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-rw-r--r--README.md74
-rw-r--r--errors.go42
-rw-r--r--examples/http/main.go41
-rw-r--r--examples/http/test.http42
-rw-r--r--go.mod3
-rw-r--r--logger.go20
-rw-r--r--server.go146
-rw-r--r--wrapper.go25
8 files changed, 393 insertions, 0 deletions
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..7f7c963
--- /dev/null
+++ b/README.md
@@ -0,0 +1,74 @@
+# JSON-RPC 2.0
+
+Golang implementation of JSON-RPC 2.0 server with generics.
+
+Go 1.18+ required
+
+## Features:
+
+- [x] Batch request and responses
+- [ ] WebSockets
+
+## Usage
+
+1. Create JSON-RPC 2.0 server:
+ ```go
+ s := jsonrpc2.New()
+ ```
+2. Write handler:
+ ```go
+ func Multiply(ctx context.Context, args *Args) (int, error) {
+ return args.A * args.B, nil
+ }
+ ```
+ Handler must have exact two arguments (context and input of any json serializable type) and exact two return values (output of any json serializable type and error)
+3. Wrap handler with `jsonrpc2.Wrap` method and register it in server:
+ ```go
+ s.Register("multiply", jsonrpc2.Wrap(Multiply))
+ ```
+4. Use server as common http handler:
+ ```go
+ http.ListenAndServe(":8000", s)
+ ```
+
+## Complete example
+
+[Full code](/examples/http)
+
+```go
+package main
+
+import (
+ "context"
+ "net/http"
+
+ "github.com/neonxp/rpc"
+)
+
+func main() {
+ s := jsonrpc2.New()
+ s.Register("multiply", jsonrpc2.Wrap(Multiply)) // Register handlers
+ s.Register("divide", jsonrpc2.Wrap(Divide))
+
+ http.ListenAndServe(":8000", s)
+}
+
+func Multiply(ctx context.Context, args *Args) (int, error) {
+ //...
+}
+
+func Divide(ctx context.Context, args *Args) (*Quotient, error) {
+ //...
+}
+
+type Args struct {
+ A int `json:"a"`
+ B int `json:"b"`
+}
+
+type Quotient struct {
+ Quo int `json:"quo"`
+ Rem int `json:"rem"`
+}
+
+``` \ No newline at end of file
diff --git a/errors.go b/errors.go
new file mode 100644
index 0000000..cd87fbb
--- /dev/null
+++ b/errors.go
@@ -0,0 +1,42 @@
+package jsonrpc2
+
+import "fmt"
+
+const (
+ ErrCodeParseError = -32700
+ ErrCodeInvalidRequest = -32600
+ ErrCodeMethodNotFound = -32601
+ ErrCodeInvalidParams = -32602
+ ErrCodeInternalError = -32603
+ ErrUser = -32000
+)
+
+var errorMap = map[int]string{
+ -32700: "Parse error", // Invalid JSON was received by the server. An error occurred on the server while parsing the JSON text.
+ -32600: "Invalid Request", // The JSON sent is not a valid Request object.
+ -32601: "Method not found", // The method does not exist / is not available.
+ -32602: "Invalid params", // Invalid method parameter(s).
+ -32603: "Internal error", // Internal JSON-RPC error.
+ -32000: "Other error",
+}
+
+//-32000 to -32099 Server error Reserved for implementation-defined server-errors.
