Add selector code

client/client_selector.go

@@ -1,9 +0,0 @@
-package client
-
-import (
-	"github.com/micro/go-micro/registry"
-)
-
-// Selector takes a Registry and returns a NodeSelector.
-// Used by the client to initialise a selector.
-type Selector func(registry.Registry) NodeSelector

client/node_selector.go

@@ -1,60 +0,0 @@
-package client
-
-import (
-	"math/rand"
-	"time"
-
-	"github.com/micro/go-micro/errors"
-	"github.com/micro/go-micro/registry"
-	"golang.org/x/net/context"
-)
-
-// NodeSelector is used to Retrieve a node to which a request
-// should be routed. It takes context and Request and returns a
-// single node. If a node cannot be selected it should return
-// an error. Response is called to inform the selector of the
-// response from a client call. Reset is called to zero out
-// any state.
-type NodeSelector interface {
-	Select(context.Context, Request) (*registry.Node, error)
-	Response(*registry.Node, error)
-	Reset()
-}
-
-func init() {
-	rand.Seed(time.Now().UnixNano())
-}
-
-// Built in random hashed node selector
-type nodeSelector struct {
-	r registry.Registry
-}
-
-func (n *nodeSelector) Select(ctx context.Context, req Request) (*registry.Node, error) {
-	service, err := n.r.GetService(req.Service())
-	if err != nil {
-		return nil, errors.InternalServerError("go.micro.client", err.Error())
-	}
-
-	if len(service) == 0 {
-		return nil, errors.NotFound("go.micro.client", "Service not found")
-	}
-
-	i := rand.Int()
-	j := i % len(service)
-
-	if len(service[j].Nodes) == 0 {
-		return nil, errors.NotFound("go.micro.client", "Service not found")
-	}
-
-	k := i % len(service[j].Nodes)
-	return service[j].Nodes[k], nil
-}
-
-func (n *nodeSelector) Response(node *registry.Node, err error) {
-	return
-}
-
-func (n *nodeSelector) Reset() {
-	return
-}

client/options.go

@@ -12,12 +12,14 @@ type options struct {
 	broker      broker.Broker
 	codecs      map[string]codec.NewCodec
 	registry    registry.Registry
+	selector    registry.Selector
 	transport   transport.Transport
 	wrappers    []Wrapper
-	selector    Selector
 }
 
-type callOptions struct{}
+type callOptions struct {
+	selectOptions []registry.SelectOption
+}
 
 type publishOptions struct{}
 
@@ -57,7 +59,7 @@ func Transport(t transport.Transport) Option {
 }
 
 // Select is used to select a node to route a request to
-func Select(s Selector) Option {
+func Selector(s registry.Selector) Option {
 	return func(o *options) {
 		o.selector = s
 	}
@@ -69,3 +71,11 @@ func Wrap(w Wrapper) Option {
 		o.wrappers = append(o.wrappers, w)
 	}
 }
+
+// Call Options
+
+func WithSelectOption(so registry.SelectOption) CallOption {
+	return func(o *callOptions) {
+		o.selectOptions = append(o.selectOptions, so)
+	}
+}

client/rpc_client.go

@@ -18,11 +18,9 @@ import (
 type rpcClient struct {
 	once sync.Once
 	opts options
-	sel  NodeSelector
 }
 
 func newRpcClient(opt ...Option) Client {
-	var sel NodeSelector
 	var once sync.Once
 
 	opts := options{
@@ -37,28 +35,27 @@ func newRpcClient(opt ...Option) Client {
 		opts.contentType = defaultContentType
 	}
 
-	if opts.transport == nil {
-		opts.transport = transport.DefaultTransport
+	if opts.broker == nil {
+		opts.broker = broker.DefaultBroker
 	}
 
 	if opts.registry == nil {
 		opts.registry = registry.DefaultRegistry
 	}
 
-	if opts.broker == nil {
-		opts.broker = broker.DefaultBroker
+	if opts.selector == nil {
+		opts.selector = registry.NewRandomSelector(
+			registry.SelectorRegistry(opts.registry),
+		)
 	}
 
-	if opts.selector != nil {
-		sel = opts.selector(opts.registry)
-	} else {
-		sel = &nodeSelector{opts.registry}
+	if opts.transport == nil {
+		opts.transport = transport.DefaultTransport
 	}
 
 	rc := &rpcClient{
 		once: once,
 		opts: opts,
-		sel:  sel,
 	}
 
 	c := Client(rc)
@@ -153,7 +150,17 @@ func (r *rpcClient) CallRemote(ctx context.Context, address string, request Requ
 }
 
 func (r *rpcClient) Call(ctx context.Context, request Request, response interface{}, opts ...CallOption) error {
-	node, err := r.sel.Select(ctx, request)
+	var copts callOptions
+	for _, opt := range opts {
+		opt(&copts)
+	}
+
+	next, err := r.opts.selector.Select(request.Service(), copts.selectOptions...)
+	if err != nil {
+		return err
+	}
+
+	node, err := next()
 	if err != nil {
 		return err
 	}
@@ -164,7 +171,7 @@ func (r *rpcClient) Call(ctx context.Context, request Request, response interfac
 	}
 
 	err = r.call(ctx, address, request, response)
-	r.sel.Response(node, err)
+	r.opts.selector.Mark(request.Service(), node, err)
 	return err
 }
 
@@ -173,7 +180,17 @@ func (r *rpcClient) StreamRemote(ctx context.Context, address string, request Re
 }
 
 func (r *rpcClient) Stream(ctx context.Context, request Request, responseChan interface{}, opts ...CallOption) (Streamer, error) {
-	node, err := r.sel.Select(ctx, request)
+	var copts callOptions
+	for _, opt := range opts {
+		opt(&copts)
+	}
+
+	next, err := r.opts.selector.Select(request.Service(), copts.selectOptions...)
+	if err != nil {
+		return nil, err
+	}
+
+	node, err := next()
 	if err != nil {
 		return nil, err
 	}
@@ -184,7 +201,7 @@ func (r *rpcClient) Stream(ctx context.Context, request Request, responseChan in
 	}
 
 	stream, err := r.stream(ctx, address, request, responseChan)
-	r.sel.Response(node, err)
+	r.opts.selector.Mark(request.Service(), node, err)
 	return stream, err
 }