CLI command to help debug the mapping of next-Objectives to the
groups that are created by device drivers.

Change-Id: Iff9e04e5e96b2cabbdb40e83215315d2e27791a6
diff --git a/core/api/src/main/java/org/onosproject/net/behaviour/Pipeliner.java b/core/api/src/main/java/org/onosproject/net/behaviour/Pipeliner.java
index dcfc588..d1604be 100644
--- a/core/api/src/main/java/org/onosproject/net/behaviour/Pipeliner.java
+++ b/core/api/src/main/java/org/onosproject/net/behaviour/Pipeliner.java
@@ -15,6 +15,8 @@
  */
 package org.onosproject.net.behaviour;
 
+import java.util.List;
+
 import org.onosproject.net.DeviceId;
 import org.onosproject.net.driver.HandlerBehaviour;
 import org.onosproject.net.flowobjective.FilteringObjective;
@@ -54,4 +56,18 @@
      * @param nextObjective a next objectives
      */
     void next(NextObjective nextObjective);
+
+    /**
+     *  Retrieves a mapping of the nextObjective to the groups in the dataplane,
+     *  and returns it in a form that can be displayed on the CLI. Typically
+     *  group-ids are returned for groups with multiple buckets, where each list element
+     *  represents a bucket. For nextObjectives that are converted to flow-actions,
+     *  an empty list is returned.
+     *
+     *  @param nextGroup representation of the nextObjective. This representation
+     *                   is stored in the distributed group store
+     *  @return a list of preformatted strings representing group information, or
+     *          an empty list if no groups were created
+     */
+    List<String> getNextMappings(NextGroup nextGroup);
 }
diff --git a/core/api/src/main/java/org/onosproject/net/flowobjective/FlowObjectiveService.java b/core/api/src/main/java/org/onosproject/net/flowobjective/FlowObjectiveService.java
index 415264e..6e905de 100644
--- a/core/api/src/main/java/org/onosproject/net/flowobjective/FlowObjectiveService.java
+++ b/core/api/src/main/java/org/onosproject/net/flowobjective/FlowObjectiveService.java
@@ -16,6 +16,9 @@
 package org.onosproject.net.flowobjective;
 
 import com.google.common.annotations.Beta;
+
+import java.util.List;
+
 import org.onosproject.net.DeviceId;
 
 /**
@@ -82,4 +85,17 @@
             throw new UnsupportedOperationException("Unsupported objective of type " + objective.getClass());
         }
     }
+
+    /**
+     * Retrieve all nextObjective to group mappings known to this onos instance,
+     * in a format meant for display on the CLI, to help with debugging. Applications
+     * are only aware of next-Ids, while the group sub-system is only aware of group-ids.
+     * This method fills in the gap by providing information on the mapping
+     * between next-ids and group-ids done by device-drivers.
+     *
+     * @return a list of strings preformatted by the device-drivers to provide
+     *         information on next-id to group-id mapping. Consumed by the
+     *         "next-ids" command on the CLI.
+     */
+    List<String> getNextMappings();
 }
diff --git a/core/api/src/main/java/org/onosproject/net/flowobjective/FlowObjectiveStore.java b/core/api/src/main/java/org/onosproject/net/flowobjective/FlowObjectiveStore.java
index 85dec0f..a0a7634 100644
--- a/core/api/src/main/java/org/onosproject/net/flowobjective/FlowObjectiveStore.java
+++ b/core/api/src/main/java/org/onosproject/net/flowobjective/FlowObjectiveStore.java
@@ -16,6 +16,9 @@
 package org.onosproject.net.flowobjective;
 
 import com.google.common.annotations.Beta;
+
+import java.util.Map;
+
 import org.onosproject.net.behaviour.NextGroup;
 import org.onosproject.store.Store;
 
@@ -53,6 +56,13 @@
     NextGroup removeNextGroup(Integer nextId);
 
