root/third_party/protobuf/java/src/main/java/com/google/protobuf/AbstractMessage.java

DEFINITIONS

1. SuppressWarnings
2. isInitialized
3. findInitializationErrors
4. getInitializationErrorString
5. delimitWithCommas
6. toString
7. writeTo
8. getSerializedSize
9. equals
10. hashCode
11. SuppressWarnings
12. hashFields
13. hashLong
14. hashBoolean
15. newUninitializedMessageException
16. hashEnum
17. hashEnumList
18. SuppressWarnings
19. clone
20. clear
21. findInitializationErrors
22. getInitializationErrorString
23. mergeFrom
24. mergeFrom
25. mergeFrom
26. addRepeatedField
27. setField
28. hasOriginalMessage
29. getOriginalMessage
30. mergeOriginalMessage
31. mergeFieldFrom
32. mergeMessageSetExtensionFromCodedStream
33. eagerlyMergeMessageSetExtension
34. mergeMessageSetExtensionFromBytes
35. mergeUnknownFields
36. getFieldBuilder
37. newUninitializedMessageException
38. findMissingFields
39. findMissingFields
40. subMessagePrefix
41. mergeFrom
42. mergeFrom
43. mergeFrom
44. mergeFrom
45. mergeFrom
46. mergeFrom
47. mergeFrom
48. mergeFrom
49. mergeDelimitedFrom
50. mergeDelimitedFrom

// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc.  All rights reserved.
// http://code.google.com/p/protobuf/
//
// 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.
//     * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
//     * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

package com.google.protobuf;

import com.google.protobuf.Descriptors.Descriptor;
import com.google.protobuf.Descriptors.FieldDescriptor;
import com.google.protobuf.GeneratedMessage.ExtendableBuilder;
import com.google.protobuf.Internal.EnumLite;

import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

/**
 * A partial implementation of the {@link Message} interface which implements
 * as many methods of that interface as possible in terms of other methods.
 *
 * @author kenton@google.com Kenton Varda
 */
public abstract class AbstractMessage extends AbstractMessageLite
                                      implements Message {
  @SuppressWarnings("unchecked")
  public boolean isInitialized() {
    // Check that all required fields are present.
    for (final FieldDescriptor field : getDescriptorForType().getFields()) {
      if (field.isRequired()) {
        if (!hasField(field)) {
          return false;
        }
      }
    }

    // Check that embedded messages are initialized.
    for (final Map.Entry<FieldDescriptor, Object> entry :
        getAllFields().entrySet()) {
      final FieldDescriptor field = entry.getKey();
      if (field.getJavaType() == FieldDescriptor.JavaType.MESSAGE) {
        if (field.isRepeated()) {
          for (final Message element : (List<Message>) entry.getValue()) {
            if (!element.isInitialized()) {
              return false;
            }
          }
        } else {
          if (!((Message) entry.getValue()).isInitialized()) {
            return false;
          }
        }
      }
    }

    return true;
  }

  public List<String> findInitializationErrors() {
    return Builder.findMissingFields(this);
  }

  public String getInitializationErrorString() {
    return delimitWithCommas(findInitializationErrors());
  }

  private static String delimitWithCommas(List<String> parts) {
    StringBuilder result = new StringBuilder();
    for (String part : parts) {
      if (result.length() > 0) {
        result.append(", ");
      }
      result.append(part);
    }
    return result.toString();
  }

  @Override
  public final String toString() {
    return TextFormat.printToString(this);
  }

  public void writeTo(final CodedOutputStream output) throws IOException {
    final boolean isMessageSet =
        getDescriptorForType().getOptions().getMessageSetWireFormat();

    for (final Map.Entry<FieldDescriptor, Object> entry :
        getAllFields().entrySet()) {
      final FieldDescriptor field = entry.getKey();
      final Object value = entry.getValue();
      if (isMessageSet && field.isExtension() &&
          field.getType() == FieldDescriptor.Type.MESSAGE &&
          !field.isRepeated()) {
        output.writeMessageSetExtension(field.getNumber(), (Message) value);
      } else {
        FieldSet.writeField(field, value, output);
      }
    }

    final UnknownFieldSet unknownFields = getUnknownFields();
    if (isMessageSet) {
      unknownFields.writeAsMessageSetTo(output);
    } else {
      unknownFields.writeTo(output);
    }
  }

