAsync returns an instance of a type that can be used to
@@ -214,22 +214,22 @@ func (c *Client) DecodeRawTransaction(serializedTx []byte) (*btcjson.TxRawResult
 
 // FutureCreateRawTransactionResult is a future promise to deliver the result
 // of a CreateRawTransactionAsync RPC invocation (or an applicable error).
-type FutureCreateRawTransactionResult chan *futureResult
+type FutureCreateRawTransactionResult chan *response
 
 // Receive waits for the response promised by the future and returns a new
 // transaction spending the provided inputs and sending to the provided
 // addresses.
 func (r FutureCreateRawTransactionResult) Receive() (*btcwire.MsgTx, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return nil, err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmarshal result as a string.
-	txHex, ok := reply.(string)
+	var txHex string
-	if !ok {
+	err = json.Unmarshal(res, &txHex)
-		return nil, fmt.Errorf("unexpected response type for "+
+	if err != nil {
-			"createrawtransaction: %T\n", reply)
+		return nil, err
 	}
 
 	// Decode the serialized transaction hex to raw bytes.
@@ -277,22 +277,22 @@ func (c *Client) CreateRawTransaction(inputs []btcjson.TransactionInput,
 
 // FutureSendRawTransactionResult is a future promise to deliver the result
 // of a SendRawTransactionAsync RPC invocation (or an applicable error).
-type FutureSendRawTransactionResult chan *futureResult
+type FutureSendRawTransactionResult chan *response
 
 // Receive waits for the response promised by the future and returns the result
 // of submitting the encoded transaction to the server which then relays it to
 // the network.
 func (r FutureSendRawTransactionResult) Receive() (*btcwire.ShaHash, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return nil, err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmarshal result as a string.
-	txHashStr, ok := reply.(string)
+	var txHashStr string
-	if !ok {
+	err = json.Unmarshal(res, &txHashStr)
-		return nil, fmt.Errorf("unexpected response type for "+
+	if err != nil {
-			"decoderawtransaction: %T\n", reply)
+		return nil, err
 	}
 
 	return btcwire.NewShaHashFromStr(txHashStr)
@@ -332,25 +332,25 @@ func (c *Client) SendRawTransaction(tx *btcwire.MsgTx, allowHighFees bool) (*btc
 // FutureSignRawTransactionResult is a future promise to deliver the result
 // of one of the SignRawTransactionAsync family of RPC invocations (or an
 // applicable error).
-type FutureSignRawTransactionResult chan *futureResult
+type FutureSignRawTransactionResult chan *response
 
 // Receive waits for the response promised by the future and returns the
 // signed transaction as well as whether or not all inputs are now signed.
 func (r FutureSignRawTransactionResult) Receive() (*btcwire.MsgTx, bool, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return nil, false, err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmarshal as a signrawtransaction result.
-	result, ok := reply.(*btcjson.SignRawTransactionResult)
+	var signRawTxResult btcjson.SignRawTransactionResult
-	if !ok {
+	err = json.Unmarshal(res, &signRawTxResult)
-		return nil, false, fmt.Errorf("unexpected response type for "+
+	if err != nil {
-			"signrawtransaction: %T\n", reply)
+		return nil, false, err
 	}
 
 	// Decode the serialized transaction hex to raw bytes.
-	serializedTx, err := hex.DecodeString(result.Hex)
+	serializedTx, err := hex.DecodeString(signRawTxResult.Hex)
 	if err != nil {
 		return nil, false, err
 	}
@@ -361,7 +361,7 @@ func (r FutureSignRawTransactionResult) Receive() (*btcwire.MsgTx, bool, error)
 		return nil, false, err
 	}
 
-	return &msgTx, result.Complete, nil
+	return &msgTx, signRawTxResult.Complete, nil
 }
 
 // SignRawTransactionAsync returns an instance of a type that can be used to get

wallet.go

@@ -5,7 +5,7 @@
 package btcrpcclient
 
 import (
-	"fmt"
+	"encoding/json"
 	"github.com/conformal/btcjson"
 	"github.com/conformal/btcnet"
 	"github.com/conformal/btcutil"
@@ -19,24 +19,24 @@ import (
 
