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// ==++==
//
// Copyright (c) Microsoft Corporation. All rights reserved.
//
// ==--==
// For code consistency between.NET Framework and .NET Core
#if WIN64
#define BIT64
#elif WIN32
#define BIT32
#else
#error Unknown architecture
#endif
#if !PLATFORM_UNIX
#define PLATFORM_WINDOWS
#endif
#if AMD64 || ARM64 || (BIT32 && !ARM)
#define HAS_CUSTOM_BLOCKS
#endif
namespace System {
//Only contains static methods. Does not require serialization
using System;
using System.Runtime.CompilerServices;
using System.Runtime.ConstrainedExecution;
using System.Runtime.InteropServices;
using System.Runtime.Versioning;
using System.Diagnostics.Contracts;
using System.Security;
using System.Runtime;
#if BIT64
using nuint = System.UInt64;
#else // BIT64
using nuint = System.UInt32;
#endif // BIT64
[System.Runtime.InteropServices.ComVisible(true)]
public static class Buffer
{
// Copies from one primitive array to another primitive array without
// respecting types. This calls memmove internally. The count and
// offset parameters here are in bytes. If you want to use traditional
// array element indices and counts, use Array.Copy.
[System.Security.SecuritySafeCritical] // auto-generated
[ResourceExposure(ResourceScope.None)]
[MethodImplAttribute(MethodImplOptions.InternalCall)]
public static extern void BlockCopy(Array src, int srcOffset,
Array dst, int dstOffset, int count);
// A very simple and efficient memmove that assumes all of the
// parameter validation has already been done. The count and offset
// parameters here are in bytes. If you want to use traditional
// array element indices and counts, use Array.Copy.
[System.Security.SecuritySafeCritical] // auto-generated
[ResourceExposure(ResourceScope.None)]
[MethodImplAttribute(MethodImplOptions.InternalCall)]
internal static extern void InternalBlockCopy(Array src, int srcOffsetBytes,
Array dst, int dstOffsetBytes, int byteCount);
// This is ported from the optimized CRT assembly in memchr.asm. The JIT generates
// pretty good code here and this ends up being within a couple % of the CRT asm.
// It is however cross platform as the CRT hasn't ported their fast version to 64-bit
// platforms.
//
[System.Security.SecurityCritical] // auto-generated
internal unsafe static int IndexOfByte(byte* src, byte value, int index, int count)
{
Contract.Assert(src != null, "src should not be null");
byte* pByte = src + index;
// Align up the pointer to sizeof(int).
while (((int)pByte & 3) != 0)
{
if (count == 0)
return -1;
else if (*pByte == value)
return (int) (pByte - src);
count--;
pByte++;
}
// Fill comparer with value byte for comparisons
//
// comparer = 0/0/value/value
uint comparer = (((uint)value << 8) + (uint)value);
// comparer = value/value/value/value
comparer = (comparer << 16) + comparer;
// Run through buffer until we hit a 4-byte section which contains
// the byte we're looking for or until we exhaust the buffer.
while (count > 3)
{
// Test the buffer for presence of value. comparer contains the byte
// replicated 4 times.
uint t1 = *(uint*)pByte;
t1 = t1 ^ comparer;
uint t2 = 0x7efefeff + t1;
t1 = t1 ^ 0xffffffff;
t1 = t1 ^ t2;
t1 = t1 & 0x81010100;
// if t1 is zero then these 4-bytes don't contain a match
if (t1 != 0)
{
// We've found a match for value, figure out which position it's in.
int foundIndex = (int) (pByte - src);
if (pByte[0] == value)
return foundIndex;
else if (pByte[1] == value)
return foundIndex + 1;
else if (pByte[2] == value)
return foundIndex + 2;
else if (pByte[3] == value)
return foundIndex + 3;
}
count -= 4;
pByte += 4;
}
// Catch any bytes that might be left at the tail of the buffer
while (count > 0)
{
if (*pByte == value)
return (int) (pByte - src);
count--;
pByte++;
}
// If we don't have a match return -1;
return -1;
}
// Returns a bool to indicate if the array is of primitive data types
// or not.
