[VOL-4289] Proto changes for gRPC migration
Change-Id: I317a0a865ccf78d0c37aa229c50d293a3f66c8bb
diff --git a/vendor/google.golang.org/grpc/balancer/base/balancer.go b/vendor/google.golang.org/grpc/balancer/base/balancer.go
new file mode 100644
index 0000000..8dd5042
--- /dev/null
+++ b/vendor/google.golang.org/grpc/balancer/base/balancer.go
@@ -0,0 +1,279 @@
+/*
+ *
+ * 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 base
+
+import (
+ "errors"
+ "fmt"
+
+ "google.golang.org/grpc/attributes"
+ "google.golang.org/grpc/balancer"
+ "google.golang.org/grpc/connectivity"
+ "google.golang.org/grpc/grpclog"
+ "google.golang.org/grpc/resolver"
+)
+
+var logger = grpclog.Component("balancer")
+
+type baseBuilder struct {
+ name string
+ pickerBuilder PickerBuilder
+ config Config
+}
+
+func (bb *baseBuilder) Build(cc balancer.ClientConn, opt balancer.BuildOptions) balancer.Balancer {
+ bal := &baseBalancer{
+ cc: cc,
+ pickerBuilder: bb.pickerBuilder,
+
+ subConns: make(map[resolver.Address]subConnInfo),
+ scStates: make(map[balancer.SubConn]connectivity.State),
+ csEvltr: &balancer.ConnectivityStateEvaluator{},
+ config: bb.config,
+ }
+ // Initialize picker to a picker that always returns
+ // ErrNoSubConnAvailable, because when state of a SubConn changes, we
+ // may call UpdateState with this picker.
+ bal.picker = NewErrPicker(balancer.ErrNoSubConnAvailable)
+ return bal
+}
+
+func (bb *baseBuilder) Name() string {
+ return bb.name
+}
+
+type subConnInfo struct {
+ subConn balancer.SubConn
+ attrs *attributes.Attributes
+}
+
+type baseBalancer struct {
+ cc balancer.ClientConn
+ pickerBuilder PickerBuilder
+
+ csEvltr *balancer.ConnectivityStateEvaluator
+ state connectivity.State
+
+ subConns map[resolver.Address]subConnInfo // `attributes` is stripped from the keys of this map (the addresses)
+ scStates map[balancer.SubConn]connectivity.State
+ picker balancer.Picker
+ config Config
+
+ resolverErr error // the last error reported by the resolver; cleared on successful resolution
+ connErr error // the last connection error; cleared upon leaving TransientFailure
+}
+
+func (b *baseBalancer) ResolverError(err error) {
+ b.resolverErr = err
+ if len(b.subConns) == 0 {
+ b.state = connectivity.TransientFailure
+ }
+
+ if b.state != connectivity.TransientFailure {
+ // The picker will not change since the balancer does not currently
+ // report an error.
+ return
+ }
+ b.regeneratePicker()
+ b.cc.UpdateState(balancer.State{
+ ConnectivityState: b.state,
+ Picker: b.picker,
+ })
+}
+
+func (b *baseBalancer) UpdateClientConnState(s balancer.ClientConnState) error {
+ // TODO: handle s.ResolverState.ServiceConfig?
+ if logger.V(2) {
+ logger.Info("base.baseBalancer: got new ClientConn state: ", s)
+ }
+ // Successful resolution; clear resolver error and ensure we return nil.
+ b.resolverErr = nil
+ // addrsSet is the set converted from addrs, it's used for quick lookup of an address.
+ addrsSet := make(map[resolver.Address]struct{})
+ for _, a := range s.ResolverState.Addresses {
+ // Strip attributes from addresses before using them as map keys. So
+ // that when two addresses only differ in attributes pointers (but with
+ // the same attribute content), they are considered the same address.
+ //
+ // Note that this doesn't handle the case where the attribute content is
+ // different. So if users want to set different attributes to create
+ // duplicate connections to the same backend, it doesn't work. This is
+ // fine for now, because duplicate is done by setting Metadata today.
+ //
+ // TODO: read attributes to handle duplicate connections.
+ aNoAttrs := a
+ aNoAttrs.Attributes = nil
+ addrsSet[aNoAttrs] = struct{}{}
+ if scInfo, ok := b.subConns[aNoAttrs]; !ok {
+ // a is a new address (not existing in b.subConns).
+ //
+ // When creating SubConn, the original address with attributes is
+ // passed through. So that connection configurations in attributes
+ // (like creds) will be used.
+ sc, err := b.cc.NewSubConn([]resolver.Address{a}, balancer.NewSubConnOptions{HealthCheckEnabled: b.config.HealthCheck})
+ if err != nil {
+ logger.Warningf("base.baseBalancer: failed to create new SubConn: %v", err)
+ continue
+ }
+ b.subConns[aNoAttrs] = subConnInfo{subConn: sc, attrs: a.Attributes}
+ b.scStates[sc] = connectivity.Idle
+ b.csEvltr.RecordTransition(connectivity.Shutdown, connectivity.Idle)
+ sc.Connect()
+ } else {
+ // Always update the subconn's address in case the attributes
+ // changed.
+ //
+ // The SubConn does a reflect.DeepEqual of the new and old
+ // addresses. So this is a noop if the current address is the same
+ // as the old one (including attributes).