     /**
+     * Fetch all groups from the store and their mapping to nextIds.
+     *
+     * @return a map that represents the current snapshot of Next-ids to NextGroups
+     */
+    Map<Integer, NextGroup> getAllGroups();
+
+    /**
      * Allocates a next objective id. This id is globally unique
      *
      * @return an integer
diff --git a/core/api/src/test/java/org/onosproject/net/behaviour/PipelinerAdapter.java b/core/api/src/test/java/org/onosproject/net/behaviour/PipelinerAdapter.java
index 73e83cd..203bbbe 100644
--- a/core/api/src/test/java/org/onosproject/net/behaviour/PipelinerAdapter.java
+++ b/core/api/src/test/java/org/onosproject/net/behaviour/PipelinerAdapter.java
@@ -15,6 +15,8 @@
  */
 package org.onosproject.net.behaviour;
 
+import java.util.List;
+
 import org.onosproject.net.DeviceId;
 import org.onosproject.net.driver.DriverData;
 import org.onosproject.net.driver.DriverHandler;
@@ -65,4 +67,9 @@
     public void setData(DriverData data) {
 
     }
+
+    @Override
+    public List<String> getNextMappings(NextGroup nextGroup) {
+        return null;
+    }
 }
diff --git a/core/net/src/main/java/org/onosproject/net/flowobjective/impl/FlowObjectiveManager.java b/core/net/src/main/java/org/onosproject/net/flowobjective/impl/FlowObjectiveManager.java
index d82b6f7..b7287c7 100644
--- a/core/net/src/main/java/org/onosproject/net/flowobjective/impl/FlowObjectiveManager.java
+++ b/core/net/src/main/java/org/onosproject/net/flowobjective/impl/FlowObjectiveManager.java
@@ -30,6 +30,7 @@
 import org.onosproject.mastership.MastershipListener;
 import org.onosproject.mastership.MastershipService;
 import org.onosproject.net.DeviceId;
+import org.onosproject.net.behaviour.NextGroup;
 import org.onosproject.net.behaviour.Pipeliner;
 import org.onosproject.net.behaviour.PipelinerContext;
 import org.onosproject.net.device.DeviceEvent;
@@ -53,7 +54,9 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.util.ArrayList;
 import java.util.Collections;
+import java.util.List;
 import java.util.Map;
 import java.util.Objects;
 import java.util.Set;
@@ -123,6 +126,10 @@
 
     private Map<Integer, Set<PendingNext>> pendingForwards = Maps.newConcurrentMap();
 
+    // local store to track which nextObjectives were sent to which device
+    // for debugging purposes
+    private Map<Integer, DeviceId> nextToDevice = Maps.newConcurrentMap();
+
     private ExecutorService executorService;
 
     @Activate
@@ -143,6 +150,7 @@
         executorService.shutdown();
         pipeliners.clear();
         driverHandlers.clear();
+        nextToDevice.clear();
         log.info("Stopped");
     }
 
@@ -215,6 +223,7 @@
     @Override
     public void next(DeviceId deviceId, NextObjective nextObjective) {
         checkPermission(FLOWRULE_WRITE);
+        nextToDevice.put(nextObjective.id(), deviceId);
         executorService.submit(new ObjectiveInstaller(deviceId, nextObjective));
     }
 
