package buffer type View []byte func NewView(size int) View { return make(View, size) } func NewViewFromBytes(b []byte) View { return append(View(nil), b...) // 没见过 🇰🇷了 } // TrimFront 从缓冲区的可见部分中删除第一个“计数”字节 func (v *View) TrimFront(count int) { *v = (*v)[count:] } // CapLength 不可逆地将缓冲区可见部分的长度减少到指定的值 func (v *View) CapLength(length int) { *v = (*v)[:length:length] } func (v View) ToVectorisedView() VectorisedView { return NewVectorisedView(len(v), []View{v}) } // VectorisedView 是使用非连续内存的 View 的矢量化版本 type VectorisedView struct { views []View size int } func NewVectorisedView(size int, views []View) VectorisedView { return VectorisedView{views: views, size: size} } // 截掉count的长度 func (vv *VectorisedView) TrimFront(count int) { for count > 0 && len(vv.views) > 0 { if count < len(vv.views[0]) { vv.size -= count vv.views[0].TrimFront(count) return } count -= len(vv.views[0]) vv.RemoveFirst() } } // 限制buffer总长度为length func (vv *VectorisedView) CapLength(length int) { if length < 0 { length = 0 } if vv.size < length { return // 不可缩减 } vv.size = length for i := range vv.views { v := &vv.views[i] if len(*v) >= length { if length == 0 { vv.views = vv.views[:i] } else { v.CapLength(length) vv.views = vv.views[:i+1] } return } length -= len(*v) } } func (vv VectorisedView) Clone(buffer []View) VectorisedView { return VectorisedView{views: append(buffer[:0], vv.views...), size: vv.size} } func (vv VectorisedView) First() View { if len(vv.views) == 0 { return nil } return vv.views[0] } func (vv *VectorisedView) RemoveFirst() { if len(vv.views) == 0 { return } vv.size -= len(vv.views[0]) vv.views = vv.views[1:] } func (vv VectorisedView) Size() int { return vv.size } func (vv VectorisedView) ToView() View { u := make([]byte, 0, vv.size) for _, v := range vv.views { u = append(u, v...) } return u } func (vv VectorisedView) Views() []View { return vv.views }