Move dead submodules in-tree

Signed-off-by: swurl <swurl@swurl.xyz>

externals/discord-rpc/src/backoff.h

@@ -0,0 +1,40 @@
+#pragma once
+
+#include <algorithm>
+#include <random>
+#include <stdint.h>
+#include <time.h>
+
+struct Backoff {
+    int64_t minAmount;
+    int64_t maxAmount;
+    int64_t current;
+    int fails;
+    std::mt19937_64 randGenerator;
+    std::uniform_real_distribution<> randDistribution;
+
+    double rand01() { return randDistribution(randGenerator); }
+
+    Backoff(int64_t min, int64_t max)
+      : minAmount(min)
+      , maxAmount(max)
+      , current(min)
+      , fails(0)
+      , randGenerator((uint64_t)time(0))
+    {
+    }
+
+    void reset()
+    {
+        fails = 0;
+        current = minAmount;
+    }
+
+    int64_t nextDelay()
+    {
+        ++fails;
+        int64_t delay = (int64_t)((double)current * 2.0 * rand01());
+        current = std::min(current + delay, maxAmount);
+        return current;
+    }
+};