Add glide.yaml and vendor deps

vendor/k8s.io/kubernetes/plugin/pkg/scheduler/schedulercache/interface.go

@@ -0,0 +1,93 @@
+/*
+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 schedulercache
+
+import (
+	"k8s.io/kubernetes/pkg/api/v1"
+	"k8s.io/kubernetes/pkg/labels"
+)
+
+// Cache collects pods' information and provides node-level aggregated information.
+// It's intended for generic scheduler to do efficient lookup.
+// Cache's operations are pod centric. It does incremental updates based on pod events.
+// Pod events are sent via network. We don't have guaranteed delivery of all events:
+// We use Reflector to list and watch from remote.
+// Reflector might be slow and do a relist, which would lead to missing events.
+//
+// State Machine of a pod's events in scheduler's cache:
+//
+//
+//   +-------------------------------------------+  +----+
+//   |                            Add            |  |    |
+//   |                                           |  |    | Update
+//   +      Assume                Add            v  v    |
+//Initial +--------> Assumed +------------+---> Added <--+
+//   ^                +   +               |       +
+//   |                |   |               |       |
+//   |                |   |           Add |       | Remove
+//   |                |   |               |       |
+//   |                |   |               +       |
+//   +----------------+   +-----------> Expired   +----> Deleted
+//         Forget             Expire
+//
+//
+// Note that an assumed pod can expire, because if we haven't received Add event notifying us
+// for a while, there might be some problems and we shouldn't keep the pod in cache anymore.
+//
+// Note that "Initial", "Expired", and "Deleted" pods do not actually exist in cache.
+// Based on existing use cases, we are making the following assumptions:
+// - No pod would be assumed twice
+// - A pod could be added without going through scheduler. In this case, we will see Add but not Assume event.
+// - If a pod wasn't added, it wouldn't be removed or updated.
+// - Both "Expired" and "Deleted" are valid end states. In case of some problems, e.g. network issue,
+//   a pod might have changed its state (e.g. added and deleted) without delivering notification to the cache.
+type Cache interface {
+	// AssumePod assumes a pod scheduled and aggregates the pod's information into its node.
+	// The implementation also decides the policy to expire pod before being confirmed (receiving Add event).
+	// After expiration, its information would be subtracted.
+	AssumePod(pod *v1.Pod) error
+
+	// ForgetPod removes an assumed pod from cache.
+	ForgetPod(pod *v1.Pod) error
+
+	// AddPod either confirms a pod if it's assumed, or adds it back if it's expired.
+	// If added back, the pod's information would be added again.
+	AddPod(pod *v1.Pod) error
+
+	// UpdatePod removes oldPod's information and adds newPod's information.
+	UpdatePod(oldPod, newPod *v1.Pod) error
+
+	// RemovePod removes a pod. The pod's information would be subtracted from assigned node.
+	RemovePod(pod *v1.Pod) error
+
+	// AddNode adds overall information about node.
+	AddNode(node *v1.Node) error
+
+	// UpdateNode updates overall information about node.
+	UpdateNode(oldNode, newNode *v1.Node) error
+
+	// RemoveNode removes overall information about node.
+	RemoveNode(node *v1.Node) error
+
+	// UpdateNodeNameToInfoMap updates the passed infoMap to the current contents of Cache.
+	// The node info contains aggregated information of pods scheduled (including assumed to be)
+	// on this node.
+	UpdateNodeNameToInfoMap(infoMap map[string]*NodeInfo) error
+
+	// List lists all cached pods (including assumed ones).
+	List(labels.Selector) ([]*v1.Pod, error)
+}