jsonrpc: Channel support

This commit is contained in:
Łukasz Magiera 2019-07-22 20:13:41 +02:00
parent 978bd5c17e
commit ff4d1b5819
8 changed files with 273 additions and 29 deletions

View File

@ -121,4 +121,6 @@ type API interface {
// Version provides information about API provider
Version(context.Context) (Version, error)
TestCh(context.Context) (<-chan int, error)
}

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@ -41,9 +41,15 @@ type Struct struct {
NetPeers func(context.Context) ([]peer.AddrInfo, error)
NetConnect func(context.Context, peer.AddrInfo) error
NetAddrsListen func(context.Context) (peer.AddrInfo, error)
TestCh func(context.Context) (<-chan int, error)
}
}
func (c *Struct) TestCh(ctx context.Context) (<-chan int, error) {
return c.Internal.TestCh(ctx)
}
func (c *Struct) ClientListImports(ctx context.Context) ([]Import, error) {
return c.Internal.ClientListImports(ctx)
}

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@ -2,6 +2,7 @@ package cli
import (
"context"
"fmt"
"os"
"os/signal"
"syscall"
@ -67,4 +68,29 @@ var Commands = []*cli.Command{
versionCmd,
walletCmd,
createMinerCmd,
{
Name:"testch",
Action: func(cctx *cli.Context) error {
api, err := getAPI(cctx)
if err != nil {
return err
}
ctx := reqContext(cctx)
c, err := api.TestCh(ctx)
if err != nil {
return err
}
for {
select {
case n := <-c:
fmt.Println(n)
case <- ctx.Done():
return nil
}
}
},
},
}

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@ -34,17 +34,10 @@ func (e *ErrClient) Unwrap(err error) error {
return e.err
}
type result []byte
func (p *result) UnmarshalJSON(raw []byte) error {
*p = make([]byte, len(raw))
copy(*p, raw)
return nil
}
type clientResponse struct {
Jsonrpc string `json:"jsonrpc"`
Result result `json:"result"`
Result json.RawMessage `json:"result"`
ID int64 `json:"id"`
Error *respError `json:"error,omitempty"`
}
@ -52,6 +45,8 @@ type clientResponse struct {
type clientRequest struct {
req request
ready chan clientResponse
retCh func() func([]byte, bool)
}
// ClientCloser is used to close Client from further use
@ -100,7 +95,7 @@ func NewClient(addr string, namespace string, handler interface{}) (ClientCloser
out := make([]reflect.Value, nout)
if valOut != -1 {
out[valOut] = rval.Elem()
out[valOut] = rval
}
if errOut != -1 {
out[errOut] = reflect.New(errorType).Elem()
@ -130,6 +125,7 @@ func NewClient(addr string, namespace string, handler interface{}) (ClientCloser
if ftyp.NumIn() > 0 && ftyp.In(0) == contextType {
hasCtx = 1
}
retCh := valOut != -1 && ftyp.Out(valOut).Kind() == reflect.Chan
fn := reflect.MakeFunc(ftyp, func(args []reflect.Value) (results []reflect.Value) {
id := atomic.AddInt64(&idCtr, 1)
@ -140,6 +136,31 @@ func NewClient(addr string, namespace string, handler interface{}) (ClientCloser
}
}
var retVal reflect.Value
var chCtor func() func([]byte, bool)
if retCh {
chCtor = func() func([]byte, bool) {
// unpack chan type to make sure it's reflect.BothDir
ctyp := reflect.ChanOf(reflect.BothDir, ftyp.Out(valOut).Elem())
ch := reflect.MakeChan(ctyp, 0) // todo: buffer?
retVal = ch.Convert(ftyp.Out(valOut))
return func(result []byte, ok bool) {
if !ok {
ch.Close()
return
}
val := reflect.New(ftyp.Out(valOut).Elem())
if err := json.Unmarshal(result, val.Interface()); err != nil {
log.Errorf("error unmarshaling chan response: %s", err)
return
}
ch.Send(val.Elem()) // todo: select on ctx
}
}
}
req := request{
Jsonrpc: "2.0",
ID: &id,
@ -151,6 +172,8 @@ func NewClient(addr string, namespace string, handler interface{}) (ClientCloser
requests <- clientRequest{
req: req,
ready: rchan,
retCh: chCtor,
}
var ctxDone <-chan struct{}
var resp clientResponse
@ -159,6 +182,7 @@ func NewClient(addr string, namespace string, handler interface{}) (ClientCloser
ctxDone = args[0].Interface().(context.Context).Done()
}
// wait for response, handle context cancellation
loop:
for {
select {
@ -176,24 +200,25 @@ func NewClient(addr string, namespace string, handler interface{}) (ClientCloser
}
}
}
var rval reflect.Value
if valOut != -1 {
rval = reflect.New(ftyp.Out(valOut))
if valOut != -1 && !retCh {
retVal = reflect.New(ftyp.Out(valOut))
if resp.Result != nil {
log.Debugw("rpc result", "type", ftyp.Out(valOut))
if err := json.Unmarshal(resp.Result, rval.Interface()); err != nil {
if err := json.Unmarshal(resp.Result, retVal.Interface()); err != nil {
return processError(xerrors.Errorf("unmarshaling result: %w", err))
}
}
retVal = retVal.Elem()
}
if resp.ID != *req.ID {
return processError(errors.New("request and response id didn't match"))
}
return processResponse(resp, rval)
return processResponse(resp, retVal)
})
val.Elem().Field(i).Set(fn)

