Optional prom-client peer dependency

package.json

@@ -22,7 +22,9 @@
     "build/**/*"
   ],
   "scripts": {
-    "build": "tsc && tsc -p tsconfig.cjs.json && node ./scripts/declareTypes.js",
+    "build": "tsc && tsc -p tsconfig.cjs.json && node ./scripts/declareTypes.js --common --module",
+    "build:cjs": "tsc -p tsconfig.cjs.json && node ./scripts/declareTypes.js --common",
+    "build:module": "tsc && node ./scripts/declareTypes.js --module",
     "test": "yarn build && jest",
     "release": "yarn build && yarn publish",
     "lint": "eslint --fix"
@@ -41,5 +43,13 @@
     "amqplib": "^0.10.3",
     "mongodb": "^5.7.0",
     "mysql": "^2.18.1"
+  },
+  "peerDependencies": {
+    "prom-client": "^15.0.0"
+  },
+  "peerDependenciesMeta": {
+    "prom-client": {
+      "optional": true
+    }
   }
 }

scripts/declareTypes.js

@@ -1,3 +1,5 @@
 import fs from 'node:fs';
-fs.writeFileSync('./build/cjs/package.json', JSON.stringify({ type: 'commonjs' }));
+if (process.argv.includes('--common'))
-fs.writeFileSync('./build/esm/package.json', JSON.stringify({ type: 'module' }));
+    fs.writeFileSync('./build/cjs/package.json', JSON.stringify({ type: 'commonjs' }));
+if (process.argv.includes('--module'))
+    fs.writeFileSync('./build/esm/package.json', JSON.stringify({ type: 'module' }));

src/MariaDB.ts

@@ -25,7 +25,8 @@ export type MariaOptions = {
     client?: PoolConfig,
     credentials: Credentials,
     loggerOptions?: LoggerClientOptions,
-    donorQuery?: boolean
+    donorQuery?: boolean,
+    recordMetrics?: boolean
 }
 
 type MariaError = {
@@ -95,6 +96,8 @@ class MariaDB
     #pool: PoolCluster | null;
     #nodes: Node[];
     #canQueryDonor: boolean;
+    #queryHistogram?: {startTimer: (labels: object) => () => void};
+    #server: IServer;
 
     constructor (server: IServer, options: MariaOptions)
     {
@@ -128,7 +131,7 @@ class MariaDB
         this.#cluster = this.#credentials.length > 1;
         this.#canQueryDonor = options.donorQuery ?? false;
         this.#logger = server.createLogger(this, options.loggerOptions);
-
+        this.#server = server;
     }
 
     get ready () 
@@ -141,6 +144,7 @@ class MariaDB
         return this.#_activeQueries;
     }
 
+    // eslint-disable-next-line max-lines-per-function
     async init () 
     {
         if (!this.#load) 
@@ -230,10 +234,27 @@ class MariaDB
             } 
         }
 
+        // eslint-disable-next-line @typescript-eslint/ban-ts-comment
+        // @ts-ignore
+        const Prometheus = await import('prom-client').catch(() => null);
+        if (this.#config.recordMetrics && !Prometheus)
+        {
+            this.#logger.warn('Metrics recording was enabled but missing prom-client dependency');
+        }
+        else if (this.#config.recordMetrics && Prometheus)
+        {
+            this.#logger.info('Setting up metric recording');
+            this.#queryHistogram = new Prometheus.Histogram({
+                name: 'sql_queries',
+                help: 'Tracks query duration and frequency',
+                buckets: Prometheus?.exponentialBuckets(0.005, 2, 10),
+                labelNames: [ 'type' ] as const
+            });
+            this.#server.registerMetric(this.#queryHistogram!);
+        }
+
         this.#_ready = true;
-
         return this;
-
     }
 
     async close () 
@@ -386,6 +407,7 @@ class MariaDB
         {
             const result = await new Promise<T[] | FieldInfo[] | [OkPacket]| undefined>((resolve, reject) => 
             {
+                const endTimer = this.#queryHistogram?.startTimer({ type: [ 'SELECT', 'UPDATE', 'INSERT', 'DELETE' ].find(entry => query.toUpperCase().includes(entry)) ?? 'OTHER' });
                 const q = connection.query({ timeout, sql: query }, values, (err, results, fields) => 
                 {
                     if (err) 
@@ -397,6 +419,8 @@ class MariaDB
                     else 
                         resolve(fields);
                     connection.release();
+                    if (endTimer)
+                        endTimer();
                 });
                 this.#logger.debug(`Constructed query: ${q.sql.substring(0, 1024)}`);
             });

