82 lines
1.3 KiB
Go
82 lines
1.3 KiB
Go
package store
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import (
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"container/heap"
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)
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// An TTLKeyHeap is a min-heap of TTLKeys order by expiration time
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type ttlKeyHeap struct {
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array []*node
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keyMap map[*node]int
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}
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func newTtlKeyHeap() *ttlKeyHeap {
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h := &ttlKeyHeap{keyMap: make(map[*node]int)}
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heap.Init(h)
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return h
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}
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func (h ttlKeyHeap) Len() int {
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return len(h.array)
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}
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func (h ttlKeyHeap) Less(i, j int) bool {
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return h.array[i].ExpireTime.Before(h.array[j].ExpireTime)
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}
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func (h ttlKeyHeap) Swap(i, j int) {
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// swap node
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h.array[i], h.array[j] = h.array[j], h.array[i]
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// update map
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h.keyMap[h.array[i]] = i
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h.keyMap[h.array[j]] = j
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}
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func (h *ttlKeyHeap) Push(x interface{}) {
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n, _ := x.(*node)
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h.keyMap[n] = len(h.array)
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h.array = append(h.array, n)
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}
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func (h *ttlKeyHeap) Pop() interface{} {
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old := h.array
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n := len(old)
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x := old[n-1]
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h.array = old[0 : n-1]
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delete(h.keyMap, x)
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return x
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}
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func (h *ttlKeyHeap) top() *node {
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if h.Len() != 0 {
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return h.array[0]
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}
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return nil
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}
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func (h *ttlKeyHeap) pop() *node {
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x := heap.Pop(h)
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n, _ := x.(*node)
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return n
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}
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func (h *ttlKeyHeap) push(x interface{}) {
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heap.Push(h, x)
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}
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func (h *ttlKeyHeap) update(n *node) {
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index, ok := h.keyMap[n]
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if ok {
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heap.Remove(h, index)
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heap.Push(h, n)
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}
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}
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func (h *ttlKeyHeap) remove(n *node) {
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index, ok := h.keyMap[n]
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if ok {
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heap.Remove(h, index)
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}
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}
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