// 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
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// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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package com.google.protobuf;

import com.google.protobuf.AbstractMessageLite.Builder.LimitedInputStream;

import java.io.IOException;
import java.io.InputStream;

/**
 * A partial implementation of the {@link Parser} interface which implements
 * as many methods of that interface as possible in terms of other methods.
 *
 * Note: This class implements all the convenience methods in the
 * {@link Parser} interface. See {@link Parser} for related javadocs.
 * Subclasses need to implement
 * {@link Parser#parsePartialFrom(CodedInputStream, ExtensionRegistryLite)}
 *
 * @author [email protected] (Pherl Liu)
 */
public abstract class AbstractParser<MessageType extends MessageLite>
    implements Parser<MessageType> {
  /**
   * Creates an UninitializedMessageException for MessageType.
   */
  private UninitializedMessageException
      newUninitializedMessageException(MessageType message) {
    if (message instanceof AbstractMessageLite) {
      return ((AbstractMessageLite) message).newUninitializedMessageException();
    }
    return new UninitializedMessageException(message);
  }

  /**
   * Helper method to check if message is initialized.
   *
   * @throws InvalidProtocolBufferException if it is not initialized.
   * @return The message to check.
   */
  private MessageType checkMessageInitialized(MessageType message)
      throws InvalidProtocolBufferException {
    if (message != null && !message.isInitialized()) {
      throw newUninitializedMessageException(message)
          .asInvalidProtocolBufferException()
          .setUnfinishedMessage(message);
    }
    return message;
  }

  private static final ExtensionRegistryLite EMPTY_REGISTRY
      = ExtensionRegistryLite.getEmptyRegistry();

  public MessageType parsePartialFrom(CodedInputStream input)
      throws InvalidProtocolBufferException {
    return parsePartialFrom(input, EMPTY_REGISTRY);
  }

  public MessageType parseFrom(CodedInputStream input,
                               ExtensionRegistryLite extensionRegistry)
      throws InvalidProtocolBufferException {
    return checkMessageInitialized(
        parsePartialFrom(input, extensionRegistry));
  }

  public MessageType parseFrom(CodedInputStream input)
      throws InvalidProtocolBufferException {
    return parseFrom(input, EMPTY_REGISTRY);
  }

  public MessageType parsePartialFrom(ByteString data,
                                      ExtensionRegistryLite extensionRegistry)
    throws InvalidProtocolBufferException {
    MessageType message;
    try {
      CodedInputStream input = data.newCodedInput();
      message = parsePartialFrom(input, extensionRegistry);
      try {
        input.checkLastTagWas(0);
      } catch (InvalidProtocolBufferException e) {
        throw e.setUnfinishedMessage(message);
      }
      return message;
    } catch (InvalidProtocolBufferException e) {
      throw e;
    } catch (IOException e) {
      throw new RuntimeException(
          "Reading from a ByteString threw an IOException (should " +
          "never happen).", e);
    }
  }

  public MessageType parsePartialFrom(ByteString data)
      throws InvalidProtocolBufferException {
    return parsePartialFrom(data, EMPTY_REGISTRY);
  }

  public MessageType parseFrom(ByteString data,
                               ExtensionRegistryLite extensionRegistry)
      throws InvalidProtocolBufferException {
    return checkMessageInitialized(parsePartialFrom(data, extensionRegistry));
  }

  public MessageType parseFrom(ByteString data)
      throws InvalidProtocolBufferException {
    return parseFrom(data, EMPTY_REGISTRY);
  }

  public MessageType parsePartialFrom(byte[] data, int off, int len,
                                      ExtensionRegistryLite extensionRegistry)
      throws InvalidProtocolBufferException {
    try {
      CodedInputStream input = CodedInputStream.newInstance(data, off, len);
      MessageType message = parsePartialFrom(input, extensionRegistry);
      try {
        input.checkLastTagWas(0);
      } catch (InvalidProtocolBufferException e) {
        throw e.setUnfinishedMessage(message);
      }
      return message;
    } catch (InvalidProtocolBufferException e) {
      throw e;
    } catch (IOException e) {
      throw new RuntimeException(
          "Reading from a byte array threw an IOException (should " +
          "never happen).", e);
    }
  }

  public MessageType parsePartialFrom(byte[] data, int off, int len)
      throws InvalidProtocolBufferException {
    return parsePartialFrom(data, off, len, EMPTY_REGISTRY);
  }

  public MessageType parsePartialFrom(byte[] data,
                                      ExtensionRegistryLite extensionRegistry)
      throws InvalidProtocolBufferException {
    return parsePartialFrom(data, 0, data.length, extensionRegistry);
  }

  public MessageType parsePartialFrom(byte[] data)
      throws InvalidProtocolBufferException {
    return parsePartialFrom(data, 0, data.length, EMPTY_REGISTRY);
  }

  public MessageType parseFrom(byte[] data, int off, int len,
                               ExtensionRegistryLite extensionRegistry)
      throws InvalidProtocolBufferException {
    return checkMessageInitialized(
        parsePartialFrom(data, off, len, extensionRegistry));
  }

  public MessageType parseFrom(byte[] data, int off, int len)
      throws InvalidProtocolBufferException {
    return parseFrom(data, off, len, EMPTY_REGISTRY);
  }

  public MessageType parseFrom(byte[] data,
                               ExtensionRegistryLite extensionRegistry)
      throws InvalidProtocolBufferException {
    return parseFrom(data, 0, data.length, extensionRegistry);
  }

  public MessageType parseFrom(byte[] data)
      throws InvalidProtocolBufferException {
    return parseFrom(data, EMPTY_REGISTRY);
  }

  public MessageType parsePartialFrom(InputStream input,
                                      ExtensionRegistryLite extensionRegistry)
      throws InvalidProtocolBufferException {
    CodedInputStream codedInput = CodedInputStream.newInstance(input);
    MessageType message = parsePartialFrom(codedInput, extensionRegistry);
    try {
      codedInput.checkLastTagWas(0);
    } catch (InvalidProtocolBufferException e) {
      throw e.setUnfinishedMessage(message);
    }
    return message;
  }

  public MessageType parsePartialFrom(InputStream input)
      throws InvalidProtocolBufferException {
    return parsePartialFrom(input, EMPTY_REGISTRY);
  }

  public MessageType parseFrom(InputStream input,
                               ExtensionRegistryLite extensionRegistry)
      throws InvalidProtocolBufferException {
    return checkMessageInitialized(
        parsePartialFrom(input, extensionRegistry));
  }

  public MessageType parseFrom(InputStream input)
      throws InvalidProtocolBufferException {
    return parseFrom(input, EMPTY_REGISTRY);
  }

  public MessageType parsePartialDelimitedFrom(
      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);
    return parsePartialFrom(limitedInput, extensionRegistry);
  }

  public MessageType parsePartialDelimitedFrom(InputStream input)
      throws InvalidProtocolBufferException {
    return parsePartialDelimitedFrom(input, EMPTY_REGISTRY);
  }

  public MessageType parseDelimitedFrom(
      InputStream input,
      ExtensionRegistryLite extensionRegistry)
      throws InvalidProtocolBufferException {
    return checkMessageInitialized(
        parsePartialDelimitedFrom(input, extensionRegistry));
  }

  public MessageType parseDelimitedFrom(InputStream input)
      throws InvalidProtocolBufferException {
    return parseDelimitedFrom(input, EMPTY_REGISTRY);
  }
}