// 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.
//     * 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.AbstractMessageLite.Builder.LimitedInputStream;
import com.google.protobuf.Internal.BooleanList;
import com.google.protobuf.Internal.DoubleList;
import com.google.protobuf.Internal.FloatList;
import com.google.protobuf.Internal.IntList;
import com.google.protobuf.Internal.LongList;
import com.google.protobuf.Internal.ProtobufList;
import com.google.protobuf.WireFormat.FieldType;
import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectStreamException;
import java.io.Serializable;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

Lite version of GeneratedMessage. 
Author:
kenton@google.com Kenton Varda/**
 * Lite version of {@link GeneratedMessage}.
 *
 * @author kenton@google.com Kenton Varda
 */
public abstract class GeneratedMessageLite<
        MessageType extends GeneratedMessageLite<MessageType, BuilderType>,
        BuilderType extends GeneratedMessageLite.Builder<MessageType, BuilderType>>
    extends AbstractMessageLite<MessageType, BuilderType> {

  
For use by generated code only. Lazily initialized to reduce allocations. /** For use by generated code only. Lazily initialized to reduce allocations. */
  protected UnknownFieldSetLite unknownFields = UnknownFieldSetLite.getDefaultInstance();

  
For use by generated code only. /** For use by generated code only. */
  protected int memoizedSerializedSize = -1;

  @Override
  @SuppressWarnings("unchecked") // Guaranteed by runtime.
  public final Parser<MessageType> getParserForType() {
    return (Parser<MessageType>) dynamicMethod(MethodToInvoke.GET_PARSER);
  }

  @Override
  @SuppressWarnings("unchecked") // Guaranteed by runtime.
  public final MessageType getDefaultInstanceForType() {
    return (MessageType) dynamicMethod(MethodToInvoke.GET_DEFAULT_INSTANCE);
  }

  @Override
  @SuppressWarnings("unchecked") // Guaranteed by runtime.
  public final BuilderType newBuilderForType() {
    return (BuilderType) dynamicMethod(MethodToInvoke.NEW_BUILDER);
  }

  
A reflective toString function. This is primarily intended as a developer aid, while keeping binary size down. The first line of the toString() representation includes a commented version of super.toString() to act as an indicator that this should not be relied on for comparisons. 
NOTE: This method relies on the field getter methods not being stripped or renamed by
proguard. If they are, the fields will not be included in the returned string representation.
NOTE: This implementation is liable to change in the future, and should not be relied on in
code.
/**
   * A reflective toString function. This is primarily intended as a developer aid, while keeping
   * binary size down. The first line of the {@code toString()} representation includes a commented
   * version of {@code super.toString()} to act as an indicator that this should not be relied on
   * for comparisons.
   *
   * <p>NOTE: This method relies on the field getter methods not being stripped or renamed by
   * proguard. If they are, the fields will not be included in the returned string representation.
   *
   * <p>NOTE: This implementation is liable to change in the future, and should not be relied on in
   * code.
   */
  @Override
  public String toString() {
    return MessageLiteToString.toString(this, super.toString());
  }

  @SuppressWarnings("unchecked") // Guaranteed by runtime
  @Override
  public int hashCode() {
    if (memoizedHashCode != 0) {
      return memoizedHashCode;
    }
    memoizedHashCode = Protobuf.getInstance().schemaFor(this).hashCode(this);
    return memoizedHashCode;
  }

  @SuppressWarnings("unchecked") // Guaranteed by isInstance + runtime
  @Override
  public boolean equals(Object other) {
    if (this == other) {
      return true;
    }

    if (!getDefaultInstanceForType().getClass().isInstance(other)) {
      return false;
    }

    return Protobuf.getInstance().schemaFor(this).equals(this, (MessageType) other);
  }

  // The general strategy for unknown fields is to use an UnknownFieldSetLite that is treated as
  // mutable during the parsing constructor and immutable after. This allows us to avoid
  // any unnecessary intermediary allocations while reducing the generated code size.

  
Lazily initializes unknown fields. /** Lazily initializes unknown fields. */
  private final void ensureUnknownFieldsInitialized() {
    if (unknownFields == UnknownFieldSetLite.getDefaultInstance()) {
      unknownFields = UnknownFieldSetLite.newInstance();
    }
  }

  
Called by subclasses to parse an unknown field. For use by generated code only.
Returns:
true unless the tag is an end-group tag./**
   * Called by subclasses to parse an unknown field. For use by generated code only.
   *
   * @return {@code true} unless the tag is an end-group tag.
   */
  protected boolean parseUnknownField(int tag, CodedInputStream input) throws IOException {
    // This will avoid the allocation of unknown fields when a group tag is encountered.
    if (WireFormat.getTagWireType(tag) == WireFormat.WIRETYPE_END_GROUP) {
      return false;
    }

    ensureUnknownFieldsInitialized();
    return unknownFields.mergeFieldFrom(tag, input);
  }

  
Called by subclasses to parse an unknown field. For use by generated code only. /** Called by subclasses to parse an unknown field. For use by generated code only. */
  protected void mergeVarintField(int tag, int value) {
    ensureUnknownFieldsInitialized();
    unknownFields.mergeVarintField(tag, value);
  }

  
Called by subclasses to parse an unknown field. For use by generated code only. /** Called by subclasses to parse an unknown field. For use by generated code only. */
  protected void mergeLengthDelimitedField(int fieldNumber, ByteString value) {
    ensureUnknownFieldsInitialized();
    unknownFields.mergeLengthDelimitedField(fieldNumber, value);
  }

  
Called by subclasses to complete parsing. For use by generated code only. /** Called by subclasses to complete parsing. For use by generated code only. */
  protected void makeImmutable() {
    Protobuf.getInstance().schemaFor(this).makeImmutable(this);
  }

  protected final <
          MessageType extends GeneratedMessageLite<MessageType, BuilderType>,
          BuilderType extends GeneratedMessageLite.Builder<MessageType, BuilderType>>
      BuilderType createBuilder() {
    return (BuilderType) dynamicMethod(MethodToInvoke.NEW_BUILDER);
  }

  protected final <
          MessageType extends GeneratedMessageLite<MessageType, BuilderType>,
          BuilderType extends GeneratedMessageLite.Builder<MessageType, BuilderType>>
      BuilderType createBuilder(MessageType prototype) {
    return ((BuilderType) createBuilder()).mergeFrom(prototype);
  }

  @Override
  public final boolean isInitialized() {
    return isInitialized((MessageType) this, Boolean.TRUE);
  }

  @Override
  @SuppressWarnings("unchecked")
  public final BuilderType toBuilder() {
    BuilderType builder = (BuilderType) dynamicMethod(MethodToInvoke.NEW_BUILDER);
    builder.mergeFrom((MessageType) this);
    return builder;
  }

  
Defines which method path to invoke in GeneratedMessageLite.dynamicMethod(MethodToInvoke, Object...). 
For use by generated code only.
/**
   * Defines which method path to invoke in {@link GeneratedMessageLite
   * #dynamicMethod(MethodToInvoke, Object...)}.
   *
   * <p>For use by generated code only.
   */
  public static enum MethodToInvoke {
    // Rely on/modify instance state
    GET_MEMOIZED_IS_INITIALIZED,
    SET_MEMOIZED_IS_INITIALIZED,

    // Rely on static state
    BUILD_MESSAGE_INFO,
    NEW_MUTABLE_INSTANCE,
    NEW_BUILDER,
    GET_DEFAULT_INSTANCE,
    GET_PARSER;
  }

  
A method that implements different types of operations described in MethodToInvoke. Theses different kinds of operations are required to implement message-level operations for builders in the runtime. This method bundles those operations to reduce the generated methods count. 

