path: root/rpc/subscription_test.go

// Copyright 2016 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.

package rpc

import (
    "context"
    "encoding/json"
    "fmt"
    "net"
    "sync"
    "testing"
    "time"
)

type NotificationTestService struct {
    mu                      sync.Mutex
    unsubscribed            chan string
    gotHangSubscriptionReq  chan struct{}
    unblockHangSubscription chan struct{}
}

func (s *NotificationTestService) Echo(i int) int {
    return i
}

func (s *NotificationTestService) Unsubscribe(subid string) {
    if s.unsubscribed != nil {
        s.unsubscribed <- subid
    }
}

func (s *NotificationTestService) SomeSubscription(ctx context.Context, n, val int) (*Subscription, error) {
    notifier, supported := NotifierFromContext(ctx)
    if !supported {
        return nil, ErrNotificationsUnsupported
    }

    // by explicitly creating an subscription we make sure that the subscription id is send back to the client
    // before the first subscription.Notify is called. Otherwise the events might be send before the response
    // for the eth_subscribe method.
    subscription := notifier.CreateSubscription()

    go func() {
        // test expects n events, if we begin sending event immediately some events
        // will probably be dropped since the subscription ID might not be send to
        // the client.
        for i := 0; i < n; i++ {
            if err := notifier.Notify(subscription.ID, val+i); err != nil {
                return
            }
        }

        select {
        case <-notifier.Closed():
        case <-subscription.Err():
        }
        if s.unsubscribed != nil {
            s.unsubscribed <- string(subscription.ID)
        }
    }()

    return subscription, nil
}

// HangSubscription blocks on s.unblockHangSubscription before
// sending anything.
func (s *NotificationTestService) HangSubscription(ctx context.Context, val int) (*Subscription, error) {
    notifier, supported := NotifierFromContext(ctx)
    if !supported {
        return nil, ErrNotificationsUnsupported
    }

    s.gotHangSubscriptionReq <- struct{}{}
    <-s.unblockHangSubscription
    subscription := notifier.CreateSubscription()

    go func() {
        notifier.Notify(subscription.ID, val)
    }()
    return subscription, nil
}

func TestNotifications(t *testing.T) {
    server := NewServer()
    service := &NotificationTestService{unsubscribed: make(chan string)}

    if err := server.RegisterName("eth", service); err != nil {
        t.Fatalf("unable to register test service %v", err)
    }

    clientConn, serverConn := net.Pipe()

    go server.ServeCodec(NewJSONCodec(serverConn), OptionMethodInvocation|OptionSubscriptions)

    out := json.NewEncoder(clientConn)
    in := json.NewDecoder(clientConn)

    n := 5
    val := 12345
    request := map[string]interface{}{
        "id":      1,
        "method":  "eth_subscribe",
        "version": "2.0",
        "params":  []interface{}{"someSubscription", n, val},
    }

    // create subscription
    if err := out.Encode(request); err != nil {
        t.Fatal(err)
    }

    var subid string
    response := jsonSuccessResponse{Result: subid}
    if err := in.Decode(&response); err != nil {
        t.Fatal(err)
    }

    var ok bool
    if _, ok = response.Result.(string); !ok {
        t.Fatalf("expected subscription id, got %T", response.Result)
    }

    for i := 0; i < n; i++ {
        var notification jsonNotification
        if err := in.Decode(&notification); err != nil {
            t.Fatalf("%v", err)
        }

        if int(notification.Params.Result.(float64)) != val+i {
            t.Fatalf("expected %d, got %d", val+i, notification.Params.Result)
        }
    }

    clientConn.Close() // causes notification unsubscribe callback to be called
    select {
    case <-service.unsubscribed:
    case <-time.After(1 * time.Second):
        t.Fatal("Unsubscribe not called after one second")
    }
}

func waitForMessages(t *testing.T, in *json.Decoder, successes chan<- jsonSuccessResponse,
    failures chan<- jsonErrResponse, notifications chan<- jsonNotification, errors chan<- error) {

