Merge commit '36bca61764984ff5395653cf8377ec5daa71b709' as 'libs/protobuf'

libs/protobuf/csharp/src/Google.Protobuf/WireFormat.cs

@@ -0,0 +1,104 @@
+#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
+
+namespace Google.Protobuf
+{
+    /// <summary>
+    /// This class is used internally by the Protocol Buffer Library and generated
+    /// message implementations. It is public only for the sake of those generated
+    /// messages. Others should not use this class directly.
+    /// <para>
+    /// This class contains constants and helper functions useful for dealing with
+    /// the Protocol Buffer wire format.
+    /// </para>
+    /// </summary>
+    public static class WireFormat
+    {
+        /// <summary>
+        /// Wire types within protobuf encoding.
+        /// </summary>
+        public enum WireType : uint
+        {
+            /// <summary>
+            /// Variable-length integer.
+            /// </summary>
+            Varint = 0,
+            /// <summary>
+            /// A fixed-length 64-bit value.
+            /// </summary>
+            Fixed64 = 1,
+            /// <summary>
+            /// A length-delimited value, i.e. a length followed by that many bytes of data.
+            /// </summary>
+            LengthDelimited = 2,
+            /// <summary>
+            /// A "start group" value
+            /// </summary>
+            StartGroup = 3,
+            /// <summary>
+            /// An "end group" value
+            /// </summary>
+            EndGroup = 4,
+            /// <summary>
+            /// A fixed-length 32-bit value.
+            /// </summary>
+            Fixed32 = 5
+        }
+
+        private const int TagTypeBits = 3;
+        private const uint TagTypeMask = (1 << TagTypeBits) - 1;
+
+        /// <summary>
+        /// Given a tag value, determines the wire type (lower 3 bits).
+        /// </summary>
+        public static WireType GetTagWireType(uint tag)
+        {
+            return (WireType) (tag & TagTypeMask);
+        }
+
+        /// <summary>
+        /// Given a tag value, determines the field number (the upper 29 bits).
+        /// </summary>
+        public static int GetTagFieldNumber(uint tag)
+        {
+            return (int) (tag >> TagTypeBits);
+        }
+
+        /// <summary>
+        /// Makes a tag value given a field number and wire type.
+        /// </summary>
+        public static uint MakeTag(int fieldNumber, WireType wireType)
+        {
+            return (uint) (fieldNumber << TagTypeBits) | (uint) wireType;
+        }
+    }
+}