need more statistics

java_console/io/src/main/java/com/rusefi/io/serial/RateCounter.java

@@ -0,0 +1,55 @@
+package com.rusefi.io.serial;
+
+import com.rusefi.Timeouts;
+
+import java.util.LinkedList;
+
+public class RateCounter {
+
+    private final LinkedList<Pair> timeStamps = new LinkedList<>();
+
+    /**
+     * @return number of events in the last second
+     */
+    public int getCurrentRate() {
+        return getCurrentRate(System.currentTimeMillis());
+    }
+
+    public synchronized int getCurrentRate(long now) {
+        long threshold = now - Timeouts.SECOND;
+
+        while (!timeStamps.isEmpty() && timeStamps.peekFirst().timestamp < threshold)
+            timeStamps.removeFirst();
+
+        int result = 0;
+        for (Pair pair : timeStamps)
+            result += pair.value;
+        return result;
+    }
+
+    public void add() {
+        add(System.currentTimeMillis());
+    }
+
+    public synchronized void add(long now) {
+        timeStamps.add(new Pair(now, 1));
+    }
+
+    private static class Pair {
+        private final long timestamp;
+        private final int value;
+
+        public Pair(long timestamp, int value) {
+            this.timestamp = timestamp;
+            this.value = value;
+        }
+
+        public long getTimestamp() {
+            return timestamp;
+        }
+
+        public int getValue() {
+            return value;
+        }
+    }
+}

java_console/io/src/test/java/com/rusefi/io/serial/RateCounterTest.java

@@ -0,0 +1,27 @@
+package com.rusefi.io.serial;
+
+import com.rusefi.Timeouts;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+public class RateCounterTest {
+    @Test
+    public void testRateCalculation() {
+
+        RateCounter rateCounter = new RateCounter();
+
+        assertEquals(0, rateCounter.getCurrentRate());
+
+        rateCounter.add(1);
+        rateCounter.add(1);
+        rateCounter.add(1);
+        rateCounter.add(1);
+
+        assertEquals(4, rateCounter.getCurrentRate(0));
+
+
+        assertEquals(0, rateCounter.getCurrentRate(2 * Timeouts.SECOND));
+    }
+}
+