csharp/src/Google.Protobuf/ByteString.cs - third_party/protobuf - Git at Google

 #region Copyright notice and license
 // 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.
 #endregion

 using System;
 using System.Collections;
 using System.Collections.Generic;
 using System.IO;
 using System.Runtime.InteropServices;
 using System.Security;
 using System.Text;
 using System.Threading;
 using System.Threading.Tasks;

 namespace Google.Protobuf
 {
     /// <summary>
     /// Immutable array of bytes.
     /// </summary>
     [SecuritySafeCritical]
     public sealed class ByteString : IEnumerable<byte>, IEquatable<ByteString>
     {
         private static readonly ByteString empty = new ByteString(new byte[0]);

         private readonly ReadOnlyMemory<byte> bytes;

         /// <summary>
         /// Internal use only. Ensure that the provided memory is not mutated and belongs to this instance.
         /// </summary>
         internal static ByteString AttachBytes(ReadOnlyMemory<byte> bytes)
         {
             return new ByteString(bytes);
         }

         /// <summary>
         /// Internal use only. Ensure that the provided memory is not mutated and belongs to this instance.
         /// This method encapsulates converting array to memory. Reduces need for SecuritySafeCritical
         /// in .NET Framework.
         /// </summary>
         internal static ByteString AttachBytes(byte[] bytes)
         {
             return AttachBytes(bytes.AsMemory());
         }

         /// <summary>
         /// Constructs a new ByteString from the given memory. The memory is
         /// *not* copied, and must not be modified after this constructor is called.
         /// </summary>
         private ByteString(ReadOnlyMemory<byte> bytes)
         {
             this.bytes = bytes;
         }

         /// <summary>
         /// Returns an empty ByteString.
         /// </summary>
         public static ByteString Empty
         {
             get { return empty; }
         }

         /// <summary>
         /// Returns the length of this ByteString in bytes.
         /// </summary>
         public int Length
         {
             get { return bytes.Length; }
         }

         /// <summary>
         /// Returns <c>true</c> if this byte string is empty, <c>false</c> otherwise.
         /// </summary>
         public bool IsEmpty
         {
             get { return Length == 0; }
         }

         /// <summary>
         /// Provides read-only access to the data of this <see cref="ByteString"/>.
         /// No data is copied so this is the most efficient way of accessing.
         /// </summary>
         public ReadOnlySpan<byte> Span
         {
             get { return bytes.Span; }
         }

         /// <summary>
         /// Provides read-only access to the data of this <see cref="ByteString"/>.
         /// No data is copied so this is the most efficient way of accessing.
         /// </summary>
         public ReadOnlyMemory<byte> Memory
         {
             get { return bytes; }
         }

         /// <summary>
         /// Converts this <see cref="ByteString"/> into a byte array.
         /// </summary>
         /// <remarks>The data is copied - changes to the returned array will not be reflected in this <c>ByteString</c>.</remarks>
         /// <returns>A byte array with the same data as this <c>ByteString</c>.</returns>
         public byte[] ToByteArray()
         {
             return bytes.ToArray();
         }

         /// <summary>
         /// Converts this <see cref="ByteString"/> into a standard base64 representation.
         /// </summary>
         /// <returns>A base64 representation of this <c>ByteString</c>.</returns>
         public string ToBase64()
         {
             if (MemoryMarshal.TryGetArray(bytes, out ArraySegment<byte> segment))
             {
                 // Fast path. ByteString was created with an array, so pass the underlying array.
                 return Convert.ToBase64String(segment.Array, segment.Offset, segment.Count);
             }
             else
             {
                 // Slow path. BytesString is not an array. Convert memory and pass result to ToBase64String.
                 return Convert.ToBase64String(bytes.ToArray());
             }
         }