src/MongoDB.ts

@@ -21,7 +21,8 @@ export type MongoOptions = {
     credentials: Credentials,
     loggerOptions?: LoggerClientOptions,
     client?: MongoClientOptions,
-    load?: boolean
+    load?: boolean,
+    recordMetrics?: boolean
 }
 
 type StringIndexable = {[key: string]: boolean | string | number | Document | object}
@@ -54,6 +55,8 @@ class MongoDB
 
     #db: Db | null;
     #_client: MongoClient;
+    #queryHistogram?: { startTimer: (labels: object) => () => void };
+    #server: IServer;
 
     constructor (server: IServer, config: MongoOptions) 
     {
@@ -73,6 +76,7 @@ class MongoDB
         this.#load = config.load ?? true;
 
         this.#logger = server.createLogger(this, config.loggerOptions);
+        this.#server = server;
 
         if (URI) 
         {
@@ -122,7 +126,6 @@ class MongoDB
      */
     async init () 
     {
-
         if (!this.#load)
             return this.#logger.info('Not loading MongoDB');
 
@@ -133,12 +136,29 @@ class MongoDB
 
         await this.#_client.connect();
         this.#logger.debug('Connected, selecting DB');
-        this.#db = await this.#_client.db(this.#_database);
+        this.#db = this.#_client.db(this.#_database);
+
+        // eslint-disable-next-line @typescript-eslint/ban-ts-comment
+        // @ts-ignore
+        const Prometheus = await import('prom-client').catch(() => null);
+        if (this.#config.recordMetrics && !Prometheus)
+        {
+            this.#logger.warn('Metrics recording was enabled but missing prom-client dependency');
+        }
+        else if (this.#config.recordMetrics && Prometheus)
+        {
+            this.#logger.info('Setting up metric recording');
+            this.#queryHistogram = new Prometheus.Histogram({
+                name: 'mongo_queries',
+                help: 'Tracks query duration and frequency',
+                buckets: Prometheus?.exponentialBuckets(0.005, 2, 10),
+                labelNames: [ 'type' ] as const
+            });
+            this.#server.registerMetric(this.#queryHistogram!);
+        }
 
         this.#logger.status('MongoDB ready');
-
         return this;
-
     }
 
     async close () 
@@ -167,7 +187,6 @@ class MongoDB
      */
     async find<T extends Document> (db: string, query: MongoQuery, options?: FindOptions<T>): Promise<WithId<T>[]> 
     {
-
         if (!this.#db)
             throw new Error('MongoDB not connected');
 
@@ -179,9 +198,12 @@ class MongoDB
 
         this.#logger.debug(`Incoming find query for ${db} with parameters ${inspect(query)}`);
 
+        const endTimer = this.#queryHistogram?.startTimer({ type: 'find' });
         const cursor = this.#db.collection<T>(db).find(query as Filter<T>, options);
-        return cursor.toArray();
+        const data = await cursor.toArray();
-
+        if (endTimer)
+            endTimer();
+        return data;
     }
 
     /**
@@ -194,7 +216,6 @@ class MongoDB
      */
     async findOne<T extends Document> (db: string, query: MongoQuery, options: FindOptions<T> = {}): Promise<WithId<T> | null> 
     {
-
         if (!this.#db)
             throw new Error('MongoDB not connected');
         if (typeof db !== 'string')
@@ -204,9 +225,11 @@ class MongoDB
             query._id = new ObjectId(query._id);
 
         this.#logger.debug(`Incoming findOne query for ${db} with parameters ${inspect(query)}`);
+        const endTimer = this.#queryHistogram?.startTimer({ type: 'findOne' });
         const result = await this.#db.collection<T>(db).findOne(query as Filter<T>, options);
+        if (endTimer)
+            endTimer();
         return result;
-
     }
 
