Squashed 'third_party/flatbuffers/' content from commit acc9990ab

Change-Id: I48550d40d78fea996ebe74e9723a5d1f910de491
git-subtree-dir: third_party/flatbuffers
git-subtree-split: acc9990abd2206491480291b0f85f925110102ea
diff --git a/net/FlatBuffers/FlatBufferBuilder.cs b/net/FlatBuffers/FlatBufferBuilder.cs
new file mode 100644
index 0000000..27c16b3
--- /dev/null
+++ b/net/FlatBuffers/FlatBufferBuilder.cs
@@ -0,0 +1,842 @@
+/*
+ * Copyright 2014 Google Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+/// @file
+/// @addtogroup flatbuffers_csharp_api
+/// @{
+
+namespace FlatBuffers
+{
+    /// <summary>
+    /// Responsible for building up and accessing a FlatBuffer formatted byte
+    /// array (via ByteBuffer).
+    /// </summary>
+    public class FlatBufferBuilder
+    {
+        private int _space;
+        private ByteBuffer _bb;
+        private int _minAlign = 1;
+
+        // The vtable for the current table (if _vtableSize >= 0)
+        private int[] _vtable = new int[16];
+        // The size of the vtable. -1 indicates no vtable
+        private int _vtableSize = -1;
+        // Starting offset of the current struct/table.
+        private int _objectStart;
+        // List of offsets of all vtables.
+        private int[] _vtables = new int[16];
+        // Number of entries in `vtables` in use.
+        private int _numVtables = 0;
+        // For the current vector being built.
+        private int _vectorNumElems = 0;
+
+        // For CreateSharedString
+        private Dictionary<string, StringOffset> _sharedStringMap = null;
+
+        /// <summary>
+        /// Create a FlatBufferBuilder with a given initial size.
+        /// </summary>
+        /// <param name="initialSize">
+        /// The initial size to use for the internal buffer.
+        /// </param>
+        public FlatBufferBuilder(int initialSize)
+        {
+            if (initialSize <= 0)
+                throw new ArgumentOutOfRangeException("initialSize",
+                    initialSize, "Must be greater than zero");
+            _space = initialSize;
+            _bb = new ByteBuffer(initialSize);
+        }
+
+        /// <summary>
+        /// Create a FlatBufferBuilder backed by the pased in ByteBuffer
+        /// </summary>
+        /// <param name="buffer">The ByteBuffer to write to</param>
+        public FlatBufferBuilder(ByteBuffer buffer)
+        {
+            _bb = buffer;
+            _space = buffer.Length;
+            buffer.Reset();
+        }
+
+        /// <summary>
+        /// Reset the FlatBufferBuilder by purging all data that it holds.
+        /// </summary>
+        public void Clear()
+        {
+            _space = _bb.Length;
+            _bb.Reset();
+            _minAlign = 1;
+            while (_vtableSize > 0) _vtable[--_vtableSize] = 0;
+            _vtableSize = -1;
+            _objectStart = 0;
+            _numVtables = 0;
+            _vectorNumElems = 0;
+        }
+
+        /// <summary>
+        /// Gets and sets a Boolean to disable the optimization when serializing
+        /// default values to a Table.
+        ///
+        /// In order to save space, fields that are set to their default value
+        /// don't get serialized into the buffer.
+        /// </summary>
+        public bool ForceDefaults { get; set; }
+
+        /// @cond FLATBUFFERS_INTERNAL
+
+        public int Offset { get { return _bb.Length - _space; } }
+
+        public void Pad(int size)
+        {
+             _bb.PutByte(_space -= size, 0, size);
+        }
+
+        // Doubles the size of the ByteBuffer, and copies the old data towards
+        // the end of the new buffer (since we build the buffer backwards).
+        void GrowBuffer()
+        {
+            _bb.GrowFront(_bb.Length << 1);
+        }
+
+        // Prepare to write an element of `size` after `additional_bytes`
+        // have been written, e.g. if you write a string, you need to align
+        // such the int length field is aligned to SIZEOF_INT, and the string
+        // data follows it directly.
