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Loop unrolled direct string inject

This commit is contained in:
Ben Adams 2015-12-17 04:09:42 +00:00
parent 6fbb9a0cfe
commit ea3e64ab87
2 changed files with 93 additions and 87 deletions
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176
src/Microsoft.AspNet.Server.Kestrel/Infrastructure/MemoryPoolIterator2Extensions.cs
View File

@ -9,8 +9,6 @@ namespace Microsoft.AspNet.Server.Kestrel.Infrastructure
{ {
public static class MemoryPoolIterator2Extensions public static class MemoryPoolIterator2Extensions
{ {
private const int _maxStackAllocBytes = 16384;
private static readonly Encoding _utf8 = Encoding.UTF8; private static readonly Encoding _utf8 = Encoding.UTF8;
public const string HttpConnectMethod = "CONNECT"; public const string HttpConnectMethod = "CONNECT";
@ -70,102 +68,110 @@ namespace Microsoft.AspNet.Server.Kestrel.Infrastructure
} }
} }
private static unsafe string GetAsciiStringStack(byte[] input, int inputOffset, int length) public unsafe static string GetAsciiString(this MemoryPoolIterator2 start, MemoryPoolIterator2 end)
{
// avoid declaring other local vars, or doing work with stackalloc
// to prevent the .locals init cil flag , see: https://github.com/dotnet/coreclr/issues/1279
char* output = stackalloc char[length];
return GetAsciiStringImplementation(output, input, inputOffset, length);
}
private static unsafe string GetAsciiStringImplementation(char* output, byte[] input, int inputOffset, int length)
{
for (var i = 0; i < length; i++)
{
output[i] = (char)input[inputOffset + i];
}
return new string(output, 0, length);
}
private static unsafe string GetAsciiStringStack(MemoryPoolBlock2 start, MemoryPoolIterator2 end, int inputOffset, int length)
{
// avoid declaring other local vars, or doing work with stackalloc
// to prevent the .locals init cil flag , see: https://github.com/dotnet/coreclr/issues/1279
char* output = stackalloc char[length];
return GetAsciiStringImplementation(output, start, end, inputOffset, length);
}
private unsafe static string GetAsciiStringHeap(MemoryPoolBlock2 start, MemoryPoolIterator2 end, int inputOffset, int length)
{
var buffer = new char[length];
fixed (char* output = buffer)
{
return GetAsciiStringImplementation(output, start, end, inputOffset, length);
}
}
private static unsafe string GetAsciiStringImplementation(char* output, MemoryPoolBlock2 start, MemoryPoolIterator2 end, int inputOffset, int length)
{
var outputOffset = 0;
var block = start;
var remaining = length;
var endBlock = end.Block;
var endIndex = end.Index;
while (true)
{
int following = (block != endBlock ? block.End : endIndex) - inputOffset;
if (following > 0)
{
var input = block.Array;
for (var i = 0; i < following; i++)
{
output[i + outputOffset] = (char)input[i + inputOffset];
}
remaining -= following;
outputOffset += following;
}
if (remaining == 0)
{
return new string(output, 0, length);
}
block = block.Next;
inputOffset = block.Start;
}
}
public static string GetAsciiString(this MemoryPoolIterator2 start, MemoryPoolIterator2 end)
{ {
if (start.IsDefault || end.IsDefault) if (start.IsDefault || end.IsDefault)
{ {
return default(string); return null;
} }
var length = start.GetLength(end); var length = start.GetLength(end);
if (length == 0)
{
return null;
}
// Bytes out of the range of ascii are treated as "opaque data" // Bytes out of the range of ascii are treated as "opaque data"
// and kept in string as a char value that casts to same input byte value // and kept in string as a char value that casts to same input byte value
// https://tools.ietf.org/html/rfc7230#section-3.2.4 // https://tools.ietf.org/html/rfc7230#section-3.2.4
if (end.Block == start.Block)
var inputOffset = start.Index;
var block = start.Block;
var asciiString = new string('\0', length);
fixed (char* outputStart = asciiString)
{ {
return GetAsciiStringStack(start.Block.Array, start.Index, length); var output = outputStart;
var remaining = length;
var endBlock = end.Block;
var endIndex = end.Index;
while (true)
{
int following = (block != endBlock ? block.End : endIndex) - inputOffset;
if (following > 0)
{
fixed (byte* blockStart = block.Array)
{
var input = blockStart + inputOffset;
var i = 0;
while (i < following - 11)
{
i += 12;
*(output) = (char)*(input);
*(output + 1) = (char)*(input + 1);
*(output + 2) = (char)*(input + 2);
*(output + 3) = (char)*(input + 3);
*(output + 4) = (char)*(input + 4);
*(output + 5) = (char)*(input + 5);
*(output + 6) = (char)*(input + 6);
*(output + 7) = (char)*(input + 7);
*(output + 8) = (char)*(input + 8);
*(output + 9) = (char)*(input + 9);
*(output + 10) = (char)*(input + 10);
*(output + 11) = (char)*(input + 11);
output += 12;
input += 12;
}
if (i < following - 5)
{
i += 6;
*(output) = (char)*(input);
*(output + 1) = (char)*(input + 1);
*(output + 2) = (char)*(input + 2);
*(output + 3) = (char)*(input + 3);
*(output + 4) = (char)*(input + 4);
*(output + 5) = (char)*(input + 5);
output += 6;
input += 6;
}
if (i < following - 3)
{
i += 4;
*(output) = (char)*(input);
*(output + 1) = (char)*(input + 1);
*(output + 2) = (char)*(input + 2);
*(output + 3) = (char)*(input + 3);
output += 4;
input += 4;
}
while (i < following)
{
i++;
*output = (char)*input;
output++;
input++;
}
remaining -= following;
}
}
if (remaining == 0)
{
break;
}
block = block.Next;
inputOffset = block.Start;
}
} }
if (length > _maxStackAllocBytes) return asciiString;
{
return GetAsciiStringHeap(start.Block, end, start.Index, length);
}
return GetAsciiStringStack(start.Block, end, start.Index, length);
} }
public static string GetUtf8String(this MemoryPoolIterator2 start, MemoryPoolIterator2 end) public static string GetUtf8String(this MemoryPoolIterator2 start, MemoryPoolIterator2 end)

4
test/Microsoft.AspNet.Server.KestrelTests/AsciiDecoder.cs
View File

@ -13,7 +13,7 @@ namespace Microsoft.AspNet.Server.KestrelTests
[Fact] [Fact]
private void FullByteRangeSupported() private void FullByteRangeSupported()
{ {
var byteRange = Enumerable.Range(0, 255).Select(x => (byte)x).ToArray(); var byteRange = Enumerable.Range(0, 256).Select(x => (byte)x).ToArray();
var mem = MemoryPoolBlock2.Create(new ArraySegment<byte>(byteRange), IntPtr.Zero, null, null); var mem = MemoryPoolBlock2.Create(new ArraySegment<byte>(byteRange), IntPtr.Zero, null, null);
mem.End = byteRange.Length; mem.End = byteRange.Length;
@ -74,7 +74,7 @@ namespace Microsoft.AspNet.Server.KestrelTests
} }
[Fact] [Fact]
private void HeapAllocationProducesCorrectResults() private void LargeAllocationProducesCorrectResults()
{ {
var byteRange = Enumerable.Range(0, 16384 + 64).Select(x => (byte)x).ToArray(); var byteRange = Enumerable.Range(0, 16384 + 64).Select(x => (byte)x).ToArray();
var expectedByteRange = byteRange.Concat(byteRange).ToArray(); var expectedByteRange = byteRange.Concat(byteRange).ToArray();