  
NEW_INSTANCE returns a new instance of the protocol buffer that has not yet been made immutable. See MAKE_IMMUTABLE. 
IS_INITIALIZED returns null for false and the default instance for true. It doesn't use or modify any memoized value. 
GET_MEMOIZED_IS_INITIALIZED returns the memoized isInitialized byte value. 
SET_MEMOIZED_IS_INITIALIZED sets the memoized isInitilaized byte value to 1 if the first parameter is not null, or to 0 if the first parameter is null. 
NEW_BUILDER returns a BuilderType instance. 
This method, plus the implementation of the Builder, enables the Builder class to be proguarded
away entirely on Android.
For use by generated code only.
/**
   * A method that implements different types of operations described in {@link MethodToInvoke}.
   * Theses different kinds of operations are required to implement message-level operations for
   * builders in the runtime. This method bundles those operations to reduce the generated methods
   * count.
   *
   * <ul>
   *   <li>{@code NEW_INSTANCE} returns a new instance of the protocol buffer that has not yet been
   *       made immutable. See {@code MAKE_IMMUTABLE}.
   *   <li>{@code IS_INITIALIZED} returns {@code null} for false and the default instance for true.
   *       It doesn't use or modify any memoized value.
   *   <li>{@code GET_MEMOIZED_IS_INITIALIZED} returns the memoized {@code isInitialized} byte
   *       value.
   *   <li>{@code SET_MEMOIZED_IS_INITIALIZED} sets the memoized {@code isInitilaized} byte value to
   *       1 if the first parameter is not null, or to 0 if the first parameter is null.
   *   <li>{@code NEW_BUILDER} returns a {@code BuilderType} instance.
   * </ul>
   *
   * This method, plus the implementation of the Builder, enables the Builder class to be proguarded
   * away entirely on Android.
   *
   * <p>For use by generated code only.
   */
  protected abstract Object dynamicMethod(MethodToInvoke method, Object arg0, Object arg1);

  
Same as dynamicMethod(MethodToInvoke, Object, Object) with null padding. /** Same as {@link #dynamicMethod(MethodToInvoke, Object, Object)} with {@code null} padding. */
  protected Object dynamicMethod(MethodToInvoke method, Object arg0) {
    return dynamicMethod(method, arg0, null);
  }

  
Same as dynamicMethod(MethodToInvoke, Object, Object) with null padding. /** Same as {@link #dynamicMethod(MethodToInvoke, Object, Object)} with {@code null} padding. */
  protected Object dynamicMethod(MethodToInvoke method) {
    return dynamicMethod(method, null, null);
  }

  @Override
  int getMemoizedSerializedSize() {
    return memoizedSerializedSize;
  }

  @Override
  void setMemoizedSerializedSize(int size) {
    memoizedSerializedSize = size;
  }

  public void writeTo(CodedOutputStream output) throws IOException {
    Protobuf.getInstance()
        .schemaFor(this)
        .writeTo(this, CodedOutputStreamWriter.forCodedOutput(output));
  }

  public int getSerializedSize() {
    if (memoizedSerializedSize == -1) {
      memoizedSerializedSize = Protobuf.getInstance().schemaFor(this).getSerializedSize(this);
    }
    return memoizedSerializedSize;
  }

  
Constructs a MessageInfo for this message type. /** Constructs a {@link MessageInfo} for this message type. */
  Object buildMessageInfo() throws Exception {
    return dynamicMethod(MethodToInvoke.BUILD_MESSAGE_INFO);
  }

  private static Map<Object, GeneratedMessageLite<?, ?>> defaultInstanceMap =
      new ConcurrentHashMap<Object, GeneratedMessageLite<?, ?>>();

  @SuppressWarnings("unchecked")
  static <T extends GeneratedMessageLite<?, ?>> T getDefaultInstance(Class<T> clazz) {
    T result = (T) defaultInstanceMap.get(clazz);
    if (result == null) {
      // Foo.class does not initialize the class so we need to force the initialization in order to
      // get the default instance registered.
      try {
        Class.forName(clazz.getName(), true, clazz.getClassLoader());
      } catch (ClassNotFoundException e) {
        throw new IllegalStateException("Class initialization cannot fail.", e);
      }
      result = (T) defaultInstanceMap.get(clazz);
    }
    if (result == null) {
      // On some Samsung devices, this still doesn't return a valid value for some reason. We add a
      // reflective fallback to keep the device running. See b/114675342.
      result = (T) UnsafeUtil.allocateInstance(clazz).getDefaultInstanceForType();
      // A sanity check to ensure that <clinit> was actually invoked.
      if (result == null) {
        throw new IllegalStateException();
      }
      defaultInstanceMap.put(clazz, result);
    }
    return result;
  }

  protected static <T extends GeneratedMessageLite<?, ?>> void registerDefaultInstance(
      Class<T> clazz, T defaultInstance) {
    defaultInstanceMap.put(clazz, defaultInstance);
  }

  protected static Object newMessageInfo(
      MessageLite defaultInstance, String info, Object[] objects) {
    return new RawMessageInfo(defaultInstance, info, objects);
  }

  
Merge some unknown fields into the UnknownFieldSetLite for this message. 
For use by generated code only.
/**
   * Merge some unknown fields into the {@link UnknownFieldSetLite} for this message.
   *
   * <p>For use by generated code only.
   */
  protected final void mergeUnknownFields(UnknownFieldSetLite unknownFields) {
    this.unknownFields = UnknownFieldSetLite.mutableCopyOf(this.unknownFields, unknownFields);
  }

  @SuppressWarnings("unchecked")
  public abstract static class Builder<
          MessageType extends GeneratedMessageLite<MessageType, BuilderType>,
          BuilderType extends Builder<MessageType, BuilderType>>
      extends AbstractMessageLite.Builder<MessageType, BuilderType> {

    private final MessageType defaultInstance;
    protected MessageType instance;
    protected boolean isBuilt;

    protected Builder(MessageType defaultInstance) {
      this.defaultInstance = defaultInstance;
      this.instance =
          (MessageType) defaultInstance.dynamicMethod(MethodToInvoke.NEW_MUTABLE_INSTANCE);
      isBuilt = false;
    }

    
Called before any method that would mutate the builder to ensure that it correctly copies any
state before the write happens to preserve immutability guarantees.
/**
     * Called before any method that would mutate the builder to ensure that it correctly copies any
     * state before the write happens to preserve immutability guarantees.
     */
    protected void copyOnWrite() {
      if (isBuilt) {
        MessageType newInstance =
            (MessageType) instance.dynamicMethod(MethodToInvoke.NEW_MUTABLE_INSTANCE);
        mergeFromInstance(newInstance, instance);
        instance = newInstance;
        isBuilt = false;
      }
    }

    @Override
    public final boolean isInitialized() {
      return GeneratedMessageLite.isInitialized(instance, /* shouldMemoize= */ false);
    }

    @Override
    public final BuilderType clear() {
      // No need to copy on write since we're dropping the instance anyways.
      instance = (MessageType) instance.dynamicMethod(MethodToInvoke.NEW_MUTABLE_INSTANCE);
      return (BuilderType) this;
    }

    @Override
    public BuilderType clone() {
      BuilderType builder = (BuilderType) getDefaultInstanceForType().newBuilderForType();
      builder.mergeFrom(buildPartial());
      return builder;
    }

    @Override
    public MessageType buildPartial() {
      if (isBuilt) {
        return instance;
      }

      instance.makeImmutable();

      isBuilt = true;
      return instance;
    }

    @Override
    public final MessageType build() {
      MessageType result = buildPartial();
      if (!result.isInitialized()) {
        throw newUninitializedMessageException(result);
      }
      return result;
    }

    @Override
    protected BuilderType internalMergeFrom(MessageType message) {
      return mergeFrom(message);
    }

    
All subclasses implement this. /** All subclasses implement this. */
    public BuilderType mergeFrom(MessageType message) {
      copyOnWrite();
      mergeFromInstance(instance, message);
      return (BuilderType) this;
    }

    private void mergeFromInstance(MessageType dest, MessageType src) {
      Protobuf.getInstance().schemaFor(dest).mergeFrom(dest, src);
    }

    @Override
    public MessageType getDefaultInstanceForType() {
      return defaultInstance;
    }

