/// <summary>
/// Parses a section of the stream that is known to be parameter data.
/// </summary>
/// <param name="parameters">
/// The header parameters of this section. "name" must be a valid key.
/// </param>
/// <param name="reader">
/// The StreamReader to read the data from
/// </param>
/// <returns>
/// The <see cref="ParameterPart" /> containing the parsed data (name, value).
/// </returns>
/// <exception cref="MultipartParseException">
/// thrown if unexpected data is found such as running out of stream before hitting the boundary.
/// </exception>
private void ParseParameterPart(Dictionary <string, string> parameters, RebufferableBinaryReader reader)
{
var data = new StringBuilder();
bool firstTime = true;
string line = reader.ReadLine();
while (line != boundary && line != endBoundary)
{
if (line == null)
{
throw new MultipartParseException("Unexpected end of stream. Is there an end boundary?");
}
if (firstTime)
{
data.Append(line);
firstTime = false;
}
else
{
data.Append(Environment.NewLine);
data.Append(line);
}
line = reader.ReadLine();
}
if (line == endBoundary)
{
readEndBoundary = true;
}
var part = new ParameterPart(parameters["name"], data.ToString());
ParameterHandler(part);
}
/// <summary>
/// Detects the boundary from the input stream. Assumes that the
/// current position of the reader is the start of the file and therefore
/// the beginning of the boundary.
/// </summary>
/// <param name="reader">
/// The binary reader to parse
/// </param>
/// <returns>
/// The boundary string
/// </returns>
private static string DetectBoundary(RebufferableBinaryReader reader)
{
string boundary = string.Concat(reader.ReadLine().Skip(2));
reader.Buffer("--" + boundary + "\n");
return(boundary);
}
/// <summary>
/// Begins executing the parser. This should be called after all handlers have been set.
/// </summary>
public void Run()
{
var reader = new RebufferableBinaryReader(stream, Encoding, BinaryBufferSize);
if (boundary == null)
{
boundary = DetectBoundary(reader);
}
boundary = "--" + boundary;
endBoundary = boundary + "--";
boundaryBinary = Encoding.GetBytes(boundary);
endBoundaryBinary = Encoding.GetBytes(endBoundary);
Debug.Assert(BinaryBufferSize >= endBoundaryBinary.Length, "binaryBufferSize must be bigger then the boundary");
Parse(reader);
}
/// <summary>
/// Parses the header of the next section of the multipart stream and
/// determines if it contains file data or parameter data.
/// </summary>
/// <param name="reader">
/// The StreamReader to read data from.
/// </param>
/// <exception cref="MultipartParseException">
/// thrown if unexpected data is hit such as end of stream.
/// </exception>
private void ParseSection(RebufferableBinaryReader reader)
{
var parameters = new Dictionary <string, string>();
string line = reader.ReadLine();
while (line != string.Empty)
{
if (line == null)
{
throw new MultipartParseException("Unexpected end of stream");
}
if (line == boundary || line == endBoundary)
{
throw new MultipartParseException("Unexpected end of section");
}
Dictionary <string, string> values = SplitBySemicolonIgnoringSemicolonsInQuotes(line).Select(x => x.Split(new[] {
':',
'='
}, 2)).Where(x => x.Length == 2).ToDictionary(x => x[0].Trim().Replace("\"", string.Empty).ToLower(), x => x[1].Trim().Replace("\"", string.Empty));
try
{
foreach (var pair in values)
{
parameters.Add(pair.Key, pair.Value);
}
}
catch (ArgumentException)
{
throw new MultipartParseException("Duplicate field in section");
}
line = reader.ReadLine();
}
if (parameters.ContainsKey("filename"))
{
ParseFilePart(parameters, reader);
}
else
{
ParseParameterPart(parameters, reader);
}
}
/// <summary>
/// Begins the parsing of the stream into objects.
/// </summary>
/// <param name="reader">
/// The multipart/form-data binary reader to parse from.
/// </param>
/// <exception cref="MultipartParseException">
/// thrown on finding unexpected data such as a boundary before we are ready for one.