View File

@ -95,6 +95,7 @@ func (h handlers) register(namespace string, r interface{}) {
// Handle
type rpcErrFunc func(w func(func(io.Writer)), req *request, code int, err error)
type chanOut func(reflect.Value) interface{}
func (h handlers) handleReader(ctx context.Context, r io.Reader, w io.Writer, rpcError rpcErrFunc) {
wf := func(cb func(io.Writer)) {
@ -107,20 +108,28 @@ func (h handlers) handleReader(ctx context.Context, r io.Reader, w io.Writer, rp
return
}
h.handle(ctx, req, wf, rpcError, func() {})
h.handle(ctx, req, wf, rpcError, func(bool) {}, nil)
}
func (h handlers) handle(ctx context.Context, req request, w func(func(io.Writer)), rpcError rpcErrFunc, done func()) {
defer done()
func (h handlers) handle(ctx context.Context, req request, w func(func(io.Writer)), rpcError rpcErrFunc, done func(keepCtx bool), chOut chanOut) {
handler, ok := h[req.Method]
if !ok {
rpcError(w, &req, rpcMethodNotFound, fmt.Errorf("method '%s' not found", req.Method))
done(false)
return
}
if len(req.Params) != handler.nParams {
rpcError(w, &req, rpcInvalidParams, fmt.Errorf("wrong param count"))
done(false)
return
}
outCh := handler.valOut != -1 && handler.handlerFunc.Type().Out(handler.valOut).Kind() == reflect.Chan
defer done(outCh)
if chOut == nil && outCh {
rpcError(w, &req, rpcMethodNotFound, fmt.Errorf("method '%s' not supported in this mode (no out channel support)", req.Method))
return
}
@ -165,6 +174,11 @@ func (h handlers) handle(ctx context.Context, req request, w func(func(io.Writer
}
if handler.valOut != -1 {
resp.Result = callResult[handler.valOut].Interface()
if reflect.TypeOf(resp.Result).Kind() == reflect.Chan {
//noinspection GoNilness // already checked above
resp.Result = chOut(callResult[handler.valOut])
}
}
w(func(w io.Writer) {

