tech.ydb.shaded.google.protobuf.Internal Maven / Gradle / Ivy
// 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,
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package com.google.protobuf;
import java.lang.reflect.Method;
import java.nio.Buffer;
import java.nio.ByteBuffer;
import java.nio.charset.Charset;
import java.util.AbstractList;
import java.util.AbstractMap;
import java.util.AbstractSet;
import java.util.Arrays;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.RandomAccess;
import java.util.Set;
/**
 * The classes contained within are used internally by the Protocol Buffer library and generated
 * message implementations. They are public only because those generated messages do not reside in
 * the {@code protobuf} package. Others should not use this class directly.
 *
 * @author [email protected] (Kenton Varda)
 */
public final class Internal {
  private Internal() {}
  static final Charset US_ASCII = Charset.forName("US-ASCII");
  static final Charset UTF_8 = Charset.forName("UTF-8");
  static final Charset ISO_8859_1 = Charset.forName("ISO-8859-1");
  /** Throws an appropriate {@link NullPointerException} if the given objects is {@code null}. */
  static  T checkNotNull(T obj) {
    if (obj == null) {
      throw new NullPointerException();
    }
    return obj;
  }
  /** Throws an appropriate {@link NullPointerException} if the given objects is {@code null}. */
  static  T checkNotNull(T obj, String message) {
    if (obj == null) {
      throw new NullPointerException(message);
    }
    return obj;
  }
  /**
   * Helper called by generated code to construct default values for string fields.
   *
   * The protocol compiler does not actually contain a UTF-8 decoder -- it just pushes
   * UTF-8-encoded text around without touching it. The one place where this presents a problem is
   * when generating Java string literals. Unicode characters in the string literal would normally
   * need to be encoded using a Unicode escape sequence, which would require decoding them. To get
   * around this, protoc instead embeds the UTF-8 bytes into the generated code and leaves it to the
   * runtime library to decode them.
   *
   * 
It gets worse, though. If protoc just generated a byte array, like: new byte[] {0x12, 0x34,
   * 0x56, 0x78} Java actually generates *code* which allocates an array and then fills in each
   * value. This is much less efficient than just embedding the bytes directly into the bytecode. To
   * get around this, we need another work-around. String literals are embedded directly, so protoc
   * actually generates a string literal corresponding to the bytes. The easiest way to do this is
   * to use the ISO-8859-1 character set, which corresponds to the first 256 characters of the
   * Unicode range. Protoc can then use good old CEscape to generate the string.
   *
   * 
So we have a string literal which represents a set of bytes which represents another string.
   * This function -- stringDefaultValue -- converts from the generated string to the string we
   * actually want. The generated code calls this automatically.
   */
  public static String stringDefaultValue(String bytes) {
    return new String(bytes.getBytes(ISO_8859_1), UTF_8);
  }
  /**
   * Helper called by generated code to construct default values for bytes fields.
   *
   * 
This is a lot like {@link #stringDefaultValue}, but for bytes fields. In this case we only
   * need the second of the two hacks -- allowing us to embed raw bytes as a string literal with
   * ISO-8859-1 encoding.
   */
  public static ByteString bytesDefaultValue(String bytes) {
    return ByteString.copyFrom(bytes.getBytes(ISO_8859_1));
  }
  /**
   * Helper called by generated code to construct default values for bytes fields.
   *
   * 
This is like {@link #bytesDefaultValue}, but returns a byte array.
   */
  public static byte[] byteArrayDefaultValue(String bytes) {
    return bytes.getBytes(ISO_8859_1);
  }
  /**
   * Helper called by generated code to construct default values for bytes fields.
   *
   * 
This is like {@link #bytesDefaultValue}, but returns a ByteBuffer.
   */
  public static ByteBuffer byteBufferDefaultValue(String bytes) {
    return ByteBuffer.wrap(byteArrayDefaultValue(bytes));
  }
  /**
   * Create a new ByteBuffer and copy all the content of {@code source} ByteBuffer to the new
   * ByteBuffer. The new ByteBuffer's limit and capacity will be source.capacity(), and its position
   * will be 0. Note that the state of {@code source} ByteBuffer won't be changed.
   */
  public static ByteBuffer copyByteBuffer(ByteBuffer source) {
    // Make a duplicate of the source ByteBuffer and read data from the
    // duplicate. This is to avoid affecting the source ByteBuffer's state.
    ByteBuffer temp = source.duplicate();
    // We want to copy all the data in the source ByteBuffer, not just the
    // remaining bytes.
