Remove cache implementation this is really an application concern

Author: andersmurphy

README.md

@@ -77,19 +77,15 @@ The only way for actions to affect the view returned by the `render-fn` running
 - Actions modify the database and return a 204 or a 200 if they `patch-signals`.
 - Render functions re-render when the database changes and send an update down the updates SSE connection.
 
-#### Work sharing (caching)
-
-Work sharing is the term I'm using for sharing renders between connected users. This can be useful when a lot of connected users share the same view. For example a leader board, game board, presence indicator etc. It ensures the work (eg: query and html generation) for that view is only done once regardless of the number of connected users. 
-
-There's a lot of ways you can do this. I've settled on a simple cache that gets invalidate when a `:refresh-event` is fired. This means the cache is invalidated at most every X msec (determined by `:max-refresh-ms`) and only if the db state has changed.
+#### Batching
 
-To add something to the cache wrap the function in the `cache` higher order function.
+Batching pairs really well with CQRS as you have a resolution window, this defines the maximum frequency the view can update, or in other terms the granularity/resolution of the view. Batching can generally be used to improve throughput by batching changes.
 
-#### Batching
+#### Work sharing (caching)
 
-Batching pairs really well with CQRS as you have a resolution window, this defines the maximum frequency the view can update, or in other terms the granularity/resolution of the view. Batching can generally be used to improve throughput by batching changes. 
+Work sharing is the term I'm using for sharing renders between connected users. This can be useful when a lot of connected users share the same view. For example a leader board, game board, presence indicator etc. It ensures the work (eg: query and html generation) for that view is only done once regardless of the number of connected users.
 
-However, there is one downsides with batching to keep in mind and that is you don't get atomic transactions. The transaction move to the batch level, not the transact/insert level. Transaction matter when you are dealing with constraints you want to deal with at the database level, classic example is accounting systems or ledgers where you want to be able to fail an atomic transaction that violates a constraint (like user balance going negative). The problem with batching is that that transaction constraint failure, fails the whole batch not only the transact that was culpable.
+The simplest way to do this is to recalculate and cache values after after a batch has been run.
 
 #### Use `data-on-pointerdown/mous` over  `data-on-click`
 

examples/billion_cells/.gitignore

@@ -1 +1 @@
-database-new.db*
+*.db*

examples/billion_cells/src/app/main.clj renamed to examples/billion_cells/src/billion_cells/main.clj

@@ -1,4 +1,4 @@
-(ns app.main
+(ns billion-cells.main
   (:gen-class)
   (:require [hyperlith.core :as h :refer [defaction defview]]
             [hyperlith.extras.sqlite :as d]
@@ -358,7 +358,7 @@
         " and "
         [:a {:href "https://data-star.dev"} "Datastar"]
         " - "
-        [:a {:href "https://github.com/andersmurphy/hyperlith/blob/master/examples/billion_cells/src/app/main.clj" } "source"]
+        [:a {:href "https://github.com/andersmurphy/hyperlith/blob/master/examples/billion_cells/src/billion_cells/main.clj" } "source"]
         " - "
         [:a {:href "https://checkboxes.andersmurphy.com"} " more like this"]]])))
 
@@ -401,7 +401,7 @@
 
 (defn ctx-start []
   (let [{:keys [writer reader]}
-        (d/init-db! "database-new.db"
+        (d/init-db! (str *ns* ".db")
           {:pool-size 4
            :pragma    {:foreign_keys false}})]
     ;; Run migrations
@@ -427,25 +427,29 @@
   (.close (:db-write ctx))
   (.close (:db-read ctx)))
 
-(defn -main [& _]
-  (h/start-app
-    {:max-refresh-ms 100
+(defonce app_ (atom nil))
+
+(defn start-app [port]
+  (reset! app_
+    (h/start-app
+    {:port           port
+     :max-refresh-ms 100
      :ctx-start      ctx-start
      :ctx-stop       ctx-stop
-     :csrf-secret    (h/env :csrf-secret)}))
+     :csrf-secret    (h/env :csrf-secret)})))
 
 ;; Refresh app when you re-eval file
-(h/refresh-all!)
+(h/refresh-all! )
 
 (comment
-  (do (-main) nil)
+  (do (start-app 8080) nil)
   ;; (clojure.java.browse/browse-url "http://localhost:8080/")
 
 
   ;; stop server
-  (((h/get-app) :stop))
+  ((@app_ :stop))
 
-  (def db (-> (h/get-app) :ctx :db))
+  (def db (-> @app_ :ctx :db))
 
 
 

examples/billion_checkboxes/.gitignore

@@ -0,0 +1 @@
+*.db*

examples/billion_checkboxes_blob/README.md renamed to examples/billion_checkboxes/README.md

