Started an initial clone for DistributedDeviceStore
diff --git a/core/store/src/main/java/org/onlab/onos/store/device/impl/DeleteMe.java b/core/store/src/main/java/org/onlab/onos/store/device/impl/DeleteMe.java
deleted file mode 100644
index 4622053..0000000
--- a/core/store/src/main/java/org/onlab/onos/store/device/impl/DeleteMe.java
+++ /dev/null
@@ -1,7 +0,0 @@
-package org.onlab.onos.store.device.impl;
-
-/**
- * Created by tom on 9/19/14.
- */
-public class DeleteMe {
-}
diff --git a/core/store/src/main/java/org/onlab/onos/store/device/impl/DistributedDeviceStore.java b/core/store/src/main/java/org/onlab/onos/store/device/impl/DistributedDeviceStore.java
new file mode 100644
index 0000000..fb0e641
--- /dev/null
+++ b/core/store/src/main/java/org/onlab/onos/store/device/impl/DistributedDeviceStore.java
@@ -0,0 +1,275 @@
+package org.onlab.onos.store.device.impl;
+
+import com.google.common.collect.ImmutableList;
+import org.apache.felix.scr.annotations.Activate;
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Deactivate;
+import org.apache.felix.scr.annotations.Service;
+import org.onlab.onos.net.DefaultDevice;
+import org.onlab.onos.net.DefaultPort;
+import org.onlab.onos.net.Device;
+import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.net.MastershipRole;
+import org.onlab.onos.net.Port;
+import org.onlab.onos.net.PortNumber;
+import org.onlab.onos.net.device.DeviceDescription;
+import org.onlab.onos.net.device.DeviceEvent;
+import org.onlab.onos.net.device.DeviceStore;
+import org.onlab.onos.net.device.PortDescription;
+import org.onlab.onos.net.provider.ProviderId;
+import org.slf4j.Logger;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static org.onlab.onos.net.device.DeviceEvent.Type.*;
+import static org.slf4j.LoggerFactory.getLogger;
+
+/**
+ * Manages inventory of infrastructure devices using Hazelcast-backed map.
+ */
+@Component(immediate = true)
+@Service
+public class DistributedDeviceStore implements DeviceStore {
+
+    private final Logger log = getLogger(getClass());
+
+    public static final String DEVICE_NOT_FOUND = "Device with ID %s not found";
+
+    private final Map<DeviceId, DefaultDevice> devices = new ConcurrentHashMap<>();
+    private final Map<DeviceId, MastershipRole> roles = new ConcurrentHashMap<>();
+    private final Set<DeviceId> availableDevices = new HashSet<>();
+    private final Map<DeviceId, Map<PortNumber, Port>> devicePorts = new HashMap<>();
+
+    @Activate
+    public void activate() {
+        log.info("Started");
+    }
+
+    @Deactivate
+    public void deactivate() {
+        log.info("Stopped");
+    }
+
+    @Override
+    public int getDeviceCount() {
+        return devices.size();
+    }
+
+    @Override
+    public Iterable<Device> getDevices() {
+        return Collections.unmodifiableSet(new HashSet<Device>(devices.values()));
+    }
+
+    @Override
+    public Device getDevice(DeviceId deviceId) {
+        return devices.get(deviceId);
+    }
+
+    @Override
+    public DeviceEvent createOrUpdateDevice(ProviderId providerId, DeviceId deviceId,
+                                     DeviceDescription deviceDescription) {
+        DefaultDevice device = devices.get(deviceId);
+        if (device == null) {
+            return createDevice(providerId, deviceId, deviceDescription);
+        }
+        return updateDevice(providerId, device, deviceDescription);
+    }
+
+    // Creates the device and returns the appropriate event if necessary.
+    private DeviceEvent createDevice(ProviderId providerId, DeviceId deviceId,
+                                     DeviceDescription desc) {
+        DefaultDevice device = new DefaultDevice(providerId, deviceId, desc.type(),
+                                                 desc.manufacturer(),
+                                                 desc.hwVersion(), desc.swVersion(),
+                                                 desc.serialNumber());
+        synchronized (this) {
+            devices.put(deviceId, device);
+            availableDevices.add(deviceId);
+
+            // For now claim the device as a master automatically.
+            roles.put(deviceId, MastershipRole.MASTER);
+        }
+        return new DeviceEvent(DeviceEvent.Type.DEVICE_ADDED, device, null);
+    }
+
+    // Updates the device and returns the appropriate event if necessary.
+    private DeviceEvent updateDevice(ProviderId providerId, DefaultDevice device,
+                                     DeviceDescription desc) {
+        // We allow only certain attributes to trigger update
+        if (!Objects.equals(device.hwVersion(), desc.hwVersion()) ||
+                !Objects.equals(device.swVersion(), desc.swVersion())) {
+            DefaultDevice updated = new DefaultDevice(providerId, device.id(),
+                                                      desc.type(),
+                                                      desc.manufacturer(),
+                                                      desc.hwVersion(),
+                                                      desc.swVersion(),
+                                                      desc.serialNumber());
+            synchronized (this) {
+                devices.put(device.id(), updated);
+                availableDevices.add(device.id());
+            }
+            return new DeviceEvent(DeviceEvent.Type.DEVICE_UPDATED, device, null);
+        }
+
+        // Otherwise merely attempt to change availability
+        synchronized (this) {
+            boolean added = availableDevices.add(device.id());
+            return !added ? null :
+                    new DeviceEvent(DEVICE_AVAILABILITY_CHANGED, device, null);
+        }
+    }
+
+    @Override
+    public DeviceEvent markOffline(DeviceId deviceId) {
+        synchronized (this) {
+            Device device = devices.get(deviceId);
+            boolean removed = device != null && availableDevices.remove(deviceId);
+            return !removed ? null :
+                    new DeviceEvent(DEVICE_AVAILABILITY_CHANGED, device, null);
+        }
+    }
+
+    @Override
+    public List<DeviceEvent> updatePorts(DeviceId deviceId,
+                                  List<PortDescription> portDescriptions) {
+        List<DeviceEvent> events = new ArrayList<>();
+        synchronized (this) {
+            Device device = devices.get(deviceId);
+            checkArgument(device != null, DEVICE_NOT_FOUND, deviceId);
+            Map<PortNumber, Port> ports = getPortMap(deviceId);
+
+            // Add new ports
+            Set<PortNumber> processed = new HashSet<>();
+            for (PortDescription portDescription : portDescriptions) {
+                Port port = ports.get(portDescription.portNumber());
+                events.add(port == null ?
