Files
ParkingRobot/ClumsyPilot/TrajectoryPlanningVisualization/Runtime/LoopbackHttpRequestReader.cs
T

126 lines
3.7 KiB
C#

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Text;
namespace TrajectoryPlanningVisualization;
internal sealed class LoopbackHttpRequest
{
public LoopbackHttpRequest(string method, string path, string token)
{
Method = method;
Path = path;
Token = token;
}
public string Method { get; }
public string Path { get; }
public string Token { get; }
}
internal static class LoopbackHttpRequestReader
{
internal const int MaximumHeaderBytes = 16 * 1024;
private const int RequestReadTimeoutMilliseconds = 2000;
public static bool TryRead(Stream stream, out LoopbackHttpRequest request)
{
request = null;
var bytes = new List<byte>();
bool tooLarge = false;
int terminatorBytes = 0;
var stopwatch = Stopwatch.StartNew();
while (stopwatch.ElapsedMilliseconds < RequestReadTimeoutMilliseconds)
{
int value;
try
{
int remainingMilliseconds = Math.Max(1, RequestReadTimeoutMilliseconds - (int)stopwatch.ElapsedMilliseconds);
stream.ReadTimeout = remainingMilliseconds;
value = stream.ReadByte();
}
catch (IOException)
{
return false;
}
if (value < 0)
{
return false;
}
byte next = (byte)value;
if (!tooLarge)
{
bytes.Add(next);
if (bytes.Count >= MaximumHeaderBytes)
{
tooLarge = true;
}
}
terminatorBytes = next == (terminatorBytes == 0 || terminatorBytes == 2 ? (byte)'\r' : (byte)'\n')
? terminatorBytes + 1
: next == '\r' ? 1 : 0;
if (terminatorBytes == 4)
{
return !tooLarge && TryParse(Encoding.ASCII.GetString(bytes.ToArray()), out request);
}
}
return false;
}
private static bool TryParse(string headerText, out LoopbackHttpRequest request)
{
request = null;
string[] lines = headerText.Split(new[] { "\r\n" }, StringSplitOptions.None);
if (lines.Length < 2 || string.IsNullOrEmpty(lines[0]))
{
return false;
}
string[] parts = lines[0].Split(' ');
if (parts.Length != 3 || parts[0].Length == 0 || parts[1].Length == 0 || parts[2] != "HTTP/1.1")
{
return false;
}
string target = parts[1];
if (!target.StartsWith("/", StringComparison.Ordinal) || target.IndexOf('#') >= 0)
{
return false;
}
int queryStart = target.IndexOf('?');
string path = queryStart < 0 ? target : target.Substring(0, queryStart);
string token = null;
if (queryStart >= 0)
{
string query = target.Substring(queryStart + 1);
string[] pairs = query.Split('&');
foreach (string pair in pairs)
{
int equals = pair.IndexOf('=');
string name = equals < 0 ? pair : pair.Substring(0, equals);
if (name == "token")
{
try
{
token = Uri.UnescapeDataString(equals < 0 ? string.Empty : pair.Substring(equals + 1));
}
catch (UriFormatException)
{
return false;
}
}
}
}
request = new LoopbackHttpRequest(parts[0], path, token);
return true;
}
}