    @Override
    public BuilderType mergeFrom(
        byte[] input, int offset, int length, ExtensionRegistryLite extensionRegistry)
        throws InvalidProtocolBufferException {
      copyOnWrite();
      try {
        Protobuf.getInstance().schemaFor(instance).mergeFrom(
            instance, input, offset, offset + length,
            new ArrayDecoders.Registers(extensionRegistry));
      } catch (InvalidProtocolBufferException e) {
        throw e;
      } catch (IndexOutOfBoundsException e) {
        throw InvalidProtocolBufferException.truncatedMessage();
      } catch (IOException e) {
        throw new RuntimeException("Reading from byte array should not throw IOException.", e);
      }
      return (BuilderType) this;
    }

    @Override
    public BuilderType mergeFrom(
        byte[] input, int offset, int length)
        throws InvalidProtocolBufferException {
      return mergeFrom(input, offset, length, ExtensionRegistryLite.getEmptyRegistry());
    }

    @Override
    public BuilderType mergeFrom(
        com.google.protobuf.CodedInputStream input,
        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
        throws IOException {
      copyOnWrite();
      try {
        // TODO(yilunchong): Try to make input with type CodedInpuStream.ArrayDecoder use
        // fast path.
        Protobuf.getInstance().schemaFor(instance).mergeFrom(
            instance, CodedInputStreamReader.forCodedInput(input), extensionRegistry);
      } catch (RuntimeException e) {
        if (e.getCause() instanceof IOException) {
          throw (IOException) e.getCause();
        }
        throw e;
      }
      return (BuilderType) this;
    }
  }


  // =================================================================
  // Extensions-related stuff

  
Lite equivalent of ExtendableMessageOrBuilder. /** Lite equivalent of {@link com.google.protobuf.GeneratedMessage.ExtendableMessageOrBuilder}. */
  public interface ExtendableMessageOrBuilder<
          MessageType extends ExtendableMessage<MessageType, BuilderType>,
          BuilderType extends ExtendableBuilder<MessageType, BuilderType>>
      extends MessageLiteOrBuilder {

    
Check if a singular extension is present. /** Check if a singular extension is present. */
    <Type> boolean hasExtension(ExtensionLite<MessageType, Type> extension);

    
Get the number of elements in a repeated extension. /** Get the number of elements in a repeated extension. */
    <Type> int getExtensionCount(ExtensionLite<MessageType, List<Type>> extension);

    
Get the value of an extension. /** Get the value of an extension. */
    <Type> Type getExtension(ExtensionLite<MessageType, Type> extension);

    
Get one element of a repeated extension. /** Get one element of a repeated extension. */
    <Type> Type getExtension(ExtensionLite<MessageType, List<Type>> extension, int index);
  }

  
Lite equivalent of ExtendableMessage. /** Lite equivalent of {@link GeneratedMessage.ExtendableMessage}. */
  public abstract static class ExtendableMessage<
          MessageType extends ExtendableMessage<MessageType, BuilderType>,
          BuilderType extends ExtendableBuilder<MessageType, BuilderType>>
      extends GeneratedMessageLite<MessageType, BuilderType>
      implements ExtendableMessageOrBuilder<MessageType, BuilderType> {

    
Represents the set of extensions on this message. For use by generated code only. /** Represents the set of extensions on this message. For use by generated code only. */
    protected FieldSet<ExtensionDescriptor> extensions = FieldSet.emptySet();

    @SuppressWarnings("unchecked")
    protected final void mergeExtensionFields(final MessageType other) {
      if (extensions.isImmutable()) {
        extensions = extensions.clone();
      }
      extensions.mergeFrom(((ExtendableMessage) other).extensions);
    }

    
Parse an unknown field or an extension. For use by generated code only.
For use by generated code only.
Returns:
true unless the tag is an end-group tag./**
     * Parse an unknown field or an extension. For use by generated code only.
     *
     * <p>For use by generated code only.
     *
     * @return {@code true} unless the tag is an end-group tag.
     */
    protected <MessageType extends MessageLite> boolean parseUnknownField(
        MessageType defaultInstance,
        CodedInputStream input,
        ExtensionRegistryLite extensionRegistry,
        int tag)
        throws IOException {
      int fieldNumber = WireFormat.getTagFieldNumber(tag);

      // TODO(dweis): How much bytecode would be saved by not requiring the generated code to
      //     provide the default instance?
      GeneratedExtension<MessageType, ?> extension =
          extensionRegistry.findLiteExtensionByNumber(defaultInstance, fieldNumber);

      return parseExtension(input, extensionRegistry, extension, tag, fieldNumber);
    }

    private boolean parseExtension(
        CodedInputStream input,
        ExtensionRegistryLite extensionRegistry,
        GeneratedExtension<?, ?> extension,
        int tag,
        int fieldNumber)
        throws IOException {
      int wireType = WireFormat.getTagWireType(tag);
      boolean unknown = false;
      boolean packed = false;
      if (extension == null) {
        unknown = true; // Unknown field.
      } else if (wireType
          == FieldSet.getWireFormatForFieldType(
              extension.descriptor.getLiteType(), /* isPacked= */ false)) {
        packed = false; // Normal, unpacked value.
      } else if (extension.descriptor.isRepeated
          && extension.descriptor.type.isPackable()
          && wireType
              == FieldSet.getWireFormatForFieldType(
                  extension.descriptor.getLiteType(), /* isPacked= */ true)) {
        packed = true; // Packed value.
      } else {
        unknown = true; // Wrong wire type.
      }

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

      ensureExtensionsAreMutable();

      if (packed) {
        int length = input.readRawVarint32();
        int limit = input.pushLimit(length);
        if (extension.descriptor.getLiteType() == WireFormat.FieldType.ENUM) {
          while (input.getBytesUntilLimit() > 0) {
            int rawValue = input.readEnum();
            Object value = extension.descriptor.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;
            }
            extensions.addRepeatedField(
                extension.descriptor, extension.singularToFieldSetType(value));
          }
        } else {
          while (input.getBytesUntilLimit() > 0) {
            Object value =
                FieldSet.readPrimitiveField(
                    input, extension.descriptor.getLiteType(), /*checkUtf8=*/ false);
            extensions.addRepeatedField(extension.descriptor, value);
          }
        }
        input.popLimit(limit);
      } else {
        Object value;
        switch (extension.descriptor.getLiteJavaType()) {
          case MESSAGE:
            {
              MessageLite.Builder subBuilder = null;
              if (!extension.descriptor.isRepeated()) {
                MessageLite existingValue = (MessageLite) extensions.getField(extension.descriptor);
                if (existingValue != null) {
                  subBuilder = existingValue.toBuilder();
                }
              }
              if (subBuilder == null) {
                subBuilder = extension.getMessageDefaultInstance().newBuilderForType();
              }
              if (extension.descriptor.getLiteType() == WireFormat.FieldType.GROUP) {
                input.readGroup(extension.getNumber(), subBuilder, extensionRegistry);
              } else {
                input.readMessage(subBuilder, extensionRegistry);
              }
              value = subBuilder.build();
              break;
            }
          case ENUM:
            int rawValue = input.readEnum();
            value = extension.descriptor.getEnumType().findValueByNumber(rawValue);
            // If the number isn't recognized as a valid value for this enum,
            // write it to unknown fields object.
            if (value == null) {
              mergeVarintField(fieldNumber, rawValue);
              return true;
            }
            break;
          default:
            value =
                FieldSet.readPrimitiveField(
                    input, extension.descriptor.getLiteType(), /*checkUtf8=*/ false);
            break;
        }

        if (extension.descriptor.isRepeated()) {
          extensions.addRepeatedField(
              extension.descriptor, extension.singularToFieldSetType(value));
        } else {
          extensions.setField(extension.descriptor, extension.singularToFieldSetType(value));
        }
      }
      return true;
    }