+
+type Error struct {
+ Code int `json:"code"`
+ Message string `json:"message"`
+}
+
+func (e Error) Error() string {
+ return fmt.Sprintf("jsonrpc2 error: code: %d message: %s", e.Code, e.Message)
+}
+
+func NewError(code int) Error {
+ if _, ok := errorMap[code]; ok {
+ return Error{
+ Code: code,
+ Message: errorMap[code],
+ }
+ }
+ return Error{Code: code}
+}
diff --git a/examples/http/main.go b/examples/http/main.go
new file mode 100644
index 0000000..fdef509
--- /dev/null
+++ b/examples/http/main.go
@@ -0,0 +1,41 @@
+package main
+
+import (
+ "context"
+ "errors"
+ "net/http"
+
+ "github.com/neonxp/rpc"
+)
+
+func main() {
+ s := jsonrpc2.New()
+ s.Register("multiply", jsonrpc2.Wrap(Multiply))
+ s.Register("divide", jsonrpc2.Wrap(Divide))
+
+ http.ListenAndServe(":8000", s)
+}
+
+func Multiply(ctx context.Context, args *Args) (int, error) {
+ return args.A * args.B, nil
+}
+
+func Divide(ctx context.Context, args *Args) (*Quotient, error) {
+ if args.B == 0 {
+ return nil, errors.New("divide by zero")
+ }
+ quo := new(Quotient)
+ quo.Quo = args.A / args.B
+ quo.Rem = args.A % args.B
+ return quo, nil
+}
+
+type Args struct {
+ A int `json:"a"`
+ B int `json:"b"`
+}
+
+type Quotient struct {
+ Quo int `json:"quo"`
+ Rem int `json:"rem"`
+}
diff --git a/examples/http/test.http b/examples/http/test.http
new file mode 100644
index 0000000..d4e68b3
--- /dev/null
+++ b/examples/http/test.http
@@ -0,0 +1,42 @@
+POST http://localhost:8000/
+Content-Type: application/json
+
+{
+ "jsonrpc": "2.0",
+ "method": "multiply",
+ "params": {
+ "a": 2,
+ "b": 3
+ },
+ "id": 1
+}
+
+###
+
+POST http://localhost:8000/
+Content-Type: application/json
+
+{
+ "jsonrpc": "2.0",
+ "method": "divide",
+ "params": {
+ "a": 10,
+ "b": 3
+ },
+ "id": 2
+}
+
+###
+
+POST http://localhost:8000/
+Content-Type: application/json
+
+[
+ { "jsonrpc": "2.0", "method": "multiply", "params": { "a": 2, "b": 3 }, "id": 10 },
+ {"jsonrpc": "2.0", "method": "sum", "params": [1,2,4], "id": "1"},
+ {"jsonrpc": "2.0", "method": "notify_hello", "params": [7]},
+ {"jsonrpc": "2.0", "method": "subtract", "params": [42,23], "id": "2"},
+ {"foo": "boo"},
+ {"jsonrpc": "2.0", "method": "foo.get", "params": {"name": "myself"}, "id": "5"},
+ {"jsonrpc": "2.0", "method": "get_data", "id": "9"}
+] \ No newline at end of file
diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..2beacc4
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,3 @@
+module github.com/neonxp/rpc
+
+go 1.18
diff --git a/logger.go b/logger.go
new file mode 100644
index 0000000..7907e4f
--- /dev/null
+++ b/logger.go
@@ -0,0 +1,20 @@
+package jsonrpc2
+
+import "log"
+
+type Logger interface {
+ Logf(format string, args ...interface{})
+}
+
+type nopLogger struct{}
+
+func (n nopLogger) Logf(format string, args ...interface{}) {
+}
+
+type stdLogger struct{}
+
+func (n stdLogger) Logf(format string, args ...interface{}) {
+ log.Printf(format, args...)
+}
+
+var StdLogger = stdLogger{}
diff --git a/server.go b/server.go
new file mode 100644
index 0000000..5625f78
--- /dev/null
+++ b/server.go
@@ -0,0 +1,146 @@
+package jsonrpc2
+
+import (
+ "bufio"
+ "context"
+ "encoding/json"
+ "io"
+ "net/http"
+ "sync"
+)
+
+const version = "2.0"
+
+type Server struct {
+ Logger Logger
+ IgnoreNotifications bool
+ handlers map[string]Handler
+ mu sync.RWMutex
+}
+
+func (r *Server) ServeHTTP(writer http.ResponseWriter, request *http.Request) {
+ writer.Header().Set("Content-Type", "application/json")
+ buf := bufio.NewReader(request.Body)
+ defer request.Body.Close()
+ firstByte, err := buf.Peek(1)
+ if err != nil {
+ r.Logger.Logf("Can't read body: %v", err)
