flatbuffers/net/FlatBuffers/ByteBuffer.cs

946 lines
30 KiB
C#

/*
* 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.
*/
// There are three conditional compilation symbols that have an impact on performance/features of this ByteBuffer implementation.
//
// UNSAFE_BYTEBUFFER
// This will use unsafe code to manipulate the underlying byte array. This
// can yield a reasonable performance increase.
//
// BYTEBUFFER_NO_BOUNDS_CHECK
// This will disable the bounds check asserts to the byte array. This can
// yield a small performance gain in normal code.
//
// ENABLE_SPAN_T
// This will enable reading and writing blocks of memory with a Span<T> instead of just
// T[]. You can also enable writing directly to shared memory or other types of memory
// by providing a custom implementation of ByteBufferAllocator.
// ENABLE_SPAN_T also requires UNSAFE_BYTEBUFFER to be defined, or .NET
// Standard 2.1.
//
// Using UNSAFE_BYTEBUFFER and BYTEBUFFER_NO_BOUNDS_CHECK together can yield a
// performance gain of ~15% for some operations, however doing so is potentially
// dangerous. Do so at your own risk!
//
using System;
using System.Collections.Generic;
using System.IO;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
using System.Text;
#if ENABLE_SPAN_T && (UNSAFE_BYTEBUFFER || NETSTANDARD2_1)
using System.Buffers.Binary;
#endif
#if ENABLE_SPAN_T && !UNSAFE_BYTEBUFFER && !NETSTANDARD2_1
#warning ENABLE_SPAN_T requires UNSAFE_BYTEBUFFER to also be defined
#endif
namespace FlatBuffers
{
public abstract class ByteBufferAllocator
{
#if ENABLE_SPAN_T && (UNSAFE_BYTEBUFFER || NETSTANDARD2_1)
public abstract Span<byte> Span { get; }
public abstract ReadOnlySpan<byte> ReadOnlySpan { get; }
public abstract Memory<byte> Memory { get; }
public abstract ReadOnlyMemory<byte> ReadOnlyMemory { get; }
#else
public byte[] Buffer
{
get;
protected set;
}
#endif
public int Length
{
get;
protected set;
}
public abstract void GrowFront(int newSize);
}
public sealed class ByteArrayAllocator : ByteBufferAllocator
{
private byte[] _buffer;
public ByteArrayAllocator(byte[] buffer)
{
_buffer = buffer;
InitBuffer();
}
public override void GrowFront(int newSize)
{
if ((Length & 0xC0000000) != 0)
throw new Exception(
"ByteBuffer: cannot grow buffer beyond 2 gigabytes.");
if (newSize < Length)
throw new Exception("ByteBuffer: cannot truncate buffer.");
byte[] newBuffer = new byte[newSize];
System.Buffer.BlockCopy(_buffer, 0, newBuffer, newSize - Length, Length);
_buffer = newBuffer;
InitBuffer();
}
#if ENABLE_SPAN_T && (UNSAFE_BYTEBUFFER || NETSTANDARD2_1)
public override Span<byte> Span => _buffer;
public override ReadOnlySpan<byte> ReadOnlySpan => _buffer;
public override Memory<byte> Memory => _buffer;
public override ReadOnlyMemory<byte> ReadOnlyMemory => _buffer;
#endif
private void InitBuffer()
{
Length = _buffer.Length;
#if !ENABLE_SPAN_T
Buffer = _buffer;
#endif
}
}
/// <summary>
/// Class to mimic Java's ByteBuffer which is used heavily in Flatbuffers.
/// </summary>
public class ByteBuffer
{
private ByteBufferAllocator _buffer;
private int _pos; // Must track start of the buffer.
public ByteBuffer(ByteBufferAllocator allocator, int position)
{
_buffer = allocator;
_pos = position;
}
public ByteBuffer(int size) : this(new byte[size]) { }
public ByteBuffer(byte[] buffer) : this(buffer, 0) { }
public ByteBuffer(byte[] buffer, int pos)
{
_buffer = new ByteArrayAllocator(buffer);
_pos = pos;
}
public int Position
{
get { return _pos; }
set { _pos = value; }
}
public int Length { get { return _buffer.Length; } }
public void Reset()
{
_pos = 0;
}
// Create a new ByteBuffer on the same underlying data.