    
Parse an unknown field or an extension. For use by generated code only.
For use by generated code only.
Returns:
true unless the tag is an end-group tag./**
     * Parse an unknown field or an extension. For use by generated code only.
     *
     * <p>For use by generated code only.
     *
     * @return {@code true} unless the tag is an end-group tag.
     */
    protected <MessageType extends MessageLite> boolean parseUnknownFieldAsMessageSet(
        MessageType defaultInstance,
        CodedInputStream input,
        ExtensionRegistryLite extensionRegistry,
        int tag)
        throws IOException {

      if (tag == WireFormat.MESSAGE_SET_ITEM_TAG) {
        mergeMessageSetExtensionFromCodedStream(defaultInstance, input, extensionRegistry);
        return true;
      }

      // TODO(dweis): Do we really want to support non message set wire format in message sets?
      // Full runtime does... So we do for now.
      int wireType = WireFormat.getTagWireType(tag);
      if (wireType == WireFormat.WIRETYPE_LENGTH_DELIMITED) {
        return parseUnknownField(defaultInstance, input, extensionRegistry, tag);
      } else {
        // TODO(dweis): Should we throw on invalid input? Full runtime does not...
        return input.skipField(tag);
      }
    }

    
Merges the message set from the input stream; requires message set wire format.
Params:
defaultInstance – the default instance of the containing message we are parsing in
input – the stream to parse from
extensionRegistry – the registry to use when parsing/**
     * Merges the message set from the input stream; requires message set wire format.
     *
     * @param defaultInstance the default instance of the containing message we are parsing in
     * @param input the stream to parse from
     * @param extensionRegistry the registry to use when parsing
     */
    private <MessageType extends MessageLite> void mergeMessageSetExtensionFromCodedStream(
        MessageType defaultInstance,
        CodedInputStream input,
        ExtensionRegistryLite extensionRegistry)
        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"
      GeneratedExtension<?, ?> 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) {
            extension = extensionRegistry.findLiteExtensionByNumber(defaultInstance, typeId);
          }

        } else if (tag == WireFormat.MESSAGE_SET_MESSAGE_TAG) {
          if (typeId != 0) {
            if (extension != null) {
              // We already know the type, so we can parse directly from the
              // input with no copying.  Hooray!
              eagerlyMergeMessageSetExtension(input, extension, extensionRegistry, typeId);
              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, extensionRegistry, extension);
        } else { // We don't know how to parse this. Ignore it.
          if (rawBytes != null) {
            mergeLengthDelimitedField(typeId, rawBytes);
          }
        }
      }
    }

    private void eagerlyMergeMessageSetExtension(
        CodedInputStream input,
        GeneratedExtension<?, ?> extension,
        ExtensionRegistryLite extensionRegistry,
        int typeId)
        throws IOException {
      int fieldNumber = typeId;
      int tag = WireFormat.makeTag(typeId, WireFormat.WIRETYPE_LENGTH_DELIMITED);
      parseExtension(input, extensionRegistry, extension, tag, fieldNumber);
    }

    private void mergeMessageSetExtensionFromBytes(
        ByteString rawBytes,
        ExtensionRegistryLite extensionRegistry,
        GeneratedExtension<?, ?> extension)
        throws IOException {
      MessageLite.Builder subBuilder = null;
      MessageLite existingValue = (MessageLite) extensions.getField(extension.descriptor);
      if (existingValue != null) {
        subBuilder = existingValue.toBuilder();
      }
      if (subBuilder == null) {
        subBuilder = extension.getMessageDefaultInstance().newBuilderForType();
      }
      subBuilder.mergeFrom(rawBytes, extensionRegistry);
      MessageLite value = subBuilder.build();

      ensureExtensionsAreMutable()
          .setField(extension.descriptor, extension.singularToFieldSetType(value));
    }

    FieldSet<ExtensionDescriptor> ensureExtensionsAreMutable() {
      if (extensions.isImmutable()) {
        extensions = extensions.clone();
      }
      return extensions;
    }

    private void verifyExtensionContainingType(final GeneratedExtension<MessageType, ?> extension) {
      if (extension.getContainingTypeDefaultInstance() != getDefaultInstanceForType()) {
        // This can only happen if someone uses unchecked operations.
        throw new IllegalArgumentException(
            "This extension is for a different message type.  Please make "
                + "sure that you are not suppressing any generics type warnings.");
      }
    }

    
Check if a singular extension is present. /** Check if a singular extension is present. */
    @Override
    public final <Type> boolean hasExtension(final ExtensionLite<MessageType, Type> extension) {
      GeneratedExtension<MessageType, Type> extensionLite = checkIsLite(extension);

      verifyExtensionContainingType(extensionLite);
      return extensions.hasField(extensionLite.descriptor);
    }

    
Get the number of elements in a repeated extension. /** Get the number of elements in a repeated extension. */
    @Override
    public final <Type> int getExtensionCount(
        final ExtensionLite<MessageType, List<Type>> extension) {
      GeneratedExtension<MessageType, List<Type>> extensionLite = checkIsLite(extension);

      verifyExtensionContainingType(extensionLite);
      return extensions.getRepeatedFieldCount(extensionLite.descriptor);
    }

    
Get the value of an extension. /** Get the value of an extension. */
    @Override
    @SuppressWarnings("unchecked")
    public final <Type> Type getExtension(final ExtensionLite<MessageType, Type> extension) {
      GeneratedExtension<MessageType, Type> extensionLite = checkIsLite(extension);

      verifyExtensionContainingType(extensionLite);
      final Object value = extensions.getField(extensionLite.descriptor);
      if (value == null) {
        return extensionLite.defaultValue;
      } else {
        return (Type) extensionLite.fromFieldSetType(value);
      }
    }

    
Get one element of a repeated extension. /** Get one element of a repeated extension. */
    @Override
    @SuppressWarnings("unchecked")
    public final <Type> Type getExtension(
        final ExtensionLite<MessageType, List<Type>> extension, final int index) {
      GeneratedExtension<MessageType, List<Type>> extensionLite = checkIsLite(extension);

      verifyExtensionContainingType(extensionLite);
      return (Type)
          extensionLite.singularFromFieldSetType(
              extensions.getRepeatedField(extensionLite.descriptor, index));
    }

    
Called by subclasses to check if all extensions are initialized. /** Called by subclasses to check if all extensions are initialized. */
    protected boolean extensionsAreInitialized() {
      return extensions.isInitialized();
    }

    
Used by subclasses to serialize extensions. Extension ranges may be interleaved with field
numbers, but we must write them in canonical (sorted by field number) order. ExtensionWriter
helps us write individual ranges of extensions at once.
/**
     * Used by subclasses to serialize extensions. Extension ranges may be interleaved with field
     * numbers, but we must write them in canonical (sorted by field number) order. ExtensionWriter
     * helps us write individual ranges of extensions at once.
     */
    protected class ExtensionWriter {
      // Imagine how much simpler this code would be if Java iterators had
      // a way to get the next element without advancing the iterator.

      private final Iterator<Map.Entry<ExtensionDescriptor, Object>> iter = extensions.iterator();
      private Map.Entry<ExtensionDescriptor, Object> next;
      private final boolean messageSetWireFormat;

      private ExtensionWriter(boolean messageSetWireFormat) {
        if (iter.hasNext()) {
          next = iter.next();
        }
        this.messageSetWireFormat = messageSetWireFormat;
      }

      public void writeUntil(final int end, final CodedOutputStream output) throws IOException {
        while (next != null && next.getKey().getNumber() < end) {
          ExtensionDescriptor extension = next.getKey();
          if (messageSetWireFormat
              && extension.getLiteJavaType() == WireFormat.JavaType.MESSAGE
              && !extension.isRepeated()) {
            output.writeMessageSetExtension(extension.getNumber(), (MessageLite) next.getValue());
          } else {
            FieldSet.writeField(extension, next.getValue(), output);
          }
          if (iter.hasNext()) {
            next = iter.next();
          } else {
            next = null;
          }
        }
      }
    }

    protected ExtensionWriter newExtensionWriter() {
      return new ExtensionWriter(false);
    }

    protected ExtensionWriter newMessageSetExtensionWriter() {
      return new ExtensionWriter(true);
    }