 // FutureGetTransactionResult is a future promise to deliver the result
 // of a GetTransactionAsync RPC invocation (or an applicable error).
-type FutureGetTransactionResult chan *futureResult
+type FutureGetTransactionResult chan *response
 
 // Receive waits for the response promised by the future and returns detailed
 // information about a wallet transaction.
 func (r FutureGetTransactionResult) Receive() (*btcjson.GetTransactionResult, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return nil, err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmarshal result as a gettransaction result object
-	result, ok := reply.(*btcjson.GetTransactionResult)
+	var getTx btcjson.GetTransactionResult
-	if !ok {
+	err = json.Unmarshal(res, &getTx)
-		return nil, fmt.Errorf("unexpected response type for "+
+	if err != nil {
-			"gettransaction: %T\n", reply)
+		return nil, err
 	}
 
-	return result, nil
+	return &getTx, nil
 }
 
 // GetTransactionAsync returns an instance of a type that can be used to get the
@@ -69,26 +69,21 @@ func (c *Client) GetTransaction(txHash *btcwire.ShaHash) (*btcjson.GetTransactio
 // FutureListTransactionsResult is a future promise to deliver the result of a
 // ListTransactionsAsync, ListTransactionsCountAsync, or
 // ListTransactionsCountFromAsync RPC invocation (or an applicable error).
-type FutureListTransactionsResult chan *futureResult
+type FutureListTransactionsResult chan *response
 
 // Receive waits for the response promised by the future and returns a list of
 // the most recent transactions.
 func (r FutureListTransactionsResult) Receive() ([]btcjson.ListTransactionsResult, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return nil, err
 	}
 
-	// No transactions.
+	// Unmarshal result as an array of listtransaction result objects.
-	if reply == nil {
+	var transactions []btcjson.ListTransactionsResult
-		return nil, nil
+	err = json.Unmarshal(res, &transactions)
-	}
+	if err != nil {
-
+		return nil, err
-	// Ensure the returned data is the expected type.
-	transactions, ok := reply.([]btcjson.ListTransactionsResult)
-	if !ok {
-		return nil, fmt.Errorf("unexpected response type for "+
-			"listtransactions: %T\n", reply)
 	}
 
 	return transactions, nil
@@ -167,7 +162,7 @@ func (c *Client) ListTransactionsCountFrom(account string, count, from int) ([]b
 // FutureListUnspentResult is a future promise to deliver the result of a
 // ListUnspentAsync, ListUnspentMinAsync, ListUnspentMinMaxAsync, or
 // ListUnspentMinMaxAddressesAsync RPC invocation (or an applicable error).
-type FutureListUnspentResult chan *futureResult
+type FutureListUnspentResult chan *response
 
 // Receive waits for the response promised by the future and returns all
 // unspent wallet transaction outputs returned by the RPC call.  If the
@@ -175,21 +170,16 @@ type FutureListUnspentResult chan *futureResult
 // or ListUnspentMinMaxAddressesAsync, the range may be limited by the
 // parameters of the RPC invocation.
 func (r FutureListUnspentResult) Receive() ([]btcjson.ListUnspentResult, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return nil, err
 	}
 
-	// No unspent transaction outputs.
+	// Unmarshal result as an array of listunspent results.
-	if reply == nil {
+	var unspent []btcjson.ListUnspentResult
-		return nil, nil
+	err = json.Unmarshal(res, &unspent)
-	}
+	if err != nil {
-
+		return nil, err
-	// Ensure the returned data is the expected type.
-	unspent, ok := reply.([]btcjson.ListUnspentResult)
-	if !ok {
-		return nil, fmt.Errorf("unexpected response type for "+
-			"listunspent: %T\n", reply)
 	}
 
 	return unspent, nil
@@ -291,25 +281,25 @@ func (c *Client) ListUnspentMinMaxAddresses(minConf, maxConf int, addrs []btcuti
 // FutureListSinceBlockResult is a future promise to deliver the result of a
 // ListSinceBlockAsync or ListSinceBlockMinConfAsync RPC invocation (or an
 // applicable error).
-type FutureListSinceBlockResult chan *futureResult
+type FutureListSinceBlockResult chan *response
 