     /**
@@ -220,7 +243,6 @@ class MongoDB
      */
     async updateMany<T extends Document> (db: string, filter: MongoQuery, data: T, upsert = false) 
     {
-
         if (!this.#db)
             throw new Error('MongoDB not connected');
         if (typeof db !== 'string')
@@ -231,9 +253,11 @@ class MongoDB
             filter._id = new ObjectId(filter._id);
 
         this.#logger.debug(`Incoming update query for '${db}' with parameters\n${inspect(filter)}\nand data\n${inspect(data)}`);
+        const endTimer = this.#queryHistogram?.startTimer({ type: 'updateMany' });
         const result = await this.#db.collection<T>(db).updateMany(filter as Filter<T>, { $set: data }, { upsert });
+        if (endTimer)
+            endTimer();
         return result;
-
     }
 
     /**
@@ -247,7 +271,6 @@ class MongoDB
      */
     async updateOne (db: string, filter: MongoQuery, data: Document, upsert = false) 
     {
-
         if (!this.#db)
             throw new Error('MongoDB not connected');
         if (typeof db !== 'string')
@@ -256,9 +279,11 @@ class MongoDB
             filter._id = new ObjectId(filter._id);
 
         this.#logger.debug(`Incoming updateOne query for ${db} with parameters ${inspect(filter)}`);
+        const endTimer = this.#queryHistogram?.startTimer({ type: 'updateOne' });
         const result = await this.#db.collection(db).updateOne(filter as Filter<Document>, { $set: data }, { upsert });
+        if (endTimer)
+            endTimer();
         return result;
-
     }
 
     /**
@@ -272,7 +297,6 @@ class MongoDB
      */
     async insertOne (db: string, data: Document) 
     {
-
         if (!this.#db)
             throw new Error('MongoDB not connected');
         if (typeof db !== 'string')
@@ -281,9 +305,11 @@ class MongoDB
             data._id = new ObjectId(data._id);
 
         this.#logger.debug(`Incoming insertOne query for ${db} with parameters ${inspect(data)}`);
+        const endTimer = this.#queryHistogram?.startTimer({ type: 'insertOne' });
         const result = await this.#db.collection(db).insertOne(data);
+        if (endTimer)
+            endTimer();
         return result;
-
     }
 
     async deleteOne (db: string, filter: Document) 
@@ -296,7 +322,10 @@ class MongoDB
             filter._id = new ObjectId(filter._id);
 
         this.#logger.debug(`Incoming deleteOne query for ${db} with parameters ${inspect(filter)}`);
+        const endTimer = this.#queryHistogram?.startTimer({ type: 'deleteOne' });
         const result = await this.#db.collection(db).deleteOne(filter);
+        if (endTimer)
+            endTimer();
         return result;
     }
 
@@ -311,7 +340,10 @@ class MongoDB
         if (typeof filter._id === 'string')
             filter._id = new ObjectId(filter._id);
 
+        const endTimer = this.#queryHistogram?.startTimer({ type: 'findOneAndDelete' });
         const result = await this.#db.collection<T>(db).findOneAndDelete(filter as Filter<T>, { includeResultMetadata: meta });
+        if (endTimer)
+            endTimer();
         return result;
     }
 
@@ -335,7 +367,10 @@ class MongoDB
             filter._id = new ObjectId(filter._id);
 
         this.#logger.debug(`Incoming push query for ${db}, with upsert ${upsert} and with parameters ${inspect(filter)} and data ${inspect(data)}`);
+        const endTimer = this.#queryHistogram?.startTimer({ type: 'push' });
         const result = await this.#db.collection(db).updateOne(filter, { $push: data }, { upsert });
+        if (endTimer)
+            endTimer();
         return result;
     }
 
@@ -350,7 +385,6 @@ class MongoDB
      */
     random<T extends Document> (db: string, filter: Document = {}, amount = 1) 
     {
-
         if (!this.#db)
             throw new Error('MongoDB not connected');
         if (typeof db !== 'string')
@@ -365,7 +399,6 @@ class MongoDB
 
         const cursor = this.#db.collection(db).aggregate<T>([{ $match: filter }, { $sample: { size: amount } }]);
         return cursor.toArray();
-
     }
 
     stats (options = {}) 

src/interfaces/Server.ts

@@ -1,5 +1,6 @@
-import { ILogger, LoggerClientOptions } from "./Logger.js";
+import { ILogger, LoggerClientOptions } from './Logger.js';
 
 export interface IServer {
     createLogger(obj: object, options?: Partial<LoggerClientOptions>): ILogger
+    registerMetric(metric: object): void
 }