fetch cache started

deno.lock

@@ -0,0 +1,16 @@
+{
+  "version": "2",
+  "remote": {
+    "http://localhost:4507/lib/iso.tsx": "edf1cf4c539900040c75824eac8472e0ec43098b13af4049bd79ddbd76a5346d",
+    "https://esm.sh/preact@10.13.2/compat": "1cf68e0c8c6c84b60d42f30665403b67229c16ff5206824709b19df60ba9cdc3",
+    "https://esm.sh/stable/preact@10.13.2/deno/compat.js": "3151a948abd84aa75dfc9e57733da7e1a45fff7a25de58c7b6025b923874b508",
+    "https://esm.sh/stable/preact@10.13.2/deno/hooks.js": "c7a8e703bcbc6a05949f329b618c33d5d1ea5fee113ddcea44ff0f527af8556f",
+    "https://esm.sh/stable/preact@10.13.2/deno/preact.mjs": "365fab897381f4f403f859c5d12939084560545567108cc90dae901bbe892578",
+    "https://esm.sh/v116/preact@10.13.2/compat/src/index.d.ts": "d02f015638a40e32649151e011cfda7b520d66f7fbd3c12a28fa03de2a5e1421",
+    "https://esm.sh/v116/preact@10.13.2/compat/src/suspense-list.d.ts": "b8e274324392157ce476ef3a48ae215c9f7003b08525d140645f19eab20d1948",
+    "https://esm.sh/v116/preact@10.13.2/compat/src/suspense.d.ts": "81f5266e0977a94347505d11b8103024211f2b4f3b2eb2aa276a10d8fd169e65",
+    "https://esm.sh/v116/preact@10.13.2/hooks/src/index.d.ts": "5c29febb624fc25d71cb0e125848c9b711e233337a08f7eacfade38fd4c14cc3",
+    "https://esm.sh/v116/preact@10.13.2/src/index.d.ts": "65398710de6aa0a07412da79784e05e6e96763f51c7c91b77344d2d0af06385c",
+    "https://esm.sh/v116/preact@10.13.2/src/jsx.d.ts": "9ac9b82c199fa7b04748807d750eba1a106c0be52041b8617416f88d6fc0a257"
+  }
+}

fetch.test.tsx

@@ -0,0 +1,24 @@
+import {Fetch} from "./lib/iso.tsx";
+
+
+const delay =async(inHandler:()=>void, inDelay:number):Promise<void>=>
+{
+    return new Promise((accept)=>{
+        setTimeout(()=>{
+            accept(inHandler());
+        }, inDelay);
+    });
+};
+
+let r1, r2, r3;
+
+delay(()=>{r1 = Fetch.Request(`https://catfact.ninja/fact`, undefined, 0.2); console.log(r1); }, 10);
+delay(()=>{r2 = Fetch.Request(`https://catfact.ninja/fact`, undefined, 0.2); console.log(r2); }, 20);
+delay(()=>{r3 = Fetch.Request(`https://catfact.ninja/fact`, undefined, 0.2); console.log(r3); }, 2000);
+
+
+await delay(()=>{}, 3000);
+
+console.log(r1);
+console.log(r2);
+console.log(r3);

lib/iso.tsx

@@ -158,4 +158,55 @@ export const Switch =({children}:{children:Children})=>
     return fallback;
 };
 export const Case =({children, value}:{children:Children, value?:string, default?:true})=>null;
-export const useRouteVars =()=> React.useContext(SwitchContext).keys;
+export const useRouteVars =()=> React.useContext(SwitchContext).keys;
+
+
+type FetchRecord = {URL:string, CacheFor:number, CachedAt:number, DelaySSR:boolean, Error:boolean, Text:false|string};
+export const Fetch = {
+    Cache:new Map() as Map<string, FetchRecord>,
+    async Request(URL:string, Init?:RequestInit, CacheFor:number = 60, DelaySSR:boolean = true)
+    {
+        let check = Fetch.Cache.get(URL);
+        
+        const load =async(inCheck:FetchRecord)=>
+        {
+            Fetch.Cache.set(URL, inCheck);
+            const resp = await fetch(URL, Init);
+            inCheck.Text = await resp.text();
+            inCheck.CachedAt = new Date().getTime();
+            console.log(`...cached!`);
+            return inCheck;
+        }
+
+        if(!check)
+        {
+            console.log(`making new cache record...`);
+            check = {URL, CacheFor, CachedAt:0, DelaySSR, Error:false, Text:false};
+            load(check);
+            return check;
+        }
+        if(check.CachedAt == 0)
+        {
+            console.log(`currently being cached...`);
+            return check;
+        }
+        else if(check?.Text)
+        {
+            console.log(`found in cache...`);
+            let secondsAge = Math.floor((new Date().getTime() - check.CachedAt)/1000);
+            if(secondsAge > check.CacheFor)
+            {
+                console.log(`...outdated...`);
+                check.CachedAt = 0;
+                load(check);
+                return check;
+            }
+            else
+            {
+                console.log(`...retrieved!`);
+                return check;
+            }
+
+        }
+    }
+};