+ scInfo.attrs = a.Attributes
+ b.subConns[aNoAttrs] = scInfo
+ b.cc.UpdateAddresses(scInfo.subConn, []resolver.Address{a})
+ }
+ }
+ for a, scInfo := range b.subConns {
+ // a was removed by resolver.
+ if _, ok := addrsSet[a]; !ok {
+ b.cc.RemoveSubConn(scInfo.subConn)
+ delete(b.subConns, a)
+ // Keep the state of this sc in b.scStates until sc's state becomes Shutdown.
+ // The entry will be deleted in UpdateSubConnState.
+ }
+ }
+ // If resolver state contains no addresses, return an error so ClientConn
+ // will trigger re-resolve. Also records this as an resolver error, so when
+ // the overall state turns transient failure, the error message will have
+ // the zero address information.
+ if len(s.ResolverState.Addresses) == 0 {
+ b.ResolverError(errors.New("produced zero addresses"))
+ return balancer.ErrBadResolverState
+ }
+ return nil
+}
+
+// mergeErrors builds an error from the last connection error and the last
+// resolver error. Must only be called if b.state is TransientFailure.
+func (b *baseBalancer) mergeErrors() error {
+ // connErr must always be non-nil unless there are no SubConns, in which
+ // case resolverErr must be non-nil.
+ if b.connErr == nil {
+ return fmt.Errorf("last resolver error: %v", b.resolverErr)
+ }
+ if b.resolverErr == nil {
+ return fmt.Errorf("last connection error: %v", b.connErr)
+ }
+ return fmt.Errorf("last connection error: %v; last resolver error: %v", b.connErr, b.resolverErr)
+}
+
+// regeneratePicker takes a snapshot of the balancer, and generates a picker
+// from it. The picker is
+// - errPicker if the balancer is in TransientFailure,
+// - built by the pickerBuilder with all READY SubConns otherwise.
+func (b *baseBalancer) regeneratePicker() {
+ if b.state == connectivity.TransientFailure {
+ b.picker = NewErrPicker(b.mergeErrors())
+ return
+ }
+ readySCs := make(map[balancer.SubConn]SubConnInfo)
+
+ // Filter out all ready SCs from full subConn map.
+ for addr, scInfo := range b.subConns {
+ if st, ok := b.scStates[scInfo.subConn]; ok && st == connectivity.Ready {
+ addr.Attributes = scInfo.attrs
+ readySCs[scInfo.subConn] = SubConnInfo{Address: addr}
+ }
+ }
+ b.picker = b.pickerBuilder.Build(PickerBuildInfo{ReadySCs: readySCs})
+}
+
+func (b *baseBalancer) UpdateSubConnState(sc balancer.SubConn, state balancer.SubConnState) {
+ s := state.ConnectivityState
+ if logger.V(2) {
+ logger.Infof("base.baseBalancer: handle SubConn state change: %p, %v", sc, s)
+ }
+ oldS, ok := b.scStates[sc]
+ if !ok {
+ if logger.V(2) {
+ logger.Infof("base.baseBalancer: got state changes for an unknown SubConn: %p, %v", sc, s)
+ }
+ return
+ }
+ if oldS == connectivity.TransientFailure &&
+ (s == connectivity.Connecting || s == connectivity.Idle) {
+ // Once a subconn enters TRANSIENT_FAILURE, ignore subsequent IDLE or
+ // CONNECTING transitions to prevent the aggregated state from being
+ // always CONNECTING when many backends exist but are all down.
+ if s == connectivity.Idle {
+ sc.Connect()
+ }
+ return
+ }
+ b.scStates[sc] = s
+ switch s {
+ case connectivity.Idle:
+ sc.Connect()
+ case connectivity.Shutdown:
+ // When an address was removed by resolver, b called RemoveSubConn but
+ // kept the sc's state in scStates. Remove state for this sc here.
+ delete(b.scStates, sc)
+ case connectivity.TransientFailure:
+ // Save error to be reported via picker.
+ b.connErr = state.ConnectionError
+ }
+
+ b.state = b.csEvltr.RecordTransition(oldS, s)
+
+ // Regenerate picker when one of the following happens:
+ // - this sc entered or left ready
+ // - the aggregated state of balancer is TransientFailure
+ // (may need to update error message)
+ if (s == connectivity.Ready) != (oldS == connectivity.Ready) ||
+ b.state == connectivity.TransientFailure {
+ b.regeneratePicker()
+ }
+ b.cc.UpdateState(balancer.State{ConnectivityState: b.state, Picker: b.picker})
+}
+
+// Close is a nop because base balancer doesn't have internal state to clean up,
+// and it doesn't need to call RemoveSubConn for the SubConns.
+func (b *baseBalancer) Close() {
+}
+
+// ExitIdle is a nop because the base balancer attempts to stay connected to
+// all SubConns at all times.
+func (b *baseBalancer) ExitIdle() {
+}
+
+// NewErrPicker returns a Picker that always returns err on Pick().
+func NewErrPicker(err error) balancer.Picker {
+ return &errPicker{err: err}
+}
+
+// NewErrPickerV2 is temporarily defined for backward compatibility reasons.
+//
+// Deprecated: use NewErrPicker instead.
+var NewErrPickerV2 = NewErrPicker
+
+type errPicker struct {
+ err error // Pick() always returns this err.
+}
+
+func (p *errPicker) Pick(info balancer.PickInfo) (balancer.PickResult, error) {
+ return balancer.PickResult{}, p.err
+}