72 lines
1.6 KiB
Go
72 lines
1.6 KiB
Go
package flow
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import (
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"fmt"
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"sync/atomic"
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"time"
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)
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// Snapshot is a rate/total snapshot.
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type Snapshot struct {
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Rate float64
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Total uint64
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LastUpdate time.Time
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}
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// NewMeter returns a new Meter with the correct idle time.
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//
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// While zero-value Meters can be used, their "last update" time will start at
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// the program start instead of when the meter was created.
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func NewMeter() *Meter {
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return &Meter{
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snapshot: Snapshot{
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LastUpdate: time.Now(),
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},
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}
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}
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func (s Snapshot) String() string {
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return fmt.Sprintf("%d (%f/s)", s.Total, s.Rate)
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}
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// Meter is a meter for monitoring a flow.
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type Meter struct {
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accumulator uint64
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// managed by the sweeper loop.
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registered bool
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// Take lock.
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snapshot Snapshot
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}
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// Mark updates the total.
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func (m *Meter) Mark(count uint64) {
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if count > 0 && atomic.AddUint64(&m.accumulator, count) == count {
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// The accumulator is 0 so we probably need to register. We may
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// already _be_ registered however, if we are, the registration
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// loop will notice that `m.registered` is set and ignore us.
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globalSweeper.Register(m)
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}
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}
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// Snapshot gets a snapshot of the total and rate.
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func (m *Meter) Snapshot() Snapshot {
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globalSweeper.snapshotMu.RLock()
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defer globalSweeper.snapshotMu.RUnlock()
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return m.snapshot
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}
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// Reset sets accumulator, total and rate to zero.
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func (m *Meter) Reset() {
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globalSweeper.snapshotMu.Lock()
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atomic.StoreUint64(&m.accumulator, 0)
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m.snapshot.Rate = 0
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m.snapshot.Total = 0
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globalSweeper.snapshotMu.Unlock()
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}
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func (m *Meter) String() string {
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return m.Snapshot().String()
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}
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