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

DEFINITIONS

1. computePreferredBufferSize
2. newInstance
3. newInstance
4. newInstance
5. newInstance
6. writeDouble
7. writeFloat
8. writeUInt64
9. writeInt64
10. writeInt32
11. writeFixed64
12. writeFixed32
13. writeBool
14. writeString
15. writeGroup
16. writeUnknownGroup
17. writeMessage
18. writeBytes
19. writeUInt32
20. writeEnum
21. writeSFixed32
22. writeSFixed64
23. writeSInt32
24. writeSInt64
25. writeMessageSetExtension
26. writeRawMessageSetExtension
27. writeDoubleNoTag
28. writeFloatNoTag
29. writeUInt64NoTag
30. writeInt64NoTag
31. writeInt32NoTag
32. writeFixed64NoTag
33. writeFixed32NoTag
34. writeBoolNoTag
35. writeStringNoTag
36. writeGroupNoTag
37. writeUnknownGroupNoTag
38. writeMessageNoTag
39. writeBytesNoTag
40. writeUInt32NoTag
41. writeEnumNoTag
42. writeSFixed32NoTag
43. writeSFixed64NoTag
44. writeSInt32NoTag
45. writeSInt64NoTag
46. computeDoubleSize
47. computeFloatSize
48. computeUInt64Size
49. computeInt64Size
50. computeInt32Size
51. computeFixed64Size
52. computeFixed32Size
53. computeBoolSize
54. computeStringSize
55. computeGroupSize
56. computeUnknownGroupSize
57. computeMessageSize
58. computeBytesSize
59. computeLazyFieldSize
60. computeUInt32Size
61. computeEnumSize
62. computeSFixed32Size
63. computeSFixed64Size
64. computeSInt32Size
65. computeSInt64Size
66. computeMessageSetExtensionSize
67. computeRawMessageSetExtensionSize
68. computeLazyFieldMessageSetExtensionSize
69. computeDoubleSizeNoTag
70. computeFloatSizeNoTag
71. computeUInt64SizeNoTag
72. computeInt64SizeNoTag
73. computeInt32SizeNoTag
74. computeFixed64SizeNoTag
75. computeFixed32SizeNoTag
76. computeBoolSizeNoTag
77. computeStringSizeNoTag
78. computeGroupSizeNoTag
79. computeUnknownGroupSizeNoTag
80. computeMessageSizeNoTag
81. computeLazyFieldSizeNoTag
82. computeBytesSizeNoTag
83. computeUInt32SizeNoTag
84. computeEnumSizeNoTag
85. computeSFixed32SizeNoTag
86. computeSFixed64SizeNoTag
87. computeSInt32SizeNoTag
88. computeSInt64SizeNoTag
89. refreshBuffer
90. flush
91. spaceLeft
92. checkNoSpaceLeft
93. writeRawByte
94. writeRawByte
95. writeRawBytes
96. writeRawBytes
97. writeRawBytes
98. writeRawBytes
99. writeTag
100. computeTagSize
101. writeRawVarint32
102. computeRawVarint32Size
103. writeRawVarint64
104. computeRawVarint64Size
105. writeRawLittleEndian32
106. writeRawLittleEndian64
107. encodeZigZag32
108. encodeZigZag64

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

package com.google.protobuf;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;

/**
 * Encodes and writes protocol message fields.
 *
 * <p>This class contains two kinds of methods:  methods that write specific
 * protocol message constructs and field types (e.g. {@link #writeTag} and
 * {@link #writeInt32}) and methods that write low-level values (e.g.
 * {@link #writeRawVarint32} and {@link #writeRawBytes}).  If you are
 * writing encoded protocol messages, you should use the former methods, but if
 * you are writing some other format of your own design, use the latter.
 *
 * <p>This class is totally unsynchronized.
 *
 * @author kneton@google.com Kenton Varda
 */
public final class CodedOutputStream {
  private final byte[] buffer;
  private final int limit;
  private int position;

  private final OutputStream output;

  /**
   * The buffer size used in {@link #newInstance(OutputStream)}.
   */
  public static final int DEFAULT_BUFFER_SIZE = 4096;

  /**
   * Returns the buffer size to efficiently write dataLength bytes to this
   * CodedOutputStream. Used by AbstractMessageLite.
   *
   * @return the buffer size to efficiently write dataLength bytes to this
   *         CodedOutputStream.
   */
  static int computePreferredBufferSize(int dataLength) {
    if (dataLength > DEFAULT_BUFFER_SIZE) return DEFAULT_BUFFER_SIZE;
    return dataLength;
  }

  private CodedOutputStream(final byte[] buffer, final int offset,
                            final int length) {
    output = null;
    this.buffer = buffer;
    position = offset;
    limit = offset + length;
  }

  private CodedOutputStream(final OutputStream output, final byte[] buffer) {
    this.output = output;
    this.buffer = buffer;
    position = 0;
    limit = buffer.length;
  }

