forked from projectcontour/contour
/
cluster.go
118 lines (103 loc) · 3.07 KB
/
cluster.go
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// Copyright © 2018 Heptio
// 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 contour
import (
"sync"
"github.com/envoyproxy/go-control-plane/envoy/api/v2"
"github.com/gogo/protobuf/proto"
"github.com/heptio/contour/internal/dag"
"github.com/heptio/contour/internal/envoy"
)
// ClusterCache manages the contents of the gRPC CDS cache.
type ClusterCache struct {
mu sync.Mutex
values map[string]*v2.Cluster
waiters []chan int
last int
}
// Register registers ch to receive a value when Notify is called.
// The value of last is the count of the times Notify has been called on this Cache.
// It functions of a sequence counter, if the value of last supplied to Register
// is less than the Cache's internal counter, then the caller has missed at least
// one notification and will fire immediately.
//
// Sends by the broadcaster to ch must not block, therefor ch must have a capacity
// of at least 1.
func (c *ClusterCache) Register(ch chan int, last int) {
c.mu.Lock()
defer c.mu.Unlock()
if last < c.last {
// notify this channel immediately
ch <- c.last
return
}
c.waiters = append(c.waiters, ch)
}
// Update replaces the contents of the cache with the supplied map.
func (c *ClusterCache) Update(v map[string]*v2.Cluster) {
c.mu.Lock()
defer c.mu.Unlock()
c.values = v
c.notify()
}
// notify notifies all registered waiters that an event has occurred.
func (c *ClusterCache) notify() {
c.last++
for _, ch := range c.waiters {
ch <- c.last
}
c.waiters = c.waiters[:0]
}
// Values returns a slice of the value stored in the cache.
func (c *ClusterCache) Values(filter func(string) bool) []proto.Message {
c.mu.Lock()
values := make([]proto.Message, 0, len(c.values))
for _, v := range c.values {
if filter(v.Name) {
values = append(values, v)
}
}
c.mu.Unlock()
return values
}
type clusterVisitor struct {
clusters map[string]*v2.Cluster
}
// visitCluster produces a map of *v2.Clusters.
func visitClusters(root dag.Vertex) map[string]*v2.Cluster {
cv := clusterVisitor{
clusters: make(map[string]*v2.Cluster),
}
cv.visit(root)
return cv.clusters
}
func (v *clusterVisitor) visit(vertex dag.Vertex) {
switch service := vertex.(type) {
case *dag.HTTPService:
name := envoy.Clustername(&service.TCPService)
if _, ok := v.clusters[name]; !ok {
c := envoy.Cluster(service)
v.clusters[c.Name] = c
}
case *dag.TCPService:
name := envoy.Clustername(service)
if _, ok := v.clusters[name]; !ok {
c := envoy.Cluster(service)
v.clusters[c.Name] = c
}
default:
// nothing
}
// recurse into children of v
vertex.Visit(v.visit)
}