         /// <summary>
         /// Constructs a <see cref="ByteString" /> from the Base64 Encoded String.
         /// </summary>
         public static ByteString FromBase64(string bytes)
         {
             // By handling the empty string explicitly, we not only optimize but we fix a
             // problem on CF 2.0. See issue 61 for details.
             return bytes == "" ? Empty : new ByteString(Convert.FromBase64String(bytes));
         }

         /// <summary>
         /// Constructs a <see cref="ByteString"/> from data in the given stream, synchronously.
         /// </summary>
         /// <remarks>If successful, <paramref name="stream"/> will be read completely, from the position
         /// at the start of the call.</remarks>
         /// <param name="stream">The stream to copy into a ByteString.</param>
         /// <returns>A ByteString with content read from the given stream.</returns>
         public static ByteString FromStream(Stream stream)
         {
             ProtoPreconditions.CheckNotNull(stream, nameof(stream));
             int capacity = stream.CanSeek ? checked((int) (stream.Length - stream.Position)) : 0;
             var memoryStream = new MemoryStream(capacity);
             stream.CopyTo(memoryStream);
 #if NETSTANDARD1_1 || NETSTANDARD2_0
             byte[] bytes = memoryStream.ToArray();
 #else
             // Avoid an extra copy if we can.
             byte[] bytes = memoryStream.Length == memoryStream.Capacity ? memoryStream.GetBuffer() : memoryStream.ToArray();
 #endif
             return AttachBytes(bytes);
         }

         /// <summary>
         /// Constructs a <see cref="ByteString"/> from data in the given stream, asynchronously.
         /// </summary>
         /// <remarks>If successful, <paramref name="stream"/> will be read completely, from the position
         /// at the start of the call.</remarks>
         /// <param name="stream">The stream to copy into a ByteString.</param>
         /// <param name="cancellationToken">The cancellation token to use when reading from the stream, if any.</param>
         /// <returns>A ByteString with content read from the given stream.</returns>
         public static Task<ByteString> FromStreamAsync(Stream stream, CancellationToken cancellationToken = default)
         {
             ProtoPreconditions.CheckNotNull(stream, nameof(stream));
             return ByteStringAsync.FromStreamAsyncCore(stream, cancellationToken);
         }

         /// <summary>
         /// Constructs a <see cref="ByteString" /> from the given array. The contents
         /// are copied, so further modifications to the array will not
         /// be reflected in the returned ByteString.
         /// This method can also be invoked in <c>ByteString.CopyFrom(0xaa, 0xbb, ...)</c> form
         /// which is primarily useful for testing.
         /// </summary>
         public static ByteString CopyFrom(params byte[] bytes)
         {
             return new ByteString((byte[]) bytes.Clone());
         }

         /// <summary>
         /// Constructs a <see cref="ByteString" /> from a portion of a byte array.
         /// </summary>
         public static ByteString CopyFrom(byte[] bytes, int offset, int count)
         {
             byte[] portion = new byte[count];
             ByteArray.Copy(bytes, offset, portion, 0, count);
             return new ByteString(portion);
         }

         /// <summary>
         /// Constructs a <see cref="ByteString" /> from a read only span. The contents
         /// are copied, so further modifications to the span will not
         /// be reflected in the returned <see cref="ByteString" />.
         /// </summary>
         public static ByteString CopyFrom(ReadOnlySpan<byte> bytes)
         {
             return new ByteString(bytes.ToArray());
         }

         /// <summary>
         /// Creates a new <see cref="ByteString" /> by encoding the specified text with
         /// the given encoding.
         /// </summary>
         public static ByteString CopyFrom(string text, Encoding encoding)
         {
             return new ByteString(encoding.GetBytes(text));
         }

         /// <summary>
         /// Creates a new <see cref="ByteString" /> by encoding the specified text in UTF-8.
         /// </summary>
         public static ByteString CopyFromUtf8(string text)
         {
             return CopyFrom(text, Encoding.UTF8);
         }

         /// <summary>
         /// Returns the byte at the given index.
         /// </summary>
         public byte this[int index]
         {
             get { return bytes.Span[index]; }
         }

