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-rw-r--r--vendor/google.golang.org/grpc/resolver/resolver.go143
1 files changed, 143 insertions, 0 deletions
diff --git a/vendor/google.golang.org/grpc/resolver/resolver.go b/vendor/google.golang.org/grpc/resolver/resolver.go
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+/*
+ *
+ * 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 resolver defines APIs for name resolution in gRPC.
+// All APIs in this package are experimental.
+package resolver
+
+var (
+ // m is a map from scheme to resolver builder.
+ m = make(map[string]Builder)
+ // defaultScheme is the default scheme to use.
+ defaultScheme string
+)
+
+// TODO(bar) install dns resolver in init(){}.
+
+// Register registers the resolver builder to the resolver map.
+// b.Scheme will be used as the scheme registered with this builder.
+func Register(b Builder) {
+ m[b.Scheme()] = b
+}
+
+// Get returns the resolver builder registered with the given scheme.
+// If no builder is register with the scheme, the default scheme will
+// be used.
+// If the default scheme is not modified, "dns" will be the default
+// scheme, and the preinstalled dns resolver will be used.
+// If the default scheme is modified, and a resolver is registered with
+// the scheme, that resolver will be returned.
+// If the default scheme is modified, and no resolver is registered with
+// the scheme, nil will be returned.
+func Get(scheme string) Builder {
+ if b, ok := m[scheme]; ok {
+ return b
+ }
+ if b, ok := m[defaultScheme]; ok {
+ return b
+ }
+ return nil
+}
+
+// SetDefaultScheme sets the default scheme that will be used.
+// The default default scheme is "dns".
+func SetDefaultScheme(scheme string) {
+ defaultScheme = scheme
+}
+
+// AddressType indicates the address type returned by name resolution.
+type AddressType uint8
+
+const (
+ // Backend indicates the address is for a backend server.
+ Backend AddressType = iota
+ // GRPCLB indicates the address is for a grpclb load balancer.
+ GRPCLB
+)
+
+// Address represents a server the client connects to.
+// This is the EXPERIMENTAL API and may be changed or extended in the future.
+type Address struct {
+ // Addr is the server address on which a connection will be established.
+ Addr string
+ // Type is the type of this address.
+ Type AddressType
+ // ServerName is the name of this address.
+ // It's the name of the grpc load balancer, which will be used for authentication.
+ ServerName string
+ // Metadata is the information associated with Addr, which may be used
+ // to make load balancing decision.
+ Metadata interface{}
+}
+
+// BuildOption includes additional information for the builder to create
+// the resolver.
+type BuildOption struct {
+}
+
+// ClientConn contains the callbacks for resolver to notify any updates
+// to the gRPC ClientConn.
+type ClientConn interface {
+ // NewAddress is called by resolver to notify ClientConn a new list
+ // of resolved addresses.
+ // The address list should be the complete list of resolved addresses.
+ NewAddress(addresses []Address)
+ // NewServiceConfig is called by resolver to notify ClientConn a new
+ // service config. The service config should be provided as a json string.
+ NewServiceConfig(serviceConfig string)
+}
+
+// Target represents a target for gRPC, as specified in:
+// https://github.com/grpc/grpc/blob/master/doc/naming.md.
+type Target struct {
+ Scheme string
+ Authority string
+ Endpoint string
+}
+
+// Builder creates a resolver that will be used to watch name resolution updates.
+type Builder interface {
+ // Build creates a new resolver for the given target.
+ //
+ // gRPC dial calls Build synchronously, and fails if the returned error is
+ // not nil.
+ Build(target Target, cc ClientConn, opts BuildOption) (Resolver, error)
+ // Scheme returns the scheme supported by this resolver.
+ // Scheme is defined at https://github.com/grpc/grpc/blob/master/doc/naming.md.
+ Scheme() string
+}
+
+// ResolveNowOption includes additional information for ResolveNow.
+type ResolveNowOption struct{}
+
+// Resolver watches for the updates on the specified target.
+// Updates include address updates and service config updates.
+type Resolver interface {
+ // ResolveNow will be called by gRPC to try to resolve the target name again.
+ // It's just a hint, resolver can ignore this if it's not necessary.
+ ResolveNow(ResolveNowOption)
+ // Close closes the resolver.
+ Close()
+}
+
+// UnregisterForTesting removes the resolver builder with the given scheme from the
+// resolver map.
+// This function is for testing only.
+func UnregisterForTesting(scheme string) {
+ delete(m, scheme)
+}