summaryrefslogtreecommitdiff
path: root/vendor/k8s.io/apimachinery/pkg/util/cache
diff options
context:
space:
mode:
authorMatthew Heon <matthew.heon@gmail.com>2017-11-01 11:24:59 -0400
committerMatthew Heon <matthew.heon@gmail.com>2017-11-01 11:24:59 -0400
commita031b83a09a8628435317a03f199cdc18b78262f (patch)
treebc017a96769ce6de33745b8b0b1304ccf38e9df0 /vendor/k8s.io/apimachinery/pkg/util/cache
parent2b74391cd5281f6fdf391ff8ad50fd1490f6bf89 (diff)
downloadpodman-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.go83
-rw-r--r--vendor/k8s.io/apimachinery/pkg/util/cache/lruexpirecache.go102
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()
+}