dcrjson: getblocksubsidy support. (decred#679)

dcrjson/chainsvrcmds.go

@@ -206,6 +206,21 @@ func NewGetBlockHeaderCmd(hash string, verbose *bool) *GetBlockHeaderCmd {
 	}
 }
 
+// GetBlockSubsidyCmd defines the getblocksubsidy JSON-RPC command.
+type GetBlockSubsidyCmd struct {
+	Height int64
+	Voters uint16
+}
+
+// NewGetBlockSubsidyCmd returns a new instance which can be used to issue a
+// getblocksubsidy JSON-RPC command.
+func NewGetBlockSubsidyCmd(height int64, voters uint16) *GetBlockSubsidyCmd {
+	return &GetBlockSubsidyCmd{
+		Height: height,
+		Voters: voters,
+	}
+}
+
 // TemplateRequest is a request object as defined in BIP22
 // (https://en.bitcoin.it/wiki/BIP_0022), it is optionally provided as an
 // pointer argument to GetBlockTemplateCmd.
@@ -775,6 +790,7 @@ func init() {
 	MustRegisterCmd("getblockcount", (*GetBlockCountCmd)(nil), flags)
 	MustRegisterCmd("getblockhash", (*GetBlockHashCmd)(nil), flags)
 	MustRegisterCmd("getblockheader", (*GetBlockHeaderCmd)(nil), flags)
+	MustRegisterCmd("getblocksubsidy", (*GetBlockSubsidyCmd)(nil), flags)
 	MustRegisterCmd("getblocktemplate", (*GetBlockTemplateCmd)(nil), flags)
 	MustRegisterCmd("getchaintips", (*GetChainTipsCmd)(nil), flags)
 	MustRegisterCmd("getconnectioncount", (*GetConnectionCountCmd)(nil), flags)

dcrjson/chainsvrcmds_test.go

@@ -234,6 +234,20 @@ func TestChainSvrCmds(t *testing.T) {
 				Verbose: dcrjson.Bool(true),
 			},
 		},
+		{
+			name: "getblocksubsidy",
+			newCmd: func() (interface{}, error) {
+				return dcrjson.NewCmd("getblocksubsidy", 123, 256)
+			},
+			staticCmd: func() interface{} {
+				return dcrjson.NewGetBlockSubsidyCmd(123, 256)
+			},
+			marshalled: `{"jsonrpc":"1.0","method":"getblocksubsidy","params":[123,256],"id":1}`,
+			unmarshalled: &dcrjson.GetBlockSubsidyCmd{
+				Height: 123,
+				Voters: 256,
+			},
+		},
 		{
 			name: "getblocktemplate",
 			newCmd: func() (interface{}, error) {

dcrjson/chainsvrresults.go

@@ -108,6 +108,15 @@ type GetBlockChainInfoResult struct {
 	ChainWork            string  `json:"chainwork"`
 }
 
+// GetBlockSubsidyResult models the data returned from the getblocksubsidy
+// command.
+type GetBlockSubsidyResult struct {
+	Developer int64 `json:"developer"`
+	PoS       int64 `json:"pos"`
+	PoW       int64 `json:"pow"`
+	Total     int64 `json:"total"`
+}
+
 // GetBlockTemplateResultTx models the transactions field of the
 // getblocktemplate command.
 type GetBlockTemplateResultTx struct {

rpcserver.go

@@ -200,6 +200,7 @@ var rpcHandlersBeforeInit = map[string]commandHandler{
 	"getblockcount":         handleGetBlockCount,
 	"getblockhash":          handleGetBlockHash,
 	"getblockheader":        handleGetBlockHeader,
+	"getblocksubsidy":       handleGetBlockSubsidy,
 	"getcoinsupply":         handleGetCoinSupply,
 	"getconnectioncount":    handleGetConnectionCount,
 	"getcurrentnet":         handleGetCurrentNet,
@@ -2128,6 +2129,36 @@ func handleGetBlockHeader(s *rpcServer, cmd interface{}, closeChan <-chan struct
 
 }
 
+// handleGetBlockSubsidy implements the getblocksubsidy command.
+func handleGetBlockSubsidy(s *rpcServer, cmd interface{}, closeChan <-chan struct{}) (interface{}, error) {
+	c := cmd.(*dcrjson.GetBlockSubsidyCmd)
+
+	height := c.Height
+	voters := c.Voters
+
+	cache := s.chain.FetchSubsidyCache()
+	if cache == nil {
+		return nil, rpcInternalError("empty subsidy cache", "")
+	}
+
+	dev := blockchain.CalcBlockTaxSubsidy(cache, height, voters,
+		s.server.chainParams)
+	pos := blockchain.CalcStakeVoteSubsidy(cache, height,
+		s.server.chainParams) * int64(voters)
+	pow := blockchain.CalcBlockWorkSubsidy(cache, height, voters,
+		s.server.chainParams)
+	total := dev + pos + pow
+
+	rep := dcrjson.GetBlockSubsidyResult{
+		Developer: dev,
+		PoS:       pos,
+		PoW:       pow,
+		Total:     total,
+	}
+
+	return rep, nil
+}
+
 // encodeTemplateID encodes the passed details into an ID that can be used to
 // uniquely identify a block template.
 func encodeTemplateID(prevHash *chainhash.Hash, lastGenerated time.Time) string {

rpcserverhelp.go

@@ -338,6 +338,17 @@ var helpDescsEnUS = map[string]string{
 	"getblockheaderverboseresult-stakeroot":         "The merkle root of the stake transaction tree",
 	"getblockheaderverboseresult-stakeversion":      "The stake version of the block",
 
+	// GetBlockSubsidyCmd help.
+	"getblocksubsidy--synopsis": "Returns information regarding subsidy amounts.",
+	"getblocksubsidy-height":    "The block height",
+	"getblocksubsidy-voters":    "The number of voters",
+
+	// GetBlockSubsidyResult help.
+	"getblocksubsidyresult-developer": "The developer subsidy",
+	"getblocksubsidyresult-pos":       "The Proof-of-Stake subsidy",
+	"getblocksubsidyresult-pow":       "The Proof-of-Work subsidy",
+	"getblocksubsidyresult-total":     "The total subsidy",
+
 	// TemplateRequest help.
 	"templaterequest-mode":         "This is 'template', 'proposal', or omitted",
 	"templaterequest-capabilities": "List of capabilities",
@@ -897,6 +908,7 @@ var rpcResultTypes = map[string][]interface{}{
 	"getblockcount":         {(*int64)(nil)},
 	"getblockhash":          {(*string)(nil)},
 	"getblockheader":        {(*string)(nil), (*dcrjson.GetBlockHeaderVerboseResult)(nil)},
+	"getblocksubsidy":       {(*dcrjson.GetBlockSubsidyResult)(nil)},
 	"getblocktemplate":      {(*dcrjson.GetBlockTemplateResult)(nil), (*string)(nil), nil},
 	"getconnectioncount":    {(*int32)(nil)},
 	"getcurrentnet":         {(*uint32)(nil)},