    
Called by subclasses to compute the size of extensions. /** Called by subclasses to compute the size of extensions. */
    protected int extensionsSerializedSize() {
      return extensions.getSerializedSize();
    }

    protected int extensionsSerializedSizeAsMessageSet() {
      return extensions.getMessageSetSerializedSize();
    }
  }

  
Lite equivalent of ExtendableBuilder. /** Lite equivalent of {@link GeneratedMessage.ExtendableBuilder}. */
  @SuppressWarnings("unchecked")
  public abstract static class ExtendableBuilder<
          MessageType extends ExtendableMessage<MessageType, BuilderType>,
          BuilderType extends ExtendableBuilder<MessageType, BuilderType>>
      extends Builder<MessageType, BuilderType>
      implements ExtendableMessageOrBuilder<MessageType, BuilderType> {
    protected ExtendableBuilder(MessageType defaultInstance) {
      super(defaultInstance);
    }

    // For immutable message conversion.
    void internalSetExtensionSet(FieldSet<ExtensionDescriptor> extensions) {
      copyOnWrite();
      instance.extensions = extensions;
    }

    @Override
    protected void copyOnWrite() {
      if (!isBuilt) {
        return;
      }

      super.copyOnWrite();
      instance.extensions = instance.extensions.clone();
    }

    private FieldSet<ExtensionDescriptor> ensureExtensionsAreMutable() {
      FieldSet<ExtensionDescriptor> extensions = instance.extensions;
      if (extensions.isImmutable()) {
        extensions = extensions.clone();
        instance.extensions = extensions;
      }
      return extensions;
    }

    @Override
    public final MessageType buildPartial() {
      if (isBuilt) {
        return instance;
      }

      instance.extensions.makeImmutable();
      return super.buildPartial();
    }

    private void verifyExtensionContainingType(final GeneratedExtension<MessageType, ?> extension) {
      if (extension.getContainingTypeDefaultInstance() != getDefaultInstanceForType()) {
        // This can only happen if someone uses unchecked operations.
        throw new IllegalArgumentException(
            "This extension is for a different message type.  Please make "
                + "sure that you are not suppressing any generics type warnings.");
      }
    }

    
Check if a singular extension is present. /** Check if a singular extension is present. */
    @Override
    public final <Type> boolean hasExtension(final ExtensionLite<MessageType, Type> extension) {
      return instance.hasExtension(extension);
    }

    
Get the number of elements in a repeated extension. /** Get the number of elements in a repeated extension. */
    @Override
    public final <Type> int getExtensionCount(
        final ExtensionLite<MessageType, List<Type>> extension) {
      return instance.getExtensionCount(extension);
    }

    
Get the value of an extension. /** Get the value of an extension. */
    @Override
    @SuppressWarnings("unchecked")
    public final <Type> Type getExtension(final ExtensionLite<MessageType, Type> extension) {
      return instance.getExtension(extension);
    }

    
Get one element of a repeated extension. /** Get one element of a repeated extension. */
    @Override
    @SuppressWarnings("unchecked")
    public final <Type> Type getExtension(
        final ExtensionLite<MessageType, List<Type>> extension, final int index) {
      return instance.getExtension(extension, index);
    }

    
Set the value of an extension. /** Set the value of an extension. */
    public final <Type> BuilderType setExtension(
        final ExtensionLite<MessageType, Type> extension, final Type value) {
      GeneratedExtension<MessageType, Type> extensionLite = checkIsLite(extension);

      verifyExtensionContainingType(extensionLite);
      copyOnWrite();
      ensureExtensionsAreMutable()
          .setField(extensionLite.descriptor, extensionLite.toFieldSetType(value));
      return (BuilderType) this;
    }

    
Set the value of one element of a repeated extension. /** Set the value of one element of a repeated extension. */
    public final <Type> BuilderType setExtension(
        final ExtensionLite<MessageType, List<Type>> extension, final int index, final Type value) {
      GeneratedExtension<MessageType, List<Type>> extensionLite = checkIsLite(extension);

      verifyExtensionContainingType(extensionLite);
      copyOnWrite();
      ensureExtensionsAreMutable()
          .setRepeatedField(
              extensionLite.descriptor, index, extensionLite.singularToFieldSetType(value));
      return (BuilderType) this;
    }

    
Append a value to a repeated extension. /** Append a value to a repeated extension. */
    public final <Type> BuilderType addExtension(
        final ExtensionLite<MessageType, List<Type>> extension, final Type value) {
      GeneratedExtension<MessageType, List<Type>> extensionLite = checkIsLite(extension);

      verifyExtensionContainingType(extensionLite);
      copyOnWrite();
      ensureExtensionsAreMutable()
          .addRepeatedField(extensionLite.descriptor, extensionLite.singularToFieldSetType(value));
      return (BuilderType) this;
    }

    
Clear an extension. /** Clear an extension. */
    public final <Type> BuilderType clearExtension(final ExtensionLite<MessageType, ?> extension) {
      GeneratedExtension<MessageType, ?> extensionLite = checkIsLite(extension);

      verifyExtensionContainingType(extensionLite);
      copyOnWrite();
      ensureExtensionsAreMutable().clearField(extensionLite.descriptor);
      return (BuilderType) this;
    }
  }

  // -----------------------------------------------------------------

  
For use by generated code only. /** For use by generated code only. */
  public static <ContainingType extends MessageLite, Type>
      GeneratedExtension<ContainingType, Type> newSingularGeneratedExtension(
          final ContainingType containingTypeDefaultInstance,
          final Type defaultValue,
          final MessageLite messageDefaultInstance,
          final Internal.EnumLiteMap<?> enumTypeMap,
          final int number,
          final WireFormat.FieldType type,
          final Class singularType) {
    return new GeneratedExtension<ContainingType, Type>(
        containingTypeDefaultInstance,
        defaultValue,
        messageDefaultInstance,
        new ExtensionDescriptor(
            enumTypeMap, number, type, /* isRepeated= */ false, /* isPacked= */ false),
        singularType);
  }

  
For use by generated code only. /** For use by generated code only. */
  public static <ContainingType extends MessageLite, Type>
      GeneratedExtension<ContainingType, Type> newRepeatedGeneratedExtension(
          final ContainingType containingTypeDefaultInstance,
          final MessageLite messageDefaultInstance,
          final Internal.EnumLiteMap<?> enumTypeMap,
          final int number,
          final WireFormat.FieldType type,
          final boolean isPacked,
          final Class singularType) {
    @SuppressWarnings("unchecked") // Subclasses ensure Type is a List
    Type emptyList = (Type) Collections.emptyList();
    return new GeneratedExtension<ContainingType, Type>(
        containingTypeDefaultInstance,
        emptyList,
        messageDefaultInstance,
        new ExtensionDescriptor(enumTypeMap, number, type, /* isRepeated= */ true, isPacked),
        singularType);
  }

  static final class ExtensionDescriptor
      implements FieldSet.FieldDescriptorLite<ExtensionDescriptor> {
    ExtensionDescriptor(
        final Internal.EnumLiteMap<?> enumTypeMap,
        final int number,
        final WireFormat.FieldType type,
        final boolean isRepeated,
        final boolean isPacked) {
      this.enumTypeMap = enumTypeMap;
      this.number = number;
      this.type = type;
      this.isRepeated = isRepeated;
      this.isPacked = isPacked;
    }

    final Internal.EnumLiteMap<?> enumTypeMap;
    final int number;
    final WireFormat.FieldType type;
    final boolean isRepeated;
    final boolean isPacked;

    @Override
    public int getNumber() {
      return number;
    }

    @Override
    public WireFormat.FieldType getLiteType() {
      return type;
    }

    @Override
    public WireFormat.JavaType getLiteJavaType() {
      return type.getJavaType();
    }

    @Override
    public boolean isRepeated() {
      return isRepeated;
    }

    @Override
    public boolean isPacked() {
      return isPacked;
    }

    @Override
    public Internal.EnumLiteMap<?> getEnumType() {
      return enumTypeMap;
    }

    @Override
    @SuppressWarnings("unchecked")
    public MessageLite.Builder internalMergeFrom(MessageLite.Builder to, MessageLite from) {
      return ((Builder) to).mergeFrom((GeneratedMessageLite) from);
    }


