ceph-csi/vendor/google.golang.org/grpc/internal/resolver/config_selector.go
Madhu Rajanna 342d282780 rebase: add kube-storage/replication to go.mod
add dependent kube-storage/replication package
to the vendor.

update grpc to latest release v1.35.0.

Signed-off-by: Madhu Rajanna <madhupr007@gmail.com>
2021-03-16 13:06:44 +00:00

96 lines
3.2 KiB
Go

/*
*
* Copyright 2020 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 provides internal resolver-related functionality.
package resolver
import (
"context"
"sync"
"google.golang.org/grpc/internal/serviceconfig"
"google.golang.org/grpc/resolver"
)
// ConfigSelector controls what configuration to use for every RPC.
type ConfigSelector interface {
// Selects the configuration for the RPC, or terminates it using the error.
// This error will be converted by the gRPC library to a status error with
// code UNKNOWN if it is not returned as a status error.
SelectConfig(RPCInfo) (*RPCConfig, error)
}
// RPCInfo contains RPC information needed by a ConfigSelector.
type RPCInfo struct {
// Context is the user's context for the RPC and contains headers and
// application timeout. It is passed for interception purposes and for
// efficiency reasons. SelectConfig should not be blocking.
Context context.Context
Method string // i.e. "/Service/Method"
}
// RPCConfig describes the configuration to use for each RPC.
type RPCConfig struct {
// The context to use for the remainder of the RPC; can pass info to LB
// policy or affect timeout or metadata.
Context context.Context
MethodConfig serviceconfig.MethodConfig // configuration to use for this RPC
OnCommitted func() // Called when the RPC has been committed (retries no longer possible)
}
type csKeyType string
const csKey = csKeyType("grpc.internal.resolver.configSelector")
// SetConfigSelector sets the config selector in state and returns the new
// state.
func SetConfigSelector(state resolver.State, cs ConfigSelector) resolver.State {
state.Attributes = state.Attributes.WithValues(csKey, cs)
return state
}
// GetConfigSelector retrieves the config selector from state, if present, and
// returns it or nil if absent.
func GetConfigSelector(state resolver.State) ConfigSelector {
cs, _ := state.Attributes.Value(csKey).(ConfigSelector)
return cs
}
// SafeConfigSelector allows for safe switching of ConfigSelector
// implementations such that previous values are guaranteed to not be in use
// when UpdateConfigSelector returns.
type SafeConfigSelector struct {
mu sync.RWMutex
cs ConfigSelector
}
// UpdateConfigSelector swaps to the provided ConfigSelector and blocks until
// all uses of the previous ConfigSelector have completed.
func (scs *SafeConfigSelector) UpdateConfigSelector(cs ConfigSelector) {
scs.mu.Lock()
defer scs.mu.Unlock()
scs.cs = cs
}
// SelectConfig defers to the current ConfigSelector in scs.
func (scs *SafeConfigSelector) SelectConfig(r RPCInfo) (*RPCConfig, error) {
scs.mu.RLock()
defer scs.mu.RUnlock()
return scs.cs.SelectConfig(r)
}