 // Receive waits for the response promised by the future and returns all
 // transactions added in blocks since the specified block hash, or all
 // transactions if it is nil.
 func (r FutureListSinceBlockResult) Receive() (*btcjson.ListSinceBlockResult, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return nil, err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmarshal result as a listsinceblock result object.
-	listResult, ok := reply.(*btcjson.ListSinceBlockResult)
+	var listResult btcjson.ListSinceBlockResult
-	if !ok {
+	err = json.Unmarshal(res, &listResult)
-		return nil, fmt.Errorf("unexpected response type for "+
+	if err != nil {
-			"listsinceblock: %T\n", reply)
+		return nil, err
 	}
 
-	return listResult, nil
+	return &listResult, nil
 }
 
 // ListSinceBlockAsync returns an instance of a type that can be used to get
@@ -376,7 +366,7 @@ func (c *Client) ListSinceBlockMinConf(blockHash *btcwire.ShaHash, minConfirms i
 
 // FutureSetTxFeeResult is a future promise to deliver the result of a
 // SetTxFeeAsync RPC invocation (or an applicable error).
-type FutureSetTxFeeResult chan *futureResult
+type FutureSetTxFeeResult chan *response
 
 // Receive waits for the response promised by the future and returns the result
 // of setting an optional transaction fee per KB that helps ensure transactions
@@ -413,20 +403,21 @@ func (c *Client) SetTxFee(fee btcutil.Amount) error {
 
 // FutureSendToAddressResult is a future promise to deliver the result of a
 // SendToAddressAsync RPC invocation (or an applicable error).
-type FutureSendToAddressResult chan *futureResult
+type FutureSendToAddressResult chan *response
 
 // Receive waits for the response promised by the future and returns the hash
 // of the transaction sending the passed amount to the given address.
 func (r FutureSendToAddressResult) Receive() (*btcwire.ShaHash, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return nil, err
 	}
 
-	txHash, ok := reply.(string)
+	// Unmarshal result as a string.
-	if !ok {
+	var txHash string
-		return nil, fmt.Errorf("unexpected response type for "+
+	err = json.Unmarshal(res, &txHash)
-			"sendtoaddress: %T\n", reply)
+	if err != nil {
+		return nil, err
 	}
 
 	return btcwire.NewShaHashFromStr(txHash)
@@ -500,22 +491,22 @@ func (c *Client) SendToAddressComment(address btcutil.Address, amount btcutil.Am
 // FutureSendFromResult is a future promise to deliver the result of a
 // SendFromAsync, SendFromMinConfAsync, or SendFromCommentAsync RPC invocation
 // (or an applicable error).
-type FutureSendFromResult chan *futureResult
+type FutureSendFromResult chan *response
 
 // Receive waits for the response promised by the future and returns the hash
 // of the transaction sending amount to the given address using the provided
 // account as a source of funds.
 func (r FutureSendFromResult) Receive() (*btcwire.ShaHash, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return nil, err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmarshal result as a string.
-	txHash, ok := reply.(string)
+	var txHash string
-	if !ok {
+	err = json.Unmarshal(res, &txHash)
-		return nil, fmt.Errorf("unexpected response type for "+
+	if err != nil {
-			"sendfrom: %T\n", reply)
+		return nil, err
 	}
 
 	return btcwire.NewShaHashFromStr(txHash)
@@ -622,22 +613,22 @@ func (c *Client) SendFromComment(fromAccount string, toAddress btcutil.Address,
 // FutureSendManyResult is a future promise to deliver the result of a
 // SendManyAsync, SendManyMinConfAsync, or SendManyCommentAsync RPC invocation
 // (or an applicable error).
-type FutureSendManyResult chan *futureResult
+type FutureSendManyResult chan *response
 
