-
Notifications
You must be signed in to change notification settings - Fork 24
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
Fix rare issue concerning captures going stale on the AWS VPC CNI, as…
… well as auto-resolve addresses with no currently seen DNS traffic in the cluster (#242) Co-authored-by: omri.s <omri.s@otterize.com>
- Loading branch information
1 parent
35157de
commit 88d4933
Showing
13 changed files
with
305 additions
and
146 deletions.
There are no files selected for viewing
Some generated files are not rendered by default. Learn more about how customized files appear on GitHub.
Oops, something went wrong.
Some generated files are not rendered by default. Learn more about how customized files appear on GitHub.
Oops, something went wrong.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,174 @@ | ||
| package dnscache | ||
|
|
||
| import ( | ||
| "container/list" | ||
| "sync" | ||
| "time" | ||
| ) | ||
|
|
||
| // CacheEntry represents an entry in the cache, linking the key with its list element for LRU | ||
| type CacheEntry[K comparable, V comparable] struct { | ||
| Key K | ||
| Value CacheValue[V] | ||
| } | ||
|
|
||
| // TTLCache is a generic TTL cache that stores unique items with individual TTLs and LRU eviction | ||
| type TTLCache[K comparable, V comparable] struct { | ||
| items map[K]map[V]*list.Element // Key to map of values, each value points to an LRU element | ||
| lru *list.List // List for LRU eviction, stores CacheEntry[K, V] | ||
| maxSize int // Maximum size of the cache | ||
| mu sync.Mutex | ||
| cleanupCh chan struct{} | ||
| } | ||
|
|
||
| // NewTTLCache creates a new TTL cache with the specified maxSize | ||
| func NewTTLCache[K comparable, V comparable](maxSize int) *TTLCache[K, V] { | ||
| cache := &TTLCache[K, V]{ | ||
| items: make(map[K]map[V]*list.Element), | ||
| lru: list.New(), | ||
| maxSize: maxSize, | ||
| cleanupCh: make(chan struct{}), | ||
| } | ||
|
|
||
| // Start the cleanup process | ||
| go cache.startCleanup() | ||
|
|
||
| return cache | ||
| } | ||
|
|
||
| // Insert adds a unique value to the cache under the specified key with its own TTL | ||
| // and manages the LRU eviction when the cache exceeds the max size. | ||
| func (c *TTLCache[K, V]) Insert(key K, value V, ttl time.Duration) { | ||
| c.mu.Lock() | ||
| defer c.mu.Unlock() | ||
|
|
||
| // If the key doesn't exist, create an entry for it | ||
| if _, exists := c.items[key]; !exists { | ||
| c.items[key] = make(map[V]*list.Element) | ||
| } | ||
|
|
||
| // Check if the value already exists under this key and remove it from LRU if so | ||
| if elem, exists := c.items[key][value]; exists { | ||
| c.lru.Remove(elem) | ||
| } | ||
|
|
||
| // Insert or update the value with its expiration time and add it to the LRU list | ||
| cacheEntry := CacheEntry[K, V]{Key: key, Value: CacheValue[V]{Value: value, Expiration: time.Now().Add(ttl)}} | ||
| lruElem := c.lru.PushFront(cacheEntry) | ||
| c.items[key][value] = lruElem | ||
|
|
||
| // Manage the cache size, evict the least recently used item if needed | ||
| if c.lru.Len() > c.maxSize { | ||
| c.evict() | ||
| } | ||
|
|
||
| } | ||
|
|
||
| // evict removes the least recently used item from the cache | ||
| func (c *TTLCache[K, V]) evict() { | ||
| // Remove the least recently used item (which is at the back of the LRU list) | ||
| lruElem := c.lru.Back() | ||
| if lruElem == nil { | ||
| return | ||
| } | ||
|
|
||
| cacheEntry := lruElem.Value.(CacheEntry[K, V]) | ||
| key, value := cacheEntry.Key, cacheEntry.Value | ||
|
|
||
| // Remove the value from the cache | ||
| if _, exists := c.items[key]; exists { | ||
| delete(c.items[key], value.Value) | ||
|
|
||
| // If no more values exist under this key, remove the key itself | ||
| if len(c.items[key]) == 0 { | ||
| delete(c.items, key) | ||
| } | ||
| } | ||
|
|
||
| // Remove from the LRU list | ||
| c.lru.Remove(lruElem) | ||
| } | ||
|
|
||
| // Get retrieves the values for a specific key and removes any expired values | ||
| // Returns a slice of valid values for the given key | ||
| func (c *TTLCache[K, V]) Get(key K) []V { | ||
| c.mu.Lock() | ||
| defer c.mu.Unlock() | ||
|
|
||
| // Check if the key exists | ||
| if _, exists := c.items[key]; !exists { | ||
| return make([]V, 0) | ||
| } | ||
|
|
||
| // Filter out expired values and prepare the result | ||
| var result []V | ||
| for value, lruElem := range c.items[key] { | ||
| cacheEntry := lruElem.Value.(CacheEntry[K, V]) | ||
|
|
||
| // If the value has expired, remove it | ||
| if time.Now().After(c.lruValueExpiration(lruElem)) { | ||
| c.lru.Remove(lruElem) | ||
| delete(c.items[key], value) | ||
| continue | ||
| } | ||
|
|
||
| // Add valid values to the result | ||
| result = append(result, cacheEntry.Value.Value) | ||
|
|
||
| // Move the accessed item to the front of the LRU list (mark as recently used) | ||
| c.lru.MoveToFront(lruElem) | ||
| } | ||
|
|
||
| // If all values are expired, remove the key entirely | ||
| if len(c.items[key]) == 0 { | ||
| delete(c.items, key) | ||
| } | ||
|
|
||
| return result | ||
| } | ||
|
|
||
| // cleanupExpired removes expired values from the cache | ||
| func (c *TTLCache[K, V]) cleanupExpired() { | ||
| for key, values := range c.items { | ||
| for value, lruElem := range values { | ||
| // If a value has expired, remove it | ||
| if time.Now().After(c.lruValueExpiration(lruElem)) { | ||
| c.lru.Remove(lruElem) | ||
| delete(values, value) | ||
| } | ||
| } | ||
|
|
||
| // If all values are expired, remove the key entirely | ||
| if len(values) == 0 { | ||
| delete(c.items, key) | ||
| } | ||
| } | ||
| } | ||
|
|
||
| // lruValueExpiration gets the expiration time for a given LRU element | ||
| func (c *TTLCache[K, V]) lruValueExpiration(elem *list.Element) time.Time { | ||
| cacheEntry := elem.Value.(CacheEntry[K, V]) | ||
| return cacheEntry.Value.Expiration | ||
| } | ||
|
|
||
| // startCleanup periodically cleans up expired items | ||
| func (c *TTLCache[K, V]) startCleanup() { | ||
| ticker := time.NewTicker(1 * time.Minute) // Cleanup interval | ||
| defer ticker.Stop() | ||
|
|
||
| for { | ||
| select { | ||
| case <-ticker.C: | ||
| c.mu.Lock() | ||
| c.cleanupExpired() | ||
| c.mu.Unlock() | ||
| case <-c.cleanupCh: | ||
| return | ||
| } | ||
| } | ||
| } | ||
|
|
||
| // Stop stops the cache cleanup process | ||
| func (c *TTLCache[K, V]) Stop() { | ||
| close(c.cleanupCh) | ||
| } |
Oops, something went wrong.