51 lines
		
	
	
		
			932 B
		
	
	
	
		
			Go
		
	
	
	
	
	
			
		
		
	
	
			51 lines
		
	
	
		
			932 B
		
	
	
	
		
			Go
		
	
	
	
	
	
package trie
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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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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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func NewCache(backend Backend) *Cache {
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	return &Cache{make(map[string][]byte), backend}
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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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	return data
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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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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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	// 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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func (self *Cache) Copy() *Cache {
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	cache := NewCache(self.backend)
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	for k, v := range self.store {
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		cache.store[k] = v
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	}
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	return cache
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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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