// The new ByteBuffer's position will be same as this buffer's.
public ByteBuffer Duplicate()
{
return new ByteBuffer(_buffer, Position);
}
// Increases the size of the ByteBuffer, and copies the old data towards
// the end of the new buffer.
public void GrowFront(int newSize)
{
_buffer.GrowFront(newSize);
}
public byte[] ToArray(int pos, int len)
{
return ToArray<byte>(pos, len);
}
/// <summary>
/// A lookup of type sizes. Used instead of Marshal.SizeOf() which has additional
/// overhead, but also is compatible with generic functions for simplified code.
/// </summary>
private static Dictionary<Type, int> genericSizes = new Dictionary<Type, int>()
{
{ typeof(bool), sizeof(bool) },
{ typeof(float), sizeof(float) },
{ typeof(double), sizeof(double) },
{ typeof(sbyte), sizeof(sbyte) },
{ typeof(byte), sizeof(byte) },
{ typeof(short), sizeof(short) },
{ typeof(ushort), sizeof(ushort) },
{ typeof(int), sizeof(int) },
{ typeof(uint), sizeof(uint) },
{ typeof(ulong), sizeof(ulong) },
{ typeof(long), sizeof(long) },
};
/// <summary>
/// Get the wire-size (in bytes) of a type supported by flatbuffers.
/// </summary>
/// <param name="t">The type to get the wire size of</param>
/// <returns></returns>
public static int SizeOf<T>()
{
return genericSizes[typeof(T)];
}
/// <summary>
/// Checks if the Type provided is supported as scalar value
/// </summary>
/// <typeparam name="T">The Type to check</typeparam>
/// <returns>True if the type is a scalar type that is supported, falsed otherwise</returns>
public static bool IsSupportedType<T>()
{
return genericSizes.ContainsKey(typeof(T));
}
/// <summary>
/// Get the wire-size (in bytes) of an typed array
/// </summary>
/// <typeparam name="T">The type of the array</typeparam>
/// <param name="x">The array to get the size of</param>
/// <returns>The number of bytes the array takes on wire</returns>
public static int ArraySize<T>(T[] x)
{
return SizeOf<T>() * x.Length;
}
#if ENABLE_SPAN_T && (UNSAFE_BYTEBUFFER || NETSTANDARD2_1)
public static int ArraySize<T>(Span<T> x)
{
return SizeOf<T>() * x.Length;
}
#endif
// Get a portion of the buffer casted into an array of type T, given
// the buffer position and length.
#if ENABLE_SPAN_T && (UNSAFE_BYTEBUFFER || NETSTANDARD2_1)
public T[] ToArray<T>(int pos, int len)
where T : struct
{
AssertOffsetAndLength(pos, len);
return MemoryMarshal.Cast<byte, T>(_buffer.ReadOnlySpan.Slice(pos)).Slice(0, len).ToArray();
}
#else
public T[] ToArray<T>(int pos, int len)
where T : struct
{
AssertOffsetAndLength(pos, len);
T[] arr = new T[len];
Buffer.BlockCopy(_buffer.Buffer, pos, arr, 0, ArraySize(arr));
return arr;
}
#endif
public byte[] ToSizedArray()
{
return ToArray<byte>(Position, Length - Position);
}
public byte[] ToFullArray()
{
return ToArray<byte>(0, Length);
}
#if ENABLE_SPAN_T && (UNSAFE_BYTEBUFFER || NETSTANDARD2_1)
public ReadOnlyMemory<byte> ToReadOnlyMemory(int pos, int len)
{
return _buffer.ReadOnlyMemory.Slice(pos, len);
}
public Memory<byte> ToMemory(int pos, int len)
{
return _buffer.Memory.Slice(pos, len);
}
public Span<byte> ToSpan(int pos, int len)
{
return _buffer.Span.Slice(pos, len);
}
#else
public ArraySegment<byte> ToArraySegment(int pos, int len)
{
return new ArraySegment<byte>(_buffer.Buffer, pos, len);
}
public MemoryStream ToMemoryStream(int pos, int len)
{
return new MemoryStream(_buffer.Buffer, pos, len);
}
#endif
#if !UNSAFE_BYTEBUFFER
// A conversion union where all the members are overlapping. This allows to reinterpret the bytes of one type
// as another, without additional copies.