  /**
   * Create a new {@code CodedOutputStream} wrapping the given
   * {@code OutputStream}.
   */
  public static CodedOutputStream newInstance(final OutputStream output) {
    return newInstance(output, DEFAULT_BUFFER_SIZE);
  }

  /**
   * Create a new {@code CodedOutputStream} wrapping the given
   * {@code OutputStream} with a given buffer size.
   */
  public static CodedOutputStream newInstance(final OutputStream output,
      final int bufferSize) {
    return new CodedOutputStream(output, new byte[bufferSize]);
  }

  /**
   * Create a new {@code CodedOutputStream} that writes directly to the given
   * byte array.  If more bytes are written than fit in the array,
   * {@link OutOfSpaceException} will be thrown.  Writing directly to a flat
   * array is faster than writing to an {@code OutputStream}.  See also
   * {@link ByteString#newCodedBuilder}.
   */
  public static CodedOutputStream newInstance(final byte[] flatArray) {
    return newInstance(flatArray, 0, flatArray.length);
  }

  /**
   * Create a new {@code CodedOutputStream} that writes directly to the given
   * byte array slice.  If more bytes are written than fit in the slice,
   * {@link OutOfSpaceException} will be thrown.  Writing directly to a flat
   * array is faster than writing to an {@code OutputStream}.  See also
   * {@link ByteString#newCodedBuilder}.
   */
  public static CodedOutputStream newInstance(final byte[] flatArray,
                                              final int offset,
                                              final int length) {
    return new CodedOutputStream(flatArray, offset, length);
  }

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

  /** Write a {@code double} field, including tag, to the stream. */
  public void writeDouble(final int fieldNumber, final double value)
                          throws IOException {
    writeTag(fieldNumber, WireFormat.WIRETYPE_FIXED64);
    writeDoubleNoTag(value);
  }

  /** Write a {@code float} field, including tag, to the stream. */
  public void writeFloat(final int fieldNumber, final float value)
                         throws IOException {
    writeTag(fieldNumber, WireFormat.WIRETYPE_FIXED32);
    writeFloatNoTag(value);
  }

  /** Write a {@code uint64} field, including tag, to the stream. */
  public void writeUInt64(final int fieldNumber, final long value)
                          throws IOException {
    writeTag(fieldNumber, WireFormat.WIRETYPE_VARINT);
    writeUInt64NoTag(value);
  }

  /** Write an {@code int64} field, including tag, to the stream. */
  public void writeInt64(final int fieldNumber, final long value)
                         throws IOException {
    writeTag(fieldNumber, WireFormat.WIRETYPE_VARINT);
    writeInt64NoTag(value);
  }

  /** Write an {@code int32} field, including tag, to the stream. */
  public void writeInt32(final int fieldNumber, final int value)
                         throws IOException {
    writeTag(fieldNumber, WireFormat.WIRETYPE_VARINT);
    writeInt32NoTag(value);
  }

  /** Write a {@code fixed64} field, including tag, to the stream. */
  public void writeFixed64(final int fieldNumber, final long value)
                           throws IOException {
    writeTag(fieldNumber, WireFormat.WIRETYPE_FIXED64);
    writeFixed64NoTag(value);
  }

  /** Write a {@code fixed32} field, including tag, to the stream. */
  public void writeFixed32(final int fieldNumber, final int value)
                           throws IOException {
    writeTag(fieldNumber, WireFormat.WIRETYPE_FIXED32);
    writeFixed32NoTag(value);
  }

  /** Write a {@code bool} field, including tag, to the stream. */
  public void writeBool(final int fieldNumber, final boolean value)
                        throws IOException {
    writeTag(fieldNumber, WireFormat.WIRETYPE_VARINT);
    writeBoolNoTag(value);
  }

  /** Write a {@code string} field, including tag, to the stream. */
  public void writeString(final int fieldNumber, final String value)
                          throws IOException {
    writeTag(fieldNumber, WireFormat.WIRETYPE_LENGTH_DELIMITED);
    writeStringNoTag(value);
  }

  /** Write a {@code group} field, including tag, to the stream. */
  public void writeGroup(final int fieldNumber, final MessageLite value)
                         throws IOException {
    writeTag(fieldNumber, WireFormat.WIRETYPE_START_GROUP);
    writeGroupNoTag(value);
    writeTag(fieldNumber, WireFormat.WIRETYPE_END_GROUP);
  }

  /**
   * Write a group represented by an {@link UnknownFieldSet}.
   *
   * @deprecated UnknownFieldSet now implements MessageLite, so you can just
   *             call {@link #writeGroup}.
   */
  @Deprecated
  public void writeUnknownGroup(final int fieldNumber,
                                final MessageLite value)
                                throws IOException {
    writeGroup(fieldNumber, value);
  }

  /** Write an embedded message field, including tag, to the stream. */
  public void writeMessage(final int fieldNumber, final MessageLite value)
                           throws IOException {
    writeTag(fieldNumber, WireFormat.WIRETYPE_LENGTH_DELIMITED);
    writeMessageNoTag(value);
  }

