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diff --git a/packages/taler-harness/src/benchMerchantIDGenerator.ts b/packages/taler-harness/src/benchMerchantIDGenerator.ts
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+/*
+ This file is part of GNU Taler
+ (C) 2022 Taler Systems S.A.
+
+ GNU Taler is free software; you can redistribute it and/or modify it under the
+ terms of the GNU General Public License as published by the Free Software
+ Foundation; either version 3, or (at your option) any later version.
+
+ GNU Taler is distributed in the hope that it will be useful, but WITHOUT ANY
+ WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+ A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License along with
+ GNU Taler; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
+ 
+ @author: Boss Marco
+ */
+
+const getRandomInt = function (max: number) {
+  return Math.floor(Math.random() * max);
+};
+
+abstract class BenchMerchantIDGenerator {
+  abstract getRandomMerchantID(): number;
+}
+
+class ZipfGenerator extends BenchMerchantIDGenerator {
+  weights: number[];
+  total_weight: number;
+
+  constructor(numMerchants: number) {
+    super();
+    this.weights = new Array<number>(numMerchants);
+    for (var i = 0; i < this.weights.length; i++) {
+      /* we use integers (floor), make sure we have big enough values
+       * by multiplying with
+       * numMerchants again */
+      this.weights[i] = Math.floor((numMerchants / (i + 1)) * numMerchants);
+    }
+    this.total_weight = this.weights.reduce((p, n) => p + n);
+  }
+
+  getRandomMerchantID(): number {
+    let random = getRandomInt(this.total_weight);
+    let current = 0;
+
+    for (var i = 0; i < this.weights.length; i++) {
+      current += this.weights[i];
+      if (random <= current) {
+        return i + 1;
+      }
+    }
+
+    /* should never come here */
+    return getRandomInt(this.weights.length);
+  }
+}
+
+class RandomGenerator extends BenchMerchantIDGenerator {
+  max: number;
+
+  constructor(numMerchants: number) {
+    super();
+    this.max = numMerchants;
+  }
+
+  getRandomMerchantID() {
+    return getRandomInt(this.max);
+  }
+}
+
+export default function (
+  type: string,
+  maxID: number,
+): BenchMerchantIDGenerator {
+  switch (type) {
+    case "zipf":
+      return new ZipfGenerator(maxID);
+    case "rand":
+      return new RandomGenerator(maxID);
+    default:
+      throw new Error("Valid types are 'zipf' and 'rand'");
+  }
+}