    // View ByteBuffer as Buffer to avoid issue with covariant return types
    // See https://issues.apache.org/jira/browse/MRESOLVER-85
    ((Buffer) temp).clear();
    ByteBuffer result = ByteBuffer.allocate(temp.capacity());
    result.put(temp);
    ((Buffer) result).clear();
    return result;
  }
  /**
   * Helper called by generated code to determine if a byte array is a valid UTF-8 encoded string
   * such that the original bytes can be converted to a String object and then back to a byte array
   * round tripping the bytes without loss. More precisely, returns {@code true} whenever:
   *
   * 
{@code
   * Arrays.equals(byteString.toByteArray(),
   *     new String(byteString.toByteArray(), "UTF-8").getBytes("UTF-8"))
   * }
   *
   * This method rejects "overlong" byte sequences, as well as 3-byte sequences that would map to
   * a surrogate character, in accordance with the restricted definition of UTF-8 introduced in
   * Unicode 3.1. Note that the UTF-8 decoder included in Oracle's JDK has been modified to also
   * reject "overlong" byte sequences, but currently (2011) still accepts 3-byte surrogate character
   * byte sequences.
   *
   * 
See the Unicode Standard,
   * Table 3-6. UTF-8 Bit Distribution,
   * Table 3-7. Well Formed UTF-8 Byte Sequences.
   *
   * 
As of 2011-02, this method simply returns the result of {@link ByteString#isValidUtf8()}.
   * Calling that method directly is preferred.
   *
   * @param byteString the string to check
   * @return whether the byte array is round trippable
   */
  public static boolean isValidUtf8(ByteString byteString) {
    return byteString.isValidUtf8();
  }
  /** Like {@link #isValidUtf8(ByteString)} but for byte arrays. */
  public static boolean isValidUtf8(byte[] byteArray) {
    return Utf8.isValidUtf8(byteArray);
  }
  /** Helper method to get the UTF-8 bytes of a string. */
  public static byte[] toByteArray(String value) {
    return value.getBytes(UTF_8);
  }
  /** Helper method to convert a byte array to a string using UTF-8 encoding. */
  public static String toStringUtf8(byte[] bytes) {
    return new String(bytes, UTF_8);
  }
  /**
   * Interface for an enum value or value descriptor, to be used in FieldSet. The lite library
   * stores enum values directly in FieldSets but the full library stores EnumValueDescriptors in
   * order to better support reflection.
   */
  public interface EnumLite {
    int getNumber();
  }
  /**
   * Interface for an object which maps integers to {@link EnumLite}s. {@link
   * Descriptors.EnumDescriptor} implements this interface by mapping numbers to {@link
   * Descriptors.EnumValueDescriptor}s. Additionally, every generated enum type has a static method
   * internalGetValueMap() which returns an implementation of this type that maps numbers to enum
   * values.
   */
  public interface EnumLiteMap {
    T findValueByNumber(int number);
  }
  /** Interface for an object which verifies integers are in range. */
  public interface EnumVerifier {
    boolean isInRange(int number);
  }
  /**
   * Helper method for implementing {@link Message#hashCode()} for longs.
   *
   * @see Long#hashCode()
   */
  public static int hashLong(long n) {
    return (int) (n ^ (n >>> 32));
  }
  /**
   * Helper method for implementing {@link Message#hashCode()} for booleans.
   *
   * @see Boolean#hashCode()
   */
  public static int hashBoolean(boolean b) {
    return b ? 1231 : 1237;
  }
  /**
   * Helper method for implementing {@link Message#hashCode()} for enums.
   *
   * 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.
   */
  public static int hashEnum(EnumLite e) {
    return e.getNumber();
  }
  /** Helper method for implementing {@link Message#hashCode()} for enum lists. */
  public static int hashEnumList(List extends EnumLite> list) {
    int hash = 1;
    for (EnumLite e : list) {
      hash = 31 * hash + hashEnum(e);
    }
    return hash;
  }
  /** Helper method for implementing {@link Message#equals(Object)} for bytes field. */
  public static boolean equals(List a, List b) {
    if (a.size() != b.size()) {
      return false;
    }
    for (int i = 0; i < a.size(); ++i) {
      if (!Arrays.equals(a.get(i), b.get(i))) {
        return false;
      }
    }
    return true;
  }
  /** Helper method for implementing {@link Message#hashCode()} for bytes field. */
  public static int hashCode(List list) {
    int hash = 1;
    for (byte[] bytes : list) {
      hash = 31 * hash + hashCode(bytes);
    }
    return hash;
  }
  /** Helper method for implementing {@link Message#hashCode()} for bytes field. */
  public static int hashCode(byte[] bytes) {
    // The hash code for a byte array should be the same as the hash code for a
    // ByteString with the same content. This is to ensure that the generated
    // hashCode() method will return the same value as the pure reflection
    // based hashCode() method.