  /** Write a {@code bytes} field, including tag, to the stream. */
  public void writeBytes(final int fieldNumber, final ByteString value)
                         throws IOException {
    writeTag(fieldNumber, WireFormat.WIRETYPE_LENGTH_DELIMITED);
    writeBytesNoTag(value);
  }

  /** Write a {@code uint32} field, including tag, to the stream. */
  public void writeUInt32(final int fieldNumber, final int value)
                          throws IOException {
    writeTag(fieldNumber, WireFormat.WIRETYPE_VARINT);
    writeUInt32NoTag(value);
  }

  /**
   * Write an enum field, including tag, to the stream.  Caller is responsible
   * for converting the enum value to its numeric value.
   */
  public void writeEnum(final int fieldNumber, final int value)
                        throws IOException {
    writeTag(fieldNumber, WireFormat.WIRETYPE_VARINT);
    writeEnumNoTag(value);
  }

  /** Write an {@code sfixed32} field, including tag, to the stream. */
  public void writeSFixed32(final int fieldNumber, final int value)
                            throws IOException {
    writeTag(fieldNumber, WireFormat.WIRETYPE_FIXED32);
    writeSFixed32NoTag(value);
  }

  /** Write an {@code sfixed64} field, including tag, to the stream. */
  public void writeSFixed64(final int fieldNumber, final long value)
                            throws IOException {
    writeTag(fieldNumber, WireFormat.WIRETYPE_FIXED64);
    writeSFixed64NoTag(value);
  }

  /** Write an {@code sint32} field, including tag, to the stream. */
  public void writeSInt32(final int fieldNumber, final int value)
                          throws IOException {
    writeTag(fieldNumber, WireFormat.WIRETYPE_VARINT);
    writeSInt32NoTag(value);
  }

  /** Write an {@code sint64} field, including tag, to the stream. */
  public void writeSInt64(final int fieldNumber, final long value)
                          throws IOException {
    writeTag(fieldNumber, WireFormat.WIRETYPE_VARINT);
    writeSInt64NoTag(value);
  }

  /**
   * Write a MessageSet extension field to the stream.  For historical reasons,
   * the wire format differs from normal fields.
   */
  public void writeMessageSetExtension(final int fieldNumber,
                                       final MessageLite value)
                                       throws IOException {
    writeTag(WireFormat.MESSAGE_SET_ITEM, WireFormat.WIRETYPE_START_GROUP);
    writeUInt32(WireFormat.MESSAGE_SET_TYPE_ID, fieldNumber);
    writeMessage(WireFormat.MESSAGE_SET_MESSAGE, value);
    writeTag(WireFormat.MESSAGE_SET_ITEM, WireFormat.WIRETYPE_END_GROUP);
  }

  /**
   * Write an unparsed MessageSet extension field to the stream.  For
   * historical reasons, the wire format differs from normal fields.
   */
  public void writeRawMessageSetExtension(final int fieldNumber,
                                          final ByteString value)
                                          throws IOException {
    writeTag(WireFormat.MESSAGE_SET_ITEM, WireFormat.WIRETYPE_START_GROUP);
    writeUInt32(WireFormat.MESSAGE_SET_TYPE_ID, fieldNumber);
    writeBytes(WireFormat.MESSAGE_SET_MESSAGE, value);
    writeTag(WireFormat.MESSAGE_SET_ITEM, WireFormat.WIRETYPE_END_GROUP);
  }

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

  /** Write a {@code double} field to the stream. */
  public void writeDoubleNoTag(final double value) throws IOException {
    writeRawLittleEndian64(Double.doubleToRawLongBits(value));
  }

  /** Write a {@code float} field to the stream. */
  public void writeFloatNoTag(final float value) throws IOException {
    writeRawLittleEndian32(Float.floatToRawIntBits(value));
  }

  /** Write a {@code uint64} field to the stream. */
  public void writeUInt64NoTag(final long value) throws IOException {
    writeRawVarint64(value);
  }

  /** Write an {@code int64} field to the stream. */
  public void writeInt64NoTag(final long value) throws IOException {
    writeRawVarint64(value);
  }

  /** Write an {@code int32} field to the stream. */
  public void writeInt32NoTag(final int value) throws IOException {
    if (value >= 0) {
      writeRawVarint32(value);
    } else {
      // Must sign-extend.
      writeRawVarint64(value);
    }
  }

  /** Write a {@code fixed64} field to the stream. */
  public void writeFixed64NoTag(final long value) throws IOException {
    writeRawLittleEndian64(value);
  }

  /** Write a {@code fixed32} field to the stream. */
  public void writeFixed32NoTag(final int value) throws IOException {
    writeRawLittleEndian32(value);
  }

  /** Write a {@code bool} field to the stream. */
  public void writeBoolNoTag(final boolean value) throws IOException {
    writeRawByte(value ? 1 : 0);
  }

