43 lines
		
	
	
		
			789 B
		
	
	
	
		
			Go
		
	
	
	
	
	
			
		
		
	
	
			43 lines
		
	
	
		
			789 B
		
	
	
	
		
			Go
		
	
	
	
	
	
| package trie
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| 
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| type Backend interface {
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| 	Get([]byte) ([]byte, error)
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| 	Put([]byte, []byte)
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| }
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| 
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| type Cache struct {
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| 	store   map[string][]byte
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| 	backend Backend
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| }
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| 
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| func NewCache(backend Backend) *Cache {
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| 	return &Cache{make(map[string][]byte), backend}
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| }
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| 
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| func (self *Cache) Get(key []byte) []byte {
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| 	data := self.store[string(key)]
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| 	if data == nil {
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| 		data, _ = self.backend.Get(key)
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| 	}
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| 
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| 	return data
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| }
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| 
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| func (self *Cache) Put(key []byte, data []byte) {
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| 	self.store[string(key)] = data
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| }
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| 
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| func (self *Cache) Flush() {
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| 	for k, v := range self.store {
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| 		self.backend.Put([]byte(k), v)
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| 	}
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| 
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| 	// This will eventually grow too large. We'd could
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| 	// do a make limit on storage and push out not-so-popular nodes.
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| 	//self.Reset()
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| }
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| 
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| func (self *Cache) Reset() {
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| 	self.store = make(map[string][]byte)
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| }
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