DefaultJavaScriptEncoder
using System.Buffers;
using System.Text.Unicode;
namespace System.Text.Encodings.Web
{
internal sealed class DefaultJavaScriptEncoder : JavaScriptEncoder
{
private sealed class EscaperImplementation : ScalarEscaperBase
{
internal static readonly EscaperImplementation Singleton = new EscaperImplementation(false);
internal static readonly EscaperImplementation SingletonMinimallyEscaped = new EscaperImplementation(true);
private readonly AsciiByteMap _preescapedMap;
private EscaperImplementation(bool allowMinimalEscaping)
{
_preescapedMap.InsertAsciiChar('\b', 98);
_preescapedMap.InsertAsciiChar('\t', 116);
_preescapedMap.InsertAsciiChar('\n', 110);
_preescapedMap.InsertAsciiChar(' ', 102);
_preescapedMap.InsertAsciiChar('\r', 114);
_preescapedMap.InsertAsciiChar('\\', 92);
if (allowMinimalEscaping)
_preescapedMap.InsertAsciiChar('"', 34);
}
internal override int EncodeUtf8(System.Text.Rune value, Span<byte> destination)
{
if (_preescapedMap.TryLookup(value, out byte value2)) {
if (SpanUtility.IsValidIndex(destination, 1)) {
destination[0] = 92;
destination[1] = value2;
return 2;
}
return -1;
}
return <EncodeUtf8>g__TryEncodeScalarAsHex|4_0(this, value, destination);
}
internal override int EncodeUtf16(System.Text.Rune value, Span<char> destination)
{
if (_preescapedMap.TryLookup(value, out byte value2)) {
if (SpanUtility.IsValidIndex(destination, 1)) {
destination[0] = '\\';
destination[1] = (char)value2;
return 2;
}
return -1;
}
return <EncodeUtf16>g__TryEncodeScalarAsHex|5_0(this, value, destination);
}
}
internal static readonly DefaultJavaScriptEncoder BasicLatinSingleton = new DefaultJavaScriptEncoder(new TextEncoderSettings(UnicodeRanges.BasicLatin));
internal static readonly DefaultJavaScriptEncoder UnsafeRelaxedEscapingSingleton = new DefaultJavaScriptEncoder(new TextEncoderSettings(UnicodeRanges.All), true);
private readonly OptimizedInboxTextEncoder _innerEncoder;
public override int MaxOutputCharactersPerInputCharacter => 6;
internal DefaultJavaScriptEncoder(TextEncoderSettings settings)
: this(settings, false)
{
}
private unsafe DefaultJavaScriptEncoder(TextEncoderSettings settings, bool allowMinimalJsonEscaping)
{
if (settings == null)
ThrowHelper.ThrowArgumentNullException(ExceptionArgument.settings);
OptimizedInboxTextEncoder innerEncoder;
if (allowMinimalJsonEscaping) {
ScalarEscaperBase singletonMinimallyEscaped = EscaperImplementation.SingletonMinimallyEscaped;
ref AllowedBmpCodePointsBitmap allowedCodePointsBitmap = ref settings.GetAllowedCodePointsBitmap();
byte* intPtr = stackalloc byte[4];
*(short*)intPtr = 34;
*(short*)(intPtr + 2) = 92;
Span<char> span = new Span<char>(intPtr, 2);
innerEncoder = new OptimizedInboxTextEncoder(singletonMinimallyEscaped, ref allowedCodePointsBitmap, false, span);
} else {
ScalarEscaperBase singleton = EscaperImplementation.Singleton;
ref AllowedBmpCodePointsBitmap allowedCodePointsBitmap2 = ref settings.GetAllowedCodePointsBitmap();
byte* intPtr2 = stackalloc byte[4];
*(short*)intPtr2 = 92;
*(short*)(intPtr2 + 2) = 96;
Span<char> span = new Span<char>(intPtr2, 2);
innerEncoder = new OptimizedInboxTextEncoder(singleton, ref allowedCodePointsBitmap2, true, span);
}
_innerEncoder = innerEncoder;
}
private protected override OperationStatus EncodeCore(ReadOnlySpan<char> source, Span<char> destination, out int charsConsumed, out int charsWritten, bool isFinalBlock)
{
return _innerEncoder.Encode(source, destination, out charsConsumed, out charsWritten, isFinalBlock);
}
private protected override OperationStatus EncodeUtf8Core(ReadOnlySpan<byte> utf8Source, Span<byte> utf8Destination, out int bytesConsumed, out int bytesWritten, bool isFinalBlock)
{
return _innerEncoder.EncodeUtf8(utf8Source, utf8Destination, out bytesConsumed, out bytesWritten, isFinalBlock);
}
private protected override int FindFirstCharacterToEncode(ReadOnlySpan<char> text)
{
return _innerEncoder.GetIndexOfFirstCharToEncode(text);
}
public unsafe override int FindFirstCharacterToEncode(char* text, int textLength)
{
return _innerEncoder.FindFirstCharacterToEncode(text, textLength);
}
public override int FindFirstCharacterToEncodeUtf8(ReadOnlySpan<byte> utf8Text)
{
return _innerEncoder.GetIndexOfFirstByteToEncode(utf8Text);
}
public unsafe override bool TryEncodeUnicodeScalar(int unicodeScalar, char* buffer, int bufferLength, out int numberOfCharactersWritten)
{
return _innerEncoder.TryEncodeUnicodeScalar(unicodeScalar, buffer, bufferLength, out numberOfCharactersWritten);
}
public override bool WillEncode(int unicodeScalar)
{
return !_innerEncoder.IsScalarValueAllowed(new System.Text.Rune(unicodeScalar));
}
}
}