Rate limit

src/RateLimit.java

@@ -0,0 +1,57 @@
+package duckutil;
+
+public class RateLimit
+{
+
+  private double max_bytes_per_ns;
+  private double last_allocated;
+  private double buffer_seconds;
+
+  public RateLimit(double maxBytesPerSecond, double buffer_seconds)
+  {
+    max_bytes_per_ns = maxBytesPerSecond / 1e9;
+    this.buffer_seconds = buffer_seconds;
+
+    resetLast();
+  }
+
+  private void resetLast()
+  {
+    last_allocated = Math.max(
+      System.nanoTime() - (buffer_seconds * 1e9),
+      last_allocated);
+  }
+
+  /**
+   * Returns true if a rate limit was applied
+   */
+  public synchronized boolean waitForRate(double bytes)
+  {
+    resetLast();
+
+
+    double end_time = last_allocated + (bytes / max_bytes_per_ns);
+    double tm = System.nanoTime();
+
+    last_allocated = end_time;
+    if (end_time > tm)
+    {
+      long wait_tm = (long)((end_time - tm) / 1e6);
+      try
+      {
+        Thread.sleep(wait_tm);
+      }
+      catch(InterruptedException e)
+      {
+        throw new RuntimeException(e);
+      }
+      return true;
+    }
+    return false;
+
+  }
+
+
+
+
+}