[System.Security.SecurityCritical] // auto-generated
[ResourceExposure(ResourceScope.None)]
[MethodImplAttribute(MethodImplOptions.InternalCall)]
private static extern bool IsPrimitiveTypeArray(Array array);
// Gets a particular byte out of the array. The array must be an
// array of primitives.
//
// This essentially does the following:
// return ((byte*)array) + index.
//
[System.Security.SecurityCritical] // auto-generated
[ResourceExposure(ResourceScope.None)]
[MethodImplAttribute(MethodImplOptions.InternalCall)]
private static extern byte _GetByte(Array array, int index);
[System.Security.SecuritySafeCritical] // auto-generated
public static byte GetByte(Array array, int index)
{
// Is the array present?
if (array == null)
throw new ArgumentNullException("array");
// Is it of primitive types?
if (!IsPrimitiveTypeArray(array))
throw new ArgumentException(Environment.GetResourceString("Arg_MustBePrimArray"), "array");
// Is the index in valid range of the array?
if (index < 0 || index >= _ByteLength(array))
throw new ArgumentOutOfRangeException("index");
return _GetByte(array, index);
}
// Sets a particular byte in an the array. The array must be an
// array of primitives.
//
// This essentially does the following:
// *(((byte*)array) + index) = value.
//
[System.Security.SecurityCritical] // auto-generated
[ResourceExposure(ResourceScope.None)]
[MethodImplAttribute(MethodImplOptions.InternalCall)]
private static extern void _SetByte(Array array, int index, byte value);
[System.Security.SecuritySafeCritical] // auto-generated
public static void SetByte(Array array, int index, byte value)
{
// Is the array present?
if (array == null)
throw new ArgumentNullException("array");
// Is it of primitive types?
if (!IsPrimitiveTypeArray(array))
throw new ArgumentException(Environment.GetResourceString("Arg_MustBePrimArray"), "array");
// Is the index in valid range of the array?
if (index < 0 || index >= _ByteLength(array))
throw new ArgumentOutOfRangeException("index");
// Make the FCall to do the work
_SetByte(array, index, value);
}
// Gets a particular byte out of the array. The array must be an
// array of primitives.
//
// This essentially does the following:
// return array.length * sizeof(array.UnderlyingElementType).
//
[System.Security.SecurityCritical] // auto-generated
[ResourceExposure(ResourceScope.None)]
[MethodImplAttribute(MethodImplOptions.InternalCall)]
private static extern int _ByteLength(Array array);
[System.Security.SecuritySafeCritical] // auto-generated
public static int ByteLength(Array array)
{
// Is the array present?
if (array == null)
throw new ArgumentNullException("array");
// Is it of primitive types?
if (!IsPrimitiveTypeArray(array))
throw new ArgumentException(Environment.GetResourceString("Arg_MustBePrimArray"), "array");
return _ByteLength(array);
}
[System.Security.SecurityCritical] // auto-generated
internal unsafe static void ZeroMemory(byte* src, long len)
{
while(len-- > 0)
*(src + len) = 0;
}
[System.Security.SecurityCritical] // auto-generated
[ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)]
internal unsafe static void Memcpy(byte[] dest, int destIndex, byte* src, int srcIndex, int len) {
Contract.Assert( (srcIndex >= 0) && (destIndex >= 0) && (len >= 0), "Index and length must be non-negative!");
Contract.Assert(dest.Length - destIndex >= len, "not enough bytes in dest");
// If dest has 0 elements, the fixed statement will throw an
// IndexOutOfRangeException. Special-case 0-byte copies.
if (len==0)
return;
fixed(byte* pDest = dest) {
Memcpy(pDest + destIndex, src + srcIndex, len);
}
}
[SecurityCritical]
[ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)]
internal unsafe static void Memcpy(byte* pDest, int destIndex, byte[] src, int srcIndex, int len)
{
Contract.Assert( (srcIndex >= 0) && (destIndex >= 0) && (len >= 0), "Index and length must be non-negative!");
Contract.Assert(src.Length - srcIndex >= len, "not enough bytes in src");
// If dest has 0 elements, the fixed statement will throw an
// IndexOutOfRangeException. Special-case 0-byte copies.
if (len==0)
return;
fixed(byte* pSrc = src) {
Memcpy(pDest + destIndex, pSrc + srcIndex, len);
}
}
// This is tricky to get right AND fast, so lets make it useful for the whole Fx.