+        // If all you need to do is align, `additional_bytes` will be 0.
+        public void Prep(int size, int additionalBytes)
+        {
+            // Track the biggest thing we've ever aligned to.
+            if (size > _minAlign)
+                _minAlign = size;
+            // Find the amount of alignment needed such that `size` is properly
+            // aligned after `additional_bytes`
+            var alignSize =
+                ((~((int)_bb.Length - _space + additionalBytes)) + 1) &
+                (size - 1);
+            // Reallocate the buffer if needed.
+            while (_space < alignSize + size + additionalBytes)
+            {
+                var oldBufSize = (int)_bb.Length;
+                GrowBuffer();
+                _space += (int)_bb.Length - oldBufSize;
+
+            }
+            if (alignSize > 0)
+                Pad(alignSize);
+        }
+
+        public void PutBool(bool x)
+        {
+          _bb.PutByte(_space -= sizeof(byte), (byte)(x ? 1 : 0));
+        }
+
+        public void PutSbyte(sbyte x)
+        {
+          _bb.PutSbyte(_space -= sizeof(sbyte), x);
+        }
+
+        public void PutByte(byte x)
+        {
+            _bb.PutByte(_space -= sizeof(byte), x);
+        }
+
+        public void PutShort(short x)
+        {
+            _bb.PutShort(_space -= sizeof(short), x);
+        }
+
+        public void PutUshort(ushort x)
+        {
+          _bb.PutUshort(_space -= sizeof(ushort), x);
+        }
+
+        public void PutInt(int x)
+        {
+            _bb.PutInt(_space -= sizeof(int), x);
+        }
+
+        public void PutUint(uint x)
+        {
+          _bb.PutUint(_space -= sizeof(uint), x);
+        }
+
+        public void PutLong(long x)
+        {
+            _bb.PutLong(_space -= sizeof(long), x);
+        }
+
+        public void PutUlong(ulong x)
+        {
+          _bb.PutUlong(_space -= sizeof(ulong), x);
+        }
+
+        public void PutFloat(float x)
+        {
+            _bb.PutFloat(_space -= sizeof(float), x);
+        }
+
+        /// <summary>
+        /// Puts an array of type T into this builder at the
+        /// current offset
+        /// </summary>
+        /// <typeparam name="T">The type of the input data </typeparam>
+        /// <param name="x">The array to copy data from</param>
+        public void Put<T>(T[] x)
+            where T : struct
+        {
+            _space = _bb.Put(_space, x);
+        }
+
+#if ENABLE_SPAN_T
+        /// <summary>
+        /// Puts a span of type T into this builder at the
+        /// current offset
+        /// </summary>
+        /// <typeparam name="T">The type of the input data </typeparam>
+        /// <param name="x">The span to copy data from</param>
+        public void Put<T>(Span<T> x)
+            where T : struct
+        {
+            _space = _bb.Put(_space, x);
+        }
+#endif
+
+        public void PutDouble(double x)
+        {
+            _bb.PutDouble(_space -= sizeof(double), x);
+        }
+        /// @endcond
+
+        /// <summary>
+        /// Add a `bool` to the buffer (aligns the data and grows if necessary).
+        /// </summary>
+        /// <param name="x">The `bool` to add to the buffer.</param>
+        public void AddBool(bool x) { Prep(sizeof(byte), 0); PutBool(x); }
+
+        /// <summary>
+        /// Add a `sbyte` to the buffer (aligns the data and grows if necessary).
+        /// </summary>
+        /// <param name="x">The `sbyte` to add to the buffer.</param>
+        public void AddSbyte(sbyte x) { Prep(sizeof(sbyte), 0); PutSbyte(x); }
+
+        /// <summary>
+        /// Add a `byte` to the buffer (aligns the data and grows if necessary).
