mihari.oyama.pictures/Tired

src/server/lib/DiscordREST.ts

@@ -1,23 +1,47 @@
-const base = "https://discord.com/api/v10/"
+const base = "https://discord.com/api/v10"
 const buckets = new Map<string, DiscordAPIBucket>()
+const routeConnections = new Map<string, DiscordAPIBucket>()
+
+interface RatelimitData {
+    bucket_name : string 
+    limit       : number
+    remaining   : number
+    expires     : number
+}
+
+interface QueuedRequest {
+    path   : `/${string}`
+    params : RequestInit
+}
+
+function extractRatelimitData(headers: Headers): RatelimitData {
+    return {
+        bucket_name : headers.get("x-ratelimit-bucket")!,
+        limit       : parseInt(headers.get("x-ratelimit-limit")!),
+        remaining   : parseInt(headers.get("x-ratelimit-remaining")!),
+        expires     : parseFloat(headers.get("x-ratelimit-reset")!),
+    }
+}
 
 class DiscordAPIBucket {
 
     readonly name             : string                        // bucket name (X-Ratelimit-Bucket)
-    // queue           : RequestInfo[] = []            // queue of requests to send
     readonly limit            : number                        // bucket limit (X-Ratelimit-Limit)
     remaining                 : number                        // requests remaining (X-Ratelimit-Remaining)
     readonly expires          : number                        // when this ratelimit expires (X-Ratelimit-Reset)
 
     readonly expirationHold   : ReturnType<typeof setTimeout> // Timeout which fires after this bucket expires
-    dead                      : boolean = false               // True if bucket has expired
+    dead                      : boolean  = false              // True if bucket has expired
+    linked_routes             : string[] = []
 
     constructor(base: Response) {
 
-        this.name      = base.headers.get("x-ratelimit-bucket")!
+        let rd = extractRatelimitData(base.headers)
-        this.limit     = parseInt(base.headers.get("x-ratelimit-limit")!)
+
-        this.remaining = parseInt(base.headers.get("x-ratelimit-remaining")!)
+        this.name      = rd.bucket_name
-        this.expires   = parseFloat(base.headers.get("x-ratelimit-reset")!)
+        this.limit     = rd.limit
+        this.remaining = rd.remaining
+        this.expires   = rd.expires
 
         this.expirationHold = 
             setTimeout(
@@ -34,6 +58,7 @@ class DiscordAPIBucket {
 
         buckets.delete(this.name)
         this.dead = true
+        this.linked_routes.forEach((v) => routeConnections.delete(v))
         Object.freeze(this)
         
     }
@@ -47,6 +72,16 @@ class DiscordAPIBucket {
         return this
     }
 
+    /**
+     * @description Link a route to this bucket
+     * @param route Route to link
+     */
+    link(route: string) {
+        if (this.linked_routes.includes(route)) return
+        routeConnections.set(route, this)
+        this.linked_routes.push(route)
+    }
+
 }
 
 /**
@@ -65,14 +100,18 @@ function checkHeaders(headers: Headers) {
 /**
  * @description Returns or creates a DiscordAPIBucket from a Response
  */
-function getBucket(response: Response) {
+function getBucket(response: string): DiscordAPIBucket | undefined
-    if (!checkHeaders(response.headers)) throw new Error("Required ratelimiting headers not found")
+function getBucket(response: Response): DiscordAPIBucket
+function getBucket(response: Response | string) {
+    if (response instanceof Response) {
+        if (!checkHeaders(response.headers)) throw new Error("Required ratelimiting headers not found")
 
-    if (buckets.has(response.headers.get("x-ratelimit-bucket")!)) 
+        if (buckets.has(response.headers.get("x-ratelimit-bucket")!)) 
-        return buckets.get(response.headers.get("x-ratelimit-bucket")!)!
+            return buckets.get(response.headers.get("x-ratelimit-bucket")!)!
 
-    else
+        else
-        return new DiscordAPIBucket(response)
+            return new DiscordAPIBucket(response)
+    } else return routeConnections.get(response)
 }
 
 export class REST {
@@ -83,9 +122,46 @@ export class REST {
         this.token = token;
     }
 
-    async fetch(options: RequestInfo) {
+    /**
+     * @description Queues a request 
+     */
+    async queue(path: `/${string}`, options?: RequestInit) {
+        // TODO: actually write the queue lmao
+        console.warn(`Request added to queue: ${(options?.method ?? "get").toUpperCase()} ${path}`)
+    }
 
+    /**
+     * @description Make a fetch requests where further requests are automatically queued in case of ratelimit
+     */
+    async fetch(path: `/${string}`, options?: RequestInit) {
 
+        // check if there's already a bucket, and check if it's full
+        let known_bucket = getBucket( path )
+
+        if (known_bucket && known_bucket.remaining) {
+            return this.queue(path, options)
+        }
+
+        // there's no known bucket for this route; let's carry on with the request
+        let response = await fetch(base+path, options)
+
+        if ( checkHeaders(response.headers) ) {
+            // a ratelimit is attached, let's set up our buckets..
+
+            let bucket = getBucket( response )
+            if (response.status == 429) {
+                bucket.link(path) // link the bucket so that hopefully no future errors occur
+
+                return this.queue(path, options) /* it was ratelimited after all
+                                                    getBucket() would have generated a DiscordAPIBucket
+                                                    so this would be fine */
+            }
+
+            // let's update the bucket...
+            let rd = extractRatelimitData( response.headers )
+            bucket.update(rd.remaining)
+
+        } else return response
 
     }