    @Override
    public int compareTo(ExtensionDescriptor other) {
      return number - other.number;
    }
  }

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

  
Calls Class.getMethod and throws a RuntimeException if it fails. /** Calls Class.getMethod and throws a RuntimeException if it fails. */
  @SuppressWarnings("unchecked")
  static Method getMethodOrDie(Class clazz, String name, Class... params) {
    try {
      return clazz.getMethod(name, params);
    } catch (NoSuchMethodException e) {
      throw new RuntimeException(
          "Generated message class \"" + clazz.getName() + "\" missing method \"" + name + "\".",
          e);
    }
  }

  
Calls invoke and throws a RuntimeException if it fails. /** Calls invoke and throws a RuntimeException if it fails. */
  static Object invokeOrDie(Method method, Object object, Object... params) {
    try {
      return method.invoke(object, params);
    } catch (IllegalAccessException e) {
      throw new RuntimeException(
          "Couldn't use Java reflection to implement protocol message reflection.", e);
    } catch (InvocationTargetException e) {
      final Throwable cause = e.getCause();
      if (cause instanceof RuntimeException) {
        throw (RuntimeException) cause;
      } else if (cause instanceof Error) {
        throw (Error) cause;
      } else {
        throw new RuntimeException(
            "Unexpected exception thrown by generated accessor method.", cause);
      }
    }
  }


  
Lite equivalent to GeneratedExtension. 
Users should ignore the contents of this class and only use objects of this type as
parameters to extension accessors and ExtensionRegistry.add().
/**
   * Lite equivalent to {@link GeneratedMessage.GeneratedExtension}.
   *
   * <p>Users should ignore the contents of this class and only use objects of this type as
   * parameters to extension accessors and ExtensionRegistry.add().
   */
  public static class GeneratedExtension<ContainingType extends MessageLite, Type>
      extends ExtensionLite<ContainingType, Type> {

    
Create a new instance with the given parameters.
The last parameter singularType is only needed for enum types. We store integer values for enum types in a ExtendableMessage and use Java reflection to convert an integer value back into a concrete enum object. /**
     * Create a new instance with the given parameters.
     *
     * <p>The last parameter {@code singularType} is only needed for enum types. We store integer
     * values for enum types in a {@link ExtendableMessage} and use Java reflection to convert an
     * integer value back into a concrete enum object.
     */
    GeneratedExtension(
        final ContainingType containingTypeDefaultInstance,
        final Type defaultValue,
        final MessageLite messageDefaultInstance,
        final ExtensionDescriptor descriptor,
        final Class singularType) {
      // Defensive checks to verify the correct initialization order of
      // GeneratedExtensions and their related GeneratedMessages.
      if (containingTypeDefaultInstance == null) {
        throw new IllegalArgumentException("Null containingTypeDefaultInstance");
      }
      if (descriptor.getLiteType() == WireFormat.FieldType.MESSAGE
          && messageDefaultInstance == null) {
        throw new IllegalArgumentException("Null messageDefaultInstance");
      }
      this.containingTypeDefaultInstance = containingTypeDefaultInstance;
      this.defaultValue = defaultValue;
      this.messageDefaultInstance = messageDefaultInstance;
      this.descriptor = descriptor;
    }

    final ContainingType containingTypeDefaultInstance;
    final Type defaultValue;
    final MessageLite messageDefaultInstance;
    final ExtensionDescriptor descriptor;

    
Default instance of the type being extended, used to identify that type. /** Default instance of the type being extended, used to identify that type. */
    public ContainingType getContainingTypeDefaultInstance() {
      return containingTypeDefaultInstance;
    }

    
Get the field number. /** Get the field number. */
    @Override
    public int getNumber() {
      return descriptor.getNumber();
    }

    
If the extension is an embedded message or group, returns the default instance of the
message.
/**
     * If the extension is an embedded message or group, returns the default instance of the
     * message.
     */
    @Override
    public MessageLite getMessageDefaultInstance() {
      return messageDefaultInstance;
    }

    @SuppressWarnings("unchecked")
    Object fromFieldSetType(final Object value) {
      if (descriptor.isRepeated()) {
        if (descriptor.getLiteJavaType() == WireFormat.JavaType.ENUM) {
          final List result = new ArrayList();
          for (final Object element : (List) value) {
            result.add(singularFromFieldSetType(element));
          }
          return result;
        } else {
          return value;
        }
      } else {
        return singularFromFieldSetType(value);
      }
    }

    Object singularFromFieldSetType(final Object value) {
      if (descriptor.getLiteJavaType() == WireFormat.JavaType.ENUM) {
        return descriptor.enumTypeMap.findValueByNumber((Integer) value);
      } else {
        return value;
      }
    }

    @SuppressWarnings("unchecked")
    Object toFieldSetType(final Object value) {
      if (descriptor.isRepeated()) {
        if (descriptor.getLiteJavaType() == WireFormat.JavaType.ENUM) {
          final List result = new ArrayList();
          for (final Object element : (List) value) {
            result.add(singularToFieldSetType(element));
          }
          return result;
        } else {
          return value;
        }
      } else {
        return singularToFieldSetType(value);
      }
    }

    Object singularToFieldSetType(final Object value) {
      if (descriptor.getLiteJavaType() == WireFormat.JavaType.ENUM) {
        return ((Internal.EnumLite) value).getNumber();
      } else {
        return value;
      }
    }

    @Override
    public FieldType getLiteType() {
      return descriptor.getLiteType();
    }

    @Override
    public boolean isRepeated() {
      return descriptor.isRepeated;
    }

    @Override
    public Type getDefaultValue() {
      return defaultValue;
    }
  }

  
A serialized (serializable) form of the generated message. Stores the message as a class name
and a byte array.
/**
   * A serialized (serializable) form of the generated message. Stores the message as a class name
   * and a byte array.
   */
  protected static final class SerializedForm implements Serializable {

    public static SerializedForm of(MessageLite message) {
      return new SerializedForm(message);
    }

    private static final long serialVersionUID = 0L;

    // since v3.6.1
    private final Class<?> messageClass;
    // only included for backwards compatibility before messageClass was added
    private final String messageClassName;
    private final byte[] asBytes;

    
Creates the serialized form by calling MessageLite.toByteArray. 
Params:
regularForm – the message to serialize/**
     * Creates the serialized form by calling {@link com.google.protobuf.MessageLite#toByteArray}.
     *
     * @param regularForm the message to serialize
     */
    SerializedForm(MessageLite regularForm) {
      messageClass = regularForm.getClass();
      messageClassName = messageClass.getName();
      asBytes = regularForm.toByteArray();
    }

    
When read from an ObjectInputStream, this method converts this object back to the regular
form. Part of Java's serialization magic.
Returns:
a GeneratedMessage of the type that was serialized/**
     * When read from an ObjectInputStream, this method converts this object back to the regular
     * form. Part of Java's serialization magic.
     *
     * @return a GeneratedMessage of the type that was serialized
     */
    @SuppressWarnings("unchecked")
    protected Object readResolve() throws ObjectStreamException {
      try {
        Class<?> messageClass = resolveMessageClass();
        java.lang.reflect.Field defaultInstanceField =
            messageClass.getDeclaredField("DEFAULT_INSTANCE");
        defaultInstanceField.setAccessible(true);
        MessageLite defaultInstance = (MessageLite) defaultInstanceField.get(null);
        return defaultInstance.newBuilderForType().mergeFrom(asBytes).buildPartial();
      } catch (ClassNotFoundException e) {
        throw new RuntimeException("Unable to find proto buffer class: " + messageClassName, e);
      } catch (NoSuchFieldException e) {
        return readResolveFallback();
      } catch (SecurityException e) {
        throw new RuntimeException("Unable to call DEFAULT_INSTANCE in " + messageClassName, e);
      } catch (IllegalAccessException e) {
        throw new RuntimeException("Unable to call parsePartialFrom", e);
      } catch (InvalidProtocolBufferException e) {
        throw new RuntimeException("Unable to understand proto buffer", e);
      }
    }

