third_party/protobuf: Update to HEAD (83d681ee2c)

third_party/protobuf/java/core/src/main/java/com/google/protobuf/ExtensionRegistryLite.java

 // Protocol Buffers - Google's data interchange format
 // Copyright 2008 Google Inc.  All rights reserved.
 // https://developers.google.com/protocol-buffers/
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 // notice, this list of conditions and the following disclaimer.
@@ skipping 61 matching lines @@
  */
 public class ExtensionRegistryLite {
 
   // Set true to enable lazy parsing feature for MessageSet.
   //
   // TODO(xiangl): Now we use a global flag to control whether enable lazy
   // parsing feature for MessageSet, which may be too crude for some
   // applications. Need to support this feature on smaller granularity.
   private static volatile boolean eagerlyParseMessageSets = false;
 
+  // Visible for testing.
+  static final String EXTENSION_CLASS_NAME = "com.google.protobuf.Extension";
+
+  /* @Nullable */
+  static Class<?> resolveExtensionClass() {
+    try {
+      return Class.forName(EXTENSION_CLASS_NAME);
+    } catch (ClassNotFoundException e) {
+      // See comment in ExtensionRegistryFactory on the potential expense of this.
+      return null;
+    }
+  }
+
+  /* @Nullable */
+  private static final Class<?> extensionClass = resolveExtensionClass();
+
   public static boolean isEagerlyParseMessageSets() {
     return eagerlyParseMessageSets;
   }
 
   public static void setEagerlyParseMessageSets(boolean isEagerlyParse) {
     eagerlyParseMessageSets = isEagerlyParse;
   }
 
-  /** Construct a new, empty instance. */
+  /**
+   * Construct a new, empty instance.
+   *
+   * <p>This may be an {@code ExtensionRegistry} if the full (non-Lite) proto libraries are
+   * available.
+   */
   public static ExtensionRegistryLite newInstance() {
-    return new ExtensionRegistryLite();
+    return ExtensionRegistryFactory.create();
   }
 
-  /** Get the unmodifiable singleton empty instance. */
+  /**
+   * Get the unmodifiable singleton empty instance of either ExtensionRegistryLite or
+   * {@code ExtensionRegistry} (if the full (non-Lite) proto libraries are available).
+   */
   public static ExtensionRegistryLite getEmptyRegistry() {
-    return EMPTY;
+    return ExtensionRegistryFactory.createEmpty();
   }
 
+
   /** Returns an unmodifiable view of the registry. */
   public ExtensionRegistryLite getUnmodifiable() {
     return new ExtensionRegistryLite(this);
   }
 
   /**
    * Find an extension by containing type and field number.
    *
    * @return Information about the extension if found, or {@code null}
    *         otherwise.
@@ skipping 11 matching lines @@
 
   /** Add an extension from a lite generated file to the registry. */
   public final void add(
       final GeneratedMessageLite.GeneratedExtension<?, ?> extension) {
     extensionsByNumber.put(
       new ObjectIntPair(extension.getContainingTypeDefaultInstance(),
                         extension.getNumber()),
       extension);
   }
 
+  /**
+   * Add an extension from a lite generated file to the registry only if it is
+   * a non-lite extension i.e. {@link GeneratedMessageLite.GeneratedExtension}. */
+  public final void add(ExtensionLite<?, ?> extension) {
+    if (GeneratedMessageLite.GeneratedExtension.class.isAssignableFrom(extension.getClass())) {
+      add((GeneratedMessageLite.GeneratedExtension<?, ?>) extension);
+    }
+    if (ExtensionRegistryFactory.isFullRegistry(this)) {
+      try {
+        this.getClass().getMethod("add", extensionClass).invoke(this, extension);
+      } catch (Exception e) {
+        throw new IllegalArgumentException(
+            String.format("Could not invoke ExtensionRegistry#add for %s", extension), e);
+      }
+    }
+  }
+
   // =================================================================
   // Private stuff.
 
   // Constructors are package-private so that ExtensionRegistry can subclass
   // this.
 
   ExtensionRegistryLite() {
     this.extensionsByNumber =
         new HashMap<ObjectIntPair,
                     GeneratedMessageLite.GeneratedExtension<?, ?>>();
   }
+  static final ExtensionRegistryLite EMPTY_REGISTRY_LITE =
+      new ExtensionRegistryLite(true);
 
   ExtensionRegistryLite(ExtensionRegistryLite other) {
-    if (other == EMPTY) {
+    if (other == EMPTY_REGISTRY_LITE) {
       this.extensionsByNumber = Collections.emptyMap();
     } else {
       this.extensionsByNumber =
         Collections.unmodifiableMap(other.extensionsByNumber);
     }
   }
 
   private final Map<ObjectIntPair,
                     GeneratedMessageLite.GeneratedExtension<?, ?>>
       extensionsByNumber;
 
-  private ExtensionRegistryLite(boolean empty) {
+  ExtensionRegistryLite(boolean empty) {
     this.extensionsByNumber = Collections.emptyMap();
   }
-  private static final ExtensionRegistryLite EMPTY =
-    new ExtensionRegistryLite(true);
 
   /** A (Object, int) pair, used as a map key. */
   private static final class ObjectIntPair {
     private final Object object;
     private final int number;
 
     ObjectIntPair(final Object object, final int number) {
       this.object = object;
       this.number = number;
     }
 
     @Override
     public int hashCode() {
       return System.identityHashCode(object) * ((1 << 16) - 1) + number;
     }
     @Override
     public boolean equals(final Object obj) {
       if (!(obj instanceof ObjectIntPair)) {
         return false;
       }
       final ObjectIntPair other = (ObjectIntPair)obj;
       return object == other.object && number == other.number;
     }
   }
 }