61 lines
1.4 KiB
Go
61 lines
1.4 KiB
Go
package vsphere
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import (
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"sync"
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"time"
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"github.com/influxdata/telegraf"
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)
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// tsCache is a cache of timestamps used to determine the validity of datapoints
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type tsCache struct {
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ttl time.Duration
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table map[string]time.Time
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mux sync.RWMutex
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log telegraf.Logger
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}
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// newTSCache creates a new tsCache with a specified time-to-live after which timestamps are discarded.
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func newTSCache(ttl time.Duration, log telegraf.Logger) *tsCache {
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return &tsCache{
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ttl: ttl,
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table: make(map[string]time.Time),
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log: log,
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}
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}
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// purge removes timestamps that are older than the time-to-live
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func (t *tsCache) purge() {
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t.mux.Lock()
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defer t.mux.Unlock()
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n := 0
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for k, v := range t.table {
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if time.Since(v) > t.ttl {
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delete(t.table, k)
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n++
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}
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}
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t.log.Debugf("purged timestamp cache. %d deleted with %d remaining", n, len(t.table))
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}
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// get returns a timestamp (if present)
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func (t *tsCache) get(key, metricName string) (time.Time, bool) {
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t.mux.RLock()
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defer t.mux.RUnlock()
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ts, ok := t.table[makeKey(key, metricName)]
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return ts, ok
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}
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// put updates the latest timestamp for the supplied key.
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func (t *tsCache) put(key, metricName string, timestamp time.Time) {
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t.mux.Lock()
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defer t.mux.Unlock()
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k := makeKey(key, metricName)
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if timestamp.After(t.table[k]) {
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t.table[k] = timestamp
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}
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}
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func makeKey(resource, metric string) string {
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return resource + "|" + metric
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}
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