forked from github/multus-cni
ac21a96804
gomodule is still in progress to migrate for now, hence multus team decide to keep vendor directory to support build without gomodule.
98 lines
2.3 KiB
Go
98 lines
2.3 KiB
Go
/*
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*
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* Copyright 2018 gRPC authors.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*
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*/
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package grpc
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import (
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"container/list"
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)
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type linkedMapKVPair struct {
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key string
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value *stickyStoreEntry
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}
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// linkedMap is an implementation of a map that supports removing the oldest
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// entry.
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//
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// linkedMap is NOT thread safe.
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//
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// It's for use of stickiness only!
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type linkedMap struct {
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m map[string]*list.Element
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l *list.List // Head of the list is the oldest element.
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}
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// newLinkedMap returns a new LinkedMap.
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func newLinkedMap() *linkedMap {
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return &linkedMap{
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m: make(map[string]*list.Element),
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l: list.New(),
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}
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}
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// put adds entry (key, value) to the map. Existing key will be overridden.
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func (m *linkedMap) put(key string, value *stickyStoreEntry) {
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if oldE, ok := m.m[key]; ok {
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// Remove existing entry.
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m.l.Remove(oldE)
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}
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e := m.l.PushBack(&linkedMapKVPair{key: key, value: value})
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m.m[key] = e
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}
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// get returns the value of the given key.
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func (m *linkedMap) get(key string) (*stickyStoreEntry, bool) {
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e, ok := m.m[key]
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if !ok {
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return nil, false
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}
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m.l.MoveToBack(e)
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return e.Value.(*linkedMapKVPair).value, true
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}
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// remove removes key from the map, and returns the value. The map is not
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// modified if key is not in the map.
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func (m *linkedMap) remove(key string) (*stickyStoreEntry, bool) {
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e, ok := m.m[key]
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if !ok {
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return nil, false
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}
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delete(m.m, key)
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m.l.Remove(e)
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return e.Value.(*linkedMapKVPair).value, true
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}
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// len returns the len of the map.
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func (m *linkedMap) len() int {
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return len(m.m)
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}
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// clear removes all elements from the map.
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func (m *linkedMap) clear() {
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m.m = make(map[string]*list.Element)
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m.l = list.New()
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}
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// removeOldest removes the oldest key from the map.
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func (m *linkedMap) removeOldest() {
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e := m.l.Front()
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m.l.Remove(e)
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delete(m.m, e.Value.(*linkedMapKVPair).key)
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}
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