  /** Write a {@code string} field to the stream. */
  public void writeStringNoTag(final String value) throws IOException {
    // Unfortunately there does not appear to be any way to tell Java to encode
    // UTF-8 directly into our buffer, so we have to let it create its own byte
    // array and then copy.
    final byte[] bytes = value.getBytes("UTF-8");
    writeRawVarint32(bytes.length);
    writeRawBytes(bytes);
  }

  /** Write a {@code group} field to the stream. */
  public void writeGroupNoTag(final MessageLite value) throws IOException {
    value.writeTo(this);
  }

  /**
   * Write a group represented by an {@link UnknownFieldSet}.
   *
   * @deprecated UnknownFieldSet now implements MessageLite, so you can just
   *             call {@link #writeGroupNoTag}.
   */
  @Deprecated
  public void writeUnknownGroupNoTag(final MessageLite value)
      throws IOException {
    writeGroupNoTag(value);
  }

  /** Write an embedded message field to the stream. */
  public void writeMessageNoTag(final MessageLite value) throws IOException {
    writeRawVarint32(value.getSerializedSize());
    value.writeTo(this);
  }

  /** Write a {@code bytes} field to the stream. */
  public void writeBytesNoTag(final ByteString value) throws IOException {
    writeRawVarint32(value.size());
    writeRawBytes(value);
  }

  /** Write a {@code uint32} field to the stream. */
  public void writeUInt32NoTag(final int value) throws IOException {
    writeRawVarint32(value);
  }

  /**
   * Write an enum field to the stream.  Caller is responsible
   * for converting the enum value to its numeric value.
   */
  public void writeEnumNoTag(final int value) throws IOException {
    writeInt32NoTag(value);
  }

  /** Write an {@code sfixed32} field to the stream. */
  public void writeSFixed32NoTag(final int value) throws IOException {
    writeRawLittleEndian32(value);
  }

  /** Write an {@code sfixed64} field to the stream. */
  public void writeSFixed64NoTag(final long value) throws IOException {
    writeRawLittleEndian64(value);
  }

  /** Write an {@code sint32} field to the stream. */
  public void writeSInt32NoTag(final int value) throws IOException {
    writeRawVarint32(encodeZigZag32(value));
  }

  /** Write an {@code sint64} field to the stream. */
  public void writeSInt64NoTag(final long value) throws IOException {
    writeRawVarint64(encodeZigZag64(value));
  }

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

  /**
   * Compute the number of bytes that would be needed to encode a
   * {@code double} field, including tag.
   */
  public static int computeDoubleSize(final int fieldNumber,
                                      final double value) {
    return computeTagSize(fieldNumber) + computeDoubleSizeNoTag(value);
  }

  /**
   * Compute the number of bytes that would be needed to encode a
   * {@code float} field, including tag.
   */
  public static int computeFloatSize(final int fieldNumber, final float value) {
    return computeTagSize(fieldNumber) + computeFloatSizeNoTag(value);
  }

  /**
   * Compute the number of bytes that would be needed to encode a
   * {@code uint64} field, including tag.
   */
  public static int computeUInt64Size(final int fieldNumber, final long value) {
    return computeTagSize(fieldNumber) + computeUInt64SizeNoTag(value);
  }

  /**
   * Compute the number of bytes that would be needed to encode an
   * {@code int64} field, including tag.
   */
  public static int computeInt64Size(final int fieldNumber, final long value) {
    return computeTagSize(fieldNumber) + computeInt64SizeNoTag(value);
  }

  /**
   * Compute the number of bytes that would be needed to encode an
   * {@code int32} field, including tag.
   */
  public static int computeInt32Size(final int fieldNumber, final int value) {
    return computeTagSize(fieldNumber) + computeInt32SizeNoTag(value);
  }

  /**
   * Compute the number of bytes that would be needed to encode a
   * {@code fixed64} field, including tag.
   */
  public static int computeFixed64Size(final int fieldNumber,
                                       final long value) {
    return computeTagSize(fieldNumber) + computeFixed64SizeNoTag(value);
  }

  /**
   * Compute the number of bytes that would be needed to encode a
   * {@code fixed32} field, including tag.
   */
  public static int computeFixed32Size(final int fieldNumber,
                                       final int value) {
    return computeTagSize(fieldNumber) + computeFixed32SizeNoTag(value);
  }

  /**
   * Compute the number of bytes that would be needed to encode a
   * {@code bool} field, including tag.
   */
  public static int computeBoolSize(final int fieldNumber,
                                    final boolean value) {
    return computeTagSize(fieldNumber) + computeBoolSizeNoTag(value);
  }

  /**
   * Compute the number of bytes that would be needed to encode a
   * {@code string} field, including tag.
   */
  public static int computeStringSize(final int fieldNumber,
                                      final String value) {
    return computeTagSize(fieldNumber) + computeStringSizeNoTag(value);
  }

  /**
   * Compute the number of bytes that would be needed to encode a
   * {@code group} field, including tag.
   */
  public static int computeGroupSize(final int fieldNumber,
                                     final MessageLite value) {
    return computeTagSize(fieldNumber) * 2 + computeGroupSizeNoTag(value);
  }