         /// <summary>
         /// Converts this <see cref="ByteString"/> into a string by applying the given encoding.
         /// </summary>
         /// <remarks>
         /// This method should only be used to convert binary data which was the result of encoding
         /// text with the given encoding.
         /// </remarks>
         /// <param name="encoding">The encoding to use to decode the binary data into text.</param>
         /// <returns>The result of decoding the binary data with the given decoding.</returns>
         public string ToString(Encoding encoding)
         {
             if (MemoryMarshal.TryGetArray(bytes, out ArraySegment<byte> segment))
             {
                 // Fast path. ByteString was created with an array.
                 return encoding.GetString(segment.Array, segment.Offset, segment.Count);
             }
             else
             {
                 // Slow path. BytesString is not an array. Convert memory and pass result to GetString.
                 // TODO: Consider using GetString overload that takes a pointer.
                 byte[] array = bytes.ToArray();
                 return encoding.GetString(array, 0, array.Length);
             }
         }

         /// <summary>
         /// Converts this <see cref="ByteString"/> into a string by applying the UTF-8 encoding.
         /// </summary>
         /// <remarks>
         /// This method should only be used to convert binary data which was the result of encoding
         /// text with UTF-8.
         /// </remarks>
         /// <returns>The result of decoding the binary data with the given decoding.</returns>
         public string ToStringUtf8()
         {
             return ToString(Encoding.UTF8);
         }

         /// <summary>
         /// Returns an iterator over the bytes in this <see cref="ByteString"/>.
         /// </summary>
         /// <returns>An iterator over the bytes in this object.</returns>
         [SecuritySafeCritical]
         public IEnumerator<byte> GetEnumerator()
         {
             return MemoryMarshal.ToEnumerable(bytes).GetEnumerator();
         }

         /// <summary>
         /// Returns an iterator over the bytes in this <see cref="ByteString"/>.
         /// </summary>
         /// <returns>An iterator over the bytes in this object.</returns>
         IEnumerator IEnumerable.GetEnumerator()
         {
             return GetEnumerator();
         }

         /// <summary>
         /// Creates a CodedInputStream from this ByteString's data.
         /// </summary>
         public CodedInputStream CreateCodedInput()
         {
             // We trust CodedInputStream not to reveal the provided byte array or modify it
             if (MemoryMarshal.TryGetArray(bytes, out ArraySegment<byte> segment) && segment.Count == bytes.Length)
             {
                 // Fast path. ByteString was created with a complete array.
                 return new CodedInputStream(segment.Array, segment.Offset, segment.Count);
             }
             else
             {
                 // Slow path. BytesString is not an array, or is a slice of an array.
                 // Convert memory and pass result to WriteRawBytes.
                 return new CodedInputStream(bytes.ToArray());
             }
         }

         /// <summary>
         /// Compares two byte strings for equality.
         /// </summary>
         /// <param name="lhs">The first byte string to compare.</param>
         /// <param name="rhs">The second byte string to compare.</param>
         /// <returns><c>true</c> if the byte strings are equal; false otherwise.</returns>
         public static bool operator ==(ByteString lhs, ByteString rhs)
         {
             if (ReferenceEquals(lhs, rhs))
             {
                 return true;
             }
             if (lhs is null || rhs is null)
             {
                 return false;
             }

             return lhs.bytes.Span.SequenceEqual(rhs.bytes.Span);
         }

         /// <summary>
         /// Compares two byte strings for inequality.
         /// </summary>
         /// <param name="lhs">The first byte string to compare.</param>
         /// <param name="rhs">The second byte string to compare.</param>
         /// <returns><c>false</c> if the byte strings are equal; true otherwise.</returns>
         public static bool operator !=(ByteString lhs, ByteString rhs)
         {
             return !(lhs == rhs);
         }