+        /// </summary>
+        /// <param name="x">The `byte` to add to the buffer.</param>
+        public void AddByte(byte x) { Prep(sizeof(byte), 0); PutByte(x); }
+
+        /// <summary>
+        /// Add a `short` to the buffer (aligns the data and grows if necessary).
+        /// </summary>
+        /// <param name="x">The `short` to add to the buffer.</param>
+        public void AddShort(short x) { Prep(sizeof(short), 0); PutShort(x); }
+
+        /// <summary>
+        /// Add an `ushort` to the buffer (aligns the data and grows if necessary).
+        /// </summary>
+        /// <param name="x">The `ushort` to add to the buffer.</param>
+        public void AddUshort(ushort x) { Prep(sizeof(ushort), 0); PutUshort(x); }
+
+        /// <summary>
+        /// Add an `int` to the buffer (aligns the data and grows if necessary).
+        /// </summary>
+        /// <param name="x">The `int` to add to the buffer.</param>
+        public void AddInt(int x) { Prep(sizeof(int), 0); PutInt(x); }
+
+        /// <summary>
+        /// Add an `uint` to the buffer (aligns the data and grows if necessary).
+        /// </summary>
+        /// <param name="x">The `uint` to add to the buffer.</param>
+        public void AddUint(uint x) { Prep(sizeof(uint), 0); PutUint(x); }
+
+        /// <summary>
+        /// Add a `long` to the buffer (aligns the data and grows if necessary).
+        /// </summary>
+        /// <param name="x">The `long` to add to the buffer.</param>
+        public void AddLong(long x) { Prep(sizeof(long), 0); PutLong(x); }
+
+        /// <summary>
+        /// Add an `ulong` to the buffer (aligns the data and grows if necessary).
+        /// </summary>
+        /// <param name="x">The `ulong` to add to the buffer.</param>
+        public void AddUlong(ulong x) { Prep(sizeof(ulong), 0); PutUlong(x); }
+
+        /// <summary>
+        /// Add a `float` to the buffer (aligns the data and grows if necessary).
+        /// </summary>
+        /// <param name="x">The `float` to add to the buffer.</param>
+        public void AddFloat(float x) { Prep(sizeof(float), 0); PutFloat(x); }
+
+        /// <summary>
+        /// Add an array of type T to the buffer (aligns the data and grows if necessary).
+        /// </summary>
+        /// <typeparam name="T">The type of the input data</typeparam>
+        /// <param name="x">The array to copy data from</param>
+        public void Add<T>(T[] x)
+            where T : struct
+        {
+            if (x == null)
+            {
+                throw new ArgumentNullException("Cannot add a null array");
+            }
+
+            if( x.Length == 0)
+            {
+                // don't do anything if the array is empty
+                return;
+            }
+
+            if(!ByteBuffer.IsSupportedType<T>())
+            {
+                throw new ArgumentException("Cannot add this Type array to the builder");
+            }
+
+            int size = ByteBuffer.SizeOf<T>();
+            // Need to prep on size (for data alignment) and then we pass the
+            // rest of the length (minus 1) as additional bytes
+            Prep(size, size * (x.Length - 1));
+            Put(x);
+        }
+
+#if ENABLE_SPAN_T
+        /// <summary>
+        /// Add a span of type T to the buffer (aligns the data and grows if necessary).
+        /// </summary>
+        /// <typeparam name="T">The type of the input data</typeparam>
+        /// <param name="x">The span to copy data from</param>
+        public void Add<T>(Span<T> x)
+            where T : struct
+        {
+            if (!ByteBuffer.IsSupportedType<T>())
+            {
+                throw new ArgumentException("Cannot add this Type array to the builder");
+            }
+
+            int size = ByteBuffer.SizeOf<T>();
+            // Need to prep on size (for data alignment) and then we pass the
+            // rest of the length (minus 1) as additional bytes
+            Prep(size, size * (x.Length - 1));
+            Put(x);
+        }
+#endif
+
+        /// <summary>
+        /// Add a `double` to the buffer (aligns the data and grows if necessary).