    
Deprecated:
from v3.0.0-beta-3+, for compatibility with v2.5.0 and v2.6.1 generated code./**
     * @deprecated from v3.0.0-beta-3+, for compatibility with v2.5.0 and v2.6.1 generated code.
     */
    @Deprecated
    private Object readResolveFallback() throws ObjectStreamException {
      try {
        Class<?> messageClass = resolveMessageClass();
        java.lang.reflect.Field defaultInstanceField =
            messageClass.getDeclaredField("defaultInstance");
        defaultInstanceField.setAccessible(true);
        MessageLite defaultInstance = (MessageLite) defaultInstanceField.get(null);
        return defaultInstance.newBuilderForType()
            .mergeFrom(asBytes)
            .buildPartial();
      } catch (ClassNotFoundException e) {
        throw new RuntimeException("Unable to find proto buffer class: " + messageClassName, e);
      } catch (NoSuchFieldException e) {
        throw new RuntimeException("Unable to find defaultInstance in " + messageClassName, e);
      } catch (SecurityException e) {
        throw new RuntimeException("Unable to call defaultInstance in " + messageClassName, e);
      } catch (IllegalAccessException e) {
        throw new RuntimeException("Unable to call parsePartialFrom", e);
      } catch (InvalidProtocolBufferException e) {
        throw new RuntimeException("Unable to understand proto buffer", e);
      }
    }

    private Class<?> resolveMessageClass() throws ClassNotFoundException {
      return messageClass != null ? messageClass : Class.forName(messageClassName);
    }
  }

  
Checks that the Extension is Lite and returns it as a GeneratedExtension. /** Checks that the {@link Extension} is Lite and returns it as a {@link GeneratedExtension}. */
  private static <
          MessageType extends ExtendableMessage<MessageType, BuilderType>,
          BuilderType extends ExtendableBuilder<MessageType, BuilderType>,
          T>
      GeneratedExtension<MessageType, T> checkIsLite(ExtensionLite<MessageType, T> extension) {
    if (!extension.isLite()) {
      throw new IllegalArgumentException("Expected a lite extension.");
    }

    return (GeneratedExtension<MessageType, T>) extension;
  }

  
A static helper method for checking if a message is initialized, optionally memoizing.
For use by generated code only.
/**
   * A static helper method for checking if a message is initialized, optionally memoizing.
   *
   * <p>For use by generated code only.
   */
  protected static final <T extends GeneratedMessageLite<T, ?>> boolean isInitialized(
      T message, boolean shouldMemoize) {
    byte memoizedIsInitialized =
        (Byte) message.dynamicMethod(MethodToInvoke.GET_MEMOIZED_IS_INITIALIZED);
    if (memoizedIsInitialized == 1) {
      return true;
    }
    if (memoizedIsInitialized == 0) {
      return false;
    }
    boolean isInitialized = Protobuf.getInstance().schemaFor(message).isInitialized(message);
    if (shouldMemoize) {
      message.dynamicMethod(
          MethodToInvoke.SET_MEMOIZED_IS_INITIALIZED, isInitialized ? message : null);
    }
    return isInitialized;
  }

  protected static IntList emptyIntList() {
    return IntArrayList.emptyList();
  }

  protected static IntList mutableCopy(IntList list) {
    int size = list.size();
    return list.mutableCopyWithCapacity(
        size == 0 ? AbstractProtobufList.DEFAULT_CAPACITY : size * 2);
  }

  protected static LongList emptyLongList() {
    return LongArrayList.emptyList();
  }

  protected static LongList mutableCopy(LongList list) {
    int size = list.size();
    return list.mutableCopyWithCapacity(
        size == 0 ? AbstractProtobufList.DEFAULT_CAPACITY : size * 2);
  }

  protected static FloatList emptyFloatList() {
    return FloatArrayList.emptyList();
  }

  protected static FloatList mutableCopy(FloatList list) {
    int size = list.size();
    return list.mutableCopyWithCapacity(
        size == 0 ? AbstractProtobufList.DEFAULT_CAPACITY : size * 2);
  }

  protected static DoubleList emptyDoubleList() {
    return DoubleArrayList.emptyList();
  }

  protected static DoubleList mutableCopy(DoubleList list) {
    int size = list.size();
    return list.mutableCopyWithCapacity(
        size == 0 ? AbstractProtobufList.DEFAULT_CAPACITY : size * 2);
  }

  protected static BooleanList emptyBooleanList() {
    return BooleanArrayList.emptyList();
  }

  protected static BooleanList mutableCopy(BooleanList list) {
    int size = list.size();
    return list.mutableCopyWithCapacity(
        size == 0 ? AbstractProtobufList.DEFAULT_CAPACITY : size * 2);
  }

  protected static <E> ProtobufList<E> emptyProtobufList() {
    return ProtobufArrayList.emptyList();
  }

  protected static <E> ProtobufList<E> mutableCopy(ProtobufList<E> list) {
    int size = list.size();
    return list.mutableCopyWithCapacity(
        size == 0 ? AbstractProtobufList.DEFAULT_CAPACITY : size * 2);
  }

  
A Parser implementation that delegates to the default instance. 
For use by generated code only.
/**
   * A {@link Parser} implementation that delegates to the default instance.
   *
   * <p>For use by generated code only.
   */
  protected static class DefaultInstanceBasedParser<T extends GeneratedMessageLite<T, ?>>
      extends AbstractParser<T> {

    private final T defaultInstance;

    public DefaultInstanceBasedParser(T defaultInstance) {
      this.defaultInstance = defaultInstance;
    }

    @Override
    public T parsePartialFrom(CodedInputStream input, ExtensionRegistryLite extensionRegistry)
        throws InvalidProtocolBufferException {
      return GeneratedMessageLite.parsePartialFrom(defaultInstance, input, extensionRegistry);
    }

    @Override
    public T parsePartialFrom(
        byte[] input, int offset, int length, ExtensionRegistryLite extensionRegistry)
        throws InvalidProtocolBufferException {
      return GeneratedMessageLite.parsePartialFrom(
          defaultInstance, input, offset, length, extensionRegistry);
    }
  }

  
A static helper method for parsing a partial from input using the extension registry and the
instance.
/**
   * A static helper method for parsing a partial from input using the extension registry and the
   * instance.
   */
  // TODO(dweis): Should this verify that the last tag was 0?
  static <T extends GeneratedMessageLite<T, ?>> T parsePartialFrom(
      T instance, CodedInputStream input, ExtensionRegistryLite extensionRegistry)
      throws InvalidProtocolBufferException {
    @SuppressWarnings("unchecked") // Guaranteed by protoc
    T result = (T) instance.dynamicMethod(MethodToInvoke.NEW_MUTABLE_INSTANCE);
    try {
      // TODO(yilunchong): Try to make input with type CodedInpuStream.ArrayDecoder use
      // fast path.
      Schema<T> schema = Protobuf.getInstance().schemaFor(result);
      schema.mergeFrom(result, CodedInputStreamReader.forCodedInput(input), extensionRegistry);
      schema.makeImmutable(result);
    } catch (IOException e) {
      if (e.getCause() instanceof InvalidProtocolBufferException) {
        throw (InvalidProtocolBufferException) e.getCause();
      }
      throw new InvalidProtocolBufferException(e.getMessage()).setUnfinishedMessage(result);
    } catch (RuntimeException e) {
      if (e.getCause() instanceof InvalidProtocolBufferException) {
        throw (InvalidProtocolBufferException) e.getCause();
      }
      throw e;
    }
    return result;
  }