  private int memoizedSize = -1;

  public int getSerializedSize() {
    int size = memoizedSize;
    if (size != -1) {
      return size;
    }

    size = 0;
    final boolean isMessageSet =
        getDescriptorForType().getOptions().getMessageSetWireFormat();

    for (final Map.Entry<FieldDescriptor, Object> entry :
        getAllFields().entrySet()) {
      final FieldDescriptor field = entry.getKey();
      final Object value = entry.getValue();
      if (isMessageSet && field.isExtension() &&
          field.getType() == FieldDescriptor.Type.MESSAGE &&
          !field.isRepeated()) {
        size += CodedOutputStream.computeMessageSetExtensionSize(
            field.getNumber(), (Message) value);
      } else {
        size += FieldSet.computeFieldSize(field, value);
      }
    }

    final UnknownFieldSet unknownFields = getUnknownFields();
    if (isMessageSet) {
      size += unknownFields.getSerializedSizeAsMessageSet();
    } else {
      size += unknownFields.getSerializedSize();
    }

    memoizedSize = size;
    return size;
  }

  @Override
  public boolean equals(final Object other) {
    if (other == this) {
      return true;
    }
    if (!(other instanceof Message)) {
      return false;
    }
    final Message otherMessage = (Message) other;
    if (getDescriptorForType() != otherMessage.getDescriptorForType()) {
      return false;
    }
    return getAllFields().equals(otherMessage.getAllFields()) &&
        getUnknownFields().equals(otherMessage.getUnknownFields());
  }

  @Override
  public int hashCode() {
    int hash = 41;
    hash = (19 * hash) + getDescriptorForType().hashCode();
    hash = hashFields(hash, getAllFields());
    hash = (29 * hash) + getUnknownFields().hashCode();
    return hash;
  }

  /** Get a hash code for given fields and values, using the given seed. */
  @SuppressWarnings("unchecked")
  protected int hashFields(int hash, Map<FieldDescriptor, Object> map) {
    for (Map.Entry<FieldDescriptor, Object> entry : map.entrySet()) {
      FieldDescriptor field = entry.getKey();
      Object value = entry.getValue();
      hash = (37 * hash) + field.getNumber();
      if (field.getType() != FieldDescriptor.Type.ENUM){
        hash = (53 * hash) + value.hashCode();
      } else if (field.isRepeated()) {
        List<? extends EnumLite> list = (List<? extends EnumLite>) value;
        hash = (53 * hash) + hashEnumList(list);
      } else {
        hash = (53 * hash) + hashEnum((EnumLite) value);
      }
    }
    return hash;
  }

  /**
   * Helper method for implementing {@link Message#hashCode()}.
   * @see Boolean#hashCode()
   */
  protected static int hashLong(long n) {
    return (int) (n ^ (n >>> 32));
  }

  /**
   * Helper method for implementing {@link Message#hashCode()}.
   * @see Boolean#hashCode()
   */
  protected static int hashBoolean(boolean b) {
    return b ? 1231 : 1237;
  }

  /**
   * Package private helper method for AbstractParser to create
   * UninitializedMessageException with missing field information.
   */
  @Override
  UninitializedMessageException newUninitializedMessageException() {
    return Builder.newUninitializedMessageException(this);
  }

  /**
   * Helper method for implementing {@link Message#hashCode()}.
   * <p>
   * This is needed because {@link java.lang.Enum#hashCode()} is final, but we
   * need to use the field number as the hash code to ensure compatibility
   * between statically and dynamically generated enum objects.
   */
  protected static int hashEnum(EnumLite e) {
    return e.getNumber();
  }

  /** Helper method for implementing {@link Message#hashCode()}. */
  protected static int hashEnumList(List<? extends EnumLite> list) {
    int hash = 1;
    for (EnumLite e : list) {
      hash = 31 * hash + hashEnum(e);
    }
    return hash;
  }

