57 lines
1.2 KiB
Go
57 lines
1.2 KiB
Go
package headbuffer
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import (
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"container/list"
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"github.com/filecoin-project/lotus/api"
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)
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type HeadChangeStackBuffer struct {
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buffer *list.List
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size int
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}
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// NewHeadChangeStackBuffer buffer HeadChange events to avoid having to
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// deal with revert changes. Initialized size should be the average reorg
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// size + 1
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func NewHeadChangeStackBuffer(size int) *HeadChangeStackBuffer {
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buffer := list.New()
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buffer.Init()
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return &HeadChangeStackBuffer{
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buffer: buffer,
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size: size,
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}
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}
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// Push adds a HeadChange to stack buffer. If the length of
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// the stack buffer grows larger than the initizlized size, the
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// oldest HeadChange is returned.
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func (h *HeadChangeStackBuffer) Push(hc *api.HeadChange) (rethc *api.HeadChange) {
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if h.buffer.Len() >= h.size {
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var ok bool
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el := h.buffer.Front()
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rethc, ok = el.Value.(*api.HeadChange)
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if !ok {
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// This shouldn't be possible, this method is typed and is the only place data
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// pushed to the buffer.
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panic("A cosmic ray made me do it")
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}
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h.buffer.Remove(el)
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}
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h.buffer.PushBack(hc)
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return
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}
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// Pop removes the last added HeadChange
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func (h *HeadChangeStackBuffer) Pop() {
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el := h.buffer.Back()
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if el != nil {
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h.buffer.Remove(el)
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}
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}
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