+ writeError(ErrCodeParseError, writer)
+ return
+ }
+ if string(firstByte) == "[" {
+ r.batchRequest(writer, request, buf)
+ return
+ }
+ r.singleRequest(writer, request, buf)
+}
+
+func New() *Server {
+ return &Server{
+ Logger: nopLogger{},
+ IgnoreNotifications: true,
+ handlers: map[string]Handler{},
+ mu: sync.RWMutex{},
+ }
+}
+
+func (r *Server) Register(method string, handler Handler) {
+ r.mu.Lock()
+ defer r.mu.Unlock()
+ r.handlers[method] = handler
+}
+
+func (r *Server) singleRequest(writer http.ResponseWriter, request *http.Request, buf *bufio.Reader) {
+ req := new(rpcRequest)
+ if err := json.NewDecoder(buf).Decode(req); err != nil {
+ r.Logger.Logf("Can't read body: %v", err)
+ writeError(ErrCodeParseError, writer)
+ return
+ }
+ resp := r.callMethod(request.Context(), req)
+ if req.Id == nil && r.IgnoreNotifications {
+ // notification request
+ return
+ }
+ if err := json.NewEncoder(writer).Encode(resp); err != nil {
+ r.Logger.Logf("Can't write response: %v", err)
+ writeError(ErrCodeInternalError, writer)
+ return
+ }
+}
+
+func (r *Server) batchRequest(writer http.ResponseWriter, request *http.Request, buf *bufio.Reader) {
+ var req []rpcRequest
+ if err := json.NewDecoder(buf).Decode(&req); err != nil {
+ r.Logger.Logf("Can't read body: %v", err)
+ writeError(ErrCodeParseError, writer)
+ return
+ }
+ var responses []*rpcResponse
+ wg := sync.WaitGroup{}
+ wg.Add(len(req))
+ for _, j := range req {
+ go func(req rpcRequest) {
+ defer wg.Done()
+ resp := r.callMethod(request.Context(), &req)
+ if req.Id == nil && r.IgnoreNotifications {
+ // notification request
+ return
+ }
+ responses = append(responses, resp)
+ }(j)
+ }
+ wg.Wait()
+ if err := json.NewEncoder(writer).Encode(responses); err != nil {
+ r.Logger.Logf("Can't write response: %v", err)
+ writeError(ErrCodeInternalError, writer)
+ }
+}
+
+func (r *Server) callMethod(ctx context.Context, req *rpcRequest) *rpcResponse {
+ r.mu.RLock()
+ h, ok := r.handlers[req.Method]
+ r.mu.RUnlock()
+ if !ok {
+ return &rpcResponse{
+ Jsonrpc: version,
+ Error: NewError(ErrCodeMethodNotFound),
+ Id: req.Id,
+ }
+ }
+ resp, err := h(ctx, req.Params)
+ if err != nil {
+ r.Logger.Logf("User error %v", err)
+ return &rpcResponse{
+ Jsonrpc: version,
+ Error: err,
+ Id: req.Id,
+ }
+ }
+ return &rpcResponse{
+ Jsonrpc: version,
+ Result: resp,
+ Id: req.Id,
+ }
+}
+
+func writeError(code int, w io.Writer) {
+ _ = json.NewEncoder(w).Encode(rpcResponse{
+ Jsonrpc: version,
+ Error: NewError(code),
+ })
+}
+
+type rpcRequest struct {
+ Jsonrpc string `json:"jsonrpc"`
+ Method string `json:"method"`
+ Params json.RawMessage `json:"params"`
+ Id any `json:"id"`
+}
+
+type rpcResponse struct {
+ Jsonrpc string `json:"jsonrpc"`
+ Result json.RawMessage `json:"result,omitempty"`
+ Error error `json:"error,omitempty"`
+ Id any `json:"id,omitempty"`
+}
diff --git a/wrapper.go b/wrapper.go
new file mode 100644
index 0000000..8058a27
--- /dev/null
+++ b/wrapper.go
@@ -0,0 +1,25 @@
+package jsonrpc2
+
+import (
+ "context"
+ "encoding/json"
+)
+
+func Wrap[RQ any, RS any](handler func(context.Context, *RQ) (RS, error)) Handler {
+ return func(ctx context.Context, in json.RawMessage) (json.RawMessage, error) {
+ req := new(RQ)
+ if err := json.Unmarshal(in, req); err != nil {
+ return nil, NewError(ErrCodeParseError)
+ }
+ resp, err := handler(ctx, req)
+ if err != nil {
+ return nil, Error{
+ Code: ErrUser,
+ Message: err.Error(),
+ }
+ }
+ return json.Marshal(resp)
+ }
+}
+
+type Handler func(context.Context, json.RawMessage) (json.RawMessage, error)
generated by cgit v1.2.3 (git 2.39.1) at 2025-01-18 16:16:27 +0300