[ONOS-3601] Add unit test for MetricCodec and correct some typos

Change-Id: I72317b3d2ea8c428bcc24aa215ae97c098a38305

@@ -26,6 +26,8 @@ import com.fasterxml.jackson.databind.node.ObjectNode;
 import org.onosproject.codec.CodecContext;
 import org.onosproject.codec.JsonCodec;
 
+import java.util.concurrent.TimeUnit;
+
 import static com.google.common.base.Preconditions.checkNotNull;
 
 /**
@@ -96,6 +98,6 @@ public class MetricCodec extends JsonCodec<Metric> {
     }
 
     private double nanoToMs(double nano) {
-        return nano / 1_000_000D;
+        return TimeUnit.MILLISECONDS.convert((long) nano, TimeUnit.NANOSECONDS);
     }
 }

@@ -51,7 +51,7 @@ public class MeterCodecTest {
     final CoreService mockCoreService = createMock(CoreService.class);
 
     /**
-     * Sets up for each test.  Creates a context and fetches the flow rule
+     * Sets up for each test.  Creates a context and fetches the meter
      * codec.
      */
     @Before

+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.codec.impl;
+
+import com.codahale.metrics.Counter;
+import com.codahale.metrics.Meter;
+import com.codahale.metrics.Metric;
+import com.codahale.metrics.Timer;
+import com.fasterxml.jackson.databind.node.ObjectNode;
+import org.junit.Before;
+import org.junit.Test;
+import org.onosproject.codec.JsonCodec;
+import org.onosproject.core.CoreService;
+
+import java.util.concurrent.TimeUnit;
+
+import static org.easymock.EasyMock.createMock;
+import static org.easymock.EasyMock.replay;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.notNullValue;
+import static org.onosproject.codec.impl.MetricJsonMatcher.matchesMetric;
+
+/**
+ * Unit tests for Metric codec.
+ */
+public class MetricCodecTest {
+
+    MockCodecContext context;
+    JsonCodec<Metric> metricCodec;
+    final CoreService mockCoreService = createMock(CoreService.class);
+
+    /**
+     * Sets up for each test.  Creates a context and fetches the metric codec.
+     */
+    @Before
+    public void setUp() {
+        context = new MockCodecContext();
+        metricCodec = context.codec(Metric.class);
+        assertThat(metricCodec, notNullValue());
+
+        replay(mockCoreService);
+        context.registerService(CoreService.class, mockCoreService);
+    }
+
+    /**
+     * Tests encoding of a Metric object.
+     */
+    @Test
+    public void testMetricEncode() {
+        Counter counter = new Counter();
+        Meter meter = new Meter();
+        Timer timer = new Timer();
+
+        counter.inc();
+        meter.mark();
+        timer.update(1, TimeUnit.MILLISECONDS);
+
+        ObjectNode counterJson = metricCodec.encode(counter, context);
+        assertThat(counterJson.get("counter"), matchesMetric(counter));
+
+        ObjectNode meterJson = metricCodec.encode(meter, context);
+        assertThat(meterJson.get("meter"), matchesMetric(meter));
+
+        ObjectNode timerJson = metricCodec.encode(timer, context);
+        assertThat(timerJson.get("timer"), matchesMetric(timer));
+    }
+}

