GetBlockTemplate RPC client implementation

btcjson/chainsvrcmds.go

@@ -322,6 +322,9 @@ type TemplateRequest struct {
 	// "proposal".
 	Data   string `json:"data,omitempty"`
 	WorkID string `json:"workid,omitempty"`
+
+	// "rules"
+	Rules []string `json:"rules,omitempty"`
 }
 
 // convertTemplateRequestField potentially converts the provided value as

rpcclient/mining.go

@@ -461,4 +461,39 @@ func (c *Client) SubmitBlock(block *btcutil.Block, options *btcjson.SubmitBlockO
 	return c.SubmitBlockAsync(block, options).Receive()
 }
 
-// TODO(davec): Implement GetBlockTemplate
+// FutureGetBlockTemplateResponse is a future promise to deliver the result of a
+// GetBlockTemplateAsync RPC invocation (or an applicable error).
+type FutureGetBlockTemplateResponse chan *response
+
+// Receive waits for the response promised by the future and returns an error if
+// any occurred when retrieving the block template.
+func (r FutureGetBlockTemplateResponse) Receive() (*btcjson.GetBlockTemplateResult, error) {
+	res, err := receiveFuture(r)
+	if err != nil {
+		return nil, err
+	}
+
+	// Unmarshal result as a getwork result object.
+	var result btcjson.GetBlockTemplateResult
+	err = json.Unmarshal(res, &result)
+	if err != nil {
+		return nil, err
+	}
+
+	return &result, nil
+}
+
+// GetBlockTemplateAsync returns an instance of a type that can be used to get the
+// result of the RPC at some future time by invoking the Receive function on the
+// returned instance.
+//
+// See GetBlockTemplate for the blocking version and more details.
+func (c *Client) GetBlockTemplateAsync(req *btcjson.TemplateRequest) FutureGetBlockTemplateResponse {
+	cmd := btcjson.NewGetBlockTemplateCmd(req)
+	return c.sendCmd(cmd)
+}
+
+// GetBlockTemplate returns a new block template for mining.
+func (c *Client) GetBlockTemplate(req *btcjson.TemplateRequest) (*btcjson.GetBlockTemplateResult, error) {
+	return c.GetBlockTemplateAsync(req).Receive()
+}

rpcserverhelp.go

@@ -296,6 +296,8 @@ var helpDescsEnUS = map[string]string{
 	"templaterequest-data":         "Hex-encoded block data (only for mode=proposal)",
 	"templaterequest-workid":       "The server provided workid if provided in block template (not applicable)",
 
+	"templaterequest-rules":        "Specific block rules that are to be enforced e.g. '[\"segwit\"]",
+
 	// GetBlockTemplateResultTx help.
 	"getblocktemplateresulttx-data":    "Hex-encoded transaction data (byte-for-byte)",
 	"getblocktemplateresulttx-hash":    "Hex-encoded transaction hash (little endian if treated as a 256-bit number)",