From 6eacfdcffa4ebcb8760f9b67d2477ea25fcb3ae6 Mon Sep 17 00:00:00 2001
From: Alice Gaudon <alice@gaudon.pro>
Date: Sun, 15 Nov 2020 15:16:18 +0100
Subject: [PATCH] Throttler: log jail triggers

---
 src/HttpError.ts |  4 ++--
 src/Throttler.ts | 16 ++++++++++++----
 2 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/src/HttpError.ts b/src/HttpError.ts
index 4de4d95..7071665 100644
--- a/src/HttpError.ts
+++ b/src/HttpError.ts
@@ -69,11 +69,11 @@ export class NotFoundHttpError extends BadRequestError {
 }
 
 export class TooManyRequestsHttpError extends BadRequestError {
-    public constructor(retryIn: number, cause?: Error) {
+    public constructor(retryIn: number, jailName: string, cause?: Error) {
         super(
             `You're making too many requests!`,
             `We need some rest. Please retry in ${Math.floor(retryIn / 1000)} seconds.`,
-            '',
+            jailName,
             cause,
         );
     }
diff --git a/src/Throttler.ts b/src/Throttler.ts
index a1c592a..9c16638 100644
--- a/src/Throttler.ts
+++ b/src/Throttler.ts
@@ -1,4 +1,5 @@
 import {TooManyRequestsHttpError} from "./HttpError";
+import {log} from "./Logger";
 
 export default class Throttler {
     private static readonly throttles: Record<string, Throttle | undefined> = {};
@@ -25,7 +26,8 @@ export default class Throttler {
         jailPeriod: number = 30 * 1000,
     ): void {
         let throttle = this.throttles[action];
-        if (!throttle) throttle = this.throttles[action] = new Throttle(max, resetPeriod, holdPeriod, jailPeriod);
+        if (!throttle)
+            throttle = this.throttles[action] = new Throttle(action, max, resetPeriod, holdPeriod, jailPeriod);
         throttle.trigger(id);
     }
 
@@ -35,6 +37,7 @@ export default class Throttler {
 }
 
 class Throttle {
+    private readonly jailName: string;
     private readonly max: number;
     private readonly resetPeriod: number;
     private readonly holdPeriod: number;
@@ -45,7 +48,8 @@ class Throttle {
         jailed?: number;
     } | undefined> = {};
 
-    public constructor(max: number, resetPeriod: number, holdPeriod: number, jailPeriod: number) {
+    public constructor(jailName: string, max: number, resetPeriod: number, holdPeriod: number, jailPeriod: number) {
+        this.jailName = jailName;
         this.max = max;
         this.resetPeriod = resetPeriod;
         this.holdPeriod = holdPeriod;
@@ -75,11 +79,15 @@ class Throttle {
 
         if (trigger.count > this.max) {
             trigger.jailed = currentDate;
-            return this.throw(trigger.jailed + this.jailPeriod - currentDate);
+
+            const unjailedIn = trigger.jailed + this.jailPeriod - currentDate;
+            log.info(`Jail ${this.jailName} triggered by ${id} and will be unjailed in ${unjailedIn}ms.`);
+
+            return this.throw(unjailedIn);
         }
     }
 
     protected throw(unjailedIn: number) {
-        throw new TooManyRequestsHttpError(unjailedIn);
+        throw new TooManyRequestsHttpError(unjailedIn, this.jailName);
     }
 }