  // =================================================================

  /**
   * A partial implementation of the {@link Message.Builder} interface which
   * implements as many methods of that interface as possible in terms of
   * other methods.
   */
  @SuppressWarnings("unchecked")
  public static abstract class Builder<BuilderType extends Builder>
      extends AbstractMessageLite.Builder<BuilderType>
      implements Message.Builder {
    // The compiler produces an error if this is not declared explicitly.
    @Override
    public abstract BuilderType clone();

    public BuilderType clear() {
      for (final Map.Entry<FieldDescriptor, Object> entry :
           getAllFields().entrySet()) {
        clearField(entry.getKey());
      }
      return (BuilderType) this;
    }

    public List<String> findInitializationErrors() {
      return findMissingFields(this);
    }

    public String getInitializationErrorString() {
      return delimitWithCommas(findInitializationErrors());
    }

    public BuilderType mergeFrom(final Message other) {
      if (other.getDescriptorForType() != getDescriptorForType()) {
        throw new IllegalArgumentException(
          "mergeFrom(Message) can only merge messages of the same type.");
      }

      // Note:  We don't attempt to verify that other's fields have valid
      //   types.  Doing so would be a losing battle.  We'd have to verify
      //   all sub-messages as well, and we'd have to make copies of all of
      //   them to insure that they don't change after verification (since
      //   the Message interface itself cannot enforce immutability of
      //   implementations).
      // TODO(kenton):  Provide a function somewhere called makeDeepCopy()
      //   which allows people to make secure deep copies of messages.

      for (final Map.Entry<FieldDescriptor, Object> entry :
           other.getAllFields().entrySet()) {
        final FieldDescriptor field = entry.getKey();
        if (field.isRepeated()) {
          for (final Object element : (List)entry.getValue()) {
            addRepeatedField(field, element);
          }
        } else if (field.getJavaType() == FieldDescriptor.JavaType.MESSAGE) {
          final Message existingValue = (Message)getField(field);
          if (existingValue == existingValue.getDefaultInstanceForType()) {
            setField(field, entry.getValue());
          } else {
            setField(field,
              existingValue.newBuilderForType()
                .mergeFrom(existingValue)
                .mergeFrom((Message)entry.getValue())
                .build());
          }
        } else {
          setField(field, entry.getValue());
        }
      }

      mergeUnknownFields(other.getUnknownFields());

      return (BuilderType) this;
    }

    @Override
    public BuilderType mergeFrom(final CodedInputStream input)
                                 throws IOException {
      return mergeFrom(input, ExtensionRegistry.getEmptyRegistry());
    }

    @Override
    public BuilderType mergeFrom(
        final CodedInputStream input,
        final ExtensionRegistryLite extensionRegistry)
        throws IOException {
      final UnknownFieldSet.Builder unknownFields =
        UnknownFieldSet.newBuilder(getUnknownFields());
      while (true) {
        final int tag = input.readTag();
        if (tag == 0) {
          break;
        }

        if (!mergeFieldFrom(input, unknownFields, extensionRegistry,
                            getDescriptorForType(), this, null, tag)) {
          // end group tag
          break;
        }
      }
      setUnknownFields(unknownFields.build());
      return (BuilderType) this;
    }

    /** helper method to handle {@code builder} and {@code extensions}. */
    private static void addRepeatedField(
        Message.Builder builder,
        FieldSet<FieldDescriptor> extensions,
        FieldDescriptor field,
        Object value) {
      if (builder != null) {
        builder.addRepeatedField(field, value);
      } else {
        extensions.addRepeatedField(field, value);
      }
    }

    /** helper method to handle {@code builder} and {@code extensions}. */
    private static void setField(
        Message.Builder builder,
        FieldSet<FieldDescriptor> extensions,
        FieldDescriptor field,
        Object value) {
      if (builder != null) {
        builder.setField(field, value);
      } else {
        extensions.setField(field, value);
      }
    }

    /** helper method to handle {@code builder} and {@code extensions}. */
    private static boolean hasOriginalMessage(
        Message.Builder builder,
        FieldSet<FieldDescriptor> extensions,
        FieldDescriptor field) {
      if (builder != null) {
        return builder.hasField(field);
      } else {
        return extensions.hasField(field);
      }
    }

    /** helper method to handle {@code builder} and {@code extensions}. */
    private static Message getOriginalMessage(
        Message.Builder builder,
        FieldSet<FieldDescriptor> extensions,
        FieldDescriptor field) {
      if (builder != null) {
        return (Message) builder.getField(field);
      } else {
        return (Message) extensions.getField(field);
      }
    }