+                                   createPort(device, portDescription, ports) :
+                                   updatePort(device, port, portDescription, ports));
+                processed.add(portDescription.portNumber());
+            }
+
+            events.addAll(pruneOldPorts(device, ports, processed));
+        }
+        return events;
+    }
+
+    // Creates a new port based on the port description adds it to the map and
+    // Returns corresponding event.
+    private DeviceEvent createPort(Device device, PortDescription portDescription,
+                                   Map<PortNumber, Port> ports) {
+        DefaultPort port = new DefaultPort(device, portDescription.portNumber(),
+                                           portDescription.isEnabled());
+        ports.put(port.number(), port);
+        return new DeviceEvent(PORT_ADDED, device, port);
+    }
+
+    // CHecks if the specified port requires update and if so, it replaces the
+    // existing entry in the map and returns corresponding event.
+    private DeviceEvent updatePort(Device device, Port port,
+                                   PortDescription portDescription,
+                                   Map<PortNumber, Port> ports) {
+        if (port.isEnabled() != portDescription.isEnabled()) {
+            DefaultPort updatedPort =
+                    new DefaultPort(device, portDescription.portNumber(),
+                                    portDescription.isEnabled());
+            ports.put(port.number(), updatedPort);
+            return new DeviceEvent(PORT_UPDATED, device, port);
+        }
+        return null;
+    }
+
+    // Prunes the specified list of ports based on which ports are in the
+    // processed list and returns list of corresponding events.
+    private List<DeviceEvent> pruneOldPorts(Device device,
+                                            Map<PortNumber, Port> ports,
+                                            Set<PortNumber> processed) {
+        List<DeviceEvent> events = new ArrayList<>();
+        Iterator<PortNumber> iterator = ports.keySet().iterator();
+        while (iterator.hasNext()) {
+            PortNumber portNumber = iterator.next();
+            if (!processed.contains(portNumber)) {
+                events.add(new DeviceEvent(PORT_REMOVED, device,
+                                           ports.get(portNumber)));
+                iterator.remove();
+            }
+        }
+        return events;
+    }
+
+    // Gets the map of ports for the specified device; if one does not already
+    // exist, it creates and registers a new one.
+    private Map<PortNumber, Port> getPortMap(DeviceId deviceId) {
+        Map<PortNumber, Port> ports = devicePorts.get(deviceId);
+        if (ports == null) {
+            ports = new HashMap<>();
+            devicePorts.put(deviceId, ports);
+        }
+        return ports;
+    }
+
+    @Override
+    public DeviceEvent updatePortStatus(DeviceId deviceId,
+                                 PortDescription portDescription) {
+        synchronized (this) {
+            Device device = devices.get(deviceId);
+            checkArgument(device != null, DEVICE_NOT_FOUND, deviceId);
+            Map<PortNumber, Port> ports = getPortMap(deviceId);
+            Port port = ports.get(portDescription.portNumber());
+            return updatePort(device, port, portDescription, ports);
+        }
+    }
+
+    @Override
+    public List<Port> getPorts(DeviceId deviceId) {
+        Map<PortNumber, Port> ports = devicePorts.get(deviceId);
+        return ports == null ? new ArrayList<Port>() : ImmutableList.copyOf(ports.values());
+    }
+
+    @Override
+    public Port getPort(DeviceId deviceId, PortNumber portNumber) {
+        Map<PortNumber, Port> ports = devicePorts.get(deviceId);
+        return ports == null ? null : ports.get(portNumber);
+    }
+
+    @Override
+    public boolean isAvailable(DeviceId deviceId) {
+        return availableDevices.contains(deviceId);
+    }
+
+    @Override
+    public MastershipRole getRole(DeviceId deviceId) {
+        MastershipRole role = roles.get(deviceId);
+        return role != null ? role : MastershipRole.NONE;
+    }
+
+    @Override
+    public DeviceEvent setRole(DeviceId deviceId, MastershipRole role) {
+        synchronized (this) {
+            Device device = getDevice(deviceId);
+            checkArgument(device != null, DEVICE_NOT_FOUND, deviceId);
+            MastershipRole oldRole = roles.put(deviceId, role);
+            return oldRole == role ? null :
+                    new DeviceEvent(DEVICE_MASTERSHIP_CHANGED, device, null);
+        }
+    }
+
+    @Override
+    public DeviceEvent removeDevice(DeviceId deviceId) {
+        synchronized (this) {
+            roles.remove(deviceId);
+            Device device = devices.remove(deviceId);
+            return device == null ? null :
+                    new DeviceEvent(DEVICE_REMOVED, device, null);
+        }
+    }
+}