all: use ZeroCopy on decoder

Author: zchee

conn.go

@@ -4,6 +4,7 @@
 package jsonrpc2
 
 import (
+	"bytes"
 	"context"
 	"fmt"
 	"sync"
@@ -141,7 +142,9 @@ func (c *conn) Call(ctx context.Context, method string, params, result interface
 			return id, nil
 		}
 
-		if err := json.Unmarshal(resp.result, result); err != nil {
+		dec := json.NewDecoder(bytes.NewReader(resp.result))
+		dec.ZeroCopy()
+		if err := dec.Decode(result); err != nil {
 			return id, fmt.Errorf("unmarshaling result: %w", err)
 		}
 

jsonrpc2_test.go

@@ -4,6 +4,7 @@
 package jsonrpc2_test
 
 import (
+	"bytes"
 	"context"
 	"fmt"
 	"io"
@@ -141,21 +142,27 @@ func testHandler() jsonrpc2.Handler {
 
 		case methodOneString:
 			var v string
-			if err := json.Unmarshal(req.Params(), &v); err != nil {
+			dec := json.NewDecoder(bytes.NewReader(req.Params()))
+			dec.ZeroCopy()
+			if err := dec.Decode(&v); err != nil {
 				return reply(ctx, nil, fmt.Errorf("%s: %w", jsonrpc2.ErrParse, err))
 			}
 			return reply(ctx, "got:"+v, nil)
 
 		case methodOneNumber:
 			var v int
-			if err := json.Unmarshal(req.Params(), &v); err != nil {
+			dec := json.NewDecoder(bytes.NewReader(req.Params()))
+			dec.ZeroCopy()
+			if err := dec.Decode(&v); err != nil {
 				return reply(ctx, nil, fmt.Errorf("%s: %w", jsonrpc2.ErrParse, err))
 			}
 			return reply(ctx, fmt.Sprintf("got:%d", v), nil)
 
 		case methodJoin:
 			var v []string
-			if err := json.Unmarshal(req.Params(), &v); err != nil {
+			dec := json.NewDecoder(bytes.NewReader(req.Params()))
+			dec.ZeroCopy()
+			if err := dec.Decode(&v); err != nil {
 				return reply(ctx, nil, fmt.Errorf("%s: %w", jsonrpc2.ErrParse, err))
 			}
 			return reply(ctx, path.Join(v...), nil)

message.go

@@ -4,6 +4,7 @@
 package jsonrpc2
 
 import (
+	"bytes"
 	"errors"
 	"fmt"
 
@@ -102,7 +103,9 @@ func (c Call) MarshalJSON() ([]byte, error) {
 // UnmarshalJSON implements json.Unmarshaler.
 func (c *Call) UnmarshalJSON(data []byte) error {
 	var req wireRequest
-	if err := json.Unmarshal(data, &req); err != nil {
+	dec := json.NewDecoder(bytes.NewReader(data))
+	dec.ZeroCopy()
+	if err := dec.Decode(&req); err != nil {
 		return fmt.Errorf("unmarshaling call: %w", err)
 	}
 
@@ -181,7 +184,9 @@ func (r Response) MarshalJSON() ([]byte, error) {
 // UnmarshalJSON implements json.Unmarshaler.
 func (r *Response) UnmarshalJSON(data []byte) error {
 	var resp wireResponse
-	if err := json.Unmarshal(data, &resp); err != nil {
+	dec := json.NewDecoder(bytes.NewReader(data))
+	dec.ZeroCopy()
+	if err := dec.Decode(&resp); err != nil {
 		return fmt.Errorf("unmarshaling jsonrpc response: %w", err)
 	}
 
@@ -276,7 +281,9 @@ func (n Notification) MarshalJSON() ([]byte, error) {
 // UnmarshalJSON implements json.Unmarshaler.
 func (n *Notification) UnmarshalJSON(data []byte) error {
 	var req wireRequest
-	if err := json.Unmarshal(data, &req); err != nil {
+	dec := json.NewDecoder(bytes.NewReader(data))
+	dec.ZeroCopy()
+	if err := dec.Decode(&req); err != nil {
 		return fmt.Errorf("unmarshaling notification: %w", err)
 	}
 
@@ -291,7 +298,9 @@ func (n *Notification) UnmarshalJSON(data []byte) error {
 // DecodeMessage decodes data to Message.
 func DecodeMessage(data []byte) (Message, error) {
 	var msg combined
-	if err := json.Unmarshal(data, &msg); err != nil {
+	dec := json.NewDecoder(bytes.NewReader(data))
+	dec.ZeroCopy()
+	if err := dec.Decode(&msg); err != nil {
 		return nil, fmt.Errorf("unmarshaling jsonrpc message: %w", err)
 	}
 

wire_test.go

@@ -85,7 +85,9 @@ func TestIDDecode(t *testing.T) {
 			t.Parallel()
 
 			var got *jsonrpc2.ID
-			if err := json.Unmarshal(tt.encoded, &got); err != nil {
+			dec := json.NewDecoder(bytes.NewReader(tt.encoded))
+			dec.ZeroCopy()
+			if err := dec.Decode(&got); err != nil {
 				t.Fatal(err)
 			}