 // Receive waits for the response promised by the future and returns the hash
 // of the transaction sending multiple amounts to multiple addresses using the
 // provided account as a source of funds.
 func (r FutureSendManyResult) Receive() (*btcwire.ShaHash, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return nil, err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmashal result as a string.
-	txHash, ok := reply.(string)
+	var txHash string
-	if !ok {
+	err = json.Unmarshal(res, &txHash)
-		return nil, fmt.Errorf("unexpected response type for "+
+	if err != nil {
-			"sendmany: %T\n", reply)
+		return nil, err
 	}
 
 	return btcwire.NewShaHashFromStr(txHash)
@@ -760,22 +751,22 @@ func (c *Client) SendManyComment(fromAccount string,
 
 // FutureAddMultisigAddressResult is a future promise to deliver the result of a
 // AddMultisigAddressAsync RPC invocation (or an applicable error).
-type FutureAddMultisigAddressResult chan *futureResult
+type FutureAddMultisigAddressResult chan *response
 
 // Receive waits for the response promised by the future and returns the
 // multisignature address that requires the specified number of signatures for
 // the provided addresses.
 func (r FutureAddMultisigAddressResult) Receive() (btcutil.Address, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return nil, err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmarshal result as a string.
-	addr, ok := reply.(string)
+	var addr string
-	if !ok {
+	err = json.Unmarshal(res, &addr)
-		return nil, fmt.Errorf("unexpected response type for "+
+	if err != nil {
-			"addmultisigaddress: %T\n", reply)
+		return nil, err
 	}
 
 	return btcutil.DecodeAddress(addr, &btcnet.MainNetParams)
@@ -811,24 +802,24 @@ func (c *Client) AddMultisigAddress(requiredSigs int, addresses []btcutil.Addres
 
 // FutureCreateMultisigResult is a future promise to deliver the result of a
 // CreateMultisigAsync RPC invocation (or an applicable error).
-type FutureCreateMultisigResult chan *futureResult
+type FutureCreateMultisigResult chan *response
 
 // Receive waits for the response promised by the future and returns the
 // multisignature address and script needed to redeem it.
 func (r FutureCreateMultisigResult) Receive() (*btcjson.CreateMultiSigResult, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return nil, err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmarshal result as a createmultisig result object.
-	result, ok := reply.(*btcjson.CreateMultiSigResult)
+	var multisigRes btcjson.CreateMultiSigResult
-	if !ok {
+	err = json.Unmarshal(res, &multisigRes)
-		return nil, fmt.Errorf("unexpected response type for "+
+	if err != nil {
-			"createmultisig: %T\n", reply)
+		return nil, err
 	}
 
-	return result, nil
+	return &multisigRes, nil
 }
 
 // CreateMultisigAsync returns an instance of a type that can be used to get
@@ -861,21 +852,21 @@ func (c *Client) CreateMultisig(requiredSigs int, addresses []btcutil.Address) (
 
 // FutureGetNewAddressResult is a future promise to deliver the result of a
 // GetNewAddressAsync RPC invocation (or an applicable error).
-type FutureGetNewAddressResult chan *futureResult
+type FutureGetNewAddressResult chan *response
 
 // Receive waits for the response promised by the future and returns a new
 // address.
 func (r FutureGetNewAddressResult) Receive() (btcutil.Address, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return nil, err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmarshal result as a string.
-	addr, ok := reply.(string)
+	var addr string
-	if !ok {
+	err = json.Unmarshal(res, &addr)
-		return nil, fmt.Errorf("unexpected response type for "+
+	if err != nil {
-			"getnewaddress: %T\n", reply)
+		return nil, err
 	}
 
 	return btcutil.DecodeAddress(addr, &btcnet.MainNetParams)
@@ -903,22 +894,22 @@ func (c *Client) GetNewAddress() (btcutil.Address, error) {
 
 // FutureGetRawChangeAddressResult is a future promise to deliver the result of
 // a GetRawChangeAddressAsync RPC invocation (or an applicable error).
-type FutureGetRawChangeAddressResult chan *futureResult
+type FutureGetRawChangeAddressResult chan *response
 
