63d18d875b
Docker-DCO-1.1-Signed-off-by: Guillaume J. Charmes <guillaume.charmes@docker.com> (github: creack)
62 lines
1.1 KiB
Go
62 lines
1.1 KiB
Go
package ipallocator
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import (
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"sync"
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)
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// iPSet is a thread-safe sorted set and a stack.
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type iPSet struct {
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sync.RWMutex
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set []string
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}
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// Push takes a string and adds it to the set. If the elem aready exists, it has no effect.
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func (s *iPSet) Push(elem string) {
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s.RLock()
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for i, e := range s.set {
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if e == elem {
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s.RUnlock()
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return
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}
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}
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s.RUnlock()
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s.Lock()
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s.set = append(s.set, elem)
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// Make sure the list is always sorted
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sort.Strings(s.set)
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s.Unlock()
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}
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// Pop returns the first elemen from the list and removes it.
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// If the list is empty, it returns an empty string
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func (s *iPSet) Pop() string {
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s.RLock()
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for i, e := range s.set {
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ret := e
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s.RUnlock()
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s.Lock()
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s.set = append(s.set[:i], s.set[i+1:]...)
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s.Unlock()
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return e
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}
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s.RUnlock()
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return ""
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}
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// Remove removes an element from the list.
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// If the element is not found, it has no effect.
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func (s *iPSet) Remove(elem string) {
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for i, e := range s.set {
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if e == elem {
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s.set = append(s.set[:i], s.set[i+1:]...)
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return
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}
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}
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}
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// Len returns the length of the list.
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func (s *iPSet) Len() int {
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return len(s.set)
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}
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