[StructLayout(LayoutKind.Explicit)]
struct ConversionUnion
{
[FieldOffset(0)] public int intValue;
[FieldOffset(0)] public float floatValue;
}
#endif // !UNSAFE_BYTEBUFFER
// Helper functions for the unsafe version.
static public ushort ReverseBytes(ushort input)
{
return (ushort)(((input & 0x00FFU) << 8) |
((input & 0xFF00U) >> 8));
}
static public uint ReverseBytes(uint input)
{
return ((input & 0x000000FFU) << 24) |
((input & 0x0000FF00U) << 8) |
((input & 0x00FF0000U) >> 8) |
((input & 0xFF000000U) >> 24);
}
static public ulong ReverseBytes(ulong input)
{
return (((input & 0x00000000000000FFUL) << 56) |
((input & 0x000000000000FF00UL) << 40) |
((input & 0x0000000000FF0000UL) << 24) |
((input & 0x00000000FF000000UL) << 8) |
((input & 0x000000FF00000000UL) >> 8) |
((input & 0x0000FF0000000000UL) >> 24) |
((input & 0x00FF000000000000UL) >> 40) |
((input & 0xFF00000000000000UL) >> 56));
}
#if !UNSAFE_BYTEBUFFER && (!ENABLE_SPAN_T || !NETSTANDARD2_1)
// Helper functions for the safe (but slower) version.
protected void WriteLittleEndian(int offset, int count, ulong data)
{
if (BitConverter.IsLittleEndian)
{
for (int i = 0; i < count; i++)
{
_buffer.Buffer[offset + i] = (byte)(data >> i * 8);
}
}
else
{
for (int i = 0; i < count; i++)
{
_buffer.Buffer[offset + count - 1 - i] = (byte)(data >> i * 8);
}
}
}
protected ulong ReadLittleEndian(int offset, int count)
{
AssertOffsetAndLength(offset, count);
ulong r = 0;
if (BitConverter.IsLittleEndian)
{
for (int i = 0; i < count; i++)
{
r |= (ulong)_buffer.Buffer[offset + i] << i * 8;
}
}
else
{
for (int i = 0; i < count; i++)
{
r |= (ulong)_buffer.Buffer[offset + count - 1 - i] << i * 8;
}
}
return r;
}
#elif ENABLE_SPAN_T && NETSTANDARD2_1
protected void WriteLittleEndian(int offset, int count, ulong data)
{
if (BitConverter.IsLittleEndian)
{
for (int i = 0; i < count; i++)
{
_buffer.Span[offset + i] = (byte)(data >> i * 8);
}
}
else
{
for (int i = 0; i < count; i++)
{
_buffer.Span[offset + count - 1 - i] = (byte)(data >> i * 8);
}
}
}
protected ulong ReadLittleEndian(int offset, int count)
{
AssertOffsetAndLength(offset, count);
ulong r = 0;
if (BitConverter.IsLittleEndian)
{
for (int i = 0; i < count; i++)
{
r |= (ulong)_buffer.Span[offset + i] << i * 8;
}
}
else
{
for (int i = 0; i < count; i++)
{
r |= (ulong)_buffer.Span[offset + count - 1 - i] << i * 8;
}
}
return r;
}
#endif
private void AssertOffsetAndLength(int offset, int length)
{
#if !BYTEBUFFER_NO_BOUNDS_CHECK
if (offset < 0 ||
offset > _buffer.Length - length)
throw new ArgumentOutOfRangeException();
#endif
}
#if ENABLE_SPAN_T && (UNSAFE_BYTEBUFFER || NETSTANDARD2_1)
public void PutSbyte(int offset, sbyte value)
{
AssertOffsetAndLength(offset, sizeof(sbyte));
_buffer.Span[offset] = (byte)value;
}
public void PutByte(int offset, byte value)
{
AssertOffsetAndLength(offset, sizeof(byte));
_buffer.Span[offset] = value;
}
public void PutByte(int offset, byte value, int count)
{
AssertOffsetAndLength(offset, sizeof(byte) * count);
Span<byte> span = _buffer.Span.Slice(offset, count);
for (var i = 0; i < span.Length; ++i)
span[i] = value;
}
#else