         /// <summary>
         /// Compares this byte string with another object.
         /// </summary>
         /// <param name="obj">The object to compare this with.</param>
         /// <returns><c>true</c> if <paramref name="obj"/> refers to an equal <see cref="ByteString"/>; <c>false</c> otherwise.</returns>
         [SecuritySafeCritical]
         public override bool Equals(object obj)
         {
             return this == (obj as ByteString);
         }

         /// <summary>
         /// Returns a hash code for this object. Two equal byte strings
         /// will return the same hash code.
         /// </summary>
         /// <returns>A hash code for this object.</returns>
         [SecuritySafeCritical]
         public override int GetHashCode()
         {
             ReadOnlySpan<byte> b = bytes.Span;

             int ret = 23;
             for (int i = 0; i < b.Length; i++)
             {
                 ret = (ret * 31) + b[i];
             }
             return ret;
         }

         /// <summary>
         /// Compares this byte string with another.
         /// </summary>
         /// <param name="other">The <see cref="ByteString"/> to compare this with.</param>
         /// <returns><c>true</c> if <paramref name="other"/> refers to an equal byte string; <c>false</c> otherwise.</returns>
         public bool Equals(ByteString other)
         {
             return this == other;
         }

         /// <summary>
         /// Copies the entire byte array to the destination array provided at the offset specified.
         /// </summary>
         public void CopyTo(byte[] array, int position)
         {
             bytes.CopyTo(array.AsMemory(position));
         }

         /// <summary>
         /// Writes the entire byte array to the provided stream
         /// </summary>
         public void WriteTo(Stream outputStream)
         {
             if (MemoryMarshal.TryGetArray(bytes, out ArraySegment<byte> segment))
             {
                 // Fast path. ByteString was created with an array, so pass the underlying array.
                 outputStream.Write(segment.Array, segment.Offset, segment.Count);
             }
             else
             {
                 // Slow path. BytesString is not an array. Convert memory and pass result to WriteRawBytes.
                 var array = bytes.ToArray();
                 outputStream.Write(array, 0, array.Length);
             }
         }
     }
 }
	#region Copyright notice and license
	// 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.
	#endregion

	using System;
	using System.Collections;
	using System.Collections.Generic;
	using System.IO;
	using System.Runtime.InteropServices;
	using System.Security;
	using System.Text;
	using System.Threading;
	using System.Threading.Tasks;

	namespace Google.Protobuf
	{
	/// <summary>
	/// Immutable array of bytes.
	/// </summary>
	[SecuritySafeCritical]
	public sealed class ByteString : IEnumerable<byte>, IEquatable<ByteString>
	{
	private static readonly ByteString empty = new ByteString(new byte[0]);

	private readonly ReadOnlyMemory<byte> bytes;

	/// <summary>
	/// Internal use only. Ensure that the provided memory is not mutated and belongs to this instance.
	/// </summary>
	internal static ByteString AttachBytes(ReadOnlyMemory<byte> bytes)
	{
	return new ByteString(bytes);
	}

	/// <summary>
	/// Internal use only. Ensure that the provided memory is not mutated and belongs to this instance.
	/// This method encapsulates converting array to memory. Reduces need for SecuritySafeCritical
	/// in .NET Framework.
	/// </summary>
	internal static ByteString AttachBytes(byte[] bytes)
	{
	return AttachBytes(bytes.AsMemory());
	}

	/// <summary>
	/// Constructs a new ByteString from the given memory. The memory is
	/// not copied, and must not be modified after this constructor is called.
	/// </summary>
	private ByteString(ReadOnlyMemory<byte> bytes)
	{
	this.bytes = bytes;
	}

	/// <summary>
	/// Returns an empty ByteString.
	/// </summary>
	public static ByteString Empty
	{
	get { return empty; }
	}

	/// <summary>
	/// Returns the length of this ByteString in bytes.
	/// </summary>
	public int Length
	{
	get { return bytes.Length; }
	}

