New RPC command to display the uptime of the server

Version 0.15.0 of Bitcoin Core will include a new RPC command that will
allow us to obtain the amount of time (in seconds) that the server has
been running.

btcjson/chainsvrcmds.go

@@ -671,6 +671,14 @@ func NewSubmitBlockCmd(hexBlock string, options *SubmitBlockOptions) *SubmitBloc
 	}
 }
 
+// UptimeCmd defines the uptime JSON-RPC command.
+type UptimeCmd struct{}
+
+// NewUptimeCmd returns a new instance which can be used to issue an uptime JSON-RPC command.
+func NewUptimeCmd() *UptimeCmd {
+	return &UptimeCmd{}
+}
+
 // ValidateAddressCmd defines the validateaddress JSON-RPC command.
 type ValidateAddressCmd struct {
 	Address string
@@ -777,6 +785,7 @@ func init() {
 	MustRegisterCmd("setgenerate", (*SetGenerateCmd)(nil), flags)
 	MustRegisterCmd("stop", (*StopCmd)(nil), flags)
 	MustRegisterCmd("submitblock", (*SubmitBlockCmd)(nil), flags)
+	MustRegisterCmd("uptime", (*UptimeCmd)(nil), flags)
 	MustRegisterCmd("validateaddress", (*ValidateAddressCmd)(nil), flags)
 	MustRegisterCmd("verifychain", (*VerifyChainCmd)(nil), flags)
 	MustRegisterCmd("verifymessage", (*VerifyMessageCmd)(nil), flags)

btcjson/chainsvrcmds_test.go

@@ -959,6 +959,17 @@ func TestChainSvrCmds(t *testing.T) {
 				},
 			},
 		},
+		{
+			name: "uptime",
+			newCmd: func() (interface{}, error) {
+				return btcjson.NewCmd("uptime")
+			},
+			staticCmd: func() interface{} {
+				return btcjson.NewUptimeCmd()
+			},
+			marshalled:   `{"jsonrpc":"1.0","method":"uptime","params":[],"id":1}`,
+			unmarshalled: &btcjson.UptimeCmd{},
+		},
 		{
 			name: "validateaddress",
 			newCmd: func() (interface{}, error) {

rpcserver.go

@@ -163,6 +163,7 @@ var rpcHandlersBeforeInit = map[string]commandHandler{
 	"setgenerate":           handleSetGenerate,
 	"stop":                  handleStop,
 	"submitblock":           handleSubmitBlock,
+	"uptime":                handleUptime,
 	"validateaddress":       handleValidateAddress,
 	"verifychain":           handleVerifyChain,
 	"verifymessage":         handleVerifyMessage,
@@ -267,6 +268,7 @@ var rpcLimited = map[string]struct{}{
 	"searchrawtransactions": {},
 	"sendrawtransaction":    {},
 	"submitblock":           {},
+	"uptime":                {},
 	"validateaddress":       {},
 	"verifymessage":         {},
 	"version":               {},
@@ -3313,6 +3315,11 @@ func handleSubmitBlock(s *rpcServer, cmd interface{}, closeChan <-chan struct{})
 	return nil, nil
 }
 
+// handleUptime implements the uptime command.
+func handleUptime(s *rpcServer, cmd interface{}, closeChan <-chan struct{}) (interface{}, error) {
+	return time.Now().Unix() - s.server.startupTime, nil
+}
+
 // handleValidateAddress implements the validateaddress command.
 func handleValidateAddress(s *rpcServer, cmd interface{}, closeChan <-chan struct{}) (interface{}, error) {
 	c := cmd.(*btcjson.ValidateAddressCmd)

rpcserverhelp.go

@@ -615,6 +615,10 @@ var helpDescsEnUS = map[string]string{
 	"rescannedblock-hash":         "Hash of the matching block.",
 	"rescannedblock-transactions": "List of matching transactions, serialized and hex-encoded.",
 
+	// Uptime help.
+	"uptime--synopsis": "Returns the total uptime of the server.",
+	"uptime--result0":  "The number of seconds that the server has been running",
+
 	// Version help.
 	"version--synopsis":       "Returns the JSON-RPC API version (semver)",
 	"version--result0--desc":  "Version objects keyed by the program or API name",
@@ -672,6 +676,7 @@ var rpcResultTypes = map[string][]interface{}{
 	"setgenerate":           nil,
 	"stop":                  {(*string)(nil)},
 	"submitblock":           {nil, (*string)(nil)},
+	"uptime":                {(*int64)(nil)},
 	"validateaddress":       {(*btcjson.ValidateAddressChainResult)(nil)},
 	"verifychain":           {(*bool)(nil)},
 	"verifymessage":         {(*bool)(nil)},

server.go

@@ -167,6 +167,7 @@ type server struct {
 	started       int32
 	shutdown      int32
 	shutdownSched int32
+	startupTime   int64
 
 	chainParams          *chaincfg.Params
 	addrManager          *addrmgr.AddrManager
@@ -2003,6 +2004,9 @@ func (s *server) Start() {
 
 	srvrLog.Trace("Starting server")
 
+	// Server startup time. Used for the uptime command for uptime calculation.
+	s.startupTime = time.Now().Unix()
+
 	// Start the peer handler which in turn starts the address and block
 	// managers.
 	s.wg.Add(1)