46 lines
686 B
Go
46 lines
686 B
Go
package acme
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import (
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"sync"
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)
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// Simple thread-safe stack impl
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type nonceStack struct {
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lock sync.Mutex
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stack []string
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}
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// Pushes a nonce to the stack.
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// Doesn't push empty nonces, or if there's more than 100 nonces on the stack
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func (ns *nonceStack) push(v string) {
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if v == "" {
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return
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}
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ns.lock.Lock()
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defer ns.lock.Unlock()
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if len(ns.stack) > 100 {
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return
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}
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ns.stack = append(ns.stack, v)
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}
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// Pops a nonce from the stack.
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// Returns empty string if there are no nonces
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func (ns *nonceStack) pop() string {
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ns.lock.Lock()
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defer ns.lock.Unlock()
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n := len(ns.stack)
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if n == 0 {
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return ""
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}
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v := ns.stack[n-1]
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ns.stack = ns.stack[:n-1]
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return v
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}
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