71 lines
1.4 KiB
Go
71 lines
1.4 KiB
Go
package dht
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import (
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"sync"
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"time"
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"github.com/lbryio/lbry.go/dht/bits"
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"github.com/lbryio/lbry.go/extras/stop"
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)
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// TODO: this should be moved out of dht and into node, and it should be completely hidden inside node. dht should not need to know about tokens
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type tokenCacheEntry struct {
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token string
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receivedAt time.Time
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}
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type tokenCache struct {
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node *Node
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tokens map[string]tokenCacheEntry
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expiration time.Duration
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lock *sync.RWMutex
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}
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func newTokenCache(node *Node, expiration time.Duration) *tokenCache {
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tc := &tokenCache{}
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tc.node = node
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tc.tokens = make(map[string]tokenCacheEntry)
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tc.expiration = expiration
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tc.lock = &sync.RWMutex{}
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return tc
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}
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// TODO: if store fails, get new token. can happen if a node restarts but we have the token cached
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func (tc *tokenCache) Get(c Contact, hash bits.Bitmap, cancelCh stop.Chan) string {
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tc.lock.RLock()
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token, exists := tc.tokens[c.String()]
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tc.lock.RUnlock()
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if exists && time.Since(token.receivedAt) < tc.expiration {
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return token.token
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}
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resCh := tc.node.SendAsync(c, Request{
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Method: findValueMethod,
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Arg: &hash,
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})
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var res *Response
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select {
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case res = <-resCh:
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case <-cancelCh:
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return ""
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}
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if res == nil {
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return ""
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}
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tc.lock.Lock()
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tc.tokens[c.String()] = tokenCacheEntry{
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token: res.Token,
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receivedAt: time.Now(),
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}
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tc.lock.Unlock()
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return res.Token
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}
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