  /**
   * Compute the number of bytes that would be needed to encode a
   * {@code group} field represented by an {@code UnknownFieldSet}, including
   * tag.
   *
   * @deprecated UnknownFieldSet now implements MessageLite, so you can just
   *             call {@link #computeGroupSize}.
   */
  @Deprecated
  public static int computeUnknownGroupSize(final int fieldNumber,
                                            final MessageLite value) {
    return computeGroupSize(fieldNumber, value);
  }

  /**
   * Compute the number of bytes that would be needed to encode an
   * embedded message field, including tag.
   */
  public static int computeMessageSize(final int fieldNumber,
                                       final MessageLite value) {
    return computeTagSize(fieldNumber) + computeMessageSizeNoTag(value);
  }

  /**
   * Compute the number of bytes that would be needed to encode a
   * {@code bytes} field, including tag.
   */
  public static int computeBytesSize(final int fieldNumber,
                                     final ByteString value) {
    return computeTagSize(fieldNumber) + computeBytesSizeNoTag(value);
  }

  /**
   * Compute the number of bytes that would be needed to encode an
   * embedded message in lazy field, including tag.
   */
  public static int computeLazyFieldSize(final int fieldNumber,
                                         final LazyField value) {
    return computeTagSize(fieldNumber) + computeLazyFieldSizeNoTag(value);
  }

  /**
   * Compute the number of bytes that would be needed to encode a
   * {@code uint32} field, including tag.
   */
  public static int computeUInt32Size(final int fieldNumber, final int value) {
    return computeTagSize(fieldNumber) + computeUInt32SizeNoTag(value);
  }

  /**
   * Compute the number of bytes that would be needed to encode an
   * enum field, including tag.  Caller is responsible for converting the
   * enum value to its numeric value.
   */
  public static int computeEnumSize(final int fieldNumber, final int value) {
    return computeTagSize(fieldNumber) + computeEnumSizeNoTag(value);
  }

  /**
   * Compute the number of bytes that would be needed to encode an
   * {@code sfixed32} field, including tag.
   */
  public static int computeSFixed32Size(final int fieldNumber,
                                        final int value) {
    return computeTagSize(fieldNumber) + computeSFixed32SizeNoTag(value);
  }

  /**
   * Compute the number of bytes that would be needed to encode an
   * {@code sfixed64} field, including tag.
   */
  public static int computeSFixed64Size(final int fieldNumber,
                                        final long value) {
    return computeTagSize(fieldNumber) + computeSFixed64SizeNoTag(value);
  }

  /**
   * Compute the number of bytes that would be needed to encode an
   * {@code sint32} field, including tag.
   */
  public static int computeSInt32Size(final int fieldNumber, final int value) {
    return computeTagSize(fieldNumber) + computeSInt32SizeNoTag(value);
  }

  /**
   * Compute the number of bytes that would be needed to encode an
   * {@code sint64} field, including tag.
   */
  public static int computeSInt64Size(final int fieldNumber, final long value) {
    return computeTagSize(fieldNumber) + computeSInt64SizeNoTag(value);
  }

  /**
   * Compute the number of bytes that would be needed to encode a
   * MessageSet extension to the stream.  For historical reasons,
   * the wire format differs from normal fields.
   */
  public static int computeMessageSetExtensionSize(
      final int fieldNumber, final MessageLite value) {
    return computeTagSize(WireFormat.MESSAGE_SET_ITEM) * 2 +
           computeUInt32Size(WireFormat.MESSAGE_SET_TYPE_ID, fieldNumber) +
           computeMessageSize(WireFormat.MESSAGE_SET_MESSAGE, value);
  }

  /**
   * Compute the number of bytes that would be needed to encode an
   * unparsed MessageSet extension field to the stream.  For
   * historical reasons, the wire format differs from normal fields.
   */
  public static int computeRawMessageSetExtensionSize(
      final int fieldNumber, final ByteString value) {
    return computeTagSize(WireFormat.MESSAGE_SET_ITEM) * 2 +
           computeUInt32Size(WireFormat.MESSAGE_SET_TYPE_ID, fieldNumber) +
           computeBytesSize(WireFormat.MESSAGE_SET_MESSAGE, value);
  }

  /**
   * Compute the number of bytes that would be needed to encode an
   * lazily parsed MessageSet extension field to the stream.  For
   * historical reasons, the wire format differs from normal fields.
   */
  public static int computeLazyFieldMessageSetExtensionSize(
      final int fieldNumber, final LazyField value) {
    return computeTagSize(WireFormat.MESSAGE_SET_ITEM) * 2 +
           computeUInt32Size(WireFormat.MESSAGE_SET_TYPE_ID, fieldNumber) +
           computeLazyFieldSize(WireFormat.MESSAGE_SET_MESSAGE, value);
  }
  
  // -----------------------------------------------------------------

  /**
   * Compute the number of bytes that would be needed to encode a
   * {@code double} field, including tag.
   */
  public static int computeDoubleSizeNoTag(final double value) {
    return LITTLE_ENDIAN_64_SIZE;
  }

