1 files changed, 139 insertions, 0 deletions
diff --git a/vendor/google.golang.org/grpc/resolver_conn_wrapper.go b/vendor/google.golang.org/grpc/resolver_conn_wrapper.go
new file mode 100644
index 0000000..7d53964
--- /dev/null
+++ b/vendor/google.golang.org/grpc/resolver_conn_wrapper.go
@@ -0,0 +1,139 @@
+/*
+ *
+ * Copyright 2017 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package grpc
+
+import (
+	"strings"
+
+	"google.golang.org/grpc/grpclog"
+	"google.golang.org/grpc/resolver"
+)
+
+// ccResolverWrapper is a wrapper on top of cc for resolvers.
+// It implements resolver.ClientConnection interface.
+type ccResolverWrapper struct {
+	cc       *ClientConn
+	resolver resolver.Resolver
+	addrCh   chan []resolver.Address
+	scCh     chan string
+	done     chan struct{}
+}
+
+// split2 returns the values from strings.SplitN(s, sep, 2).
+// If sep is not found, it returns "", s instead.
+func split2(s, sep string) (string, string) {
+	spl := strings.SplitN(s, sep, 2)
+	if len(spl) < 2 {
+		return "", s
+	}
+	return spl[0], spl[1]
+}
+
+// parseTarget splits target into a struct containing scheme, authority and
+// endpoint.
+func parseTarget(target string) (ret resolver.Target) {
+	ret.Scheme, ret.Endpoint = split2(target, "://")
+	ret.Authority, ret.Endpoint = split2(ret.Endpoint, "/")
+	return ret
+}
+
+// newCCResolverWrapper parses cc.target for scheme and gets the resolver
+// builder for this scheme. It then builds the resolver and starts the
+// monitoring goroutine for it.
+//
+// This function could return nil, nil, in tests for old behaviors.
+// TODO(bar) never return nil, nil when DNS becomes the default resolver.
+func newCCResolverWrapper(cc *ClientConn) (*ccResolverWrapper, error) {
+	target := parseTarget(cc.target)
+	grpclog.Infof("dialing to target with scheme: %q", target.Scheme)
+
+	rb := resolver.Get(target.Scheme)
+	if rb == nil {
+		// TODO(bar) return error when DNS becomes the default (implemented and
+		// registered by DNS package).
+		grpclog.Infof("could not get resolver for scheme: %q", target.Scheme)
+		return nil, nil
+	}
+
+	ccr := &ccResolverWrapper{
+		cc:     cc,
+		addrCh: make(chan []resolver.Address, 1),
+		scCh:   make(chan string, 1),
+		done:   make(chan struct{}),
+	}
+
+	var err error
+	ccr.resolver, err = rb.Build(target, ccr, resolver.BuildOption{})
+	if err != nil {
+		return nil, err
+	}
+	go ccr.watcher()
+	return ccr, nil
+}
+
+// watcher processes address updates and service config updates sequencially.
+// Otherwise, we need to resolve possible races between address and service
+// config (e.g. they specify different balancer types).
+func (ccr *ccResolverWrapper) watcher() {
+	for {
+		select {
+		case <-ccr.done:
+			return
+		default:
+		}
+
+		select {
+		case addrs := <-ccr.addrCh:
+			grpclog.Infof("ccResolverWrapper: sending new addresses to balancer wrapper: %v", addrs)
+			// TODO(bar switching) this should never be nil. Pickfirst should be default.
+			if ccr.cc.balancerWrapper != nil {
+				// TODO(bar switching) create balancer if it's nil?
+				ccr.cc.balancerWrapper.handleResolvedAddrs(addrs, nil)
+			}
+		case sc := <-ccr.scCh:
+			grpclog.Infof("ccResolverWrapper: got new service config: %v", sc)
+		case <-ccr.done:
+			return
+		}
+	}
+}
+
+func (ccr *ccResolverWrapper) close() {
+	ccr.resolver.Close()
+	close(ccr.done)
+}
+
+// NewAddress is called by the resolver implemenetion to send addresses to gRPC.
+func (ccr *ccResolverWrapper) NewAddress(addrs []resolver.Address) {
+	select {
+	case <-ccr.addrCh:
+	default:
+	}
+	ccr.addrCh <- addrs
+}
+
+// NewServiceConfig is called by the resolver implemenetion to send service
+// configs to gPRC.
+func (ccr *ccResolverWrapper) NewServiceConfig(sc string) {
+	select {
+	case <-ccr.scCh:
+	default:
+	}
+	ccr.scCh <- sc
+}