    /** helper method to handle {@code builder} and {@code extensions}. */
    private static void mergeOriginalMessage(
        Message.Builder builder,
        FieldSet<FieldDescriptor> extensions,
        FieldDescriptor field,
        Message.Builder subBuilder) {
      Message originalMessage = getOriginalMessage(builder, extensions, field);
      if (originalMessage != null) {
        subBuilder.mergeFrom(originalMessage);
      }
    }

    /**
     * Like {@link #mergeFrom(CodedInputStream, ExtensionRegistryLite)}, but
     * parses a single field.
     *
     * When {@code builder} is not null, the method will parse and merge the
     * field into {@code builder}. Otherwise, it will try to parse the field
     * into {@code extensions}, when it's called by the parsing constructor in
     * generated classes.
     *
     * Package-private because it is used by GeneratedMessage.ExtendableMessage.
     * @param tag The tag, which should have already been read.
     * @return {@code true} unless the tag is an end-group tag.
     */
    static boolean mergeFieldFrom(
        CodedInputStream input,
        UnknownFieldSet.Builder unknownFields,
        ExtensionRegistryLite extensionRegistry,
        Descriptor type,
        Message.Builder builder,
        FieldSet<FieldDescriptor> extensions,
        int tag) throws IOException {
      if (type.getOptions().getMessageSetWireFormat() &&
          tag == WireFormat.MESSAGE_SET_ITEM_TAG) {
        mergeMessageSetExtensionFromCodedStream(
            input, unknownFields, extensionRegistry, type, builder, extensions);
        return true;
      }

      final int wireType = WireFormat.getTagWireType(tag);
      final int fieldNumber = WireFormat.getTagFieldNumber(tag);

      final FieldDescriptor field;
      Message defaultInstance = null;

      if (type.isExtensionNumber(fieldNumber)) {
        // extensionRegistry may be either ExtensionRegistry or
        // ExtensionRegistryLite.  Since the type we are parsing is a full
        // message, only a full ExtensionRegistry could possibly contain
        // extensions of it.  Otherwise we will treat the registry as if it
        // were empty.
        if (extensionRegistry instanceof ExtensionRegistry) {
          final ExtensionRegistry.ExtensionInfo extension =
            ((ExtensionRegistry) extensionRegistry)
              .findExtensionByNumber(type, fieldNumber);
          if (extension == null) {
            field = null;
          } else {
            field = extension.descriptor;
            defaultInstance = extension.defaultInstance;
            if (defaultInstance == null &&
                field.getJavaType() == FieldDescriptor.JavaType.MESSAGE) {
              throw new IllegalStateException(
                  "Message-typed extension lacked default instance: " +
                  field.getFullName());
            }
          }
        } else {
          field = null;
        }
      } else if (builder != null) {
        field = type.findFieldByNumber(fieldNumber);
      } else {
        field = null;
      }

      boolean unknown = false;
      boolean packed = false;
      if (field == null) {
        unknown = true;  // Unknown field.
      } else if (wireType == FieldSet.getWireFormatForFieldType(
                   field.getLiteType(),
                   false  /* isPacked */)) {
        packed = false;
      } else if (field.isPackable() &&
                 wireType == FieldSet.getWireFormatForFieldType(
                   field.getLiteType(),
                   true  /* isPacked */)) {
        packed = true;
      } else {
        unknown = true;  // Unknown wire type.
      }

      if (unknown) {  // Unknown field or wrong wire type.  Skip.
        return unknownFields.mergeFieldFrom(tag, input);
      }