  /**
   * Compute the number of bytes that would be needed to encode a
   * {@code float} field, including tag.
   */
  public static int computeFloatSizeNoTag(final float value) {
    return LITTLE_ENDIAN_32_SIZE;
  }

  /**
   * Compute the number of bytes that would be needed to encode a
   * {@code uint64} field, including tag.
   */
  public static int computeUInt64SizeNoTag(final long value) {
    return computeRawVarint64Size(value);
  }

  /**
   * Compute the number of bytes that would be needed to encode an
   * {@code int64} field, including tag.
   */
  public static int computeInt64SizeNoTag(final long value) {
    return computeRawVarint64Size(value);
  }

  /**
   * Compute the number of bytes that would be needed to encode an
   * {@code int32} field, including tag.
   */
  public static int computeInt32SizeNoTag(final int value) {
    if (value >= 0) {
      return computeRawVarint32Size(value);
    } else {
      // Must sign-extend.
      return 10;
    }
  }

  /**
   * Compute the number of bytes that would be needed to encode a
   * {@code fixed64} field.
   */
  public static int computeFixed64SizeNoTag(final long value) {
    return LITTLE_ENDIAN_64_SIZE;
  }

  /**
   * Compute the number of bytes that would be needed to encode a
   * {@code fixed32} field.
   */
  public static int computeFixed32SizeNoTag(final int value) {
    return LITTLE_ENDIAN_32_SIZE;
  }

  /**
   * Compute the number of bytes that would be needed to encode a
   * {@code bool} field.
   */
  public static int computeBoolSizeNoTag(final boolean value) {
    return 1;
  }

  /**
   * Compute the number of bytes that would be needed to encode a
   * {@code string} field.
   */
  public static int computeStringSizeNoTag(final String value) {
    try {
      final byte[] bytes = value.getBytes("UTF-8");
      return computeRawVarint32Size(bytes.length) +
             bytes.length;
    } catch (UnsupportedEncodingException e) {
      throw new RuntimeException("UTF-8 not supported.", e);
    }
  }

  /**
   * Compute the number of bytes that would be needed to encode a
   * {@code group} field.
   */
  public static int computeGroupSizeNoTag(final MessageLite value) {
    return value.getSerializedSize();
  }

  /**
   * Compute the number of bytes that would be needed to encode a
   * {@code group} field represented by an {@code UnknownFieldSet}, including
   * tag.
   *
   * @deprecated UnknownFieldSet now implements MessageLite, so you can just
   *             call {@link #computeUnknownGroupSizeNoTag}.
   */
  @Deprecated
  public static int computeUnknownGroupSizeNoTag(final MessageLite value) {
    return computeGroupSizeNoTag(value);
  }

  /**
   * Compute the number of bytes that would be needed to encode an embedded
   * message field.
   */
  public static int computeMessageSizeNoTag(final MessageLite value) {
    final int size = value.getSerializedSize();
    return computeRawVarint32Size(size) + size;
  }

  /**
   * Compute the number of bytes that would be needed to encode an embedded
   * message stored in lazy field.
   */
  public static int computeLazyFieldSizeNoTag(final LazyField value) {
    final int size = value.getSerializedSize();
    return computeRawVarint32Size(size) + size;
  }

  /**
   * Compute the number of bytes that would be needed to encode a
   * {@code bytes} field.
   */
  public static int computeBytesSizeNoTag(final ByteString value) {
    return computeRawVarint32Size(value.size()) +
           value.size();
  }

  /**
   * Compute the number of bytes that would be needed to encode a
   * {@code uint32} field.
   */
  public static int computeUInt32SizeNoTag(final int value) {
    return computeRawVarint32Size(value);
  }

  /**
   * Compute the number of bytes that would be needed to encode an enum field.
   * Caller is responsible for converting the enum value to its numeric value.
   */
  public static int computeEnumSizeNoTag(final int value) {
    return computeInt32SizeNoTag(value);
  }

  /**
   * Compute the number of bytes that would be needed to encode an
   * {@code sfixed32} field.
   */
  public static int computeSFixed32SizeNoTag(final int value) {
    return LITTLE_ENDIAN_32_SIZE;
  }

  /**
   * Compute the number of bytes that would be needed to encode an
   * {@code sfixed64} field.
   */
  public static int computeSFixed64SizeNoTag(final long value) {
    return LITTLE_ENDIAN_64_SIZE;
  }

  /**
   * Compute the number of bytes that would be needed to encode an
   * {@code sint32} field.
   */
  public static int computeSInt32SizeNoTag(final int value) {
    return computeRawVarint32Size(encodeZigZag32(value));
  }

  /**
   * Compute the number of bytes that would be needed to encode an
   * {@code sint64} field.
   */
  public static int computeSInt64SizeNoTag(final long value) {
    return computeRawVarint64Size(encodeZigZag64(value));
  }