	/// <summary>
	/// Returns <c>true</c> if this byte string is empty, <c>false</c> otherwise.
	/// </summary>
	public bool IsEmpty
	{
	get { return Length == 0; }
	}

	/// <summary>
	/// Provides read-only access to the data of this <see cref="ByteString"/>.
	/// No data is copied so this is the most efficient way of accessing.
	/// </summary>
	public ReadOnlySpan<byte> Span
	{
	get { return bytes.Span; }
	}

	/// <summary>
	/// Provides read-only access to the data of this <see cref="ByteString"/>.
	/// No data is copied so this is the most efficient way of accessing.
	/// </summary>
	public ReadOnlyMemory<byte> Memory
	{
	get { return bytes; }
	}

	/// <summary>
	/// Converts this <see cref="ByteString"/> into a byte array.
	/// </summary>
	/// <remarks>The data is copied - changes to the returned array will not be reflected in this <c>ByteString</c>.</remarks>
	/// <returns>A byte array with the same data as this <c>ByteString</c>.</returns>
	public byte[] ToByteArray()
	{
	return bytes.ToArray();
	}

	/// <summary>
	/// Converts this <see cref="ByteString"/> into a standard base64 representation.
	/// </summary>
	/// <returns>A base64 representation of this <c>ByteString</c>.</returns>
	public string ToBase64()
	{
	if (MemoryMarshal.TryGetArray(bytes, out ArraySegment<byte> segment))
	{
	// Fast path. ByteString was created with an array, so pass the underlying array.
	return Convert.ToBase64String(segment.Array, segment.Offset, segment.Count);
	}
	else
	{
	// Slow path. BytesString is not an array. Convert memory and pass result to ToBase64String.
	return Convert.ToBase64String(bytes.ToArray());
	}
	}

	/// <summary>
	/// Constructs a <see cref="ByteString" /> from the Base64 Encoded String.
	/// </summary>
	public static ByteString FromBase64(string bytes)
	{
	// By handling the empty string explicitly, we not only optimize but we fix a
	// problem on CF 2.0. See issue 61 for details.
	return bytes == "" ? Empty : new ByteString(Convert.FromBase64String(bytes));
	}

	/// <summary>
	/// Constructs a <see cref="ByteString"/> from data in the given stream, synchronously.
	/// </summary>
	/// <remarks>If successful, <paramref name="stream"/> will be read completely, from the position
	/// at the start of the call.</remarks>
	/// <param name="stream">The stream to copy into a ByteString.</param>
	/// <returns>A ByteString with content read from the given stream.</returns>
	public static ByteString FromStream(Stream stream)
	{
	ProtoPreconditions.CheckNotNull(stream, nameof(stream));
	int capacity = stream.CanSeek ? checked((int) (stream.Length - stream.Position)) : 0;
	var memoryStream = new MemoryStream(capacity);
	stream.CopyTo(memoryStream);
	#if NETSTANDARD1_1 \|\| NETSTANDARD2_0
	byte[] bytes = memoryStream.ToArray();
	#else
	// Avoid an extra copy if we can.
	byte[] bytes = memoryStream.Length == memoryStream.Capacity ? memoryStream.GetBuffer() : memoryStream.ToArray();
	#endif
	return AttachBytes(bytes);
	}

	/// <summary>
	/// Constructs a <see cref="ByteString"/> from data in the given stream, asynchronously.
	/// </summary>
	/// <remarks>If successful, <paramref name="stream"/> will be read completely, from the position
	/// at the start of the call.</remarks>
	/// <param name="stream">The stream to copy into a ByteString.</param>
	/// <param name="cancellationToken">The cancellation token to use when reading from the stream, if any.</param>
	/// <returns>A ByteString with content read from the given stream.</returns>
	public static Task<ByteString> FromStreamAsync(Stream stream, CancellationToken cancellationToken = default)
	{
	ProtoPreconditions.CheckNotNull(stream, nameof(stream));
	return ByteStringAsync.FromStreamAsyncCore(stream, cancellationToken);
	}

