67 lines
1.7 KiB
Go
67 lines
1.7 KiB
Go
package model
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import (
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"fmt"
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"sync"
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)
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// communicates with calling apis when config is applied or fails
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var coordinator *Coordinator
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func init() {
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subscribers := make(map[string][]OnChangeCallback, 0)
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coordinator = &Coordinator{
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subscribers: subscribers,
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}
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}
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type OnChangeCallback func(agentId string, hash string, err error)
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// responsible for managing subscribers on config change
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type Coordinator struct {
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mutex sync.Mutex
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// hash wise list of subscribers
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subscribers map[string][]OnChangeCallback
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}
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func onConfigSuccess(agentId string, hash string) {
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notifySubscribers(agentId, hash, nil)
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}
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func onConfigFailure(agentId string, hash string, errorMessage string) {
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notifySubscribers(agentId, hash, fmt.Errorf(errorMessage))
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}
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// OnSuccess listens to config changes and notifies subscribers
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func notifySubscribers(agentId string, hash string, err error) {
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// this method currently does not handle multi-agent scenario.
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// as soon as a message is delivered, we release all the subscribers
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// for a given hash
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subs, ok := coordinator.subscribers[hash]
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if !ok {
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return
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}
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for _, s := range subs {
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s(agentId, hash, err)
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}
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// delete all subscribers for this hash, assume future
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// notifies will be disabled. the first response is processed
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delete(coordinator.subscribers, hash)
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}
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// callers subscribe to this function to listen on config change requests
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func ListenToConfigUpdate(agentId string, hash string, ss OnChangeCallback) {
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coordinator.mutex.Lock()
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defer coordinator.mutex.Unlock()
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if subs, ok := coordinator.subscribers[hash]; ok {
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subs = append(subs, ss)
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coordinator.subscribers[hash] = subs
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} else {
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coordinator.subscribers[hash] = []OnChangeCallback{ss}
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}
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}
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