public void PutSbyte(int offset, sbyte value)
{
AssertOffsetAndLength(offset, sizeof(sbyte));
_buffer.Buffer[offset] = (byte)value;
}
public void PutByte(int offset, byte value)
{
AssertOffsetAndLength(offset, sizeof(byte));
_buffer.Buffer[offset] = value;
}
public void PutByte(int offset, byte value, int count)
{
AssertOffsetAndLength(offset, sizeof(byte) * count);
for (var i = 0; i < count; ++i)
_buffer.Buffer[offset + i] = value;
}
#endif
// this method exists in order to conform with Java ByteBuffer standards
public void Put(int offset, byte value)
{
PutByte(offset, value);
}
#if ENABLE_SPAN_T && UNSAFE_BYTEBUFFER
public unsafe void PutStringUTF8(int offset, string value)
{
AssertOffsetAndLength(offset, value.Length);
fixed (char* s = value)
{
fixed (byte* buffer = &MemoryMarshal.GetReference(_buffer.Span))
{
Encoding.UTF8.GetBytes(s, value.Length, buffer + offset, Length - offset);
}
}
}
#elif ENABLE_SPAN_T && NETSTANDARD2_1
public void PutStringUTF8(int offset, string value)
{
AssertOffsetAndLength(offset, value.Length);
Encoding.UTF8.GetBytes(value.AsSpan().Slice(0, value.Length),
_buffer.Span.Slice(offset));
}
#else
public void PutStringUTF8(int offset, string value)
{
AssertOffsetAndLength(offset, value.Length);
Encoding.UTF8.GetBytes(value, 0, value.Length,
_buffer.Buffer, offset);
}
#endif
#if UNSAFE_BYTEBUFFER
// Unsafe but more efficient versions of Put*.
public void PutShort(int offset, short value)
{
PutUshort(offset, (ushort)value);
}
public unsafe void PutUshort(int offset, ushort value)
{
AssertOffsetAndLength(offset, sizeof(ushort));
#if ENABLE_SPAN_T // && UNSAFE_BYTEBUFFER
Span<byte> span = _buffer.Span.Slice(offset);
BinaryPrimitives.WriteUInt16LittleEndian(span, value);
#else
fixed (byte* ptr = _buffer.Buffer)
{
*(ushort*)(ptr + offset) = BitConverter.IsLittleEndian
? value
: ReverseBytes(value);
}
#endif
}
public void PutInt(int offset, int value)
{
PutUint(offset, (uint)value);
}
public unsafe void PutUint(int offset, uint value)
{
AssertOffsetAndLength(offset, sizeof(uint));
#if ENABLE_SPAN_T // && UNSAFE_BYTEBUFFER
Span<byte> span = _buffer.Span.Slice(offset);
BinaryPrimitives.WriteUInt32LittleEndian(span, value);
#else
fixed (byte* ptr = _buffer.Buffer)
{
*(uint*)(ptr + offset) = BitConverter.IsLittleEndian
? value
: ReverseBytes(value);
}
#endif
}
public unsafe void PutLong(int offset, long value)
{
PutUlong(offset, (ulong)value);
}
public unsafe void PutUlong(int offset, ulong value)
{
AssertOffsetAndLength(offset, sizeof(ulong));
#if ENABLE_SPAN_T // && UNSAFE_BYTEBUFFER
Span<byte> span = _buffer.Span.Slice(offset);
BinaryPrimitives.WriteUInt64LittleEndian(span, value);
#else
fixed (byte* ptr = _buffer.Buffer)
{
*(ulong*)(ptr + offset) = BitConverter.IsLittleEndian
? value
: ReverseBytes(value);
}
#endif
}
public unsafe void PutFloat(int offset, float value)
{
AssertOffsetAndLength(offset, sizeof(float));
#if ENABLE_SPAN_T // && UNSAFE_BYTEBUFFER
fixed (byte* ptr = &MemoryMarshal.GetReference(_buffer.Span))
#else
fixed (byte* ptr = _buffer.Buffer)
#endif
{
if (BitConverter.IsLittleEndian)
{
*(float*)(ptr + offset) = value;
}
else
{
