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33 lines
620 B
Go
33 lines
620 B
Go
package buffer
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// prependable 可预先考虑分配的
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type Prependable struct {
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buf View
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usedIdx int
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}
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func NewPrependable(size int) Prependable {
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return Prependable{buf: NewView(size), usedIdx: size}
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}
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func NewPrependableFromView(v View) Prependable {
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return Prependable{buf: v, usedIdx: 0}
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}
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func (p Prependable) View() View {
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return p.buf[p.usedIdx:]
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}
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func (p Prependable) UsedLength() int {
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return len(p.buf) - p.usedIdx
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}
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func (p *Prependable) Prepend(size int) []byte {
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if size > p.usedIdx {
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return nil
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}
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p.usedIdx -= size
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return p.View()[:size:size] // p.buf[p.usedIdx:p.usedIdx+size:size]
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}
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