+        /// </summary>
+        /// <param name="x">The `double` to add to the buffer.</param>
+        public void AddDouble(double x) { Prep(sizeof(double), 0);
+                                          PutDouble(x); }
+
+        /// <summary>
+        /// Adds an offset, relative to where it will be written.
+        /// </summary>
+        /// <param name="off">The offset to add to the buffer.</param>
+        public void AddOffset(int off)
+        {
+            Prep(sizeof(int), 0);  // Ensure alignment is already done.
+            if (off > Offset)
+                throw new ArgumentException();
+
+            off = Offset - off + sizeof(int);
+            PutInt(off);
+        }
+
+        /// @cond FLATBUFFERS_INTERNAL
+        public void StartVector(int elemSize, int count, int alignment)
+        {
+            NotNested();
+            _vectorNumElems = count;
+            Prep(sizeof(int), elemSize * count);
+            Prep(alignment, elemSize * count); // Just in case alignment > int.
+        }
+        /// @endcond
+
+        /// <summary>
+        /// Writes data necessary to finish a vector construction.
+        /// </summary>
+        public VectorOffset EndVector()
+        {
+            PutInt(_vectorNumElems);
+            return new VectorOffset(Offset);
+        }
+
+        /// <summary>
+        /// Creates a vector of tables.
+        /// </summary>
+        /// <param name="offsets">Offsets of the tables.</param>
+        public VectorOffset CreateVectorOfTables<T>(Offset<T>[] offsets) where T : struct
+        {
+            NotNested();
+            StartVector(sizeof(int), offsets.Length, sizeof(int));
+            for (int i = offsets.Length - 1; i >= 0; i--) AddOffset(offsets[i].Value);
+            return EndVector();
+        }
+
+        /// @cond FLATBUFFERS_INTENRAL
+        public void Nested(int obj)
+        {
+            // Structs are always stored inline, so need to be created right
+            // where they are used. You'll get this assert if you created it
+            // elsewhere.
+            if (obj != Offset)
+                throw new Exception(
+                    "FlatBuffers: struct must be serialized inline.");
+        }
+
+        public void NotNested()
+        {
+            // You should not be creating any other objects or strings/vectors
+            // while an object is being constructed
+            if (_vtableSize >= 0)
+                throw new Exception(
+                    "FlatBuffers: object serialization must not be nested.");
+        }
+
+        public void StartTable(int numfields)
+        {
+            if (numfields < 0)
+                throw new ArgumentOutOfRangeException("Flatbuffers: invalid numfields");
+
+            NotNested();
+
+            if (_vtable.Length < numfields)
+                _vtable = new int[numfields];
+
+            _vtableSize = numfields;
+            _objectStart = Offset;
+        }
+
+
+        // Set the current vtable at `voffset` to the current location in the
+        // buffer.
