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prevent subscriber and subscribed lists from endlessly filling up

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in practice this would probably only be a problem for applications
with lots of views that can be subscribed to that also have very long
uptimes.
This commit is contained in:
Gered 2016-05-19 10:20:07 -04:00
parent 5ec96d6db2
commit 4559d39bb7
1 changed files with 28 additions and 4 deletions
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30
src/views/core.clj
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@ -73,15 +73,39 @@
(defn- remove-from-subscribers (defn- remove-from-subscribers
[view-system view-sig subscriber-key] [view-system view-sig subscriber-key]
(update-in view-system [:subscribers view-sig] disj subscriber-key)) (-> view-system
(update-in [:subscribers view-sig] disj subscriber-key)
; remove view-sig entry if no subscribers. helps prevent the subscribers
; map from e.g. endlessly filling up with all sorts of different
; view-sigs with crazy amounts of only-slightly-varying parameters
(update-in [:subscribers]
(fn [subscribers]
(if (empty? (get subscribers view-sig))
(dissoc subscribers view-sig)
subscribers)))))
(defn- remove-from-subscribed
[view-system view-sig subscriber-key]
(-> view-system
(update-in [:subscribed subscriber-key] disj view-sig)
; remove subscriber-key entry if no current subscriptions. this helps prevent
; the subscribed map from (for example) endlessly filling up with massive
; amounts of entries with no subscriptions. this could easily happen over time
; naturally for applications with long uptimes.
(update-in [:subscribed]
(fn [subscribed]
(if (empty? (get subscribed subscriber-key))
(dissoc subscribed subscriber-key)
subscribed)))))
(defn unsubscribe! (defn unsubscribe!
[namespace view-id parameters subscriber-key] [namespace view-id parameters subscriber-key]
(swap! view-system (swap! view-system
(fn [vs] (fn [vs]
(let [view-sig [namespace view-id parameters]]
(-> vs (-> vs
(update-in [:subscribed subscriber-key] disj [namespace view-id parameters]) (remove-from-subscribed view-sig subscriber-key)
(remove-from-subscribers [namespace view-id parameters] subscriber-key))))) (remove-from-subscribers view-sig subscriber-key))))))
(defn unsubscribe-all! (defn unsubscribe-all!
"Remove all subscriptions by a given subscriber." "Remove all subscriptions by a given subscriber."