|
public static TryParse ( Byte buffer, |
||
| buffer | Byte | |
| offset | ||
| headerFlags | ||
| return | System.Boolean | |
public static Boolean TryParse(Byte[] frameStart, Int32 offset, Int32 headerLength, ArraySegment <Byte> keySegment, out WebSocketFrameHeader header)
{
header = null;
if (frameStart == null || frameStart.Length < 6 || frameStart.Length < (offset + headerLength))
{
return(false);
}
Int32 value = frameStart[offset + 1];
Int64 contentLength = (Int64)(value >= 128?value - 128:value);
if (contentLength <= 125)
{
// small frame
}
else if (contentLength == 126)
{
if (frameStart.Length < headerLength)
{
return(false);
}
if (BitConverter.IsLittleEndian)
{
frameStart.ReversePortion(offset + 2, 2);
}
contentLength = BitConverter.ToUInt16(frameStart, 2);
}
else if (contentLength == 127)
{
if (frameStart.Length < headerLength)
{
return(false);
}
if (BitConverter.IsLittleEndian)
{
frameStart.ReversePortion(offset + 2, 8);
}
UInt64 length = BitConverter.ToUInt64(frameStart, 2);
if (length > Int64.MaxValue)
{
throw new WebSocketException("The maximum supported frame length is 9223372036854775807, current frame is " + length.ToString());
}
contentLength = (Int64)length;
}
else
{
return(false);
}
WebSocketFrameHeaderFlags flags;
if (WebSocketFrameHeaderFlags.TryParse(frameStart, offset, out flags))
{
header = new WebSocketFrameHeader(keySegment)
{
ContentLength = contentLength,
HeaderLength = headerLength,
Flags = flags,
RemainingBytes = contentLength
};
if (flags.MASK)
{
headerLength -= 4;
for (int i = 0; i < 4; i++)
{
header._key.Array[header._key.Offset + i] = frameStart[offset + i + headerLength];
}
}
return(true);
}
return(false);
}
public static bool TryParse(byte[] frameStart, int offset, int headerLength, out WebSocketFrameHeader header)
{
if (frameStart == null)
{
throw new ArgumentNullException(nameof(frameStart));
}
header = null;
var availableLength = frameStart.Length - offset;
if (availableLength < 6 || availableLength < headerLength)
{
return(false);
}
var value = frameStart[offset + 1];
var contentLength = (long)(value >= 128 ? value - 128 : value);
if (contentLength <= 125)
{
// small frame
}
else if (contentLength == 126)
{
if (availableLength < headerLength)
{
return(false);
}
contentLength = EndianBitConverter.ToUInt16Be(frameStart, offset + 2);
}
else if (contentLength == 127)
{
if (availableLength < headerLength)
{
return(false);
}
var length = EndianBitConverter.ToUInt64Be(frameStart, offset + 2);
if (length > long.MaxValue)
{
throw new WebSocketException("The maximum supported frame length is 9223372036854775807, current frame is " + length.ToString());
}
contentLength = (long)length;
}
else
{
return(false);
}
WebSocketFrameHeaderFlags flags;
if (!WebSocketFrameHeaderFlags.TryParse(frameStart, offset, out flags))
{
return(false);
}
var maskKey = 0U;
if (flags.MASK)
{
headerLength -= 4;
maskKey = EndianBitConverter.ToUInt32Le(frameStart, offset + headerLength);
}
header = new WebSocketFrameHeader
{
ContentLength = contentLength,
HeaderLength = headerLength,
Flags = flags,
RemainingBytes = contentLength,
MaskKey = maskKey
};
return(true);
}
public static Boolean TryParse(Byte[] frameStart, Int32 offset, Int32 headerLength, ArraySegment <Byte> keySegment, out WebSocketFrameHeader header)
{
header = null;
if (frameStart == null || frameStart.Length < 6 || frameStart.Length < (offset + headerLength))
{
return(false);
}
Int32 value = frameStart[offset + 1];
UInt64 contentLength = (UInt64)(value >= 128?value - 128:value);
if (contentLength <= 125)
{
// small frame
}
else if (contentLength == 126)
{
if (frameStart.Length < headerLength)
{
return(false);
}
if (BitConverter.IsLittleEndian)
{
frameStart.ReversePortion(offset + 2, 2);
}
contentLength = BitConverter.ToUInt16(frameStart, 2);
}
else if (contentLength == 127)
{
if (frameStart.Length < headerLength)
{
return(false);
}
if (BitConverter.IsLittleEndian)
{
frameStart.ReversePortion(offset + 2, 8);
}
contentLength = (UInt64)BitConverter.ToUInt64(frameStart, 2);
}
else
{
return(false);
}
WebSocketFrameHeaderFlags flags;
if (WebSocketFrameHeaderFlags.TryParse(frameStart, offset, out flags))
{
header = new WebSocketFrameHeader(keySegment)
{
ContentLength = contentLength,
HeaderLength = headerLength,
Flags = flags,
RemainingBytes = contentLength
};
if (flags.MASK)
{
headerLength -= 4;
for (int i = 0; i < 4; i++)
{
header._key.Array[header._key.Offset + i] = frameStart[offset + i + headerLength];
}
}
return(true);
}
return(false);
}
