76 lines
1.6 KiB
Go
76 lines
1.6 KiB
Go
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package physical
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import "github.com/hashicorp/golang-lru"
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const (
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// DefaultCacheSize is used if no cache size is specified
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// for NewPhysicalCache
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DefaultCacheSize = 32 * 1024
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)
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// PhysicalCache is used to wrap an underlying physical backend
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// and provide an LRU cache layer on top. Most of the reads done by
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// Vault are for policy objects so there is a large read reduction
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// by using a simple write-through cache.
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type PhysicalCache struct {
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backend Backend
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lru *lru.Cache
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}
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// NewPhysicalCache returns a physical cache of the given size.
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// If no size is provided, the default size is used.
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func NewPhysicalCache(b Backend, size int) *PhysicalCache {
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if size <= 0 {
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size = DefaultCacheSize
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}
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cache, _ := lru.New(size)
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c := &PhysicalCache{
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backend: b,
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lru: cache,
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}
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return c
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}
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// Purge is used to clear the cache
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func (c *PhysicalCache) Purge() {
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c.lru.Purge()
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}
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func (c *PhysicalCache) Put(entry *Entry) error {
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err := c.backend.Put(entry)
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c.lru.Add(entry.Key, entry)
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return err
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}
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func (c *PhysicalCache) Get(key string) (*Entry, error) {
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// Check the LRU first
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if raw, ok := c.lru.Get(key); ok {
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if raw == nil {
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return nil, nil
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} else {
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return raw.(*Entry), nil
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}
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}
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// Read from the underlying backend
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ent, err := c.backend.Get(key)
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if err != nil {
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return nil, err
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}
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// Cache the result
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c.lru.Add(key, ent)
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return ent, err
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}
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func (c *PhysicalCache) Delete(key string) error {
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err := c.backend.Delete(key)
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c.lru.Remove(key)
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return err
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}
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func (c *PhysicalCache) List(prefix string) ([]string, error) {
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// Always pass-through as this would be difficult to cache.
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return c.backend.List(prefix)
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}
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