*(uint*)(ptr + offset) = ReverseBytes(*(uint*)(&value));
}
}
}
public unsafe void PutDouble(int offset, double value)
{
AssertOffsetAndLength(offset, sizeof(double));
#if ENABLE_SPAN_T // && UNSAFE_BYTEBUFFER
fixed (byte* ptr = &MemoryMarshal.GetReference(_buffer.Span))
#else
fixed (byte* ptr = _buffer.Buffer)
#endif
{
if (BitConverter.IsLittleEndian)
{
*(double*)(ptr + offset) = value;
}
else
{
*(ulong*)(ptr + offset) = ReverseBytes(*(ulong*)(&value));
}
}
}
#else // !UNSAFE_BYTEBUFFER
// Slower versions of Put* for when unsafe code is not allowed.
public void PutShort(int offset, short value)
{
AssertOffsetAndLength(offset, sizeof(short));
WriteLittleEndian(offset, sizeof(short), (ulong)value);
}
public void PutUshort(int offset, ushort value)
{
AssertOffsetAndLength(offset, sizeof(ushort));
WriteLittleEndian(offset, sizeof(ushort), (ulong)value);
}
public void PutInt(int offset, int value)
{
AssertOffsetAndLength(offset, sizeof(int));
WriteLittleEndian(offset, sizeof(int), (ulong)value);
}
public void PutUint(int offset, uint value)
{
AssertOffsetAndLength(offset, sizeof(uint));
WriteLittleEndian(offset, sizeof(uint), (ulong)value);
}
public void PutLong(int offset, long value)
{
AssertOffsetAndLength(offset, sizeof(long));
WriteLittleEndian(offset, sizeof(long), (ulong)value);
}
public void PutUlong(int offset, ulong value)
{
AssertOffsetAndLength(offset, sizeof(ulong));
WriteLittleEndian(offset, sizeof(ulong), value);
}
public void PutFloat(int offset, float value)
{
AssertOffsetAndLength(offset, sizeof(float));
// TODO(derekbailey): use BitConvert.SingleToInt32Bits() whenever flatbuffers upgrades to a .NET version
// that contains it.
ConversionUnion union;
union.intValue = 0;
union.floatValue = value;
WriteLittleEndian(offset, sizeof(float), (ulong)union.intValue);
}
public void PutDouble(int offset, double value)
{
AssertOffsetAndLength(offset, sizeof(double));
WriteLittleEndian(offset, sizeof(double), (ulong)BitConverter.DoubleToInt64Bits(value));
}
#endif // UNSAFE_BYTEBUFFER
#if ENABLE_SPAN_T && (UNSAFE_BYTEBUFFER || NETSTANDARD2_1)
public sbyte GetSbyte(int index)
{
AssertOffsetAndLength(index, sizeof(sbyte));
return (sbyte)_buffer.ReadOnlySpan[index];
}
public byte Get(int index)
{
AssertOffsetAndLength(index, sizeof(byte));
return _buffer.ReadOnlySpan[index];
}
#else
public sbyte GetSbyte(int index)
{
AssertOffsetAndLength(index, sizeof(sbyte));
return (sbyte)_buffer.Buffer[index];
}
public byte Get(int index)
{
AssertOffsetAndLength(index, sizeof(byte));
return _buffer.Buffer[index];
}
#endif
#if ENABLE_SPAN_T && UNSAFE_BYTEBUFFER
public unsafe string GetStringUTF8(int startPos, int len)
{
fixed (byte* buffer = &MemoryMarshal.GetReference(_buffer.ReadOnlySpan.Slice(startPos)))
{
return Encoding.UTF8.GetString(buffer, len);
}
}
#elif ENABLE_SPAN_T && NETSTANDARD2_1
public string GetStringUTF8(int startPos, int len)
{
return Encoding.UTF8.GetString(_buffer.Span.Slice(startPos, len));
}
#else
public string GetStringUTF8(int startPos, int len)
{
return Encoding.UTF8.GetString(_buffer.Buffer, startPos, len);
}
#endif
#if UNSAFE_BYTEBUFFER
// Unsafe but more efficient versions of Get*.