	/// <summary>
	/// Constructs a <see cref="ByteString" /> from the given array. The contents
	/// are copied, so further modifications to the array will not
	/// be reflected in the returned ByteString.
	/// This method can also be invoked in <c>ByteString.CopyFrom(0xaa, 0xbb, ...)</c> form
	/// which is primarily useful for testing.
	/// </summary>
	public static ByteString CopyFrom(params byte[] bytes)
	{
	return new ByteString((byte[]) bytes.Clone());
	}

	/// <summary>
	/// Constructs a <see cref="ByteString" /> from a portion of a byte array.
	/// </summary>
	public static ByteString CopyFrom(byte[] bytes, int offset, int count)
	{
	byte[] portion = new byte[count];
	ByteArray.Copy(bytes, offset, portion, 0, count);
	return new ByteString(portion);
	}

	/// <summary>
	/// Constructs a <see cref="ByteString" /> from a read only span. The contents
	/// are copied, so further modifications to the span will not
	/// be reflected in the returned <see cref="ByteString" />.
	/// </summary>
	public static ByteString CopyFrom(ReadOnlySpan<byte> bytes)
	{
	return new ByteString(bytes.ToArray());
	}

	/// <summary>
	/// Creates a new <see cref="ByteString" /> by encoding the specified text with
	/// the given encoding.
	/// </summary>
	public static ByteString CopyFrom(string text, Encoding encoding)
	{
	return new ByteString(encoding.GetBytes(text));
	}

	/// <summary>
	/// Creates a new <see cref="ByteString" /> by encoding the specified text in UTF-8.
	/// </summary>
	public static ByteString CopyFromUtf8(string text)
	{
	return CopyFrom(text, Encoding.UTF8);
	}

	/// <summary>
	/// Returns the byte at the given index.
	/// </summary>
	public byte this[int index]
	{
	get { return bytes.Span[index]; }
	}

	/// <summary>
	/// Converts this <see cref="ByteString"/> into a string by applying the given encoding.
	/// </summary>
	/// <remarks>
	/// This method should only be used to convert binary data which was the result of encoding
	/// text with the given encoding.
	/// </remarks>
	/// <param name="encoding">The encoding to use to decode the binary data into text.</param>
	/// <returns>The result of decoding the binary data with the given decoding.</returns>
	public string ToString(Encoding encoding)
	{
	if (MemoryMarshal.TryGetArray(bytes, out ArraySegment<byte> segment))
	{
	// Fast path. ByteString was created with an array.
	return encoding.GetString(segment.Array, segment.Offset, segment.Count);
	}
	else
	{
	// Slow path. BytesString is not an array. Convert memory and pass result to GetString.
	// TODO: Consider using GetString overload that takes a pointer.
	byte[] array = bytes.ToArray();
	return encoding.GetString(array, 0, array.Length);
	}
	}

	/// <summary>
	/// Converts this <see cref="ByteString"/> into a string by applying the UTF-8 encoding.
	/// </summary>
	/// <remarks>
	/// This method should only be used to convert binary data which was the result of encoding
	/// text with UTF-8.
	/// </remarks>
	/// <returns>The result of decoding the binary data with the given decoding.</returns>
	public string ToStringUtf8()
	{
	return ToString(Encoding.UTF8);
	}

	/// <summary>
	/// Returns an iterator over the bytes in this <see cref="ByteString"/>.
	/// </summary>
	/// <returns>An iterator over the bytes in this object.</returns>
	[SecuritySafeCritical]
	public IEnumerator<byte> GetEnumerator()
	{
	return MemoryMarshal.ToEnumerable(bytes).GetEnumerator();
	}

	/// <summary>
	/// Returns an iterator over the bytes in this <see cref="ByteString"/>.
	/// </summary>
	/// <returns>An iterator over the bytes in this object.</returns>
	IEnumerator IEnumerable.GetEnumerator()
	{
	return GetEnumerator();
	}