// E.g. System.Runtime.WindowsRuntime!WindowsRuntimeBufferExtensions.MemCopy uses it.
// This method has a slightly different behavior on arm and other platforms.
// On arm this method behaves like memcpy and does not handle overlapping buffers.
// While on other platforms it behaves like memmove and handles overlapping buffers.
// This behavioral difference is unfortunate but intentional because
// 1. This method is given access to other internal dlls and this close to release we do not want to change it.
// 2. It is difficult to get this right for arm and again due to release dates we would like to visit it later.
[FriendAccessAllowed]
[System.Security.SecurityCritical]
[ResourceExposure(ResourceScope.None)]
[ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)]
#if ARM
[MethodImplAttribute(MethodImplOptions.InternalCall)]
internal unsafe static extern void Memcpy(byte* dest, byte* src, int len);
#else // ARM
[MethodImplAttribute(MethodImplOptions.AggressiveInlining)]
internal unsafe static void Memcpy(byte* dest, byte* src, int len) {
Contract.Assert(len >= 0, "Negative length in memcopy!");
Memmove(dest, src, (uint)len);
}
#endif // ARM
// This method has different signature for x64 and other platforms and is done for performance reasons.
[System.Security.SecurityCritical]
[ResourceExposure(ResourceScope.None)]
[ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)]
internal unsafe static void Memmove(byte* dest, byte* src, nuint len)
{
#if AMD64 || (BIT32 && !ARM)
const nuint CopyThreshold = 2048;
#elif ARM64
#if PLATFORM_WINDOWS
//
const nuint CopyThreshold = 2048;
#else // PLATFORM_WINDOWS
// Managed code is currently faster than glibc unoptimized memmove
//
const nuint CopyThreshold = UInt64.MaxValue;
#endif // PLATFORM_WINDOWS
#else
const nuint CopyThreshold = 512;
#endif // AMD64 || (BIT32 && !ARM)
// P/Invoke into the native version when the buffers are overlapping.
if (((nuint)dest - (nuint)src < len) || ((nuint)src - (nuint)dest < len)) goto PInvoke;
byte* srcEnd = src + len;
byte* destEnd = dest + len;
if (len <= 16) goto MCPY02;
if (len > 64) goto MCPY05;
MCPY00:
// Copy bytes which are multiples of 16 and leave the remainder for MCPY01 to handle.
Contract.Assert(len > 16 && len <= 64);
#if HAS_CUSTOM_BLOCKS
*(Block16*)dest = *(Block16*)src; // [0,16]
#elif BIT64
*(long*)dest = *(long*)src;
*(long*)(dest + 8) = *(long*)(src + 8); // [0,16]
#else
*(int*)dest = *(int*)src;
*(int*)(dest + 4) = *(int*)(src + 4);
*(int*)(dest + 8) = *(int*)(src + 8);
*(int*)(dest + 12) = *(int*)(src + 12); // [0,16]
#endif
if (len <= 32) goto MCPY01;
#if HAS_CUSTOM_BLOCKS
*(Block16*)(dest + 16) = *(Block16*)(src + 16); // [0,32]
#elif BIT64
*(long*)(dest + 16) = *(long*)(src + 16);
*(long*)(dest + 24) = *(long*)(src + 24); // [0,32]
#else
*(int*)(dest + 16) = *(int*)(src + 16);
*(int*)(dest + 20) = *(int*)(src + 20);
*(int*)(dest + 24) = *(int*)(src + 24);
*(int*)(dest + 28) = *(int*)(src + 28); // [0,32]
#endif
if (len <= 48) goto MCPY01;
#if HAS_CUSTOM_BLOCKS
*(Block16*)(dest + 32) = *(Block16*)(src + 32); // [0,48]
#elif BIT64
*(long*)(dest + 32) = *(long*)(src + 32);
*(long*)(dest + 40) = *(long*)(src + 40); // [0,48]
#else
*(int*)(dest + 32) = *(int*)(src + 32);
*(int*)(dest + 36) = *(int*)(src + 36);
*(int*)(dest + 40) = *(int*)(src + 40);
*(int*)(dest + 44) = *(int*)(src + 44); // [0,48]
#endif
MCPY01:
// Unconditionally copy the last 16 bytes using destEnd and srcEnd and return.