+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.codec.impl;
+
+import com.codahale.metrics.Counter;
+import com.codahale.metrics.Meter;
+import com.codahale.metrics.Metric;
+import com.codahale.metrics.Timer;
+import com.fasterxml.jackson.databind.JsonNode;
+import org.hamcrest.Description;
+import org.hamcrest.TypeSafeDiagnosingMatcher;
+
+import java.util.concurrent.TimeUnit;
+
+/**
+ * Hamcrest matcher for metrics.
+ */
+public final class MetricJsonMatcher extends TypeSafeDiagnosingMatcher<JsonNode> {
+
+    private final Metric metric;
+
+    private MetricJsonMatcher(Metric metric) {
+        this.metric = metric;
+    }
+
+    @Override
+    protected boolean matchesSafely(JsonNode jsonMetric, Description description) {
+
+        // check counter
+        if (metric instanceof Counter) {
+            Counter counter = (Counter) metric;
+            long jsonCounter = jsonMetric.get("counter").asLong();
+            long counterVal = counter.getCount();
+            if (jsonCounter != counterVal) {
+                description.appendText("counter was " + jsonCounter);
+                return false;
+            }
+        }
+
+        // check meter
+        if (metric instanceof Meter) {
+            Meter meter = (Meter) metric;
+
+            long jsonCounter = jsonMetric.get("counter").asLong();
+            long counterVal = meter.getCount();
+            if (jsonCounter != counterVal) {
+                description.appendText("counter was " + jsonCounter);
+                return false;
+            }
+
+            double jsonOneMinRate = jsonMetric.get("1_min_rate").asDouble();
+            double oneMinRate = meter.getOneMinuteRate();
+            if (jsonOneMinRate != oneMinRate) {
+                description.appendText("one minute rate was " + jsonOneMinRate);
+                return false;
+            }
+
+            double jsonFiveMinRate = jsonMetric.get("5_min_rate").asDouble();
+            double fiveMinRate = meter.getFiveMinuteRate();
+            if (jsonFiveMinRate != fiveMinRate) {
+                description.appendText("five minute rate was " + jsonFiveMinRate);
+                return false;
+            }
+
+            double jsonFiftMinRate = jsonMetric.get("15_min_rate").asDouble();
+            double fiftMinRate = meter.getFifteenMinuteRate();
+            if (jsonFiftMinRate != fiftMinRate) {
+                description.appendText("fifteen minute rate was " + jsonFiftMinRate);
+                return false;
+            }
+        }
+
+        // check timer
+        if (metric instanceof Timer) {
+            Timer timer = (Timer) metric;
+
+            long jsonCounter = jsonMetric.get("counter").asLong();
+            long counterVal = timer.getCount();
+            if (jsonCounter != counterVal) {
+                description.appendText("counter was " + jsonCounter);
+                return false;
+            }
+
+            double jsonOneMinRate = jsonMetric.get("1_min_rate").asDouble();
+            double oneMinRate = timer.getOneMinuteRate();
+            if (jsonOneMinRate != oneMinRate) {
+                description.appendText("one minute rate was " + jsonOneMinRate);
+                return false;
+            }
+
+            double jsonFiveMinRate = jsonMetric.get("5_min_rate").asDouble();
+            double fiveMinRate = timer.getFiveMinuteRate();
+            if (jsonFiveMinRate != fiveMinRate) {
+                description.appendText("five minute rate was " + jsonFiveMinRate);
+                return false;
+            }
+
+            double jsonFiftMinRate = jsonMetric.get("15_min_rate").asDouble();
+            double fiftMinRate = timer.getFifteenMinuteRate();
+            if (jsonFiftMinRate != fiftMinRate) {
+                description.appendText("fifteen minute rate was " + jsonFiftMinRate);
+                return false;
+            }
+
+            double jsonMean = jsonMetric.get("mean").asDouble();
+            double mean = nanoToMs(timer.getSnapshot().getMean());
+            if (jsonMean != mean) {
+                description.appendText("mean was " + jsonMean);
+                return false;
+            }
+
+            double jsonMin = jsonMetric.get("min").asDouble();
+            double min = nanoToMs(timer.getSnapshot().getMin());
+            if (jsonMin != min) {
+                description.appendText("json min was " + jsonMin);
+                return false;
+            }
+
+            double jsonMax = jsonMetric.get("max").asDouble();
+            double max = nanoToMs(timer.getSnapshot().getMax());
+            if (jsonMax != max) {
+                description.appendText("max was " + jsonMax);
+                return false;
+            }
+
+            double jsonStdDev = jsonMetric.get("stddev").asDouble();
+            double stdDev = nanoToMs(timer.getSnapshot().getStdDev());
+            if (jsonStdDev != stdDev) {
+                description.appendText("stddev was " + jsonStdDev);
+                return false;
+            }
+        }
+
+        return true;
+    }
+
+    @Override
+    public void describeTo(Description description) {
+        description.appendText(metric.toString());
+    }
+
+    /**
+     * Factory to allocate a metric matcher.
+     *
+     * @param metric metric object we are looking for
+     * @return matcher
+     */
+    public static MetricJsonMatcher matchesMetric(Metric metric) {
+        return new MetricJsonMatcher(metric);
+    }
+
+    private double nanoToMs(double nano) {
+        return TimeUnit.MILLISECONDS.convert((long) nano, TimeUnit.NANOSECONDS);
+    }
+}
\ No newline at end of file

@@ -122,8 +122,8 @@ public class MetricsResourceTest extends ResourceTest {
     }
 
     /**
-     * Hamcrest matcher to check that an device representation in JSON matches
-     * the actual device.
+     * Hamcrest matcher to check that a metric representation in JSON matches
+     * the actual metric.
      */
     public static class MetricJsonMatcher extends TypeSafeMatcher<JsonObject> {
         private final Metric metric;