/// </exception>
private void Parse(RebufferableBinaryReader reader)
{
while (true)
{
string line = reader.ReadLine();
if (line == boundary)
{
break;
}
if (line == null)
{
throw new MultipartParseException("Could not find expected boundary");
}
}
while (!readEndBoundary)
{
ParseSection(reader);
}
if (StreamClosedHandler != null)
{
StreamClosedHandler();
}
}
/// <summary>
/// Parses a section of the stream that is known to be file data.
/// </summary>
/// <param name="parameters">
/// The header parameters of this file, expects "name" and "filename" to be valid keys
/// </param>
/// <param name="reader">
/// The StreamReader to read the data from
/// </param>
/// <returns>
/// The <see cref="FilePart" /> con[] taining the parsed data (name, filename, stream containing file).
/// </returns>
private void ParseFilePart(Dictionary <string, string> parameters, RebufferableBinaryReader reader)
{
string name = parameters["name"];
string filename = parameters["filename"];
string contentType = parameters.ContainsKey("content-type") ? parameters["content-type"] : "text/plain";
string contentDisposition = parameters.ContainsKey("content-disposition") ? parameters["content-disposition"] : "form-data";
var curBuffer = new byte[BinaryBufferSize];
var prevBuffer = new byte[BinaryBufferSize];
var fullBuffer = new byte[BinaryBufferSize * 2];
int curLength = 0;
int prevLength = 0;
int fullLength = 0;
prevLength = reader.Read(prevBuffer, 0, prevBuffer.Length);
do
{
curLength = reader.Read(curBuffer, 0, curBuffer.Length);
Buffer.BlockCopy(prevBuffer, 0, fullBuffer, 0, prevLength);
Buffer.BlockCopy(curBuffer, 0, fullBuffer, prevLength, curLength);
fullLength = prevLength + curLength;
int endBoundaryPos = SubsequenceFinder.Search(fullBuffer, endBoundaryBinary, fullLength);
int endBoundaryLength = endBoundaryBinary.Length;
int boundaryPos = SubsequenceFinder.Search(fullBuffer, boundaryBinary, fullLength);
int boundaryLength = boundaryBinary.Length;
if (boundaryPos + boundaryLength == fullLength)
{
boundaryPos = -1;
}
int endPos = -1;
int endPosLength = 0;
if (endBoundaryPos >= 0 && boundaryPos >= 0)
{
if (boundaryPos < endBoundaryPos)
{
endPos = boundaryPos;
endPosLength = boundaryLength;
}
else
{
endPos = endBoundaryPos;
endPosLength = endBoundaryLength;
readEndBoundary = true;
}
}
else if (boundaryPos >= 0 && endBoundaryPos < 0)
{
endPos = boundaryPos;
endPosLength = boundaryLength;
}
else if (boundaryPos < 0 && endBoundaryPos >= 0)
{
endPos = endBoundaryPos;
endPosLength = endBoundaryLength;
readEndBoundary = true;
}
if (endPos != -1)
{
int boundaryNewlineOffset = CalculateNewlineLength(ref fullBuffer, Math.Min(fullLength - 1, endPos + endPosLength));
int maxNewlineBytes = Encoding.GetMaxByteCount(2);
int bufferNewlineOffset = FindNextNewline(ref fullBuffer, Math.Max(0, endPos - maxNewlineBytes), maxNewlineBytes);
int bufferNewlineLength = CalculateNewlineLength(ref fullBuffer, bufferNewlineOffset);
FileHandler(name, filename, contentType, contentDisposition, fullBuffer, endPos - bufferNewlineLength);
int writeBackOffset = endPos + endPosLength + boundaryNewlineOffset;
int writeBackAmount = (prevLength + curLength) - writeBackOffset;
var writeBackBuffer = new byte[writeBackAmount];
Buffer.BlockCopy(fullBuffer, writeBackOffset, writeBackBuffer, 0, writeBackAmount);
reader.Buffer(writeBackBuffer);
break;
}
FileHandler(name, filename, contentType, contentDisposition, prevBuffer, prevLength);
byte[] tempBuffer = curBuffer;
curBuffer = prevBuffer;
prevBuffer = tempBuffer;
prevLength = curLength;
}while (prevLength != 0);
}