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

  /**
   * Internal helper that writes the current buffer to the output. The
   * buffer position is reset to its initial value when this returns.
   */
  private void refreshBuffer() throws IOException {
    if (output == null) {
      // We're writing to a single buffer.
      throw new OutOfSpaceException();
    }

    // Since we have an output stream, this is our buffer
    // and buffer offset == 0
    output.write(buffer, 0, position);
    position = 0;
  }

  /**
   * Flushes the stream and forces any buffered bytes to be written.  This
   * does not flush the underlying OutputStream.
   */
  public void flush() throws IOException {
    if (output != null) {
      refreshBuffer();
    }
  }

  /**
   * If writing to a flat array, return the space left in the array.
   * Otherwise, throws {@code UnsupportedOperationException}.
   */
  public int spaceLeft() {
    if (output == null) {
      return limit - position;
    } else {
      throw new UnsupportedOperationException(
        "spaceLeft() can only be called on CodedOutputStreams that are " +
        "writing to a flat array.");
    }
  }

  /**
   * Verifies that {@link #spaceLeft()} returns zero.  It's common to create
   * a byte array that is exactly big enough to hold a message, then write to
   * it with a {@code CodedOutputStream}.  Calling {@code checkNoSpaceLeft()}
   * after writing verifies that the message was actually as big as expected,
   * which can help catch bugs.
   */
  public void checkNoSpaceLeft() {
    if (spaceLeft() != 0) {
      throw new IllegalStateException(
        "Did not write as much data as expected.");
    }
  }

  /**
   * If you create a CodedOutputStream around a simple flat array, you must
   * not attempt to write more bytes than the array has space.  Otherwise,
   * this exception will be thrown.
   */
  public static class OutOfSpaceException extends IOException {
    private static final long serialVersionUID = -6947486886997889499L;

    OutOfSpaceException() {
      super("CodedOutputStream was writing to a flat byte array and ran " +
            "out of space.");
    }
  }

  /** Write a single byte. */
  public void writeRawByte(final byte value) throws IOException {
    if (position == limit) {
      refreshBuffer();
    }

    buffer[position++] = value;
  }

  /** Write a single byte, represented by an integer value. */
  public void writeRawByte(final int value) throws IOException {
    writeRawByte((byte) value);
  }

  /** Write a byte string. */
  public void writeRawBytes(final ByteString value) throws IOException {
    writeRawBytes(value, 0, value.size());
  }

  /** Write an array of bytes. */
  public void writeRawBytes(final byte[] value) throws IOException {
    writeRawBytes(value, 0, value.length);
  }

  /** Write part of an array of bytes. */
  public void writeRawBytes(final byte[] value, int offset, int length)
                            throws IOException {
    if (limit - position >= length) {
      // We have room in the current buffer.
      System.arraycopy(value, offset, buffer, position, length);
      position += length;
    } else {
      // Write extends past current buffer.  Fill the rest of this buffer and
      // flush.
      final int bytesWritten = limit - position;
      System.arraycopy(value, offset, buffer, position, bytesWritten);
      offset += bytesWritten;
      length -= bytesWritten;
      position = limit;
      refreshBuffer();

      // Now deal with the rest.
      // Since we have an output stream, this is our buffer
      // and buffer offset == 0
      if (length <= limit) {
        // Fits in new buffer.
        System.arraycopy(value, offset, buffer, 0, length);
        position = length;
      } else {
        // Write is very big.  Let's do it all at once.
        output.write(value, offset, length);
      }
    }
  }

  /** Write part of a byte string. */
  public void writeRawBytes(final ByteString value, int offset, int length)
                            throws IOException {
    if (limit - position >= length) {
      // We have room in the current buffer.
      value.copyTo(buffer, offset, position, length);
      position += length;
    } else {
      // Write extends past current buffer.  Fill the rest of this buffer and
      // flush.
      final int bytesWritten = limit - position;
      value.copyTo(buffer, offset, position, bytesWritten);
      offset += bytesWritten;
      length -= bytesWritten;
      position = limit;
      refreshBuffer();

      // Now deal with the rest.
      // Since we have an output stream, this is our buffer
      // and buffer offset == 0
      if (length <= limit) {
        // Fits in new buffer.
        value.copyTo(buffer, offset, 0, length);
        position = length;
      } else {
        // Write is very big, but we can't do it all at once without allocating
        // an a copy of the byte array since ByteString does not give us access
        // to the underlying bytes. Use the InputStream interface on the
        // ByteString and our buffer to copy between the two.
        InputStream inputStreamFrom = value.newInput();
        if (offset != inputStreamFrom.skip(offset)) {
          throw new IllegalStateException("Skip failed? Should never happen.");
        }
        // Use the buffer as the temporary buffer to avoid allocating memory.
        while (length > 0) {
          int bytesToRead = Math.min(length, limit);
          int bytesRead = inputStreamFrom.read(buffer, 0, bytesToRead);
          if (bytesRead != bytesToRead) {
            throw new IllegalStateException("Read failed? Should never happen");
          }
          output.write(buffer, 0, bytesRead);
          length -= bytesRead;
        }
      }
    }
  }