+        public void Slot(int voffset)
+        {
+            if (voffset >= _vtableSize)
+                throw new IndexOutOfRangeException("Flatbuffers: invalid voffset");
+
+            _vtable[voffset] = Offset;
+        }
+
+        /// <summary>
+        /// Adds a Boolean to the Table at index `o` in its vtable using the value `x` and default `d`
+        /// </summary>
+        /// <param name="o">The index into the vtable</param>
+        /// <param name="x">The value to put into the buffer. If the value is equal to the default
+        /// and <see cref="ForceDefaults"/> is false, the value will be skipped.</param>
+        /// <param name="d">The default value to compare the value against</param>
+        public void AddBool(int o, bool x, bool d) { if (ForceDefaults || x != d) { AddBool(x); Slot(o); } }
+
+        /// <summary>
+        /// Adds a SByte to the Table at index `o` in its vtable using the value `x` and default `d`
+        /// </summary>
+        /// <param name="o">The index into the vtable</param>
+        /// <param name="x">The value to put into the buffer. If the value is equal to the default
+        /// and <see cref="ForceDefaults"/> is false, the value will be skipped.</param>
+        /// <param name="d">The default value to compare the value against</param>
+        public void AddSbyte(int o, sbyte x, sbyte d) { if (ForceDefaults || x != d) { AddSbyte(x); Slot(o); } }
+
+        /// <summary>
+        /// Adds a Byte to the Table at index `o` in its vtable using the value `x` and default `d`
+        /// </summary>
+        /// <param name="o">The index into the vtable</param>
+        /// <param name="x">The value to put into the buffer. If the value is equal to the default
+        /// and <see cref="ForceDefaults"/> is false, the value will be skipped.</param>
+        /// <param name="d">The default value to compare the value against</param>
+        public void AddByte(int o, byte x, byte d) { if (ForceDefaults || x != d) { AddByte(x); Slot(o); } }
+
+        /// <summary>
+        /// Adds a Int16 to the Table at index `o` in its vtable using the value `x` and default `d`
+        /// </summary>
+        /// <param name="o">The index into the vtable</param>
+        /// <param name="x">The value to put into the buffer. If the value is equal to the default
+        /// and <see cref="ForceDefaults"/> is false, the value will be skipped.</param>
+        /// <param name="d">The default value to compare the value against</param>
+        public void AddShort(int o, short x, int d) { if (ForceDefaults || x != d) { AddShort(x); Slot(o); } }
+
+        /// <summary>
+        /// Adds a UInt16 to the Table at index `o` in its vtable using the value `x` and default `d`
+        /// </summary>
+        /// <param name="o">The index into the vtable</param>
+        /// <param name="x">The value to put into the buffer. If the value is equal to the default
+        /// and <see cref="ForceDefaults"/> is false, the value will be skipped.</param>
+        /// <param name="d">The default value to compare the value against</param>
+        public void AddUshort(int o, ushort x, ushort d) { if (ForceDefaults || x != d) { AddUshort(x); Slot(o); } }
+
+        /// <summary>
+        /// Adds an Int32 to the Table at index `o` in its vtable using the value `x` and default `d`
+        /// </summary>
+        /// <param name="o">The index into the vtable</param>
+        /// <param name="x">The value to put into the buffer. If the value is equal to the default
+        /// and <see cref="ForceDefaults"/> is false, the value will be skipped.</param>
+        /// <param name="d">The default value to compare the value against</param>
+        public void AddInt(int o, int x, int d) { if (ForceDefaults || x != d) { AddInt(x); Slot(o); } }
+
+        /// <summary>
+        /// Adds a UInt32 to the Table at index `o` in its vtable using the value `x` and default `d`
+        /// </summary>
+        /// <param name="o">The index into the vtable</param>
+        /// <param name="x">The value to put into the buffer. If the value is equal to the default
+        /// and <see cref="ForceDefaults"/> is false, the value will be skipped.</param>
+        /// <param name="d">The default value to compare the value against</param>
+        public void AddUint(int o, uint x, uint d) { if (ForceDefaults || x != d) { AddUint(x); Slot(o); } }
+
+        /// <summary>
+        /// Adds an Int64 to the Table at index `o` in its vtable using the value `x` and default `d`
+        /// </summary>
+        /// <param name="o">The index into the vtable</param>
+        /// <param name="x">The value to put into the buffer. If the value is equal to the default
+        /// and <see cref="ForceDefaults"/> is false, the value will be skipped.</param>
+        /// <param name="d">The default value to compare the value against</param>