public short GetShort(int offset)
{
return (short)GetUshort(offset);
}
public unsafe ushort GetUshort(int offset)
{
AssertOffsetAndLength(offset, sizeof(ushort));
#if ENABLE_SPAN_T // && UNSAFE_BYTEBUFFER
ReadOnlySpan<byte> span = _buffer.ReadOnlySpan.Slice(offset);
return BinaryPrimitives.ReadUInt16LittleEndian(span);
#else
fixed (byte* ptr = _buffer.Buffer)
{
return BitConverter.IsLittleEndian
? *(ushort*)(ptr + offset)
: ReverseBytes(*(ushort*)(ptr + offset));
}
#endif
}
public int GetInt(int offset)
{
return (int)GetUint(offset);
}
public unsafe uint GetUint(int offset)
{
AssertOffsetAndLength(offset, sizeof(uint));
#if ENABLE_SPAN_T // && UNSAFE_BYTEBUFFER
ReadOnlySpan<byte> span = _buffer.ReadOnlySpan.Slice(offset);
return BinaryPrimitives.ReadUInt32LittleEndian(span);
#else
fixed (byte* ptr = _buffer.Buffer)
{
return BitConverter.IsLittleEndian
? *(uint*)(ptr + offset)
: ReverseBytes(*(uint*)(ptr + offset));
}
#endif
}
public long GetLong(int offset)
{
return (long)GetUlong(offset);
}
public unsafe ulong GetUlong(int offset)
{
AssertOffsetAndLength(offset, sizeof(ulong));
#if ENABLE_SPAN_T // && UNSAFE_BYTEBUFFER
ReadOnlySpan<byte> span = _buffer.ReadOnlySpan.Slice(offset);
return BinaryPrimitives.ReadUInt64LittleEndian(span);
#else
fixed (byte* ptr = _buffer.Buffer)
{
return BitConverter.IsLittleEndian
? *(ulong*)(ptr + offset)
: ReverseBytes(*(ulong*)(ptr + offset));
}
#endif
}
public unsafe float GetFloat(int offset)
{
AssertOffsetAndLength(offset, sizeof(float));
#if ENABLE_SPAN_T // && UNSAFE_BYTEBUFFER
fixed (byte* ptr = &MemoryMarshal.GetReference(_buffer.ReadOnlySpan))
#else
fixed (byte* ptr = _buffer.Buffer)
#endif
{
if (BitConverter.IsLittleEndian)
{
return *(float*)(ptr + offset);
}
else
{
uint uvalue = ReverseBytes(*(uint*)(ptr + offset));
return *(float*)(&uvalue);
}
}
}
public unsafe double GetDouble(int offset)
{
AssertOffsetAndLength(offset, sizeof(double));
#if ENABLE_SPAN_T // && UNSAFE_BYTEBUFFER
fixed (byte* ptr = &MemoryMarshal.GetReference(_buffer.ReadOnlySpan))
#else
fixed (byte* ptr = _buffer.Buffer)
#endif
{
if (BitConverter.IsLittleEndian)
{
return *(double*)(ptr + offset);
}
else
{
ulong uvalue = ReverseBytes(*(ulong*)(ptr + offset));
return *(double*)(&uvalue);
}
}
}
#else // !UNSAFE_BYTEBUFFER
// Slower versions of Get* for when unsafe code is not allowed.