 // Receive waits for the response promised by the future and returns a new
 // address for receiving change that will be associated with the provided
 // account.  Note that this is only for raw transactions and NOT for normal use.
 func (r FutureGetRawChangeAddressResult) Receive() (btcutil.Address, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return nil, err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmarshal result as a string.
-	addr, ok := reply.(string)
+	var addr string
-	if !ok {
+	err = json.Unmarshal(res, &addr)
-		return nil, fmt.Errorf("unexpected response type for "+
+	if err != nil {
-			"getrawchangeaddress: %T\n", reply)
+		return nil, err
 	}
 
 	return btcutil.DecodeAddress(addr, &btcnet.MainNetParams)
@@ -948,21 +939,21 @@ func (c *Client) GetRawChangeAddress(account string) (btcutil.Address, error) {
 
 // FutureGetAccountAddressResult is a future promise to deliver the result of a
 // GetAccountAddressAsync RPC invocation (or an applicable error).
-type FutureGetAccountAddressResult chan *futureResult
+type FutureGetAccountAddressResult chan *response
 
 // Receive waits for the response promised by the future and returns the current
 // Bitcoin address for receiving payments to the specified account.
 func (r FutureGetAccountAddressResult) Receive() (btcutil.Address, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return nil, err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmarshal result as a string.
-	addr, ok := reply.(string)
+	var addr string
-	if !ok {
+	err = json.Unmarshal(res, &addr)
-		return nil, fmt.Errorf("unexpected response type for "+
+	if err != nil {
-			"getaccountaddress: %T\n", reply)
+		return nil, err
 	}
 
 	return btcutil.DecodeAddress(addr, &btcnet.MainNetParams)
@@ -991,21 +982,21 @@ func (c *Client) GetAccountAddress(account string) (btcutil.Address, error) {
 
 // FutureGetAccountResult is a future promise to deliver the result of a
 // GetAccountAsync RPC invocation (or an applicable error).
-type FutureGetAccountResult chan *futureResult
+type FutureGetAccountResult chan *response
 
 // Receive waits for the response promised by the future and returns the account
 // associated with the passed address.
 func (r FutureGetAccountResult) Receive() (string, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return "", err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmarshal result as a string.
-	account, ok := reply.(string)
+	var account string
-	if !ok {
+	err = json.Unmarshal(res, &account)
-		return "", fmt.Errorf("unexpected response type for "+
+	if err != nil {
-			"getaccount: %T\n", reply)
+		return "", err
 	}
 
 	return account, nil
@@ -1034,7 +1025,7 @@ func (c *Client) GetAccount(address btcutil.Address) (string, error) {
 
 // FutureSetAccountResult is a future promise to deliver the result of a
 // SetAccountAsync RPC invocation (or an applicable error).
-type FutureSetAccountResult chan *futureResult
+type FutureSetAccountResult chan *response
 
 // Receive waits for the response promised by the future and returns the result
 // of setting the account to be associated with the passed address.
@@ -1070,21 +1061,21 @@ func (c *Client) SetAccount(address btcutil.Address, account string) error {
 
 // FutureGetAddressesByAccountResult is a future promise to deliver the result
 // of a GetAddressesByAccountAsync RPC invocation (or an applicable error).
-type FutureGetAddressesByAccountResult chan *futureResult
+type FutureGetAddressesByAccountResult chan *response
 
 // Receive waits for the response promised by the future and returns the list of
 // addresses associated with the passed account.
 func (r FutureGetAddressesByAccountResult) Receive() ([]btcutil.Address, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return nil, err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmashal result as an array of string.
-	addrStrings, ok := reply.([]string)
+	var addrStrings []string
-	if !ok {
+	err = json.Unmarshal(res, &addrStrings)
-		return nil, fmt.Errorf("unexpected response type for "+
+	if err != nil {
-			"getaddressesbyaccount: %T\n", reply)
+		return nil, err
 	}
 
 	addrs := make([]btcutil.Address, 0, len(addrStrings))
@@ -1122,24 +1113,24 @@ func (c *Client) GetAddressesByAccount(account string) ([]btcutil.Address, error
 
 // FutureValidateAddressResult is a future promise to deliver the result of a
 // ValidateAddressAsync RPC invocation (or an applicable error).
-type FutureValidateAddressResult chan *futureResult
+type FutureValidateAddressResult chan *response
 