      if (packed) {
        final int length = input.readRawVarint32();
        final int limit = input.pushLimit(length);
        if (field.getLiteType() == WireFormat.FieldType.ENUM) {
          while (input.getBytesUntilLimit() > 0) {
            final int rawValue = input.readEnum();
            final Object value = field.getEnumType().findValueByNumber(rawValue);
            if (value == null) {
              // If the number isn't recognized as a valid value for this
              // enum, drop it (don't even add it to unknownFields).
              return true;
            }
            addRepeatedField(builder, extensions, field, value);
          }
        } else {
          while (input.getBytesUntilLimit() > 0) {
            final Object value =
              FieldSet.readPrimitiveField(input, field.getLiteType());
            addRepeatedField(builder, extensions, field, value);
          }
        }
        input.popLimit(limit);
      } else {
        final Object value;
        switch (field.getType()) {
          case GROUP: {
            final Message.Builder subBuilder;
            if (defaultInstance != null) {
              subBuilder = defaultInstance.newBuilderForType();
            } else {
              subBuilder = builder.newBuilderForField(field);
            }
            if (!field.isRepeated()) {
              mergeOriginalMessage(builder, extensions, field, subBuilder);
            }
            input.readGroup(field.getNumber(), subBuilder, extensionRegistry);
            value = subBuilder.buildPartial();
            break;
          }
          case MESSAGE: {
            final Message.Builder subBuilder;
            if (defaultInstance != null) {
              subBuilder = defaultInstance.newBuilderForType();
            } else {
              subBuilder = builder.newBuilderForField(field);
            }
            if (!field.isRepeated()) {
              mergeOriginalMessage(builder, extensions, field, subBuilder);
            }
            input.readMessage(subBuilder, extensionRegistry);
            value = subBuilder.buildPartial();
            break;
          }
          case ENUM:
            final int rawValue = input.readEnum();
            value = field.getEnumType().findValueByNumber(rawValue);
            // If the number isn't recognized as a valid value for this enum,
            // drop it.
            if (value == null) {
              unknownFields.mergeVarintField(fieldNumber, rawValue);
              return true;
            }
            break;
          default:
            value = FieldSet.readPrimitiveField(input, field.getLiteType());
            break;
        }

        if (field.isRepeated()) {
          addRepeatedField(builder, extensions, field, value);
        } else {
          setField(builder, extensions, field, value);
        }
      }

      return true;
    }

    /**
     * Called by {@code #mergeFieldFrom()} to parse a MessageSet extension.
     * If {@code builder} is not null, this method will merge MessageSet into
     * the builder.  Otherwise, it will merge the MessageSet into {@code
     * extensions}.
     */
    private static void mergeMessageSetExtensionFromCodedStream(
        CodedInputStream input,
        UnknownFieldSet.Builder unknownFields,
        ExtensionRegistryLite extensionRegistry,
        Descriptor type,
        Message.Builder builder,
        FieldSet<FieldDescriptor> extensions) throws IOException {

      // The wire format for MessageSet is:
      //   message MessageSet {
      //     repeated group Item = 1 {
      //       required int32 typeId = 2;
      //       required bytes message = 3;
      //     }
      //   }
      // "typeId" is the extension's field number.  The extension can only be
      // a message type, where "message" contains the encoded bytes of that
      // message.
      //
      // In practice, we will probably never see a MessageSet item in which
      // the message appears before the type ID, or where either field does not
      // appear exactly once.  However, in theory such cases are valid, so we
      // should be prepared to accept them.

      int typeId = 0;
      ByteString rawBytes = null; // If we encounter "message" before "typeId"
      ExtensionRegistry.ExtensionInfo extension = null;

      // Read bytes from input, if we get it's type first then parse it eagerly,
      // otherwise we store the raw bytes in a local variable.
      while (true) {
        final int tag = input.readTag();
        if (tag == 0) {
          break;
        }

        if (tag == WireFormat.MESSAGE_SET_TYPE_ID_TAG) {
          typeId = input.readUInt32();
          if (typeId != 0) {
            // extensionRegistry may be either ExtensionRegistry or
            // ExtensionRegistryLite. Since the type we are parsing is a full
            // message, only a full ExtensionRegistry could possibly contain
            // extensions of it. Otherwise we will treat the registry as if it
            // were empty.
            if (extensionRegistry instanceof ExtensionRegistry) {
              extension = ((ExtensionRegistry) extensionRegistry)
                  .findExtensionByNumber(type, typeId);
            }
          }

        } else if (tag == WireFormat.MESSAGE_SET_MESSAGE_TAG) {
          if (typeId != 0) {
            if (extension != null && ExtensionRegistryLite.isEagerlyParseMessageSets()) {
              // We already know the type, so we can parse directly from the
              // input with no copying.  Hooray!
              eagerlyMergeMessageSetExtension(
                  input, extension, extensionRegistry, builder, extensions);
              rawBytes = null;
              continue;
            }
          }
          // We haven't seen a type ID yet or we want parse message lazily.
          rawBytes = input.readBytes();

        } else { // Unknown tag. Skip it.
          if (!input.skipField(tag)) {
            break; // End of group
          }
        }
      }
      input.checkLastTagWas(WireFormat.MESSAGE_SET_ITEM_END_TAG);

