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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 | |
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')
-rw-r--r-- | vendor/k8s.io/apimachinery/pkg/util/cache/cache.go | 83 | ||||
-rw-r--r-- | vendor/k8s.io/apimachinery/pkg/util/cache/lruexpirecache.go | 102 |
2 files changed, 185 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 +} diff --git a/vendor/k8s.io/apimachinery/pkg/util/cache/lruexpirecache.go b/vendor/k8s.io/apimachinery/pkg/util/cache/lruexpirecache.go new file mode 100644 index 000000000..f6b307aa6 --- /dev/null +++ b/vendor/k8s.io/apimachinery/pkg/util/cache/lruexpirecache.go @@ -0,0 +1,102 @@ +/* +Copyright 2016 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" + "time" + + "github.com/hashicorp/golang-lru" +) + +// Clock defines an interface for obtaining the current time +type Clock interface { + Now() time.Time +} + +// realClock implements the Clock interface by calling time.Now() +type realClock struct{} + +func (realClock) Now() time.Time { return time.Now() } + +// LRUExpireCache is a cache that ensures the mostly recently accessed keys are returned with +// a ttl beyond which keys are forcibly expired. +type LRUExpireCache struct { + // clock is used to obtain the current time + clock Clock + + cache *lru.Cache + lock sync.Mutex +} + +// NewLRUExpireCache creates an expiring cache with the given size +func NewLRUExpireCache(maxSize int) *LRUExpireCache { + return NewLRUExpireCacheWithClock(maxSize, realClock{}) +} + +// NewLRUExpireCacheWithClock creates an expiring cache with the given size, using the specified clock to obtain the current time. +func NewLRUExpireCacheWithClock(maxSize int, clock Clock) *LRUExpireCache { + cache, err := lru.New(maxSize) + if err != nil { + // if called with an invalid size + panic(err) + } + return &LRUExpireCache{clock: clock, cache: cache} +} + +type cacheEntry struct { + value interface{} + expireTime time.Time +} + +// Add adds the value to the cache at key with the specified maximum duration. +func (c *LRUExpireCache) Add(key interface{}, value interface{}, ttl time.Duration) { + c.lock.Lock() + defer c.lock.Unlock() + c.cache.Add(key, &cacheEntry{value, c.clock.Now().Add(ttl)}) +} + +// Get returns the value at the specified key from the cache if it exists and is not +// expired, or returns false. +func (c *LRUExpireCache) Get(key interface{}) (interface{}, bool) { + c.lock.Lock() + defer c.lock.Unlock() + e, ok := c.cache.Get(key) + if !ok { + return nil, false + } + if c.clock.Now().After(e.(*cacheEntry).expireTime) { + c.cache.Remove(key) + return nil, false + } + return e.(*cacheEntry).value, true +} + +// Remove removes the specified key from the cache if it exists +func (c *LRUExpireCache) Remove(key interface{}) { + c.lock.Lock() + defer c.lock.Unlock() + c.cache.Remove(key) +} + +// Keys returns all the keys in the cache, even if they are expired. Subsequent calls to +// get may return not found. It returns all keys from oldest to newest. +func (c *LRUExpireCache) Keys() []interface{} { + c.lock.Lock() + defer c.lock.Unlock() + return c.cache.Keys() +} |