+        public void AddLong(int o, long x, long d) { if (ForceDefaults || x != d) { AddLong(x); Slot(o); } }
+
+        /// <summary>
+        /// Adds a UInt64 to the Table at index `o` in its vtable using the value `x` and default `d`
+        /// </summary>
+        /// <param name="o">The index into the vtable</param>
+        /// <param name="x">The value to put into the buffer. If the value is equal to the default
+        /// and <see cref="ForceDefaults"/> is false, the value will be skipped.</param>
+        /// <param name="d">The default value to compare the value against</param>
+        public void AddUlong(int o, ulong x, ulong d) { if (ForceDefaults || x != d) { AddUlong(x); Slot(o); } }
+
+        /// <summary>
+        /// Adds a Single to the Table at index `o` in its vtable using the value `x` and default `d`
+        /// </summary>
+        /// <param name="o">The index into the vtable</param>
+        /// <param name="x">The value to put into the buffer. If the value is equal to the default
+        /// and <see cref="ForceDefaults"/> is false, the value will be skipped.</param>
+        /// <param name="d">The default value to compare the value against</param>
+        public void AddFloat(int o, float x, double d) { if (ForceDefaults || x != d) { AddFloat(x); Slot(o); } }
+
+        /// <summary>
+        /// Adds a Double to the Table at index `o` in its vtable using the value `x` and default `d`
+        /// </summary>
+        /// <param name="o">The index into the vtable</param>
+        /// <param name="x">The value to put into the buffer. If the value is equal to the default
+        /// and <see cref="ForceDefaults"/> is false, the value will be skipped.</param>
+        /// <param name="d">The default value to compare the value against</param>
+        public void AddDouble(int o, double x, double d) { if (ForceDefaults || x != d) { AddDouble(x); Slot(o); } }
+
+        /// <summary>
+        /// Adds a buffer offset to the Table at index `o` in its vtable using the value `x` and default `d`
+        /// </summary>
+        /// <param name="o">The index into the vtable</param>
+        /// <param name="x">The value to put into the buffer. If the value is equal to the default
+        /// the value will be skipped.</param>
+        /// <param name="d">The default value to compare the value against</param>
+        public void AddOffset(int o, int x, int d) { if (x != d) { AddOffset(x); Slot(o); } }
+        /// @endcond
+
+        /// <summary>
+        /// Encode the string `s` in the buffer using UTF-8.
+        /// </summary>
+        /// <param name="s">The string to encode.</param>
+        /// <returns>
+        /// The offset in the buffer where the encoded string starts.
+        /// </returns>
+        public StringOffset CreateString(string s)
+        {
+            NotNested();
+            AddByte(0);
+            var utf8StringLen = Encoding.UTF8.GetByteCount(s);
+            StartVector(1, utf8StringLen, 1);
+            _bb.PutStringUTF8(_space -= utf8StringLen, s);
+            return new StringOffset(EndVector().Value);
+        }
+
+
+#if ENABLE_SPAN_T
+        /// <summary>
+        /// Creates a string in the buffer from a Span containing
+        /// a UTF8 string.
+        /// </summary>
+        /// <param name="chars">the UTF8 string to add to the buffer</param>
+        /// <returns>
+        /// The offset in the buffer where the encoded string starts.
+        /// </returns>
+        public StringOffset CreateUTF8String(Span<byte> chars)
+        {
+            NotNested();
+            AddByte(0);
+            var utf8StringLen = chars.Length;
+            StartVector(1, utf8StringLen, 1);
+            _space = _bb.Put(_space, chars);
+            return new StringOffset(EndVector().Value);
+        }
+#endif
+
+        /// <summary>
+        /// Store a string in the buffer, which can contain any binary data.
+        /// If a string with this exact contents has already been serialized before,
+        /// instead simply returns the offset of the existing string.
+        /// </summary>
+        /// <param name="s">The string to encode.</param>
+        /// <returns>
+        /// The offset in the buffer where the encoded string starts.
+        /// </returns>
+        public StringOffset CreateSharedString(string s)
+        {
+            if (_sharedStringMap == null)
+            {
+                _sharedStringMap = new Dictionary<string, StringOffset>();
+            }
+
+            if (_sharedStringMap.ContainsKey(s))
+            {
+                return _sharedStringMap[s];
+            }
+
+            var stringOffset = CreateString(s);
+            _sharedStringMap.Add(s, stringOffset);
+            return stringOffset;
+        }
+
+        /// @cond FLATBUFFERS_INTERNAL
+        // Structs are stored inline, so nothing additional is being added.
