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author | Matthew Heon <matthew.heon@gmail.com> | 2017-11-01 11:24:59 -0400 |
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committer | Matthew Heon <matthew.heon@gmail.com> | 2017-11-01 11:24:59 -0400 |
commit | a031b83a09a8628435317a03f199cdc18b78262f (patch) | |
tree | bc017a96769ce6de33745b8b0b1304ccf38e9df0 /vendor/k8s.io/apimachinery/pkg/util/cache/cache.go | |
parent | 2b74391cd5281f6fdf391ff8ad50fd1490f6bf89 (diff) | |
download | podman-a031b83a09a8628435317a03f199cdc18b78262f.tar.gz podman-a031b83a09a8628435317a03f199cdc18b78262f.tar.bz2 podman-a031b83a09a8628435317a03f199cdc18b78262f.zip |
Initial checkin from CRI-O repo
Signed-off-by: Matthew Heon <matthew.heon@gmail.com>
Diffstat (limited to 'vendor/k8s.io/apimachinery/pkg/util/cache/cache.go')
-rw-r--r-- | vendor/k8s.io/apimachinery/pkg/util/cache/cache.go | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/vendor/k8s.io/apimachinery/pkg/util/cache/cache.go b/vendor/k8s.io/apimachinery/pkg/util/cache/cache.go new file mode 100644 index 000000000..9a09fe54d --- /dev/null +++ b/vendor/k8s.io/apimachinery/pkg/util/cache/cache.go @@ -0,0 +1,83 @@ +/* +Copyright 2014 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 cache + +import ( + "sync" +) + +const ( + shardsCount int = 32 +) + +type Cache []*cacheShard + +func NewCache(maxSize int) Cache { + if maxSize < shardsCount { + maxSize = shardsCount + } + cache := make(Cache, shardsCount) + for i := 0; i < shardsCount; i++ { + cache[i] = &cacheShard{ + items: make(map[uint64]interface{}), + maxSize: maxSize / shardsCount, + } + } + return cache +} + +func (c Cache) getShard(index uint64) *cacheShard { + return c[index%uint64(shardsCount)] +} + +// Returns true if object already existed, false otherwise. +func (c *Cache) Add(index uint64, obj interface{}) bool { + return c.getShard(index).add(index, obj) +} + +func (c *Cache) Get(index uint64) (obj interface{}, found bool) { + return c.getShard(index).get(index) +} + +type cacheShard struct { + items map[uint64]interface{} + sync.RWMutex + maxSize int +} + +// Returns true if object already existed, false otherwise. +func (s *cacheShard) add(index uint64, obj interface{}) bool { + s.Lock() + defer s.Unlock() + _, isOverwrite := s.items[index] + if !isOverwrite && len(s.items) >= s.maxSize { + var randomKey uint64 + for randomKey = range s.items { + break + } + delete(s.items, randomKey) + } + s.items[index] = obj + return isOverwrite +} + +func (s *cacheShard) get(index uint64) (obj interface{}, found bool) { + s.RLock() + defer s.RUnlock() + obj, found = s.items[index] + return +} |