	/// <summary>
	/// Creates a CodedInputStream from this ByteString's data.
	/// </summary>
	public CodedInputStream CreateCodedInput()
	{
	// We trust CodedInputStream not to reveal the provided byte array or modify it
	if (MemoryMarshal.TryGetArray(bytes, out ArraySegment<byte> segment) && segment.Count == bytes.Length)
	{
	// Fast path. ByteString was created with a complete array.
	return new CodedInputStream(segment.Array, segment.Offset, segment.Count);
	}
	else
	{
	// Slow path. BytesString is not an array, or is a slice of an array.
	// Convert memory and pass result to WriteRawBytes.
	return new CodedInputStream(bytes.ToArray());
	}
	}

	/// <summary>
	/// Compares two byte strings for equality.
	/// </summary>
	/// <param name="lhs">The first byte string to compare.</param>
	/// <param name="rhs">The second byte string to compare.</param>
	/// <returns><c>true</c> if the byte strings are equal; false otherwise.</returns>
	public static bool operator ==(ByteString lhs, ByteString rhs)
	{
	if (ReferenceEquals(lhs, rhs))
	{
	return true;
	}
	if (lhs is null \|\| rhs is null)
	{
	return false;
	}

	return lhs.bytes.Span.SequenceEqual(rhs.bytes.Span);
	}

	/// <summary>
	/// Compares two byte strings for inequality.
	/// </summary>
	/// <param name="lhs">The first byte string to compare.</param>
	/// <param name="rhs">The second byte string to compare.</param>
	/// <returns><c>false</c> if the byte strings are equal; true otherwise.</returns>
	public static bool operator !=(ByteString lhs, ByteString rhs)
	{
	return !(lhs == rhs);
	}

	/// <summary>
	/// Compares this byte string with another object.
	/// </summary>
	/// <param name="obj">The object to compare this with.</param>
	/// <returns><c>true</c> if <paramref name="obj"/> refers to an equal <see cref="ByteString"/>; <c>false</c> otherwise.</returns>
	[SecuritySafeCritical]
	public override bool Equals(object obj)
	{
	return this == (obj as ByteString);
	}

	/// <summary>
	/// Returns a hash code for this object. Two equal byte strings
	/// will return the same hash code.
	/// </summary>
	/// <returns>A hash code for this object.</returns>
	[SecuritySafeCritical]
	public override int GetHashCode()
	{
	ReadOnlySpan<byte> b = bytes.Span;

	int ret = 23;
	for (int i = 0; i < b.Length; i++)
	{
	ret = (ret * 31) + b[i];
	}
	return ret;
	}

	/// <summary>
	/// Compares this byte string with another.
	/// </summary>
	/// <param name="other">The <see cref="ByteString"/> to compare this with.</param>
	/// <returns><c>true</c> if <paramref name="other"/> refers to an equal byte string; <c>false</c> otherwise.</returns>
	public bool Equals(ByteString other)
	{
	return this == other;
	}

	/// <summary>
	/// Copies the entire byte array to the destination array provided at the offset specified.
	/// </summary>
	public void CopyTo(byte[] array, int position)
	{
	bytes.CopyTo(array.AsMemory(position));
	}

	/// <summary>
	/// Writes the entire byte array to the provided stream
	/// </summary>
	public void WriteTo(Stream outputStream)
	{
	if (MemoryMarshal.TryGetArray(bytes, out ArraySegment<byte> segment))
	{
	// Fast path. ByteString was created with an array, so pass the underlying array.
	outputStream.Write(segment.Array, segment.Offset, segment.Count);
	}
	else
	{
	// Slow path. BytesString is not an array. Convert memory and pass result to WriteRawBytes.
	var array = bytes.ToArray();
	outputStream.Write(array, 0, array.Length);
	}
	}
	}
	}