 // Receive waits for the response promised by the future and returns information
 // about the given bitcoin address.
 func (r FutureValidateAddressResult) Receive() (*btcjson.ValidateAddressResult, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return nil, err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmarshal result as a validateaddress result object.
-	result, ok := reply.(*btcjson.ValidateAddressResult)
+	var addrResult btcjson.ValidateAddressResult
-	if !ok {
+	err = json.Unmarshal(res, &addrResult)
-		return nil, fmt.Errorf("unexpected response type for "+
+	if err != nil {
-			"validateaddress: %T\n", reply)
+		return nil, err
 	}
 
-	return result, nil
+	return &addrResult, nil
 }
 
 // ValidateAddressAsync returns an instance of a type that can be used to get
@@ -1165,7 +1156,7 @@ func (c *Client) ValidateAddress(address btcutil.Address) (*btcjson.ValidateAddr
 
 // FutureKeyPoolRefillResult is a future promise to deliver the result of a
 // KeyPoolRefillAsync RPC invocation (or an applicable error).
-type FutureKeyPoolRefillResult chan *futureResult
+type FutureKeyPoolRefillResult chan *response
 
 // Receive waits for the response promised by the future and returns the result
 // of refilling the key pool.
@@ -1228,21 +1219,21 @@ func (c *Client) KeyPoolRefillSize(newSize uint) error {
 // FutureListAccountsResult is a future promise to deliver the result of a
 // ListAccountsAsync or ListAccountsMinConfAsync RPC invocation (or an
 // applicable error).
-type FutureListAccountsResult chan *futureResult
+type FutureListAccountsResult chan *response
 
 // Receive waits for the response promised by the future and returns returns a
 // map of account names and their associated balances.
 func (r FutureListAccountsResult) Receive() (map[string]btcutil.Amount, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return nil, err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmarshal result as a json object.
-	accounts, ok := reply.(map[string]float64)
+	var accounts map[string]float64
-	if !ok {
+	err = json.Unmarshal(res, &accounts)
-		return nil, fmt.Errorf("unexpected response type for "+
+	if err != nil {
-			"listaccounts: %T\n", reply)
+		return nil, err
 	}
 
 	accountsMap := make(map[string]btcutil.Amount)
@@ -1307,21 +1298,21 @@ func (c *Client) ListAccountsMinConf(minConfirms int) (map[string]btcutil.Amount
 // FutureGetBalanceResult is a future promise to deliver the result of a
 // GetBalanceAsync or GetBalanceMinConfAsync RPC invocation (or an applicable
 // error).
-type FutureGetBalanceResult chan *futureResult
+type FutureGetBalanceResult chan *response
 
 // Receive waits for the response promised by the future and returns the
 // available balance from the server for the specified account.
 func (r FutureGetBalanceResult) Receive() (btcutil.Amount, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return 0, err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmarshal result as a floating point number.
-	balance, ok := reply.(float64)
+	var balance float64
-	if !ok {
+	err = json.Unmarshal(res, &balance)
-		return 0, fmt.Errorf("unexpected response type for "+
+	if err != nil {
-			"getbalance: %T\n", reply)
+		return 0, err
 	}
 
 	satoshi, err := btcjson.JSONToAmount(balance)
@@ -1391,21 +1382,21 @@ func (c *Client) GetBalanceMinConf(account string, minConfirms int) (btcutil.Amo
 // FutureGetReceivedByAccountResult is a future promise to deliver the result of
 // a GetReceivedByAccountAsync or GetReceivedByAccountMinConfAsync RPC
 // invocation (or an applicable error).
-type FutureGetReceivedByAccountResult chan *futureResult
+type FutureGetReceivedByAccountResult chan *response
 
