45 lines
642 B
Go
45 lines
642 B
Go
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package main
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type History struct {
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entries []string
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head int
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size int
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}
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func NewHistory(size int) *History {
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return &History{
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entries: make([]string, size),
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}
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}
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func (h *History) Add(entry string) {
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max := cap(h.entries)
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h.head = (h.head + 1) % max
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h.entries[h.head] = entry
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if h.size < max {
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h.size++
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}
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}
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func (h *History) Len() int {
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return h.size
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}
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func (h *History) Get(num int) []string {
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max := cap(h.entries)
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if num > h.size {
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num = h.size
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}
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r := make([]string, num)
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for i := 0; i < num; i++ {
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idx := (h.head - i) % max
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if idx < 0 {
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idx += max
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}
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r[num-i-1] = h.entries[idx]
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}
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return r
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}
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