Implement REST APIs for link flow statistics

Change-Id: I65ca3cec9dd1771a70811afd319619827f7b9010

@@ -47,6 +47,7 @@ import org.onosproject.net.intent.Constraint;
 import org.onosproject.net.intent.HostToHostIntent;
 import org.onosproject.net.intent.Intent;
 import org.onosproject.net.intent.PointToPointIntent;
+import org.onosproject.net.statistic.Load;
 import org.onosproject.net.topology.Topology;
 import org.onosproject.net.topology.TopologyCluster;
 import org.slf4j.Logger;
@@ -97,6 +98,7 @@ public class CodecManager implements CodecService {
         registerCodec(Group.class, new GroupCodec());
         registerCodec(Driver.class, new DriverCodec());
         registerCodec(GroupBucket.class, new GroupBucketCodec());
+        registerCodec(Load.class, new LoadCodec());
         log.info("Started");
     }
 

+/*
+ * 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 org.onosproject.codec.CodecContext;
+import org.onosproject.codec.JsonCodec;
+import org.onosproject.net.statistic.Load;
+
+import com.fasterxml.jackson.databind.node.ObjectNode;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+/**
+ * Codec for the Load class.
+ */
+public class LoadCodec extends JsonCodec<Load> {
+
+    private static final String RATE = "rate";
+    private static final String LATEST = "latest";
+    private static final String VALID = "valid";
+    private static final String TIME = "time";
+
+    @Override
+    public ObjectNode encode(Load load, CodecContext context) {
+        checkNotNull(load, "Load cannot be null");
+        return context.mapper().createObjectNode()
+                .put(RATE, load.rate())
+                .put(LATEST, load.latest())
+                .put(VALID, load.isValid())
+                .put(TIME, load.time());
+    }
+}

+/*
+ * 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 org.junit.Test;
+import org.onosproject.net.statistic.DefaultLoad;
+import org.onosproject.net.statistic.Load;
+
+import com.fasterxml.jackson.databind.JsonNode;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.greaterThanOrEqualTo;
+import static org.hamcrest.Matchers.is;
+
+/**
+ * Unit tests for Load codec.
+ */
+public class LoadCodecTest {
+
+    /**
+     * Tests encoding of a Load object.
+     */
+    @Test
+    public void testLoadEncode() {
+        final long startTime = System.currentTimeMillis();
+        final Load load = new DefaultLoad(20, 10, 1);
+        final JsonNode node = new LoadCodec()
+                .encode(load, new MockCodecContext());
+        assertThat(node.get("valid").asBoolean(), is(true));
+        assertThat(node.get("latest").asLong(), is(20L));
+        assertThat(node.get("rate").asLong(), is(10L));
+        assertThat(node.get("time").asLong(), greaterThanOrEqualTo(startTime));
+    }
+}

