Ejemplo n.º 1
0
  String[] getPluginDirectories() {

    ArrayList<String> directories = new ArrayList<String>();
    PackageManager pm = this.mAppContext.getPackageManager();
    List<ResolveInfo> plugins =
        pm.queryIntentServices(
            new Intent(PLUGIN_ACTION), PackageManager.GET_SERVICES | PackageManager.GET_META_DATA);

    synchronized (mPackageInfoCache) {

      // clear the list of existing packageInfo objects
      mPackageInfoCache.clear();

      for (ResolveInfo info : plugins) {

        // retrieve the plugin's service information
        ServiceInfo serviceInfo = info.serviceInfo;
        if (serviceInfo == null) {
          Log.w(LOGTAG, "Ignore bad plugin");
          continue;
        }

        Log.w(LOGTAG, "Loading plugin: " + serviceInfo.packageName);

        // retrieve information from the plugin's manifest
        PackageInfo pkgInfo;
        try {
          pkgInfo =
              pm.getPackageInfo(
                  serviceInfo.packageName,
                  PackageManager.GET_PERMISSIONS | PackageManager.GET_SIGNATURES);
        } catch (Exception e) {
          Log.w(LOGTAG, "Can't find plugin: " + serviceInfo.packageName);
          continue;
        }
        if (pkgInfo == null) {
          Log.w(
              LOGTAG,
              "Loading plugin: "
                  + serviceInfo.packageName
                  + ". Could not load package information.");
          continue;
        }

        /*
         * find the location of the plugin's shared library. The default
         * is to assume the app is either a user installed app or an
         * updated system app. In both of these cases the library is
         * stored in the app's data directory.
         */
        String directory = pkgInfo.applicationInfo.dataDir + "/lib";
        final int appFlags = pkgInfo.applicationInfo.flags;
        final int updatedSystemFlags =
            ApplicationInfo.FLAG_SYSTEM | ApplicationInfo.FLAG_UPDATED_SYSTEM_APP;
        // preloaded system app with no user updates
        if ((appFlags & updatedSystemFlags) == ApplicationInfo.FLAG_SYSTEM) {
          directory = PLUGIN_SYSTEM_LIB + pkgInfo.packageName;
        }

        // check if the plugin has the required permissions
        String permissions[] = pkgInfo.requestedPermissions;
        if (permissions == null) {
          Log.w(
              LOGTAG,
              "Loading plugin: "
                  + serviceInfo.packageName
                  + ". Does not have required permission.");
          continue;
        }
        boolean permissionOk = false;
        for (String permit : permissions) {
          if (PLUGIN_PERMISSION.equals(permit)) {
            permissionOk = true;
            break;
          }
        }
        if (!permissionOk) {
          Log.w(
              LOGTAG,
              "Loading plugin: "
                  + serviceInfo.packageName
                  + ". Does not have required permission (2).");
          continue;
        }

        // check to ensure the plugin is properly signed
        Signature signatures[] = pkgInfo.signatures;
        if (signatures == null) {
          Log.w(LOGTAG, "Loading plugin: " + serviceInfo.packageName + ". Not signed.");
          continue;
        }

        // determine the type of plugin from the manifest
        if (serviceInfo.metaData == null) {
          Log.e(LOGTAG, "The plugin '" + serviceInfo.name + "' has no type defined");
          continue;
        }

        String pluginType = serviceInfo.metaData.getString(PLUGIN_TYPE);
        if (!TYPE_NATIVE.equals(pluginType)) {
          Log.e(LOGTAG, "Unrecognized plugin type: " + pluginType);
          continue;
        }

        try {
          Class<?> cls = getPluginClass(serviceInfo.packageName, serviceInfo.name);

          // TODO implement any requirements of the plugin class here!
          boolean classFound = true;

          if (!classFound) {
            Log.e(
                LOGTAG,
                "The plugin's class' "
                    + serviceInfo.name
                    + "' does not extend the appropriate class.");
            continue;
          }

        } catch (NameNotFoundException e) {
          Log.e(LOGTAG, "Can't find plugin: " + serviceInfo.packageName);
          continue;
        } catch (ClassNotFoundException e) {
          Log.e(LOGTAG, "Can't find plugin's class: " + serviceInfo.name);
          continue;
        }

        // if all checks have passed then make the plugin available
        mPackageInfoCache.add(pkgInfo);
        directories.add(directory);
      }
    }

    return directories.toArray(new String[directories.size()]);
  }
  /*
   * Non-recursive version of object descend. This consumes more memory than recursive in-depth
   * traversal but prevents stack overflows on long chains of objects
   * or complex graphs (a max. recursion depth on my machine was ~5000 objects linked in a chain
   * so not too much).
   */
  private static long measureObjectSize(Object root) {
    // Objects seen so far.
    final IdentityHashSet<Object> seen = new IdentityHashSet<Object>();
    // Class cache with reference Field and precalculated shallow size.
    final IdentityHashMap<Class<?>, ClassCache> classCache =
        new IdentityHashMap<Class<?>, ClassCache>();
    // Stack of objects pending traversal. Recursion caused stack overflows.
    final ArrayList<Object> stack = new ArrayList<Object>();
    stack.add(root);

    long totalSize = 0;
    while (!stack.isEmpty()) {
      final Object ob = stack.remove(stack.size() - 1);

      if (ob == null || seen.contains(ob)) {
        continue;
      }
      seen.add(ob);

      final Class<?> obClazz = ob.getClass();
      if (obClazz.isArray()) {
        /*
         * Consider an array, possibly of primitive types. Push any of its references to
         * the processing stack and accumulate this array's shallow size.
         */
        long size = NUM_BYTES_ARRAY_HEADER;
        final int len = Array.getLength(ob);
        if (len > 0) {
          Class<?> componentClazz = obClazz.getComponentType();
          if (componentClazz.isPrimitive()) {
            size += (long) len * primitiveSizes.get(componentClazz);
          } else {
            size += (long) NUM_BYTES_OBJECT_REF * len;

            // Push refs for traversal later.
            for (int i = len; --i >= 0; ) {
              final Object o = Array.get(ob, i);
              if (o != null && !seen.contains(o)) {
                stack.add(o);
              }
            }
          }
        }
        totalSize += alignObjectSize(size);
      } else {
        /*
         * Consider an object. Push any references it has to the processing stack
         * and accumulate this object's shallow size.
         */
        try {
          ClassCache cachedInfo = classCache.get(obClazz);
          if (cachedInfo == null) {
            classCache.put(obClazz, cachedInfo = createCacheEntry(obClazz));
          }

          for (Field f : cachedInfo.referenceFields) {
            // Fast path to eliminate redundancies.
            final Object o = f.get(ob);
            if (o != null && !seen.contains(o)) {
              stack.add(o);
            }
          }

          totalSize += cachedInfo.alignedShallowInstanceSize;
        } catch (IllegalAccessException e) {
          // this should never happen as we enabled setAccessible().
          throw new RuntimeException("Reflective field access failed?", e);
        }
      }
    }

    // Help the GC (?).
    seen.clear();
    stack.clear();
    classCache.clear();

    return totalSize;
  }