rpc: add new client, use it everywhere

The new client implementation supports concurrent requests,
subscriptions and replaces the various ad hoc RPC clients
throughout go-ethereum.

2 files changed, 27 insertions, 31 deletions

diff --git a/cmd/geth/consolecmd.go b/cmd/geth/consolecmd.go
index 257050a62..8d53809ce 100644
--- a/cmd/geth/consolecmd.go
+++ b/cmd/geth/consolecmd.go
@@ -19,9 +19,12 @@ package main
 import (
 	"os"
 	"os/signal"
+	"strings"
 
 	"github.com/ethereum/go-ethereum/cmd/utils"
 	"github.com/ethereum/go-ethereum/console"
+	"github.com/ethereum/go-ethereum/node"
+	"github.com/ethereum/go-ethereum/rpc"
 	"gopkg.in/urfave/cli.v1"
 )
 
@@ -99,7 +102,7 @@ func localConsole(ctx *cli.Context) error {
 // console to it.
 func remoteConsole(ctx *cli.Context) error {
 	// Attach to a remotely running geth instance and start the JavaScript console
-	client, err := utils.NewRemoteRPCClient(ctx)
+	client, err := dialRPC(ctx.Args().First())
 	if err != nil {
 		utils.Fatalf("Unable to attach to remote geth: %v", err)
 	}
@@ -127,6 +130,20 @@ func remoteConsole(ctx *cli.Context) error {
 	return nil
 }
 
+// dialRPC returns a RPC client which connects to the given endpoint.
+// The check for empty endpoint implements the defaulting logic
+// for "geth attach" and "geth monitor" with no argument.
+func dialRPC(endpoint string) (*rpc.Client, error) {
+	if endpoint == "" {
+		endpoint = node.DefaultIPCEndpoint()
+	} else if strings.HasPrefix(endpoint, "rpc:") || strings.HasPrefix(endpoint, "ipc:") {
+		// Backwards compatibility with geth < 1.5 which required
+		// these prefixes.
+		endpoint = endpoint[4:]
+	}
+	return rpc.Dial(endpoint)
+}
+
 // ephemeralConsole starts a new geth node, attaches an ephemeral JavaScript
 // console to it, and each of the files specified as arguments and tears the
 // everything down.
diff --git a/cmd/geth/monitorcmd.go b/cmd/geth/monitorcmd.go
index 11fdca89c..d1490dce2 100644
--- a/cmd/geth/monitorcmd.go
+++ b/cmd/geth/monitorcmd.go
@@ -21,11 +21,10 @@ import (
 	"math"
 	"reflect"
 	"runtime"
+	"sort"
 	"strings"
 	"time"
 
-	"sort"
-
 	"github.com/ethereum/go-ethereum/cmd/utils"
 	"github.com/ethereum/go-ethereum/node"
 	"github.com/ethereum/go-ethereum/rpc"
@@ -36,7 +35,7 @@ import (
 var (
 	monitorCommandAttachFlag = cli.StringFlag{
 		Name:  "attach",
-		Value: "ipc:" + node.DefaultIPCEndpoint(),
+		Value: node.DefaultIPCEndpoint(),
 		Usage: "API endpoint to attach to",
 	}
 	monitorCommandRowsFlag = cli.IntFlag{
@@ -69,12 +68,12 @@ to display multiple metrics simultaneously.
 // monitor starts a terminal UI based monitoring tool for the requested metrics.
 func monitor(ctx *cli.Context) error {
 	var (
-		client rpc.Client
+		client *rpc.Client
 		err    error
 	)
 	// Attach to an Ethereum node over IPC or RPC
 	endpoint := ctx.String(monitorCommandAttachFlag.Name)
-	if client, err = utils.NewRemoteRPCClientFromString(endpoint); err != nil {
+	if client, err = dialRPC(endpoint); err != nil {
 		utils.Fatalf("Unable to attach to geth node: %v", err)
 	}
 	defer client.Close()
@@ -159,30 +158,10 @@ func monitor(ctx *cli.Context) error {
 
 // retrieveMetrics contacts the attached geth node and retrieves the entire set
 // of collected system metrics.
-func retrieveMetrics(client rpc.Client) (map[string]interface{}, error) {
-	req := map[string]interface{}{
-		"id":      new(int64),
-		"method":  "debug_metrics",
-		"jsonrpc": "2.0",
-		"params":  []interface{}{true},
-	}
-
-	if err := client.Send(req); err != nil {
-		return nil, err
-	}
-
-	var res rpc.JSONSuccessResponse
-	if err := client.Recv(&res); err != nil {
-		return nil, err
-	}
-
-	if res.Result != nil {
-		if mets, ok := res.Result.(map[string]interface{}); ok {
-			return mets, nil
-		}
-	}
-
-	return nil, fmt.Errorf("unable to retrieve metrics")
+func retrieveMetrics(client *rpc.Client) (map[string]interface{}, error) {
+	var metrics map[string]interface{}
+	err := client.Call(&metrics, "debug_metrics", true)
+	return metrics, err
 }
 
 // resolveMetrics takes a list of input metric patterns, and resolves each to one
@@ -270,7 +249,7 @@ func fetchMetric(metrics map[string]interface{}, metric string) float64 {
 
 // refreshCharts retrieves a next batch of metrics, and inserts all the new
 // values into the active datasets and charts
-func refreshCharts(client rpc.Client, metrics []string, data [][]float64, units []int, charts []*termui.LineChart, ctx *cli.Context, footer *termui.Par) (realign bool) {
+func refreshCharts(client *rpc.Client, metrics []string, data [][]float64, units []int, charts []*termui.LineChart, ctx *cli.Context, footer *termui.Par) (realign bool) {
 	values, err := retrieveMetrics(client)
 	for i, metric := range metrics {
 		if len(data) < 512 {