    // read and parse server messages
    for {
        var rmsg json.RawMessage
        if err := in.Decode(&rmsg); err != nil {
            return
        }

        var responses []map[string]interface{}
        if rmsg[0] == '[' {
            if err := json.Unmarshal(rmsg, &responses); err != nil {
                errors <- fmt.Errorf("Received invalid message: %s", rmsg)
                return
            }
        } else {
            var msg map[string]interface{}
            if err := json.Unmarshal(rmsg, &msg); err != nil {
                errors <- fmt.Errorf("Received invalid message: %s", rmsg)
                return
            }
            responses = append(responses, msg)
        }

        for _, msg := range responses {
            // determine what kind of msg was received and broadcast
            // it to over the corresponding channel
            if _, found := msg["result"]; found {
                successes <- jsonSuccessResponse{
                    Version: msg["jsonrpc"].(string),
                    Id:      msg["id"],
                    Result:  msg["result"],
                }
                continue
            }
            if _, found := msg["error"]; found {
                params := msg["params"].(map[string]interface{})
                failures <- jsonErrResponse{
                    Version: msg["jsonrpc"].(string),
                    Id:      msg["id"],
                    Error:   jsonError{int(params["subscription"].(float64)), params["message"].(string), params["data"]},
                }
                continue
            }
            if _, found := msg["params"]; found {
                params := msg["params"].(map[string]interface{})
                notifications <- jsonNotification{
                    Version: msg["jsonrpc"].(string),
                    Method:  msg["method"].(string),
                    Params:  jsonSubscription{params["subscription"].(string), params["result"]},
                }
                continue
            }
            errors <- fmt.Errorf("Received invalid message: %s", msg)
        }
    }
}

// TestSubscriptionMultipleNamespaces ensures that subscriptions can exists
// for multiple different namespaces.
func TestSubscriptionMultipleNamespaces(t *testing.T) {
    var (
        namespaces        = []string{"eth", "shh", "bzz"}
        service           = NotificationTestService{}
        subCount          = len(namespaces) * 2
        notificationCount = 3

        server                 = NewServer()
        clientConn, serverConn = net.Pipe()
        out                    = json.NewEncoder(clientConn)
        in                     = json.NewDecoder(clientConn)
        successes              = make(chan jsonSuccessResponse)
        failures               = make(chan jsonErrResponse)
        notifications          = make(chan jsonNotification)
        errors                 = make(chan error, 10)
    )

    // setup and start server
    for _, namespace := range namespaces {
        if err := server.RegisterName(namespace, &service); err != nil {
            t.Fatalf("unable to register test service %v", err)
        }
    }

    go server.ServeCodec(NewJSONCodec(serverConn), OptionMethodInvocation|OptionSubscriptions)
    defer server.Stop()

    // wait for message and write them to the given channels
    go waitForMessages(t, in, successes, failures, notifications, errors)

    // create subscriptions one by one
    for i, namespace := range namespaces {
        request := map[string]interface{}{
            "id":      i,
            "method":  fmt.Sprintf("%s_subscribe", namespace),
            "version": "2.0",
            "params":  []interface{}{"someSubscription", notificationCount, i},
        }

        if err := out.Encode(&request); err != nil {
            t.Fatalf("Could not create subscription: %v", err)
        }
    }

    // create all subscriptions in 1 batch
    var requests []interface{}
    for i, namespace := range namespaces {
        requests = append(requests, map[string]interface{}{
            "id":      i,
            "method":  fmt.Sprintf("%s_subscribe", namespace),
            "version": "2.0",
            "params":  []interface{}{"someSubscription", notificationCount, i},
        })
    }

    if err := out.Encode(&requests); err != nil {
        t.Fatalf("Could not create subscription in batch form: %v", err)
    }

    timeout := time.After(30 * time.Second)
    subids := make(map[string]string, subCount)
    count := make(map[string]int, subCount)
    allReceived := func() bool {
        done := len(count) == subCount
        for _, c := range count {
            if c < notificationCount {
                done = false
            }
        }
        return done
    }

    for !allReceived() {
        select {
        case suc := <-successes: // subscription created
            subids[namespaces[int(suc.Id.(float64))]] = suc.Result.(string)
        case notification := <-notifications:
            count[notification.Params.Subscription]++
        case err := <-errors:
            t.Fatal(err)
        case failure := <-failures:
            t.Errorf("received error: %v", failure.Error)
        case <-timeout:
            for _, namespace := range namespaces {
                subid, found := subids[namespace]
                if !found {
                    t.Errorf("subscription for %q not created", namespace)
                    continue
                }
                if count, found := count[subid]; !found || count < notificationCount {
                    t.Errorf("didn't receive all notifications (%d<%d) in time for namespace %q", count, notificationCount, namespace)
                }
            }
            t.Fatal("timed out")
        }
    }
}