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@ -60,6 +60,8 @@ func rpcError(wf func(func(io.Writer)), req *request, code int, err error) {
hw.WriteHeader(500)
}
log.Warnf("rpc error: %s", err)
if req.ID == nil { // notification
return
}
@ -73,7 +75,11 @@ func rpcError(wf func(func(io.Writer)), req *request, code int, err error) {
},
}
_ = json.NewEncoder(w).Encode(resp)
err = json.NewEncoder(w).Encode(resp)
if err != nil {
log.Warnf("failed to write rpc error: %s", err)
return
}
})
}

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@ -6,12 +6,16 @@ import (
"errors"
"io"
"io/ioutil"
"reflect"
"sync"
"sync/atomic"
"github.com/gorilla/websocket"
)
const wsCancel = "xrpc.cancel"
const chValue = "xrpc.ch.val"
const chClose = "xrpc.ch.close"
type frame struct {
// common
@ -23,7 +27,7 @@ type frame struct {
Params []param `json:"params,omitempty"`
// response
Result result `json:"result,omitempty"`
Result json.RawMessage `json:"result,omitempty"`
Error *respError `json:"error,omitempty"`
}
@ -31,6 +35,7 @@ func handleWsConn(ctx context.Context, conn *websocket.Conn, handler handlers, r
incoming := make(chan io.Reader)
var incErr error
// nextMessage wait for one message and puts it to the incoming channel
nextMessage := func() {
mtype, r, err := conn.NextReader()
if err != nil {
@ -47,6 +52,9 @@ func handleWsConn(ctx context.Context, conn *websocket.Conn, handler handlers, r
}
var writeLk sync.Mutex
// nextWriter waits for writeLk and invokes the cb callback with WS message
// writer when the lock is acquired
nextWriter := func(cb func(io.Writer)) {
writeLk.Lock()
defer writeLk.Unlock()
@ -65,12 +73,113 @@ func handleWsConn(ctx context.Context, conn *websocket.Conn, handler handlers, r
}
}
sendReq := func(req request) {
writeLk.Lock()
if err := conn.WriteJSON(req); err != nil {
log.Error("handle me:", err)
writeLk.Unlock()
return
}
writeLk.Unlock()
}
// wait for the first message
go nextMessage()
// inflight are requests we sent to the remote
inflight := map[int64]clientRequest{}
// handling are the calls we handle
handling := map[int64]context.CancelFunc{}
var handlingLk sync.Mutex
// ////
// Subscriptions (func() <-chan Typ - like methods)
var chOnce sync.Once
var outId uint64
type chReg struct { id uint64; ch reflect.Value }
registerCh := make(chan chReg)
defer close(registerCh)
handleOutChans := func() {
regV := reflect.ValueOf(registerCh)
cases := []reflect.SelectCase{
{ // registration chan always 0
Dir: reflect.SelectRecv,
Chan: regV,
},
}
var caseToId []uint64
for {
chosen, val, ok := reflect.Select(cases)
if chosen == 0 { // control channel
if !ok {
// not closing any channels as we're on receiving end.
// Also, context cancellation below should take care of any running
// requests
return
}
registration := val.Interface().(chReg)
caseToId = append(caseToId, registration.id)
cases = append(cases, reflect.SelectCase{
Dir: reflect.SelectRecv,
Chan: registration.ch,
})
continue
}
if !ok {
n := len(caseToId)
if n > 0 {
cases[chosen] = cases[n]
caseToId[chosen - 1] = caseToId[n - 1]
}
cases = cases[:n]
caseToId = caseToId[:n-1]
continue
}
sendReq(request{
Jsonrpc: "2.0",
ID: nil, // notification
Method: chValue,
Params: []param{{v: reflect.ValueOf(caseToId[chosen - 1])}, {v: val}},
})
}
}
handleChanOut := func(ch reflect.Value) interface{} {
chOnce.Do(func() {
go handleOutChans()
})
id := atomic.AddUint64(&outId, 1)
registerCh <- chReg{
id: id,
ch: ch,
}
return id
}
// client side subs