+/*
+ * 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.rest.resources;
+
+import java.util.Spliterator;
+import java.util.Spliterators;
+import java.util.stream.StreamSupport;
+
+import javax.ws.rs.GET;
+import javax.ws.rs.Path;
+import javax.ws.rs.Produces;
+import javax.ws.rs.QueryParam;
+import javax.ws.rs.core.Context;
+import javax.ws.rs.core.MediaType;
+import javax.ws.rs.core.Response;
+import javax.ws.rs.core.UriBuilder;
+import javax.ws.rs.core.UriInfo;
+
+import org.onosproject.codec.JsonCodec;
+import org.onosproject.net.ConnectPoint;
+import org.onosproject.net.Link;
+import org.onosproject.net.link.LinkService;
+import org.onosproject.net.statistic.Load;
+import org.onosproject.net.statistic.StatisticService;
+import org.onosproject.rest.AbstractWebResource;
+
+import com.fasterxml.jackson.databind.node.ArrayNode;
+import com.fasterxml.jackson.databind.node.ObjectNode;
+
+import static org.onosproject.net.DeviceId.deviceId;
+import static org.onosproject.net.PortNumber.portNumber;
+
+/**
+ * Statistics REST APIs.
+ */
+@Path("statistics")
+public class StatisticsWebResource  extends AbstractWebResource {
+    @Context
+    UriInfo uriInfo;
+
+    /**
+     * Gets the Load statistics for all links, or for a specific link.
+     *
+     * @param deviceId (optional) device ID for a specific link
+     * @param port (optional) port number for a specified link
+     * @return JSON encoded array lof Load objects
+     */
+    @GET
+    @Path("flows/link")
+    @Produces(MediaType.APPLICATION_JSON)
+    public Response getLoads(@QueryParam("device") String deviceId,
+                             @QueryParam("port") String port) {
+        Iterable<Link> links;
+
+        if (deviceId == null || port == null) {
+            links = get(LinkService.class).getLinks();
+        } else {
+            ConnectPoint connectPoint = new ConnectPoint(deviceId(deviceId),
+                    portNumber(port));
+            links = get(LinkService.class).getLinks(connectPoint);
+        }
+        ObjectNode result = mapper().createObjectNode();
+        ArrayNode loads = mapper().createArrayNode();
+        JsonCodec<Load> loadCodec = codec(Load.class);
+        StatisticService statsService = getService(StatisticService.class);
+
+
+        StreamSupport.stream(Spliterators.spliteratorUnknownSize(
+                links.iterator(), Spliterator.ORDERED), false)
+                .forEach(link -> {
+                    ObjectNode loadNode = loadCodec.encode(statsService.load(link), this);
+
+                    UriBuilder locationBuilder = uriInfo.getBaseUriBuilder()
+                            .path("links")
+                            .queryParam("device", link.src().deviceId().toString())
+                            .queryParam("port", link.src().port().toString());
+                    loadNode.put("link", locationBuilder.build().toString());
+                    loads.add(loadNode);
+                });
+        result.set("loads", loads);
+        return ok(result).build();
+    }
+}

@@ -76,7 +76,8 @@
                 org.onosproject.rest.resources.FlowsWebResource,
                 org.onosproject.rest.resources.TopologyWebResource,
                 org.onosproject.rest.resources.ConfigWebResource,
-                org.onosproject.rest.resources.PathsWebResource
+                org.onosproject.rest.resources.PathsWebResource,
+                org.onosproject.rest.resources.StatisticsWebResource
             </param-value>
         </init-param>
         <load-on-startup>1</load-on-startup>

