Пример #1
0
        /// <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"/> containing the parsed data (name, filename, stream containing file).
        /// </returns>
        private FilePart ParseFilePart(Dictionary <string, string> parameters, RebufferableBinaryReader reader)
        {
            // We want to create a stream and fill it with the data from the
            // file.
            var data       = new MemoryStream();
            var curBuffer  = new byte[this.BinaryBufferSize];
            var prevBuffer = new byte[this.BinaryBufferSize];
            int curLength  = 0;
            int prevLength = 0;

            prevLength = reader.Read(prevBuffer, 0, prevBuffer.Length);
            do
            {
                curLength = reader.Read(curBuffer, 0, curBuffer.Length);

                // Combine both buffers into the fullBuffer
                // See: http://stackoverflow.com/questions/415291/best-way-to-combine-two-or-more-byte-arrays-in-c-sharp
                var fullBuffer = new byte[this.BinaryBufferSize * 2];
                Buffer.BlockCopy(prevBuffer, 0, fullBuffer, 0, prevLength);
                Buffer.BlockCopy(curBuffer, 0, fullBuffer, prevLength, curLength);

                // Now we want to check for a substring within the current buffer.
                // We need to find the closest substring greedily. That is find the
                // closest boundary and don't miss the end --'s if it's an end boundary.
                int endBoundaryPos    = SubsequenceFinder.Search(fullBuffer, this.endBoundaryBinary);
                int endBoundaryLength = this.endBoundaryBinary.Length;
                int boundaryPos       = SubsequenceFinder.Search(fullBuffer, this.boundaryBinary);
                int boundaryLength    = this.boundaryBinary.Length;

                // We need to select the appropriate position and length
                // based on the smallest non-negative position.
                int endPos       = -1;
                int endPosLength = 0;

                if (endBoundaryPos >= 0 && boundaryPos >= 0)
                {
                    if (boundaryPos < endBoundaryPos)
                    {
                        // Select boundary
                        endPos       = boundaryPos;
                        endPosLength = boundaryLength;
                    }
                    else
                    {
                        // Select end boundary
                        endPos               = endBoundaryPos;
                        endPosLength         = endBoundaryLength;
                        this.readEndBoundary = true;
                    }
                }
                else if (boundaryPos >= 0 && endBoundaryPos < 0)
                {
                    // Select boundary
                    endPos       = boundaryPos;
                    endPosLength = boundaryLength;
                }
                else if (boundaryPos < 0 && endBoundaryPos >= 0)
                {
                    // Select end boundary
                    endPos               = endBoundaryPos;
                    endPosLength         = endBoundaryLength;
                    this.readEndBoundary = true;
                }

                if (endPos != -1)
                {
                    // Now we need to check if the endPos is followed by \r\n or just \n. HTTP
                    // specifies \r\n but some clients might encode with \n. Or we might get 0 if
                    // we are at the end of the file.
                    int boundaryNewlineOffset = this.CalculateNewlineLength(ref fullBuffer, endPos + endPosLength);

                    // We also need to check if the last n characters of the buffer to write
                    // are a newline and if they are ignore them.
                    var maxNewlineBytes     = Encoding.GetMaxByteCount(2);
                    int bufferNewlineOffset = this.FindNextNewline(
                        ref fullBuffer, Math.Max(0, endPos - maxNewlineBytes), maxNewlineBytes);
                    int bufferNewlineLength = this.CalculateNewlineLength(ref fullBuffer, bufferNewlineOffset);

                    // We've found an end. We need to consume all the binary up to it
                    // and then write the remainder back to the original stream. Then we
                    // need to modify the original streams position to take into account
                    // the new data.
                    // We also want to chop off the newline that is inserted by the protocl.
                    // We can do this by reducing endPos by the length of newline in this environment
                    // and encoding
                    data.Write(fullBuffer, 0, 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);

                    // stream.Write(fullBuffer, writeBackOffset, writeBackAmount);
                    // stream.Position = stream.Position - writeBackAmount;
                    // stream.Flush();
                    data.Position = 0;
                    data.Flush();
                    break;
                }

                // No end, consume the entire previous buffer
                data.Write(prevBuffer, 0, prevLength);
                data.Flush();

                // Now we want to swap the two buffers, we don't care
                // what happens to the data from prevBuffer so we set
                // curBuffer to it so it gets overwrited.
                byte[] tempBuffer = curBuffer;
                curBuffer  = prevBuffer;
                prevBuffer = tempBuffer;

                // We don't need to swap the lengths because
                // curLength will be overwritten in the next
                // iteration of the loop.
                prevLength = curLength;
            }while (prevLength != 0);

            var contentType        = parameters.ContainsKey("content-type") ? parameters["content-type"] : "text/plain";
            var contentDisposition = parameters.ContainsKey("content-disposition") ? parameters["content-disposition"] : "form-data";
            var part = new FilePart(parameters["name"], parameters["filename"], data.ToArray(), contentType, contentDisposition);

            return(part);
        }