Contract.Assert(len > 16 && len <= 64);
#if HAS_CUSTOM_BLOCKS
*(Block16*)(destEnd - 16) = *(Block16*)(srcEnd - 16);
#elif BIT64
*(long*)(destEnd - 16) = *(long*)(srcEnd - 16);
*(long*)(destEnd - 8) = *(long*)(srcEnd - 8);
#else
*(int*)(destEnd - 16) = *(int*)(srcEnd - 16);
*(int*)(destEnd - 12) = *(int*)(srcEnd - 12);
*(int*)(destEnd - 8) = *(int*)(srcEnd - 8);
*(int*)(destEnd - 4) = *(int*)(srcEnd - 4);
#endif
return;
MCPY02:
// Copy the first 8 bytes and then unconditionally copy the last 8 bytes and return.
if ((len & 24) == 0) goto MCPY03;
Contract.Assert(len >= 8 && len <= 16);
#if BIT64
*(long*)dest = *(long*)src;
*(long*)(destEnd - 8) = *(long*)(srcEnd - 8);
#else
*(int*)dest = *(int*)src;
*(int*)(dest + 4) = *(int*)(src + 4);
*(int*)(destEnd - 8) = *(int*)(srcEnd - 8);
*(int*)(destEnd - 4) = *(int*)(srcEnd - 4);
#endif
return;
MCPY03:
// Copy the first 4 bytes and then unconditionally copy the last 4 bytes and return.
if ((len & 4) == 0) goto MCPY04;
Contract.Assert(len >= 4 && len < 8);
*(int*)dest = *(int*)src;
*(int*)(destEnd - 4) = *(int*)(srcEnd - 4);
return;
MCPY04:
// Copy the first byte. For pending bytes, do an unconditionally copy of the last 2 bytes and return.
Contract.Assert(len < 4);
if (len == 0) return;
*dest = *src;
if ((len & 2) == 0) return;
*(short*)(destEnd - 2) = *(short*)(srcEnd - 2);
return;
MCPY05:
// PInvoke to the native version when the copy length exceeds the threshold.
if (len > CopyThreshold)
{
goto PInvoke;
}
// Copy 64-bytes at a time until the remainder is less than 64.
// If remainder is greater than 16 bytes, then jump to MCPY00. Otherwise, unconditionally copy the last 16 bytes and return.
