neo-go/pkg/rpcclient/local.go
Roman Khimov 6f7fed344b rpcclient: add Internal client for direct RPC server calls
It has a special `requestF` and a special initialization function, but other
than that it's an absolutely regular WSClient. Can be used to call, can be
used to subscribe. Fixes #2909.
2023-02-16 23:49:58 +03:00

82 lines
2.2 KiB
Go

package rpcclient
import (
"context"
"github.com/nspcc-dev/neo-go/pkg/neorpc"
"go.uber.org/atomic"
)
// InternalHook is a function signature that is required to create a local client
// (see NewInternal). It performs registration of local client's event channel
// and returns a request handler function.
type InternalHook func(context.Context, chan<- neorpc.Notification) func(*neorpc.Request) (*neorpc.Response, error)
// Internal is an experimental "local" client that does not connect to RPC via
// network. It's made for deeply integrated applications like NeoFS that have
// blockchain running in the same process, so use it only if you know what you're
// doing. It provides the same interface WSClient does.
type Internal struct {
WSClient
events chan neorpc.Notification
}
// NewInternal creates an instance of internal client. It accepts a method
// provided by RPC server.
func NewInternal(ctx context.Context, register InternalHook) (*Internal, error) {
c := &Internal{
WSClient: WSClient{
Client: Client{},
Notifications: make(chan Notification),
shutdown: make(chan struct{}),
done: make(chan struct{}),
closeCalled: *atomic.NewBool(false),
subscriptions: make(map[string]notificationReceiver),
receivers: make(map[interface{}][]string),
},
events: make(chan neorpc.Notification),
}
err := initClient(ctx, &c.WSClient.Client, "localhost:0", Options{})
if err != nil {
return nil, err // Can't really happen for internal client.
}
c.cli = nil
go c.eventLoop()
// c.ctx is inherited from ctx in fact (see initClient).
c.requestF = register(c.ctx, c.events) //nolint:contextcheck // Non-inherited new context, use function like `context.WithXXX` instead
return c, nil
}
func (c *Internal) eventLoop() {
eventloop:
for {
select {
case <-c.ctx.Done():
break eventloop
case <-c.shutdown:
break eventloop
case ev := <-c.events:
ntf := Notification{Type: ev.Event}
if len(ev.Payload) > 0 {
ntf.Value = ev.Payload[0]
}
c.notifySubscribers(ntf)
}
}
close(c.done)
close(c.Notifications)
c.ctxCancel()
// ctx is cancelled, server is notified and will finish soon.
drainloop:
for {
select {
case <-c.events:
default:
break drainloop
}
}
close(c.events)
}