  /** Encode and write a tag. */
  public void writeTag(final int fieldNumber, final int wireType)
                       throws IOException {
    writeRawVarint32(WireFormat.makeTag(fieldNumber, wireType));
  }

  /** Compute the number of bytes that would be needed to encode a tag. */
  public static int computeTagSize(final int fieldNumber) {
    return computeRawVarint32Size(WireFormat.makeTag(fieldNumber, 0));
  }

  /**
   * Encode and write a varint.  {@code value} is treated as
   * unsigned, so it won't be sign-extended if negative.
   */
  public void writeRawVarint32(int value) throws IOException {
    while (true) {
      if ((value & ~0x7F) == 0) {
        writeRawByte(value);
        return;
      } else {
        writeRawByte((value & 0x7F) | 0x80);
        value >>>= 7;
      }
    }
  }

  /**
   * Compute the number of bytes that would be needed to encode a varint.
   * {@code value} is treated as unsigned, so it won't be sign-extended if
   * negative.
   */
  public static int computeRawVarint32Size(final int value) {
    if ((value & (0xffffffff <<  7)) == 0) return 1;
    if ((value & (0xffffffff << 14)) == 0) return 2;
    if ((value & (0xffffffff << 21)) == 0) return 3;
    if ((value & (0xffffffff << 28)) == 0) return 4;
    return 5;
  }

  /** Encode and write a varint. */
  public void writeRawVarint64(long value) throws IOException {
    while (true) {
      if ((value & ~0x7FL) == 0) {
        writeRawByte((int)value);
        return;
      } else {
        writeRawByte(((int)value & 0x7F) | 0x80);
        value >>>= 7;
      }
    }
  }

  /** Compute the number of bytes that would be needed to encode a varint. */
  public static int computeRawVarint64Size(final long value) {
    if ((value & (0xffffffffffffffffL <<  7)) == 0) return 1;
    if ((value & (0xffffffffffffffffL << 14)) == 0) return 2;
    if ((value & (0xffffffffffffffffL << 21)) == 0) return 3;
    if ((value & (0xffffffffffffffffL << 28)) == 0) return 4;
    if ((value & (0xffffffffffffffffL << 35)) == 0) return 5;
    if ((value & (0xffffffffffffffffL << 42)) == 0) return 6;
    if ((value & (0xffffffffffffffffL << 49)) == 0) return 7;
    if ((value & (0xffffffffffffffffL << 56)) == 0) return 8;
    if ((value & (0xffffffffffffffffL << 63)) == 0) return 9;
    return 10;
  }

  /** Write a little-endian 32-bit integer. */
  public void writeRawLittleEndian32(final int value) throws IOException {
    writeRawByte((value      ) & 0xFF);
    writeRawByte((value >>  8) & 0xFF);
    writeRawByte((value >> 16) & 0xFF);
    writeRawByte((value >> 24) & 0xFF);
  }

  public static final int LITTLE_ENDIAN_32_SIZE = 4;

  /** Write a little-endian 64-bit integer. */
  public void writeRawLittleEndian64(final long value) throws IOException {
    writeRawByte((int)(value      ) & 0xFF);
    writeRawByte((int)(value >>  8) & 0xFF);
    writeRawByte((int)(value >> 16) & 0xFF);
    writeRawByte((int)(value >> 24) & 0xFF);
    writeRawByte((int)(value >> 32) & 0xFF);
    writeRawByte((int)(value >> 40) & 0xFF);
    writeRawByte((int)(value >> 48) & 0xFF);
    writeRawByte((int)(value >> 56) & 0xFF);
  }

  public static final int LITTLE_ENDIAN_64_SIZE = 8;

  /**
   * Encode a ZigZag-encoded 32-bit value.  ZigZag encodes signed integers
   * into values that can be efficiently encoded with varint.  (Otherwise,
   * negative values must be sign-extended to 64 bits to be varint encoded,
   * thus always taking 10 bytes on the wire.)
   *
   * @param n A signed 32-bit integer.
   * @return An unsigned 32-bit integer, stored in a signed int because
   *         Java has no explicit unsigned support.
   */
  public static int encodeZigZag32(final int n) {
    // Note:  the right-shift must be arithmetic
    return (n << 1) ^ (n >> 31);
  }

  /**
   * Encode a ZigZag-encoded 64-bit value.  ZigZag encodes signed integers
   * into values that can be efficiently encoded with varint.  (Otherwise,
   * negative values must be sign-extended to 64 bits to be varint encoded,
   * thus always taking 10 bytes on the wire.)
   *
   * @param n A signed 64-bit integer.
   * @return An unsigned 64-bit integer, stored in a signed int because
   *         Java has no explicit unsigned support.
   */
  public static long encodeZigZag64(final long n) {
    // Note:  the right-shift must be arithmetic
    return (n << 1) ^ (n >> 63);
  }
}