    return Internal.hashCode(bytes, 0, bytes.length);
  }
  /** Helper method for implementing {@link LiteralByteString#hashCode()}. */
  static int hashCode(byte[] bytes, int offset, int length) {
    // The hash code for a byte array should be the same as the hash code for a
    // ByteString with the same content. This is to ensure that the generated
    // hashCode() method will return the same value as the pure reflection
    // based hashCode() method.
    int h = Internal.partialHash(length, bytes, offset, length);
    return h == 0 ? 1 : h;
  }
  /** Helper method for continuously hashing bytes. */
  static int partialHash(int h, byte[] bytes, int offset, int length) {
    for (int i = offset; i < offset + length; i++) {
      h = h * 31 + bytes[i];
    }
    return h;
  }
  /** Helper method for implementing {@link Message#equals(Object)} for bytes field. */
  public static boolean equalsByteBuffer(ByteBuffer a, ByteBuffer b) {
    if (a.capacity() != b.capacity()) {
      return false;
    }
    // ByteBuffer.equals() will only compare the remaining bytes, but we want to
    // compare all the content.
    ByteBuffer aDuplicate = a.duplicate();
    Java8Compatibility.clear(aDuplicate);
    ByteBuffer bDuplicate = b.duplicate();
    Java8Compatibility.clear(bDuplicate);
    return aDuplicate.equals(bDuplicate);
  }
  /** Helper method for implementing {@link Message#equals(Object)} for bytes field. */
  public static boolean equalsByteBuffer(List a, List b) {
    if (a.size() != b.size()) {
      return false;
    }
    for (int i = 0; i < a.size(); ++i) {
      if (!equalsByteBuffer(a.get(i), b.get(i))) {
        return false;
      }
    }
    return true;
  }
  /** Helper method for implementing {@link Message#hashCode()} for bytes field. */
  public static int hashCodeByteBuffer(List list) {
    int hash = 1;
    for (ByteBuffer bytes : list) {
      hash = 31 * hash + hashCodeByteBuffer(bytes);
    }
    return hash;
  }
  private static final int DEFAULT_BUFFER_SIZE = 4096;
  /** Helper method for implementing {@link Message#hashCode()} for bytes field. */
  public static int hashCodeByteBuffer(ByteBuffer bytes) {
    if (bytes.hasArray()) {
      // Fast path.
      int h = partialHash(bytes.capacity(), bytes.array(), bytes.arrayOffset(), bytes.capacity());
      return h == 0 ? 1 : h;
    } else {
      // Read the data into a temporary byte array before calculating the
      // hash value.
      final int bufferSize =
          bytes.capacity() > DEFAULT_BUFFER_SIZE ? DEFAULT_BUFFER_SIZE : bytes.capacity();
      final byte[] buffer = new byte[bufferSize];
      final ByteBuffer duplicated = bytes.duplicate();
      Java8Compatibility.clear(duplicated);
      int h = bytes.capacity();
      while (duplicated.remaining() > 0) {
        final int length =
            duplicated.remaining() <= bufferSize ? duplicated.remaining() : bufferSize;
        duplicated.get(buffer, 0, length);
        h = partialHash(h, buffer, 0, length);
      }
      return h == 0 ? 1 : h;
    }
  }
  @SuppressWarnings("unchecked")
  public static  T getDefaultInstance(Class clazz) {
    try {
      Method method = clazz.getMethod("getDefaultInstance");
      return (T) method.invoke(method);
    } catch (Exception e) {
      throw new RuntimeException("Failed to get default instance for " + clazz, e);
    }
  }
  /** An empty byte array constant used in generated code. */
  public static final byte[] EMPTY_BYTE_ARRAY = new byte[0];
  /** An empty byte array constant used in generated code. */
  public static final ByteBuffer EMPTY_BYTE_BUFFER = ByteBuffer.wrap(EMPTY_BYTE_ARRAY);
  /** An empty coded input stream constant used in generated code. */
  public static final CodedInputStream EMPTY_CODED_INPUT_STREAM =
      CodedInputStream.newInstance(EMPTY_BYTE_ARRAY);
  /** Helper method to merge two MessageLite instances. */
  static Object mergeMessage(Object destination, Object source) {
    return ((MessageLite) destination).toBuilder().mergeFrom((MessageLite) source).buildPartial();
  }
  /**
   * Provides an immutable view of {@code List} around a {@code List}.
   *
   *