+        // `d` is always 0.
+        public void AddStruct(int voffset, int x, int d)
+        {
+            if (x != d)
+            {
+                Nested(x);
+                Slot(voffset);
+            }
+        }
+
+        public int EndTable()
+        {
+            if (_vtableSize < 0)
+                throw new InvalidOperationException(
+                  "Flatbuffers: calling EndTable without a StartTable");
+
+            AddInt((int)0);
+            var vtableloc = Offset;
+            // Write out the current vtable.
+            int i = _vtableSize - 1;
+            // Trim trailing zeroes.
+            for (; i >= 0 && _vtable[i] == 0; i--) {}
+            int trimmedSize = i + 1;
+            for (; i >= 0 ; i--) {
+                // Offset relative to the start of the table.
+                short off = (short)(_vtable[i] != 0
+                                        ? vtableloc - _vtable[i]
+                                        : 0);
+                AddShort(off);
+
+                // clear out written entry
+                _vtable[i] = 0;
+            }
+
+            const int standardFields = 2; // The fields below:
+            AddShort((short)(vtableloc - _objectStart));
+            AddShort((short)((trimmedSize + standardFields) *
+                             sizeof(short)));
+
+            // Search for an existing vtable that matches the current one.
+            int existingVtable = 0;
+            for (i = 0; i < _numVtables; i++) {
+                int vt1 = _bb.Length - _vtables[i];
+                int vt2 = _space;
+                short len = _bb.GetShort(vt1);
+                if (len == _bb.GetShort(vt2)) {
+                    for (int j = sizeof(short); j < len; j += sizeof(short)) {
+                        if (_bb.GetShort(vt1 + j) != _bb.GetShort(vt2 + j)) {
+                            goto endLoop;
+                        }
+                    }
+                    existingVtable = _vtables[i];
+                    break;
+                }
+
+                endLoop: { }
+            }
+
+            if (existingVtable != 0) {
+                // Found a match:
+                // Remove the current vtable.
+                _space = _bb.Length - vtableloc;
+                // Point table to existing vtable.
+                _bb.PutInt(_space, existingVtable - vtableloc);
+            } else {
+                // No match:
+                // Add the location of the current vtable to the list of
+                // vtables.
+                if (_numVtables == _vtables.Length)
+                {
+                    // Arrays.CopyOf(vtables num_vtables * 2);
+                    var newvtables = new int[ _numVtables * 2];
+                    Array.Copy(_vtables, newvtables, _vtables.Length);
+
+                    _vtables = newvtables;
+                };
+                _vtables[_numVtables++] = Offset;
+                // Point table to current vtable.
+                _bb.PutInt(_bb.Length - vtableloc, Offset - vtableloc);
+            }
+
+            _vtableSize = -1;
+            return vtableloc;
+        }
+
+        // This checks a required field has been set in a given table that has
+        // just been constructed.
+        public void Required(int table, int field)
+        {
+          int table_start = _bb.Length - table;
+          int vtable_start = table_start - _bb.GetInt(table_start);
+          bool ok = _bb.GetShort(vtable_start + field) != 0;
+          // If this fails, the caller will show what field needs to be set.
+          if (!ok)
+            throw new InvalidOperationException("FlatBuffers: field " + field +
+                                                " must be set");
+        }
+        /// @endcond
+
+        /// <summary>
+        /// Finalize a buffer, pointing to the given `root_table`.
+        /// </summary>
+        /// <param name="rootTable">
+        /// An offset to be added to the buffer.
+        /// </param>
+        /// <param name="sizePrefix">
+        /// Whether to prefix the size to the buffer.
+        /// </param>
+        protected void Finish(int rootTable, bool sizePrefix)
+        {
+            Prep(_minAlign, sizeof(int) + (sizePrefix ? sizeof(int) : 0));
+            AddOffset(rootTable);
+            if (sizePrefix) {
+                AddInt(_bb.Length - _space);
+            }
+            _bb.Position = _space;
+        }
+
+        /// <summary>
+        /// Finalize a buffer, pointing to the given `root_table`.