 // Receive waits for the response promised by the future and returns the total
 // amount received with the specified account.
 func (r FutureGetReceivedByAccountResult) Receive() (btcutil.Amount, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return 0, err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmarshal result as a floating point number.
-	balance, ok := reply.(float64)
+	var balance float64
-	if !ok {
+	err = json.Unmarshal(res, &balance)
-		return 0, fmt.Errorf("unexpected response type for "+
+	if err != nil {
-			"getreceivedbyaccount: %T\n", reply)
+		return 0, err
 	}
 
 	satoshi, err := btcjson.JSONToAmount(balance)
@@ -1466,21 +1457,21 @@ func (c *Client) GetReceivedByAccountMinConf(account string, minConfirms int) (b
 
 // FutureGetUnconfirmedBalanceResult is a future promise to deliver the result
 // of a GetUnconfirmedBalanceAsync RPC invocation (or an applicable error).
-type FutureGetUnconfirmedBalanceResult chan *futureResult
+type FutureGetUnconfirmedBalanceResult chan *response
 
 // Receive waits for the response promised by the future and returns returns the
 // unconfirmed balance from the server for the specified account.
 func (r FutureGetUnconfirmedBalanceResult) Receive() (btcutil.Amount, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return 0, err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmarshal result as a floating point number.
-	balance, ok := reply.(float64)
+	var balance float64
-	if !ok {
+	err = json.Unmarshal(res, &balance)
-		return 0, fmt.Errorf("unexpected response type for "+
+	if err != nil {
-			"getunconfirmedbalance: %T\n", reply)
+		return 0, err
 	}
 
 	satoshi, err := btcjson.JSONToAmount(balance)
@@ -1515,21 +1506,21 @@ func (c *Client) GetUnconfirmedBalance(account string) (btcutil.Amount, error) {
 // FutureGetReceivedByAddressResult is a future promise to deliver the result of
 // a GetReceivedByAddressAsync or GetReceivedByAddressMinConfAsync RPC
 // invocation (or an applicable error).
-type FutureGetReceivedByAddressResult chan *futureResult
+type FutureGetReceivedByAddressResult chan *response
 
 // Receive waits for the response promised by the future and returns the total
 // amount received by the specified address.
 func (r FutureGetReceivedByAddressResult) Receive() (btcutil.Amount, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return 0, err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmarshal result as a floating point number.
-	balance, ok := reply.(float64)
+	var balance float64
-	if !ok {
+	err = json.Unmarshal(res, &balance)
-		return 0, fmt.Errorf("unexpected response type for "+
+	if err != nil {
-			"getreceivedbyaddress: %T\n", reply)
+		return 0, err
 	}
 
 	satoshi, err := btcjson.JSONToAmount(balance)
@@ -1594,29 +1585,24 @@ func (c *Client) GetReceivedByAddressMinConf(address btcutil.Address, minConfirm
 // of a ListReceivedByAccountAsync, ListReceivedByAccountMinConfAsync, or
 // ListReceivedByAccountIncludeEmptyAsync RPC invocation (or an applicable
 // error).
-type FutureListReceivedByAccountResult chan *futureResult
+type FutureListReceivedByAccountResult chan *response
 
 // Receive waits for the response promised by the future and returns a list of
 // balances by account.
 func (r FutureListReceivedByAccountResult) Receive() ([]btcjson.ListReceivedByAccountResult, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return nil, err
 	}
 
-	// No results.
+	// Unmarshal as an array of listreceivedbyaccount result objects.
-	if reply == nil {
+	var received []btcjson.ListReceivedByAccountResult
-		return nil, nil
+	err = json.Unmarshal(res, &received)
+	if err != nil {
+		return nil, err
 	}
 
-	// Ensure the returned data is the expected type.
+	return received, nil
-	result, ok := reply.([]btcjson.ListReceivedByAccountResult)
-	if !ok {
-		return nil, fmt.Errorf("unexpected response type for "+
-			"listreceivedbyaccount: %T\n", reply)
-	}
-
-	return result, nil
 }
 
 // ListReceivedByAccountAsync returns an instance of a type that can be used to
@@ -1702,7 +1688,7 @@ func (c *Client) ListReceivedByAccountIncludeEmpty(minConfirms int, includeEmpty
 
 // FutureWalletLockResult is a future promise to deliver the result of a
 // WalletLockAsync RPC invocation (or an applicable error).
-type FutureWalletLockResult chan *futureResult
+type FutureWalletLockResult chan *response
 
