59 lines
1.8 KiB
Go
59 lines
1.8 KiB
Go
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package cfg
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import (
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"sync"
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"time"
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)
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// Source is the interface required for any source of name/value pairs.
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type Source interface {
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// GetProps fetches all the properties from a source and returns
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// them as a map.
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GetProps() (map[string]string, error)
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}
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// SourceMonitored is the interface required for any config source that is
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// monitored for changes.
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type SourceMonitored interface {
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Source
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// GetLastModified returns the time of the latest modification to any
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// property value within the source. If a source does not support
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// modifying properties at runtime then the zero value for `Time`
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// should be returned to ensure reload events are not generated.
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GetLastModified() (time.Time, error)
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// GetMonitorFreq returns the frequency as a `time.Duration` between
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// checks for changes to this config source.
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//
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// Returning zero (or less) will temporarily suspend calls to `GetLastModified`
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// and `GetMonitorFreq` will be called every 10 seconds until resumed, after which
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// `GetMontitorFreq` will be called at a frequency roughly equal to the `time.Duration`
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// returned.
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GetMonitorFreq() time.Duration
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}
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// AbstractSourceMonitor can be embedded in a custom `Source` to provide the
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// basic plumbing for monitor frequency.
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type AbstractSourceMonitor struct {
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mutex sync.RWMutex
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freq time.Duration
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}
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// GetMonitorFreq returns the frequency as a `time.Duration` between
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// checks for changes to this config source.
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func (asm *AbstractSourceMonitor) GetMonitorFreq() (freq time.Duration) {
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asm.mutex.RLock()
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freq = asm.freq
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asm.mutex.RUnlock()
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return
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}
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// SetMonitorFreq sets the frequency between checks for changes to this config source.
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func (asm *AbstractSourceMonitor) SetMonitorFreq(freq time.Duration) {
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asm.mutex.Lock()
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asm.freq = freq
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asm.mutex.Unlock()
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}
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