@@ -1,4 +1,4 @@
-(ns app.main
+(ns billion-checkboxes.main
   (:gen-class)
   (:require [hyperlith.core :as h :refer [defaction defview]]
             [hyperlith.extras.sqlite :as d]
@@ -351,7 +351,7 @@
         " and "
         [:a {:href "https://data-star.dev"} "Datastar"]
         " - "
-        [:a {:href "https://github.com/andersmurphy/hyperlith/blob/master/examples/billion_checkboxes_blob/src/app/main.clj" } "source"]
+        [:a {:href "https://github.com/andersmurphy/hyperlith/blob/master/examples/billion_checkboxes/src/billion_checkboxes/main.clj" } "source"]
         " - "
         [:a {:href "https://cells.andersmurphy.com"} " more like this"]]])))
 
@@ -389,7 +389,7 @@
 
 (defn ctx-start []
   (let [{:keys [writer reader]}
-        (d/init-db! "database-new.db"
+        (d/init-db! (str *ns* ".db")
           {:pool-size 4
            :pragma    {:foreign_keys false}})]
     ;; Run migrations
@@ -416,30 +416,34 @@
   (.close (:db-write ctx))
   (.close (:db-read ctx)))
 
-(defn -main [& _]
-  (h/start-app
-    {:max-refresh-ms 100
-     :ctx-start      ctx-start
-     :ctx-stop       ctx-stop
-     :csrf-secret    (h/env :csrf-secret)}))
+(defonce app_ (atom nil))
+
+(defn start-app [port]
+  (reset! app_
+    (h/start-app
+      {:port           port
+       :max-refresh-ms 100
+       :ctx-start      ctx-start
+       :ctx-stop       ctx-stop
+       :csrf-secret    (h/env :csrf-secret)})))
 
 ;; Refresh app when you re-eval file
 (h/refresh-all!)
 
 (comment
-  (do (-main) nil)
+  (do (start-app 8080) nil)
   ;; (clojure.java.browse/browse-url "http://localhost:8080/")
-  
+
 
   ;; stop server
-  (((h/get-app) :stop))
+  ((@app_ :stop))
 
-  (def db (-> (h/get-app) :ctx :db))
+  (def db (-> @app_ :ctx :db))
 
   ,)
 
 (comment
-  (def db (-> (h/get-app) :ctx :db))
+  (def db (-> @app_ :ctx :db))
   (d/pragma-check db)
 
   ;; Execution time mean : 148.516131 ms
@@ -475,11 +479,11 @@
     (d/q db
       ["SELECT chunk_id, JSON_GROUP_ARRAY(state) AS chunk_cells FROM cell WHERE chunk_id IN (?, ?, ?, ?, ?, ?, ?, ?, ?)  GROUP BY chunk_id" 1978 3955 5932 1979 3956 5933 1980 3957 5934]))
 
-  (def tab-state (-> (h/get-app) :ctx :tab))
+  (def tab-state (-> @app_ :ctx :tab))
 
   (count @tab-state)
 
-  (def db-write (-> (h/get-app) :ctx :db-write))
+  (def db-write (-> @app_ :ctx :db-write))
 
   (d/q db-write
     {:update :chunk
@@ -504,15 +508,15 @@
   )
 
 (comment
-  (def wraped-router (-> (h/get-app) :wraped-router))
+  (def wrapped-router (-> @app_ :wrapped-router))
 
   (future
     (time
       (run!
         (fn [_]
           (run!
             (fn [_]
-              (wraped-router
+              (wrapped-router
                 {:headers
                  {"accept-encoding" "br"
                   "cookie"          "__Host-sid=5SNfeDa90PhXl0expOLFGdjtrpY; __Host-csrf=3UsG62ic9wLsg9EVQhGupw"

examples/billion_checkboxes_blob/deps.edn renamed to examples/billion_checkboxes/deps.edn

@@ -29,11 +29,9 @@
 (defn get-messages [db]
   (reverse (@db :messages)))
 
-(def messages
-  (h/cache
-    (fn [db]
-      (for [[id content] (get-messages db)]
-        [:p {:id id} content]))))
+(defn messages [db]
+  (for [[id content] (get-messages db)]
+    [:p {:id id} content]))
 
 (defaction handler-send-message [{:keys [_sid db] {:keys [message]} :body}]
   (when-not (str/blank? message)
@@ -76,12 +74,12 @@
 (h/refresh-all!)
 
 (comment
-  (-main)
+  (def app (-main))
   ;; (clojure.java.browse/browse-url "http://localhost:8080/")
 
   ;; stop server
-  (((h/get-app) :stop))
+  ((app :stop))
 
   ;; query outside of handler
-  (get-messages (-> (h/get-app) :ctx :db))
+  (get-messages (-> app :ctx :db))
   ,)

examples/billion_checkboxes_blob/resources/.env.edn renamed to examples/billion_checkboxes/resources/.env.edn

@@ -64,11 +64,11 @@
 (h/refresh-all!)
 
 (comment
-  (-main)
+  (def app (-main))
   ;; (clojure.java.browse/browse-url "http://localhost:8080/")
 
   ;; stop server
-  (((h/get-app) :stop))
+  ((app :stop))
 
 
   ,)