chanHandlers := map[uint64]func(m []byte, ok bool){}
// ////
// on close, make sure to return from all pending calls, and cancel context
// on all calls we handle
defer func() {
for id, req := range inflight {
req.ready <- clientResponse{
@ -89,6 +198,7 @@ func handleWsConn(ctx context.Context, conn *websocket.Conn, handler handlers, r
}
}()
// cancelCtx is a built-in rpc which handles context cancellation over rpc
cancelCtx := func(req frame) {
if req.ID != nil {
log.Warnf("%s call with ID set, won't respond", wsCancel)
@ -125,6 +235,10 @@ func handleWsConn(ctx context.Context, conn *websocket.Conn, handler handlers, r
return
}
// Get message type by method name:
// "" - response
// "xrpc.*" - builtin
// anything else - incoming remote call
switch frame.Method {
case "": // Response to our call
req, ok := inflight[*frame.ID]
@ -133,6 +247,17 @@ func handleWsConn(ctx context.Context, conn *websocket.Conn, handler handlers, r
continue
}
if req.retCh != nil {
// output is channel
var chid uint64
if err := json.Unmarshal(frame.Result, &chid); err != nil {
log.Error("failed to unmarshal channel id response: %s", err)
continue
}
chanHandlers[chid] = req.retCh()
}
req.ready <- clientResponse{
Jsonrpc: frame.Jsonrpc,
Result: frame.Result,
@ -142,6 +267,20 @@ func handleWsConn(ctx context.Context, conn *websocket.Conn, handler handlers, r
delete(inflight, *frame.ID)
case wsCancel:
cancelCtx(frame)
case chValue:
var chid uint64
if err := json.Unmarshal(frame.Params[0].data, &chid); err != nil {
log.Error("failed to unmarshal channel id in xrpc.ch.val: %s", err)
continue
}
hnd, ok := chanHandlers[chid]
if !ok {
log.Error("xrpc.ch.val: handler %d not found", chid)
continue
}
hnd(frame.Params[1].data, true)
default: // Remote call
req := request{
Jsonrpc: frame.Jsonrpc,
@ -155,7 +294,11 @@ func handleWsConn(ctx context.Context, conn *websocket.Conn, handler handlers, r
nw := func(cb func(io.Writer)) {
cb(ioutil.Discard)
}
done := cf
done := func(keepctx bool) {
if !keepctx {
cf()
}
}
if frame.ID != nil {
nw = nextWriter
@ -163,27 +306,27 @@ func handleWsConn(ctx context.Context, conn *websocket.Conn, handler handlers, r
handling[*frame.ID] = cf
handlingLk.Unlock()
done = func() {
done = func(keepctx bool) {
handlingLk.Lock()
defer handlingLk.Unlock()
if !keepctx {
cf()
}
delete(handling, *frame.ID)
}
}
go handler.handle(ctx, req, nw, rpcError, done)
go handler.handle(ctx, req, nw, rpcError, done, handleChanOut)
}
go nextMessage()
go nextMessage() // TODO: fix on errors
case req := <-requests:
if req.req.ID != nil {
inflight[*req.req.ID] = req
}
if err := conn.WriteJSON(req.req); err != nil {
log.Error("handle me:", err)
return
}
sendReq(req.req)
case <-stop:
if err := conn.Close(); err != nil {
log.Debugf("websocket close error", "error", err)

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@ -2,6 +2,8 @@ package node
import (
"context"
"fmt"
"time"
"github.com/filecoin-project/go-lotus/api"
"github.com/filecoin-project/go-lotus/build"
@ -28,6 +30,26 @@ type API struct {
Wallet *chain.Wallet
}
func (a *API) TestCh(ctx context.Context) (<-chan int, error) {
out := make(chan int)
go func() {
defer close(out)
var n int
for {
time.Sleep(time.Millisecond * 100)
n++
select {
case <-ctx.Done():
fmt.Println("CTXCANCEL!")
return
case out <- n:
}
}
}()
return out, nil
}
func (a *API) ChainSubmitBlock(ctx context.Context, blk *chain.BlockMsg) error {
if err := a.Chain.AddBlock(blk.Header); err != nil {
return err