Contract.Assert(len > 64 && len <= CopyThreshold);
nuint n = len >> 6;
MCPY06:
#if HAS_CUSTOM_BLOCKS
*(Block64*)dest = *(Block64*)src;
#elif BIT64
*(long*)dest = *(long*)src;
*(long*)(dest + 8) = *(long*)(src + 8);
*(long*)(dest + 16) = *(long*)(src + 16);
*(long*)(dest + 24) = *(long*)(src + 24);
*(long*)(dest + 32) = *(long*)(src + 32);
*(long*)(dest + 40) = *(long*)(src + 40);
*(long*)(dest + 48) = *(long*)(src + 48);
*(long*)(dest + 56) = *(long*)(src + 56);
#else
*(int*)dest = *(int*)src;
*(int*)(dest + 4) = *(int*)(src + 4);
*(int*)(dest + 8) = *(int*)(src + 8);
*(int*)(dest + 12) = *(int*)(src + 12);
*(int*)(dest + 16) = *(int*)(src + 16);
*(int*)(dest + 20) = *(int*)(src + 20);
*(int*)(dest + 24) = *(int*)(src + 24);
*(int*)(dest + 28) = *(int*)(src + 28);
*(int*)(dest + 32) = *(int*)(src + 32);
*(int*)(dest + 36) = *(int*)(src + 36);
*(int*)(dest + 40) = *(int*)(src + 40);
*(int*)(dest + 44) = *(int*)(src + 44);
*(int*)(dest + 48) = *(int*)(src + 48);
*(int*)(dest + 52) = *(int*)(src + 52);
*(int*)(dest + 56) = *(int*)(src + 56);
*(int*)(dest + 60) = *(int*)(src + 60);
#endif
dest += 64;
src += 64;
n--;
if (n != 0) goto MCPY06;
len %= 64;
if (len > 16) goto MCPY00;
#if HAS_CUSTOM_BLOCKS
*(Block16*)(destEnd - 16) = *(Block16*)(srcEnd - 16);
#elif BIT64
*(long*)(destEnd - 16) = *(long*)(srcEnd - 16);
*(long*)(destEnd - 8) = *(long*)(srcEnd - 8);
#else
*(int*)(destEnd - 16) = *(int*)(srcEnd - 16);
*(int*)(destEnd - 12) = *(int*)(srcEnd - 12);
*(int*)(destEnd - 8) = *(int*)(srcEnd - 8);
*(int*)(destEnd - 4) = *(int*)(srcEnd - 4);
#endif
return;
PInvoke:
_Memmove(dest, src, len);
}
// Non-inlinable wrapper around the QCall that avoids poluting the fast path
// with P/Invoke prolog/epilog.
[SecurityCritical]
[ResourceExposure(ResourceScope.None)]
[ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)]
[MethodImplAttribute(MethodImplOptions.NoInlining)]
private unsafe static void _Memmove(byte* dest, byte* src, nuint len)
{
__Memmove(dest, src, len);
}
[DllImport(JitHelpers.QCall, CharSet = CharSet.Unicode)]
[SuppressUnmanagedCodeSecurity]
[SecurityCritical]
[ResourceExposure(ResourceScope.None)]
[ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)]
extern private unsafe static void __Memmove(byte* dest, byte* src, nuint len);
// The attributes on this method are chosen for best JIT performance.
// Please do not edit unless intentional.
[System.Security.SecurityCritical]
[MethodImplAttribute(MethodImplOptions.AggressiveInlining)]
[CLSCompliant(false)]
public static unsafe void MemoryCopy(void* source, void* destination, long destinationSizeInBytes, long sourceBytesToCopy)
{
if (sourceBytesToCopy > destinationSizeInBytes)
{
ThrowHelper.ThrowArgumentOutOfRangeException(ExceptionArgument.sourceBytesToCopy);
}
Memmove((byte*)destination, (byte*)source, checked((nuint)sourceBytesToCopy));
}
// The attributes on this method are chosen for best JIT performance.
// Please do not edit unless intentional.
[System.Security.SecurityCritical]
[MethodImplAttribute(MethodImplOptions.AggressiveInlining)]
[CLSCompliant(false)]
public static unsafe void MemoryCopy(void* source, void* destination, ulong destinationSizeInBytes, ulong sourceBytesToCopy)
{
if (sourceBytesToCopy > destinationSizeInBytes)
{
ThrowHelper.ThrowArgumentOutOfRangeException(ExceptionArgument.sourceBytesToCopy);
}
#if BIT64
Memmove((byte*)destination, (byte*)source, sourceBytesToCopy);
#else // BIT64
Memmove((byte*)destination, (byte*)source, checked((uint)sourceBytesToCopy));
#endif // BIT64
}
#if HAS_CUSTOM_BLOCKS
[StructLayout(LayoutKind.Sequential, Size = 16)]
private struct Block16 { }
[StructLayout(LayoutKind.Sequential, Size = 64)]
private struct Block64 { }
#endif // HAS_CUSTOM_BLOCKS
}
}
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