      // Process the raw bytes.
      if (rawBytes != null && typeId != 0) { // Zero is not a valid type ID.
        if (extension != null) { // We known the type
          mergeMessageSetExtensionFromBytes(
              rawBytes, extension, extensionRegistry, builder, extensions);
        } else { // We don't know how to parse this. Ignore it.
          if (rawBytes != null) {
            unknownFields.mergeField(typeId, UnknownFieldSet.Field.newBuilder()
                .addLengthDelimited(rawBytes).build());
          }
        }
      }
    }

    private static void eagerlyMergeMessageSetExtension(
        CodedInputStream input,
        ExtensionRegistry.ExtensionInfo extension,
        ExtensionRegistryLite extensionRegistry,
        Message.Builder builder,
        FieldSet<FieldDescriptor> extensions) throws IOException {

      FieldDescriptor field = extension.descriptor;
      Message value = null;
      if (hasOriginalMessage(builder, extensions, field)) {
        Message originalMessage =
            getOriginalMessage(builder, extensions, field);
        Message.Builder subBuilder = originalMessage.toBuilder();
        input.readMessage(subBuilder, extensionRegistry);
        value = subBuilder.buildPartial();
      } else {
        value = input.readMessage(extension.defaultInstance.getParserForType(),
          extensionRegistry);
      }

      if (builder != null) {
        builder.setField(field, value);
      } else {
        extensions.setField(field, value);
      }
    }

    private static void mergeMessageSetExtensionFromBytes(
        ByteString rawBytes,
        ExtensionRegistry.ExtensionInfo extension,
        ExtensionRegistryLite extensionRegistry,
        Message.Builder builder,
        FieldSet<FieldDescriptor> extensions) throws IOException {

      FieldDescriptor field = extension.descriptor;
      boolean hasOriginalValue = hasOriginalMessage(builder, extensions, field);

      if (hasOriginalValue || ExtensionRegistryLite.isEagerlyParseMessageSets()) {
        // If the field already exists, we just parse the field.
        Message value = null;
        if (hasOriginalValue) {
          Message originalMessage =
              getOriginalMessage(builder, extensions, field);
          Message.Builder subBuilder= originalMessage.toBuilder();
          subBuilder.mergeFrom(rawBytes, extensionRegistry);
          value = subBuilder.buildPartial();
        } else {
          value = extension.defaultInstance.getParserForType()
              .parsePartialFrom(rawBytes, extensionRegistry);
        }
        setField(builder, extensions, field, value);
      } else {
        // Use LazyField to load MessageSet lazily.
        LazyField lazyField = new LazyField(
            extension.defaultInstance, extensionRegistry, rawBytes);
        if (builder != null) {
          // TODO(xiangl): it looks like this method can only be invoked by
          // ExtendableBuilder, but I'm not sure. So I double check the type of
          // builder here. It may be useless and need more investigation.
          if (builder instanceof ExtendableBuilder) {
            builder.setField(field, lazyField);
          } else {
            builder.setField(field, lazyField.getValue());
          }
        } else {
          extensions.setField(field, lazyField);
        }
      }
    }

    public BuilderType mergeUnknownFields(final UnknownFieldSet unknownFields) {
      setUnknownFields(
        UnknownFieldSet.newBuilder(getUnknownFields())
                       .mergeFrom(unknownFields)
                       .build());
      return (BuilderType) this;
    }

    public Message.Builder getFieldBuilder(final FieldDescriptor field) {
      throw new UnsupportedOperationException(
          "getFieldBuilder() called on an unsupported message type.");
    }

    /**
     * Construct an UninitializedMessageException reporting missing fields in
     * the given message.
     */
    protected static UninitializedMessageException
        newUninitializedMessageException(Message message) {
      return new UninitializedMessageException(findMissingFields(message));
    }

    /**
     * Populates {@code this.missingFields} with the full "path" of each
     * missing required field in the given message.
     */
    private static List<String> findMissingFields(
        final MessageOrBuilder message) {
      final List<String> results = new ArrayList<String>();
      findMissingFields(message, "", results);
      return results;
    }

