commit 635c2d7ed17dc21674d8cd7fcfe0239948d17804
author Thomas Vachuska <tom@onlab.us> Fri May 08 14:32:13 2015 -0700
committer Gerrit Code Review <gerrit@onlab.us> Mon May 11 15:49:23 2015 +0000
tree 23dba1ee4034ed602ea36fa484678287a504cd2e
parent 16f857baa359445bf8dbb8e6cee6924ebd23c03c

Adding device driver inheritance mechanism.

Change-Id: I9c883d32ce0c39f961eddd5c4624dc23f794fe4d

core/api/src/main/java/org/onosproject/net/driver/XmlDriverLoader.java

diff --git a/core/api/src/main/java/org/onosproject/net/driver/XmlDriverLoader.java b/core/api/src/main/java/org/onosproject/net/driver/XmlDriverLoader.java
index c3bb7ac..fc5e04a 100644
--- a/core/api/src/main/java/org/onosproject/net/driver/XmlDriverLoader.java
+++ b/core/api/src/main/java/org/onosproject/net/driver/XmlDriverLoader.java
@@ -16,6 +16,7 @@
 package org.onosproject.net.driver;
 
 import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.Maps;
 import org.apache.commons.configuration.ConfigurationException;
 import org.apache.commons.configuration.HierarchicalConfiguration;
 import org.apache.commons.configuration.XMLConfiguration;
@@ -51,6 +52,7 @@
     private static final String PROPERTY = "property";
 
     private static final String NAME = "[@name]";
+    private static final String EXTENDS = "[@extends]";
     private static final String MFG = "[@manufacturer]";
     private static final String HW = "[@hwVersion]";
     private static final String SW = "[@swVersion]";
@@ -59,6 +61,8 @@
 
     private final ClassLoader classLoader;
 
+    private Map<String, Driver> drivers = Maps.newHashMap();
+
     /**
      * Creates a new driver loader capable of loading drivers from the supplied
      * class loader.
@@ -74,18 +78,20 @@
      * produce a ready-to-register driver provider.
      *
      * @param driversStream stream containing the drivers definitions
+     * @param resolver      driver resolver
      * @return driver provider
      * @throws java.io.IOException if issues are encountered reading the stream
      *                             or parsing the driver definitions within
      */
-    public DefaultDriverProvider loadDrivers(InputStream driversStream) throws IOException {
+    public DefaultDriverProvider loadDrivers(InputStream driversStream,
+                                             DriverResolver resolver) throws IOException {
         try {
             XMLConfiguration cfg = new XMLConfiguration();
             cfg.setRootElementName(DRIVERS);
             cfg.setAttributeSplittingDisabled(true);
 
             cfg.load(driversStream);
-            return loadDrivers(cfg);
+            return loadDrivers(cfg, resolver);
         } catch (ConfigurationException e) {
             throw new IOException("Unable to load drivers", e);
         }
@@ -95,13 +101,18 @@
      * Loads a driver provider from the supplied hierarchical configuration.
      *
      * @param driversCfg hierarchical configuration containing the drivers definitions
+     * @param resolver   driver resolver
      * @return driver provider
      */
-    public DefaultDriverProvider loadDrivers(HierarchicalConfiguration driversCfg) {
+    public DefaultDriverProvider loadDrivers(HierarchicalConfiguration driversCfg,
+                                             DriverResolver resolver) {
         DefaultDriverProvider provider = new DefaultDriverProvider();
         for (HierarchicalConfiguration cfg : driversCfg.configurationsAt(DRIVER)) {
-            provider.addDriver(loadDriver(cfg));
+            DefaultDriver driver = loadDriver(cfg, resolver);
+            drivers.put(driver.name(), driver);
+            provider.addDriver(driver);
         }
+        drivers.clear();
         return provider;
     }
 
@@ -109,19 +120,30 @@
      * Loads a driver from the supplied hierarchical configuration.
      *
      * @param driverCfg hierarchical configuration containing the driver definition
+     * @param resolver  driver resolver
      * @return driver
      */
-    public DefaultDriver loadDriver(HierarchicalConfiguration driverCfg) {
+    public DefaultDriver loadDriver(HierarchicalConfiguration driverCfg,
+                                    DriverResolver resolver) {
         String name = driverCfg.getString(NAME);
+        String parentName = driverCfg.getString(EXTENDS);
         String manufacturer = driverCfg.getString(MFG, "");
         String hwVersion = driverCfg.getString(HW, "");
         String swVersion = driverCfg.getString(SW, "");
 
-        return new DefaultDriver(name, manufacturer, hwVersion, swVersion,
+        Driver parent = parentName != null ? resolve(parentName, resolver) : null;
+        return new DefaultDriver(name, parent, manufacturer, hwVersion, swVersion,
                                  parseBehaviours(driverCfg),
                                  parseProperties(driverCfg));
     }
 
+    // Resolves the driver by name locally at first and then using the specified resolver.
+    private Driver resolve(String parentName, DriverResolver resolver) {
+        Driver driver = drivers.get(parentName);
+        return driver != null ? driver :
+                (resolver != null ? resolver.getDriver(parentName) : null);
+    }
+
     // Parses the behaviours section.
     private Map<Class<? extends Behaviour>, Class<? extends Behaviour>>
     parseBehaviours(HierarchicalConfiguration driverCfg) {