65 lines
1.2 KiB
Go
65 lines
1.2 KiB
Go
package pilorama
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import (
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"container/heap"
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)
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type heapInfo struct {
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id Node
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filename string
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}
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type filenameHeap []heapInfo
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func (h filenameHeap) Len() int { return len(h) }
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func (h filenameHeap) Less(i, j int) bool { return h[i].filename < h[j].filename }
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func (h filenameHeap) Swap(i, j int) { h[i], h[j] = h[j], h[i] }
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func (h *filenameHeap) Push(x any) {
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*h = append(*h, x.(heapInfo))
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}
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func (h *filenameHeap) Pop() any {
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old := *h
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n := len(old)
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x := old[n-1]
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*h = old[0 : n-1]
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return x
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}
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// fixedHeap maintains a fixed number of smallest elements started at some point.
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type fixedHeap struct {
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start *string
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max string
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count int
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h *filenameHeap
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}
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func newHeap(start *string, count int) *fixedHeap {
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h := new(filenameHeap)
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heap.Init(h)
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return &fixedHeap{
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start: start,
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max: "",
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count: count,
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h: h,
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}
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}
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func (h *fixedHeap) push(id Node, filename string) bool {
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if h.start != nil && filename <= *h.start {
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return false
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}
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heap.Push(h.h, heapInfo{id: id, filename: filename})
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if h.h.Len() > h.count {
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heap.Remove(h.h, h.h.Len()-1)
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}
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return true
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}
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func (h *fixedHeap) pop() (heapInfo, bool) {
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if h.h.Len() != 0 {
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return heap.Pop(h.h).(heapInfo), true
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}
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return heapInfo{}, false
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}
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