    /** Recursive helper implementing {@link #findMissingFields(Message)}. */
    private static void findMissingFields(final MessageOrBuilder message,
                                          final String prefix,
                                          final List<String> results) {
      for (final FieldDescriptor field :
          message.getDescriptorForType().getFields()) {
        if (field.isRequired() && !message.hasField(field)) {
          results.add(prefix + field.getName());
        }
      }

      for (final Map.Entry<FieldDescriptor, Object> entry :
           message.getAllFields().entrySet()) {
        final FieldDescriptor field = entry.getKey();
        final Object value = entry.getValue();

        if (field.getJavaType() == FieldDescriptor.JavaType.MESSAGE) {
          if (field.isRepeated()) {
            int i = 0;
            for (final Object element : (List) value) {
              findMissingFields((MessageOrBuilder) element,
                                subMessagePrefix(prefix, field, i++),
                                results);
            }
          } else {
            if (message.hasField(field)) {
              findMissingFields((MessageOrBuilder) value,
                                subMessagePrefix(prefix, field, -1),
                                results);
            }
          }
        }
      }
    }

    private static String subMessagePrefix(final String prefix,
                                           final FieldDescriptor field,
                                           final int index) {
      final StringBuilder result = new StringBuilder(prefix);
      if (field.isExtension()) {
        result.append('(')
              .append(field.getFullName())
              .append(')');
      } else {
        result.append(field.getName());
      }
      if (index != -1) {
        result.append('[')
              .append(index)
              .append(']');
      }
      result.append('.');
      return result.toString();
    }

    // ===============================================================
    // The following definitions seem to be required in order to make javac
    // not produce weird errors like:
    //
    // java/com/google/protobuf/DynamicMessage.java:203: types
    //   com.google.protobuf.AbstractMessage.Builder<
    //     com.google.protobuf.DynamicMessage.Builder> and
    //   com.google.protobuf.AbstractMessage.Builder<
    //     com.google.protobuf.DynamicMessage.Builder> are incompatible; both
    //   define mergeFrom(com.google.protobuf.ByteString), but with unrelated
    //   return types.
    //
    // Strangely, these lines are only needed if javac is invoked separately
    // on AbstractMessage.java and AbstractMessageLite.java.  If javac is
    // invoked on both simultaneously, it works.  (Or maybe the important
    // point is whether or not DynamicMessage.java is compiled together with
    // AbstractMessageLite.java -- not sure.)  I suspect this is a compiler
    // bug.

    @Override
    public BuilderType mergeFrom(final ByteString data)
        throws InvalidProtocolBufferException {
      return super.mergeFrom(data);
    }

    @Override
    public BuilderType mergeFrom(
        final ByteString data,
        final ExtensionRegistryLite extensionRegistry)
        throws InvalidProtocolBufferException {
      return super.mergeFrom(data, extensionRegistry);
    }

    @Override
    public BuilderType mergeFrom(final byte[] data)
        throws InvalidProtocolBufferException {
      return super.mergeFrom(data);
    }

    @Override
    public BuilderType mergeFrom(
        final byte[] data, final int off, final int len)
        throws InvalidProtocolBufferException {
      return super.mergeFrom(data, off, len);
    }

    @Override
    public BuilderType mergeFrom(
        final byte[] data,
        final ExtensionRegistryLite extensionRegistry)
        throws InvalidProtocolBufferException {
      return super.mergeFrom(data, extensionRegistry);
    }

    @Override
    public BuilderType mergeFrom(
        final byte[] data, final int off, final int len,
        final ExtensionRegistryLite extensionRegistry)
        throws InvalidProtocolBufferException {
      return super.mergeFrom(data, off, len, extensionRegistry);
    }

    @Override
    public BuilderType mergeFrom(final InputStream input)
        throws IOException {
      return super.mergeFrom(input);
    }

    @Override
    public BuilderType mergeFrom(
        final InputStream input,
        final ExtensionRegistryLite extensionRegistry)
        throws IOException {
      return super.mergeFrom(input, extensionRegistry);
    }

    @Override
    public boolean mergeDelimitedFrom(final InputStream input)
        throws IOException {
      return super.mergeDelimitedFrom(input);
    }

    @Override
    public boolean mergeDelimitedFrom(
        final InputStream input,
        final ExtensionRegistryLite extensionRegistry)
        throws IOException {
      return super.mergeDelimitedFrom(input, extensionRegistry);
    }

  }
}