vendor files

vendor/k8s.io/kubernetes/pkg/api/endpoints/util.go

@@ -0,0 +1,226 @@
+/*
+Copyright 2015 The Kubernetes 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 endpoints
+
+import (
+	"bytes"
+	"crypto/md5"
+	"encoding/hex"
+	"hash"
+	"sort"
+
+	"k8s.io/apimachinery/pkg/types"
+	api "k8s.io/kubernetes/pkg/apis/core"
+	hashutil "k8s.io/kubernetes/pkg/util/hash"
+)
+
+// RepackSubsets takes a slice of EndpointSubset objects, expands it to the full
+// representation, and then repacks that into the canonical layout.  This
+// ensures that code which operates on these objects can rely on the common
+// form for things like comparison.  The result is a newly allocated slice.
+func RepackSubsets(subsets []api.EndpointSubset) []api.EndpointSubset {
+	// First map each unique port definition to the sets of hosts that
+	// offer it.
+	allAddrs := map[addressKey]*api.EndpointAddress{}
+	portToAddrReadyMap := map[api.EndpointPort]addressSet{}
+	for i := range subsets {
+		for _, port := range subsets[i].Ports {
+			for k := range subsets[i].Addresses {
+				mapAddressByPort(&subsets[i].Addresses[k], port, true, allAddrs, portToAddrReadyMap)
+			}
+			for k := range subsets[i].NotReadyAddresses {
+				mapAddressByPort(&subsets[i].NotReadyAddresses[k], port, false, allAddrs, portToAddrReadyMap)
+			}
+		}
+	}
+
+	// Next, map the sets of hosts to the sets of ports they offer.
+	// Go does not allow maps or slices as keys to maps, so we have
+	// to synthesize an artificial key and do a sort of 2-part
+	// associative entity.
+	type keyString string
+	keyToAddrReadyMap := map[keyString]addressSet{}
+	addrReadyMapKeyToPorts := map[keyString][]api.EndpointPort{}
+	for port, addrs := range portToAddrReadyMap {
+		key := keyString(hashAddresses(addrs))
+		keyToAddrReadyMap[key] = addrs
+		addrReadyMapKeyToPorts[key] = append(addrReadyMapKeyToPorts[key], port)
+	}
+
+	// Next, build the N-to-M association the API wants.
+	final := []api.EndpointSubset{}
+	for key, ports := range addrReadyMapKeyToPorts {
+		var readyAddrs, notReadyAddrs []api.EndpointAddress
+		for addr, ready := range keyToAddrReadyMap[key] {
+			if ready {
+				readyAddrs = append(readyAddrs, *addr)
+			} else {
+				notReadyAddrs = append(notReadyAddrs, *addr)
+			}
+		}
+		final = append(final, api.EndpointSubset{Addresses: readyAddrs, NotReadyAddresses: notReadyAddrs, Ports: ports})
+	}
+
+	// Finally, sort it.
+	return SortSubsets(final)
+}
+
+// The sets of hosts must be de-duped, using IP+UID as the key.
+type addressKey struct {
+	ip  string
+	uid types.UID
+}
+
+// mapAddressByPort adds an address into a map by its ports, registering the address with a unique pointer, and preserving
+// any existing ready state.
+func mapAddressByPort(addr *api.EndpointAddress, port api.EndpointPort, ready bool, allAddrs map[addressKey]*api.EndpointAddress, portToAddrReadyMap map[api.EndpointPort]addressSet) *api.EndpointAddress {
+	// use addressKey to distinguish between two endpoints that are identical addresses
+	// but may have come from different hosts, for attribution. For instance, Mesos
+	// assigns pods the node IP, but the pods are distinct.
+	key := addressKey{ip: addr.IP}
+	if addr.TargetRef != nil {
+		key.uid = addr.TargetRef.UID
+	}
+
+	// Accumulate the address. The full EndpointAddress structure is preserved for use when
+	// we rebuild the subsets so that the final TargetRef has all of the necessary data.
+	existingAddress := allAddrs[key]
+	if existingAddress == nil {
+		// Make a copy so we don't write to the
+		// input args of this function.
+		existingAddress = &api.EndpointAddress{}
+		*existingAddress = *addr
+		allAddrs[key] = existingAddress
+	}
+
+	// Remember that this port maps to this address.
+	if _, found := portToAddrReadyMap[port]; !found {
+		portToAddrReadyMap[port] = addressSet{}
+	}
+	// if we have not yet recorded this port for this address, or if the previous
+	// state was ready, write the current ready state. not ready always trumps
+	// ready.