  
A static helper method for parsing a partial from byte array. /** A static helper method for parsing a partial from byte array. */
  static <T extends GeneratedMessageLite<T, ?>> T parsePartialFrom(
      T instance, byte[] input, int offset, int length, ExtensionRegistryLite extensionRegistry)
      throws InvalidProtocolBufferException {
    @SuppressWarnings("unchecked") // Guaranteed by protoc
    T result = (T) instance.dynamicMethod(MethodToInvoke.NEW_MUTABLE_INSTANCE);
    try {
      Schema<T> schema = Protobuf.getInstance().schemaFor(result);
      schema.mergeFrom(
          result, input, offset, offset + length, new ArrayDecoders.Registers(extensionRegistry));
      schema.makeImmutable(result);
      if (result.memoizedHashCode != 0) {
        throw new RuntimeException();
      }
    } catch (IOException e) {
      if (e.getCause() instanceof InvalidProtocolBufferException) {
        throw (InvalidProtocolBufferException) e.getCause();
      }
      throw new InvalidProtocolBufferException(e.getMessage()).setUnfinishedMessage(result);
    } catch (IndexOutOfBoundsException e) {
      throw InvalidProtocolBufferException.truncatedMessage().setUnfinishedMessage(result);
    }
    return result;
  }

  protected static <T extends GeneratedMessageLite<T, ?>> T parsePartialFrom(
      T defaultInstance, CodedInputStream input) throws InvalidProtocolBufferException {
    return parsePartialFrom(defaultInstance, input, ExtensionRegistryLite.getEmptyRegistry());
  }

  
Helper method to check if message is initialized.
Throws:
InvalidProtocolBufferException – if it is not initialized.
Returns:
The message to check./**
   * Helper method to check if message is initialized.
   *
   * @throws InvalidProtocolBufferException if it is not initialized.
   * @return The message to check.
   */
  private static <T extends GeneratedMessageLite<T, ?>> T checkMessageInitialized(T message)
      throws InvalidProtocolBufferException {
    if (message != null && !message.isInitialized()) {
      throw message
          .newUninitializedMessageException()
          .asInvalidProtocolBufferException()
          .setUnfinishedMessage(message);
    }
    return message;
  }

  // Validates last tag.
  protected static <T extends GeneratedMessageLite<T, ?>> T parseFrom(
      T defaultInstance, ByteBuffer data, ExtensionRegistryLite extensionRegistry)
      throws InvalidProtocolBufferException {
    return checkMessageInitialized(
        parseFrom(defaultInstance, CodedInputStream.newInstance(data), extensionRegistry));
  }

  // Validates last tag.
  protected static <T extends GeneratedMessageLite<T, ?>> T parseFrom(
      T defaultInstance, ByteBuffer data) throws InvalidProtocolBufferException {
    return parseFrom(defaultInstance, data, ExtensionRegistryLite.getEmptyRegistry());
  }

  // Validates last tag.
  protected static <T extends GeneratedMessageLite<T, ?>> T parseFrom(
      T defaultInstance, ByteString data) throws InvalidProtocolBufferException {
    return checkMessageInitialized(
        parseFrom(defaultInstance, data, ExtensionRegistryLite.getEmptyRegistry()));
  }

  // Validates last tag.
  protected static <T extends GeneratedMessageLite<T, ?>> T parseFrom(
      T defaultInstance, ByteString data, ExtensionRegistryLite extensionRegistry)
      throws InvalidProtocolBufferException {
    return checkMessageInitialized(parsePartialFrom(defaultInstance, data, extensionRegistry));
  }

  // This is a special case since we want to verify that the last tag is 0. We assume we exhaust the
  // ByteString.
  private static <T extends GeneratedMessageLite<T, ?>> T parsePartialFrom(
      T defaultInstance, ByteString data, ExtensionRegistryLite extensionRegistry)
      throws InvalidProtocolBufferException {
    T message;
    try {
      CodedInputStream input = data.newCodedInput();
      message = parsePartialFrom(defaultInstance, input, extensionRegistry);
      try {
        input.checkLastTagWas(0);
      } catch (InvalidProtocolBufferException e) {
        throw e.setUnfinishedMessage(message);
      }
      return message;
    } catch (InvalidProtocolBufferException e) {
      throw e;
    }
  }

  // This is a special case since we want to verify that the last tag is 0. We assume we exhaust the
  // ByteString.
  private static <T extends GeneratedMessageLite<T, ?>> T parsePartialFrom(
      T defaultInstance, byte[] data, ExtensionRegistryLite extensionRegistry)
      throws InvalidProtocolBufferException {
    return checkMessageInitialized(
        parsePartialFrom(defaultInstance, data, 0, data.length, extensionRegistry));
  }

  // Validates last tag.
  protected static <T extends GeneratedMessageLite<T, ?>> T parseFrom(
      T defaultInstance, byte[] data) throws InvalidProtocolBufferException {
    return checkMessageInitialized(parsePartialFrom(
        defaultInstance, data, 0, data.length, ExtensionRegistryLite.getEmptyRegistry()));
  }

  // Validates last tag.
  protected static <T extends GeneratedMessageLite<T, ?>> T parseFrom(
      T defaultInstance, byte[] data, ExtensionRegistryLite extensionRegistry)
      throws InvalidProtocolBufferException {
    return checkMessageInitialized(
        parsePartialFrom(defaultInstance, data, 0, data.length, extensionRegistry));
  }

  // Does not validate last tag.
  protected static <T extends GeneratedMessageLite<T, ?>> T parseFrom(
      T defaultInstance, InputStream input) throws InvalidProtocolBufferException {
    return checkMessageInitialized(
        parsePartialFrom(
            defaultInstance,
            CodedInputStream.newInstance(input),
            ExtensionRegistryLite.getEmptyRegistry()));
  }

  // Does not validate last tag.
  protected static <T extends GeneratedMessageLite<T, ?>> T parseFrom(
      T defaultInstance, InputStream input, ExtensionRegistryLite extensionRegistry)
      throws InvalidProtocolBufferException {
    return checkMessageInitialized(
        parsePartialFrom(defaultInstance, CodedInputStream.newInstance(input), extensionRegistry));
  }

  // Does not validate last tag.
  protected static <T extends GeneratedMessageLite<T, ?>> T parseFrom(
      T defaultInstance, CodedInputStream input) throws InvalidProtocolBufferException {
    return parseFrom(defaultInstance, input, ExtensionRegistryLite.getEmptyRegistry());
  }

  // Does not validate last tag.
  protected static <T extends GeneratedMessageLite<T, ?>> T parseFrom(
      T defaultInstance, CodedInputStream input, ExtensionRegistryLite extensionRegistry)
      throws InvalidProtocolBufferException {
    return checkMessageInitialized(parsePartialFrom(defaultInstance, input, extensionRegistry));
  }

  // Validates last tag.
  protected static <T extends GeneratedMessageLite<T, ?>> T parseDelimitedFrom(
      T defaultInstance, InputStream input) throws InvalidProtocolBufferException {
    return checkMessageInitialized(
        parsePartialDelimitedFrom(
            defaultInstance, input, ExtensionRegistryLite.getEmptyRegistry()));
  }

  // Validates last tag.
  protected static <T extends GeneratedMessageLite<T, ?>> T parseDelimitedFrom(
      T defaultInstance, InputStream input, ExtensionRegistryLite extensionRegistry)
      throws InvalidProtocolBufferException {
    return checkMessageInitialized(
        parsePartialDelimitedFrom(defaultInstance, input, extensionRegistry));
  }

  private static <T extends GeneratedMessageLite<T, ?>> T parsePartialDelimitedFrom(
      T defaultInstance, InputStream input, ExtensionRegistryLite extensionRegistry)
      throws InvalidProtocolBufferException {
    int size;
    try {
      int firstByte = input.read();
      if (firstByte == -1) {
        return null;
      }
      size = CodedInputStream.readRawVarint32(firstByte, input);
    } catch (IOException e) {
      throw new InvalidProtocolBufferException(e.getMessage());
    }
    InputStream limitedInput = new LimitedInputStream(input, size);
    CodedInputStream codedInput = CodedInputStream.newInstance(limitedInput);
    T message = parsePartialFrom(defaultInstance, codedInput, extensionRegistry);
    try {
      codedInput.checkLastTagWas(0);
    } catch (InvalidProtocolBufferException e) {
      throw e.setUnfinishedMessage(message);
    }
    return message;
  }
}