+        /// </summary>
+        /// <param name="rootTable">
+        /// An offset to be added to the buffer.
+        /// </param>
+        public void Finish(int rootTable)
+        {
+            Finish(rootTable, false);
+        }
+
+        /// <summary>
+        /// Finalize a buffer, pointing to the given `root_table`, with the size prefixed.
+        /// </summary>
+        /// <param name="rootTable">
+        /// An offset to be added to the buffer.
+        /// </param>
+        public void FinishSizePrefixed(int rootTable)
+        {
+            Finish(rootTable, true);
+        }
+
+        /// <summary>
+        /// Get the ByteBuffer representing the FlatBuffer.
+        /// </summary>
+        /// <remarks>
+        /// This is typically only called after you call `Finish()`.
+        /// The actual data starts at the ByteBuffer's current position,
+        /// not necessarily at `0`.
+        /// </remarks>
+        /// <returns>
+        /// Returns the ByteBuffer for this FlatBuffer.
+        /// </returns>
+        public ByteBuffer DataBuffer { get { return _bb; } }
+
+        /// <summary>
+        /// A utility function to copy and return the ByteBuffer data as a
+        /// `byte[]`.
+        /// </summary>
+        /// <returns>
+        /// A full copy of the FlatBuffer data.
+        /// </returns>
+        public byte[] SizedByteArray()
+        {
+            return _bb.ToSizedArray();
+        }
+
+        /// <summary>
+        /// Finalize a buffer, pointing to the given `rootTable`.
+        /// </summary>
+        /// <param name="rootTable">
+        /// An offset to be added to the buffer.
+        /// </param>
+        /// <param name="fileIdentifier">
+        /// A FlatBuffer file identifier to be added to the buffer before
+        /// `root_table`.
+        /// </param>
+        /// <param name="sizePrefix">
+        /// Whether to prefix the size to the buffer.
+        /// </param>
+        protected void Finish(int rootTable, string fileIdentifier, bool sizePrefix)
+        {
+            Prep(_minAlign, sizeof(int) + (sizePrefix ? sizeof(int) : 0) +
+                            FlatBufferConstants.FileIdentifierLength);
+            if (fileIdentifier.Length !=
+                FlatBufferConstants.FileIdentifierLength)
+                throw new ArgumentException(
+                    "FlatBuffers: file identifier must be length " +
+                    FlatBufferConstants.FileIdentifierLength,
+                    "fileIdentifier");
+            for (int i = FlatBufferConstants.FileIdentifierLength - 1; i >= 0;
+                 i--)
+            {
+               AddByte((byte)fileIdentifier[i]);
+            }
+            Finish(rootTable, sizePrefix);
+        }
+
+        /// <summary>
+        /// Finalize a buffer, pointing to the given `rootTable`.
+        /// </summary>
+        /// <param name="rootTable">
+        /// An offset to be added to the buffer.
+        /// </param>
+        /// <param name="fileIdentifier">
+        /// A FlatBuffer file identifier to be added to the buffer before
+        /// `root_table`.
+        /// </param>
+        public void Finish(int rootTable, string fileIdentifier)
+        {
+            Finish(rootTable, fileIdentifier, false);
+        }
+
+        /// <summary>
+        /// Finalize a buffer, pointing to the given `rootTable`, with the size prefixed.
+        /// </summary>
+        /// <param name="rootTable">
+        /// An offset to be added to the buffer.
+        /// </param>
+        /// <param name="fileIdentifier">
+        /// A FlatBuffer file identifier to be added to the buffer before
+        /// `root_table`.
+        /// </param>
+        public void FinishSizePrefixed(int rootTable, string fileIdentifier)
+        {
+            Finish(rootTable, fileIdentifier, true);
+        }
+    }
+}
+
+/// @}