@@ -443,4 +452,33 @@
             return false;
         }
     }
+
+    @Override
+    public List<String> getNextMappings() {
+        List<String> mappings = new ArrayList<>();
+        Map<Integer, NextGroup> allnexts = flowObjectiveStore.getAllGroups();
+        // XXX if the NextGroup upon decoding stored info of the deviceId
+        // then info on any nextObj could be retrieved from one controller instance.
+        // Right now the drivers on one instance can only fetch for next-ids that came
+        // to them.
+        // Also, we still need to send the right next-id to the right driver as potentially
+        // there can be different drivers for different devices. But on that account,
+        // no instance should be decoding for another instance's nextIds.
+
+        for (Map.Entry<Integer, NextGroup> e : allnexts.entrySet()) {
+            // get the device this next Objective was sent to
+            DeviceId deviceId = nextToDevice.get(e.getKey());
+            mappings.add("NextId " + e.getKey() + ": " +
+                    ((deviceId != null) ? deviceId : "nextId not in this onos instance"));
+            if (deviceId != null) {
+                // this instance of the controller sent the nextObj to a driver
+                Pipeliner pipeliner = getDevicePipeliner(deviceId);
+                List<String> nextMappings = pipeliner.getNextMappings(e.getValue());
+                if (nextMappings != null) {
+                    mappings.addAll(nextMappings);
+                }
+            }
+        }
+        return mappings;
+    }
 }
diff --git a/core/net/src/main/java/org/onosproject/net/flowobjective/impl/composition/FlowObjectiveCompositionManager.java b/core/net/src/main/java/org/onosproject/net/flowobjective/impl/composition/FlowObjectiveCompositionManager.java
index 2041b5b..b0bca13 100644
--- a/core/net/src/main/java/org/onosproject/net/flowobjective/impl/composition/FlowObjectiveCompositionManager.java
+++ b/core/net/src/main/java/org/onosproject/net/flowobjective/impl/composition/FlowObjectiveCompositionManager.java
@@ -436,4 +436,10 @@
         str += ")";
         return str;
     }
+
+    @Override
+    public List<String> getNextMappings() {
+        // TODO Implementation deferred as this is an experimental component.
+        return null;
+    }
 }
diff --git a/core/net/src/test/java/org/onosproject/net/flowobjective/impl/FlowObjectiveStoreAdapter.java b/core/net/src/test/java/org/onosproject/net/flowobjective/impl/FlowObjectiveStoreAdapter.java
index 378ea73..d73cc59 100644
--- a/core/net/src/test/java/org/onosproject/net/flowobjective/impl/FlowObjectiveStoreAdapter.java
+++ b/core/net/src/test/java/org/onosproject/net/flowobjective/impl/FlowObjectiveStoreAdapter.java
@@ -15,6 +15,8 @@
  */
 package org.onosproject.net.flowobjective.impl;
 
+import java.util.Map;
+
 import org.onosproject.net.behaviour.NextGroup;
 import org.onosproject.net.flowobjective.FlowObjectiveStore;
 import org.onosproject.net.flowobjective.FlowObjectiveStoreDelegate;
@@ -57,4 +59,9 @@
     public boolean hasDelegate() {
         return false;
     }
+
+    @Override
+    public Map<Integer, NextGroup> getAllGroups() {
+        return null;
+    }
 }
diff --git a/core/store/dist/src/main/java/org/onosproject/store/flowobjective/impl/DistributedFlowObjectiveStore.java b/core/store/dist/src/main/java/org/onosproject/store/flowobjective/impl/DistributedFlowObjectiveStore.java
index 75a9b89..534289c 100644
--- a/core/store/dist/src/main/java/org/onosproject/store/flowobjective/impl/DistributedFlowObjectiveStore.java
+++ b/core/store/dist/src/main/java/org/onosproject/store/flowobjective/impl/DistributedFlowObjectiveStore.java
@@ -37,6 +37,9 @@
 
 import static org.slf4j.LoggerFactory.getLogger;
 
+import java.util.HashMap;
+import java.util.Map;
+
 /**
  * Manages the inventory of created next groups.
  */
@@ -106,6 +109,18 @@
     }
 
     @Override
+    public Map<Integer, NextGroup> getAllGroups() {
+        Map<Integer, NextGroup> nextGroupMappings = new HashMap<>();
+        for (int key : nextGroups.keySet()) {
+            NextGroup nextGroup = getNextGroup(key);
+            if (nextGroup != null) {
+                nextGroupMappings.put(key, nextGroup);
+            }
+        }
+        return nextGroupMappings;
+    }
+
+    @Override
     public int allocateNextId() {
         return (int) nextIds.incrementAndGet();
     }