+	if wasReady, found := portToAddrReadyMap[port][existingAddress]; !found || wasReady {
+		portToAddrReadyMap[port][existingAddress] = ready
+	}
+	return existingAddress
+}
+
+type addressSet map[*api.EndpointAddress]bool
+
+type addrReady struct {
+	addr  *api.EndpointAddress
+	ready bool
+}
+
+func hashAddresses(addrs addressSet) string {
+	// Flatten the list of addresses into a string so it can be used as a
+	// map key.  Unfortunately, DeepHashObject is implemented in terms of
+	// spew, and spew does not handle non-primitive map keys well.  So
+	// first we collapse it into a slice, sort the slice, then hash that.
+	slice := make([]addrReady, 0, len(addrs))
+	for k, ready := range addrs {
+		slice = append(slice, addrReady{k, ready})
+	}
+	sort.Sort(addrsReady(slice))
+	hasher := md5.New()
+	hashutil.DeepHashObject(hasher, slice)
+	return hex.EncodeToString(hasher.Sum(nil)[0:])
+}
+
+func lessAddrReady(a, b addrReady) bool {
+	// ready is not significant to hashing since we can't have duplicate addresses
+	return LessEndpointAddress(a.addr, b.addr)
+}
+
+type addrsReady []addrReady
+
+func (sl addrsReady) Len() int      { return len(sl) }
+func (sl addrsReady) Swap(i, j int) { sl[i], sl[j] = sl[j], sl[i] }
+func (sl addrsReady) Less(i, j int) bool {
+	return lessAddrReady(sl[i], sl[j])
+}
+
+func LessEndpointAddress(a, b *api.EndpointAddress) bool {
+	ipComparison := bytes.Compare([]byte(a.IP), []byte(b.IP))
+	if ipComparison != 0 {
+		return ipComparison < 0
+	}
+	if b.TargetRef == nil {
+		return false
+	}
+	if a.TargetRef == nil {
+		return true
+	}
+	return a.TargetRef.UID < b.TargetRef.UID
+}
+
+type addrPtrsByIpAndUID []*api.EndpointAddress
+
+func (sl addrPtrsByIpAndUID) Len() int      { return len(sl) }
+func (sl addrPtrsByIpAndUID) Swap(i, j int) { sl[i], sl[j] = sl[j], sl[i] }
+func (sl addrPtrsByIpAndUID) Less(i, j int) bool {
+	return LessEndpointAddress(sl[i], sl[j])
+}
+
+// SortSubsets sorts an array of EndpointSubset objects in place.  For ease of
+// use it returns the input slice.
+func SortSubsets(subsets []api.EndpointSubset) []api.EndpointSubset {
+	for i := range subsets {
+		ss := &subsets[i]
+		sort.Sort(addrsByIpAndUID(ss.Addresses))
+		sort.Sort(addrsByIpAndUID(ss.NotReadyAddresses))
+		sort.Sort(portsByHash(ss.Ports))
+	}
+	sort.Sort(subsetsByHash(subsets))
+	return subsets
+}
+
+func hashObject(hasher hash.Hash, obj interface{}) []byte {
+	hashutil.DeepHashObject(hasher, obj)
+	return hasher.Sum(nil)
+}
+
+type subsetsByHash []api.EndpointSubset
+
+func (sl subsetsByHash) Len() int      { return len(sl) }
+func (sl subsetsByHash) Swap(i, j int) { sl[i], sl[j] = sl[j], sl[i] }
+func (sl subsetsByHash) Less(i, j int) bool {
+	hasher := md5.New()
+	h1 := hashObject(hasher, sl[i])
+	h2 := hashObject(hasher, sl[j])
+	return bytes.Compare(h1, h2) < 0
+}
+
+type addrsByIpAndUID []api.EndpointAddress
+
+func (sl addrsByIpAndUID) Len() int      { return len(sl) }
+func (sl addrsByIpAndUID) Swap(i, j int) { sl[i], sl[j] = sl[j], sl[i] }
+func (sl addrsByIpAndUID) Less(i, j int) bool {
+	return LessEndpointAddress(&sl[i], &sl[j])
+}
+
+type portsByHash []api.EndpointPort
+
+func (sl portsByHash) Len() int      { return len(sl) }
+func (sl portsByHash) Swap(i, j int) { sl[i], sl[j] = sl[j], sl[i] }
+func (sl portsByHash) Less(i, j int) bool {
+	hasher := md5.New()
+	h1 := hashObject(hasher, sl[i])
+	h2 := hashObject(hasher, sl[j])
+	return bytes.Compare(h1, h2) < 0
+}