80 lines
1.3 KiB
Go
80 lines
1.3 KiB
Go
package wal
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import "sync"
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type segmentState struct {
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Closed bool
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Archived bool
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FirstSeqNum int64
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LastSeqNum int64
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}
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func newSegmentState(closed bool, header segmentHeader) segmentState {
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return segmentState{
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Closed: closed,
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Archived: header.ArchivedAt != 0,
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FirstSeqNum: header.FirstSeqNum,
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LastSeqNum: header.LastSeqNum,
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}
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}
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type notifyMux struct {
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lock sync.Mutex
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nextID int64
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recvrs map[int64]chan segmentState
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}
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type stateRecvr struct {
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// Each recvr will always get the most recent sequence number on C.
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// When the segment is closed, a -1 is sent.
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C chan segmentState
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Close func()
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}
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func newNotifyMux() *notifyMux {
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return ¬ifyMux{
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recvrs: map[int64]chan segmentState{},
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}
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}
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func (m *notifyMux) NewRecvr(header segmentHeader) stateRecvr {
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state := newSegmentState(false, header)
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m.lock.Lock()
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defer m.lock.Unlock()
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m.nextID++
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recvrID := m.nextID
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recvr := stateRecvr{
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C: make(chan segmentState, 1),
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Close: func() {
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m.lock.Lock()
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defer m.lock.Unlock()
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delete(m.recvrs, recvrID)
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},
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}
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recvr.C <- state
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m.recvrs[recvrID] = recvr.C
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return recvr
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}
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func (m *notifyMux) Notify(closed bool, header segmentHeader) {
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state := newSegmentState(closed, header)
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m.lock.Lock()
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defer m.lock.Unlock()
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for _, c := range m.recvrs {
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select {
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case c <- state:
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case <-c:
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c <- state
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}
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}
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}
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