 // Receive waits for the response promised by the future and returns the result
 // of locking the wallet.
@@ -1759,7 +1745,7 @@ func (c *Client) WalletPassphrase(passphrase string, timeoutSecs int64) error {
 
 // FutureWalletPassphraseChangeResult is a future promise to deliver the result
 // of a WalletPassphraseChangeAsync RPC invocation (or an applicable error).
-type FutureWalletPassphraseChangeResult chan *futureResult
+type FutureWalletPassphraseChangeResult chan *response
 
 // Receive waits for the response promised by the future and returns the result
 // of changing the wallet passphrase.
@@ -1799,21 +1785,21 @@ func (c *Client) WalletPassphraseChange(old, new string) error {
 
 // FutureSignMessageResult is a future promise to deliver the result of a
 // SignMessageAsync RPC invocation (or an applicable error).
-type FutureSignMessageResult chan *futureResult
+type FutureSignMessageResult chan *response
 
 // Receive waits for the response promised by the future and returns the message
 // signed with the private key of the specified address.
 func (r FutureSignMessageResult) Receive() (string, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return "", err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmarshal result as a string.
-	b64, ok := reply.(string)
+	var b64 string
-	if !ok {
+	err = json.Unmarshal(res, &b64)
-		return "", fmt.Errorf("unexpected response type for "+
+	if err != nil {
-			"signmessage: %T\n", reply)
+		return "", err
 	}
 
 	return b64, nil
@@ -1845,21 +1831,21 @@ func (c *Client) SignMessage(address btcutil.Address, message string) (string, e
 
 // FutureVerifyMessageResult is a future promise to deliver the result of a
 // VerifyMessageAsync RPC invocation (or an applicable error).
-type FutureVerifyMessageResult chan *futureResult
+type FutureVerifyMessageResult chan *response
 
 // Receive waits for the response promised by the future and returns whether or
 // not the message was successfully verified.
 func (r FutureVerifyMessageResult) Receive() (bool, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return false, err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmarshal result as a boolean.
-	verified, ok := reply.(bool)
+	var verified bool
-	if !ok {
+	err = json.Unmarshal(res, &verified)
-		return false, fmt.Errorf("unexpected response type for "+
+	if err != nil {
-			"verifymessage: %T\n", reply)
+		return false, err
 	}
 
 	return verified, nil
@@ -1895,22 +1881,22 @@ func (c *Client) VerifyMessage(address btcutil.Address, signature, message strin
 
 // FutureDumpPrivKeyResult is a future promise to deliver the result of a
 // DumpPrivKeyAsync RPC invocation (or an applicable error).
-type FutureDumpPrivKeyResult chan *futureResult
+type FutureDumpPrivKeyResult chan *response
 
 // Receive waits for the response promised by the future and returns the private
 // key corresponding to the passed address encoded in the wallet import format
 // (WIF)
 func (r FutureDumpPrivKeyResult) Receive() (*btcutil.WIF, error) {
-	reply, err := receiveFuture(r)
+	res, err := receiveFuture(r)
 	if err != nil {
 		return nil, err
 	}
 
-	// Ensure the returned data is the expected type.
+	// Unmarshal result as a string.
-	privKeyWIF, ok := reply.(string)
+	var privKeyWIF string
-	if !ok {
+	err = json.Unmarshal(res, &privKeyWIF)
-		return nil, fmt.Errorf("unexpected response type for "+
+	if err != nil {
-			"dumpprivkey: %T\n", reply)
+		return nil, err
 	}
 
 	return btcutil.DecodeWIF(privKeyWIF)
@@ -1943,7 +1929,7 @@ func (c *Client) DumpPrivKey(address btcutil.Address) (*btcutil.WIF, error) {
 
 // FutureImportPrivKeyResult is a future promise to deliver the result of an
 // ImportPrivKeyAsync RPC invocation (or an applicable error).
-type FutureImportPrivKeyResult chan *futureResult
+type FutureImportPrivKeyResult chan *response
 
 // Receive waits for the response promised by the future and returns the result
 // of importing the passed private key which must be the wallet import format