From d6cea4832ae946b770bd71529ef539f92c5ba06a Mon Sep 17 00:00:00 2001 From: Delweng Date: Wed, 22 Nov 2023 18:24:54 +0800 Subject: [PATCH] rpc: improve performance of subscription notification encoding (#28328) It turns out that encoding json.RawMessage is slow because package json basically parses the message again to ensure it is valid. We can avoid the slowdown by encoding the entire RPC notification once, which yields a 30% speedup. --- rpc/json.go | 11 ++++++++ rpc/subscription.go | 27 ++++++++---------- rpc/subscription_test.go | 60 ++++++++++++++++++++++++++++++++++++++++ 3 files changed, 82 insertions(+), 16 deletions(-) diff --git a/rpc/json.go b/rpc/json.go index 78f7d7a65..5557a8076 100644 --- a/rpc/json.go +++ b/rpc/json.go @@ -46,6 +46,17 @@ type subscriptionResult struct { Result json.RawMessage `json:"result,omitempty"` } +type subscriptionResultEnc struct { + ID string `json:"subscription"` + Result any `json:"result"` +} + +type jsonrpcSubscriptionNotification struct { + Version string `json:"jsonrpc"` + Method string `json:"method"` + Params subscriptionResultEnc `json:"params"` +} + // A value of this type can a JSON-RPC request, notification, successful response or // error response. Which one it is depends on the fields. type jsonrpcMessage struct { diff --git a/rpc/subscription.go b/rpc/subscription.go index 3231c2cee..9cb072754 100644 --- a/rpc/subscription.go +++ b/rpc/subscription.go @@ -105,7 +105,7 @@ type Notifier struct { mu sync.Mutex sub *Subscription - buffer []json.RawMessage + buffer []any callReturned bool activated bool } @@ -129,12 +129,7 @@ func (n *Notifier) CreateSubscription() *Subscription { // Notify sends a notification to the client with the given data as payload. // If an error occurs the RPC connection is closed and the error is returned. -func (n *Notifier) Notify(id ID, data interface{}) error { - enc, err := json.Marshal(data) - if err != nil { - return err - } - +func (n *Notifier) Notify(id ID, data any) error { n.mu.Lock() defer n.mu.Unlock() @@ -144,9 +139,9 @@ func (n *Notifier) Notify(id ID, data interface{}) error { panic("Notify with wrong ID") } if n.activated { - return n.send(n.sub, enc) + return n.send(n.sub, data) } - n.buffer = append(n.buffer, enc) + n.buffer = append(n.buffer, data) return nil } @@ -181,16 +176,16 @@ func (n *Notifier) activate() error { return nil } -func (n *Notifier) send(sub *Subscription, data json.RawMessage) error { - params, _ := json.Marshal(&subscriptionResult{ID: string(sub.ID), Result: data}) - ctx := context.Background() - - msg := &jsonrpcMessage{ +func (n *Notifier) send(sub *Subscription, data any) error { + msg := jsonrpcSubscriptionNotification{ Version: vsn, Method: n.namespace + notificationMethodSuffix, - Params: params, + Params: subscriptionResultEnc{ + ID: string(sub.ID), + Result: data, + }, } - return n.h.conn.writeJSON(ctx, msg, false) + return n.h.conn.writeJSON(context.Background(), &msg, false) } // A Subscription is created by a notifier and tied to that notifier. The client can use diff --git a/rpc/subscription_test.go b/rpc/subscription_test.go index b27045782..3a131c8e6 100644 --- a/rpc/subscription_test.go +++ b/rpc/subscription_test.go @@ -17,12 +17,19 @@ package rpc import ( + "bytes" + "context" "encoding/json" "fmt" + "io" + "math/big" "net" "strings" "testing" "time" + + "github.com/ethereum/go-ethereum/common" + "github.com/ethereum/go-ethereum/core/types" ) func TestNewID(t *testing.T) { @@ -218,3 +225,56 @@ func readAndValidateMessage(in *json.Decoder) (*subConfirmation, *subscriptionRe return nil, nil, fmt.Errorf("unrecognized message: %v", msg) } } + +type mockConn struct { + enc *json.Encoder +} + +// writeJSON writes a message to the connection. +func (c *mockConn) writeJSON(ctx context.Context, msg interface{}, isError bool) error { + return c.enc.Encode(msg) +} + +// Closed returns a channel which is closed when the connection is closed. +func (c *mockConn) closed() <-chan interface{} { return nil } + +// RemoteAddr returns the peer address of the connection. +func (c *mockConn) remoteAddr() string { return "" } + +// BenchmarkNotify benchmarks the performance of notifying a subscription. +func BenchmarkNotify(b *testing.B) { + id := ID("test") + notifier := &Notifier{ + h: &handler{conn: &mockConn{json.NewEncoder(io.Discard)}}, + sub: &Subscription{ID: id}, + activated: true, + } + msg := &types.Header{ + ParentHash: common.HexToHash("0x01"), + Number: big.NewInt(100), + } + b.ResetTimer() + for i := 0; i < b.N; i++ { + notifier.Notify(id, msg) + } +} + +func TestNotify(t *testing.T) { + out := new(bytes.Buffer) + id := ID("test") + notifier := &Notifier{ + h: &handler{conn: &mockConn{json.NewEncoder(out)}}, + sub: &Subscription{ID: id}, + activated: true, + } + msg := &types.Header{ + ParentHash: common.HexToHash("0x01"), + Number: big.NewInt(100), + } + notifier.Notify(id, msg) + have := strings.TrimSpace(out.String()) + want := `{"jsonrpc":"2.0","method":"_subscription","params":{"subscription":"test","result":{"parentHash":"0x0000000000000000000000000000000000000000000000000000000000000001","sha3Uncles":"0x0000000000000000000000000000000000000000000000000000000000000000","miner":"0x0000000000000000000000000000000000000000","stateRoot":"0x0000000000000000000000000000000000000000000000000000000000000000","transactionsRoot":"0x0000000000000000000000000000000000000000000000000000000000000000","receiptsRoot":"0x0000000000000000000000000000000000000000000000000000000000000000","logsBloom":"0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000","difficulty":null,"number":"0x64","gasLimit":"0x0","gasUsed":"0x0","timestamp":"0x0","extraData":"0x","mixHash":"0x0000000000000000000000000000000000000000000000000000000000000000","nonce":"0x0000000000000000","baseFeePerGas":null,"withdrawalsRoot":null,"blobGasUsed":null,"excessBlobGas":null,"parentBeaconBlockRoot":null,"hash":"0xe5fb877dde471b45b9742bb4bb4b3d74a761e2fb7cb849a3d2b687eed90fb604"}}}` + if have != want { + t.Errorf("have:\n%v\nwant:\n%v\n", have, want) + } +}