public short GetShort(int index)
{
return (short)ReadLittleEndian(index, sizeof(short));
}
public ushort GetUshort(int index)
{
return (ushort)ReadLittleEndian(index, sizeof(ushort));
}
public int GetInt(int index)
{
return (int)ReadLittleEndian(index, sizeof(int));
}
public uint GetUint(int index)
{
return (uint)ReadLittleEndian(index, sizeof(uint));
}
public long GetLong(int index)
{
return (long)ReadLittleEndian(index, sizeof(long));
}
public ulong GetUlong(int index)
{
return ReadLittleEndian(index, sizeof(ulong));
}
public float GetFloat(int index)
{
// TODO(derekbailey): use BitConvert.Int32BitsToSingle() whenever flatbuffers upgrades to a .NET version
// that contains it.
ConversionUnion union;
union.floatValue = 0;
union.intValue = (int)ReadLittleEndian(index, sizeof(float));
return union.floatValue;
}
public double GetDouble(int index)
{
return BitConverter.Int64BitsToDouble((long)ReadLittleEndian(index, sizeof(double)));
}
#endif // UNSAFE_BYTEBUFFER
/// <summary>
/// Copies an array of type T into this buffer, ending at the given
/// offset into this buffer. The starting offset is calculated based on the length
/// of the array and is the value returned.
/// </summary>
/// <typeparam name="T">The type of the input data (must be a struct)</typeparam>
/// <param name="offset">The offset into this buffer where the copy will end</param>
/// <param name="x">The array to copy data from</param>
/// <returns>The 'start' location of this buffer now, after the copy completed</returns>
public int Put<T>(int offset, T[] x)
where T : struct
{
if (x == null)
{
throw new ArgumentNullException("Cannot put a null array");
}
if (x.Length == 0)
{
throw new ArgumentException("Cannot put an empty array");
}
if (!IsSupportedType<T>())
{
throw new ArgumentException("Cannot put an array of type "
+ typeof(T) + " into this buffer");
}
if (BitConverter.IsLittleEndian)
{
int numBytes = ByteBuffer.ArraySize(x);
offset -= numBytes;
AssertOffsetAndLength(offset, numBytes);
// if we are LE, just do a block copy
#if ENABLE_SPAN_T && (UNSAFE_BYTEBUFFER || NETSTANDARD2_1)
MemoryMarshal.Cast<T, byte>(x).CopyTo(_buffer.Span.Slice(offset, numBytes));
#else
Buffer.BlockCopy(x, 0, _buffer.Buffer, offset, numBytes);
#endif
}
else
{
throw new NotImplementedException("Big Endian Support not implemented yet " +
"for putting typed arrays");
// if we are BE, we have to swap each element by itself
//for(int i = x.Length - 1; i >= 0; i--)
//{
// todo: low priority, but need to genericize the Put<T>() functions
//}
}
return offset;
}
#if ENABLE_SPAN_T && (UNSAFE_BYTEBUFFER || NETSTANDARD2_1)
public int Put<T>(int offset, Span<T> x)
where T : struct
{
if (x.Length == 0)
{
throw new ArgumentException("Cannot put an empty array");
}
if (!IsSupportedType<T>())
{
throw new ArgumentException("Cannot put an array of type "
+ typeof(T) + " into this buffer");
}
if (BitConverter.IsLittleEndian)
{
int numBytes = ByteBuffer.ArraySize(x);
offset -= numBytes;
AssertOffsetAndLength(offset, numBytes);
// if we are LE, just do a block copy
MemoryMarshal.Cast<T, byte>(x).CopyTo(_buffer.Span.Slice(offset, numBytes));
}
else
{
throw new NotImplementedException("Big Endian Support not implemented yet " +
"for putting typed arrays");
// if we are BE, we have to swap each element by itself
//for(int i = x.Length - 1; i >= 0; i--)
//{
// todo: low priority, but need to genericize the Put<T>() functions
//}
}
return offset;
}
#endif
}
}