+/*
+ * 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.rest;
+
+import java.util.HashMap;
+import java.util.stream.IntStream;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.onlab.osgi.ServiceDirectory;
+import org.onlab.osgi.TestServiceDirectory;
+import org.onlab.rest.BaseResource;
+import org.onosproject.codec.CodecService;
+import org.onosproject.codec.impl.CodecManager;
+import org.onosproject.net.Link;
+import org.onosproject.net.link.LinkService;
+import org.onosproject.net.statistic.DefaultLoad;
+import org.onosproject.net.statistic.StatisticService;
+
+import com.eclipsesource.json.JsonArray;
+import com.eclipsesource.json.JsonObject;
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableSet;
+import com.sun.jersey.api.client.WebResource;
+
+import static org.easymock.EasyMock.createMock;
+import static org.easymock.EasyMock.expect;
+import static org.easymock.EasyMock.replay;
+import static org.hamcrest.Matchers.containsString;
+import static org.hamcrest.Matchers.hasSize;
+import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.lessThanOrEqualTo;
+import static org.hamcrest.Matchers.notNullValue;
+import static org.junit.Assert.assertThat;
+import static org.onosproject.net.NetTestTools.connectPoint;
+import static org.onosproject.net.NetTestTools.link;
+
+/**
+ * Unit tests for statistics REST APIs.
+ */
+public class StatisticsResourceTest extends ResourceTest {
+
+    Link link1 = link("src1", 1, "dst1", 1);
+    Link link2 = link("src2", 2, "dst2", 2);
+    Link link3 = link("src3", 3, "dst3", 3);
+
+    LinkService mockLinkService;
+    StatisticService mockStatisticService;
+
+    /**
+     * Initializes test mocks and environment.
+     */
+    @Before
+    public void setUpTest() {
+        mockLinkService = createMock(LinkService.class);
+        expect(mockLinkService.getLinks())
+                .andReturn(ImmutableList.of(link1, link2, link3));
+        expect(mockLinkService.getLinks(connectPoint("0000000000000001", 2)))
+                .andReturn(ImmutableSet.of(link3));
+
+        mockStatisticService = createMock(StatisticService.class);
+        expect(mockStatisticService.load(link1))
+                .andReturn(new DefaultLoad(2, 1, 1));
+        expect(mockStatisticService.load(link2))
+                .andReturn(new DefaultLoad(22, 11, 1));
+        expect(mockStatisticService.load(link3))
+                .andReturn(new DefaultLoad(222, 111, 1));
+
+        replay(mockLinkService, mockStatisticService);
+
+        // Register the services needed for the test
+        CodecManager codecService = new CodecManager();
+        codecService.activate();
+        ServiceDirectory testDirectory =
+                new TestServiceDirectory()
+                        .add(LinkService.class, mockLinkService)
+                        .add(StatisticService.class, mockStatisticService)
+                        .add(CodecService.class, codecService);
+
+        BaseResource.setServiceDirectory(testDirectory);
+    }
+
+    /**
+     * Checks that the values in a JSON representation of a Load are
+     * correct.
+     *
+     * @param load JSON for the Loan object
+     * @param rate expected vale fo rate
+     * @param latest expected value for latest
+     * @param valid expected value for valid flag
+     * @param device expected device ID
+     */
+    private void checkValues(JsonObject load, int rate, int latest,
+                             boolean valid, String device) {
+        assertThat(load, notNullValue());
+        assertThat(load.get("rate").asInt(), is(rate));
+        assertThat(load.get("latest").asInt(), is(latest));
+        assertThat(load.get("valid").asBoolean(), is(valid));
+        assertThat(load.get("time").asLong(),
+                lessThanOrEqualTo((System.currentTimeMillis())));
+        assertThat(load.get("link").asString(),
+                containsString("device=of:" + device));
+    }
+
+    /**
+     * Tests GET of a single Load statistics object.
+     */
+    @Test
+    public void testSingleLoadGet() {
+        final WebResource rs = resource();
+        final String response = rs.path("statistics/flows/link")
+                .queryParam("device", "of:0000000000000001")
+                .queryParam("port", "2")
+                .get(String.class);
+
+        final JsonObject result = JsonObject.readFrom(response);
+        assertThat(result, notNullValue());
+
+        assertThat(result.names(), hasSize(1));
+        assertThat(result.names().get(0), is("loads"));
+
+        final JsonArray jsonLoads = result.get("loads").asArray();
+        assertThat(jsonLoads, notNullValue());
+        assertThat(jsonLoads.size(), is(1));
+
+        JsonObject load1 = jsonLoads.get(0).asObject();
+        checkValues(load1, 111, 222, true, "src3");
+    }
+
+    /**
+     * Tests GET of all Load statistics objects.
+     */
+    @Test
+    public void testLoadsGet() {
+        final WebResource rs = resource();
+        final String response = rs.path("statistics/flows/link/").get(String.class);
+
+        final JsonObject result = JsonObject.readFrom(response);
+        assertThat(result, notNullValue());
+
+        assertThat(result.names(), hasSize(1));
+        assertThat(result.names().get(0), is("loads"));
+
+        final JsonArray jsonLoads = result.get("loads").asArray();
+        assertThat(jsonLoads, notNullValue());
+        assertThat(jsonLoads.size(), is(3));
+
+        // Hash the loads by the current field to allow easy lookup if the
+        // order changes.
+        HashMap<Integer, JsonObject> currentMap = new HashMap<>();
+        IntStream.range(0, jsonLoads.size())
+                .forEach(index -> currentMap.put(
+                        jsonLoads.get(index).asObject().get("latest").asInt(),
+                        jsonLoads.get(index).asObject()));
+
+        JsonObject load1 = currentMap.get(2);
+        checkValues(load1, 1, 2, true, "src1");
+
+        JsonObject load2 = currentMap.get(22);
+        checkValues(load2, 11, 22, true, "src2");
+
+        JsonObject load3 = currentMap.get(222);
+        checkValues(load3, 111, 222, true, "src3");
+
+    }
+}