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Diffstat (limited to 'Net.Messaging.FBM/src/Client/Helpers.cs')
| -rw-r--r-- | Net.Messaging.FBM/src/Client/Helpers.cs | 272 |
1 files changed, 0 insertions, 272 deletions
diff --git a/Net.Messaging.FBM/src/Client/Helpers.cs b/Net.Messaging.FBM/src/Client/Helpers.cs deleted file mode 100644 index 8f895fa..0000000 --- a/Net.Messaging.FBM/src/Client/Helpers.cs +++ /dev/null @@ -1,272 +0,0 @@ -/* -* Copyright (c) 2022 Vaughn Nugent -* -* Library: VNLib -* Package: VNLib.Net.Messaging.FBM -* File: Helpers.cs -* -* Helpers.cs is part of VNLib.Net.Messaging.FBM which is part of the larger -* VNLib collection of libraries and utilities. -* -* VNLib.Net.Messaging.FBM is free software: you can redistribute it and/or modify -* it under the terms of the GNU Affero General Public License as -* published by the Free Software Foundation, either version 3 of the -* License, or (at your option) any later version. -* -* VNLib.Net.Messaging.FBM is distributed in the hope that it will be useful, -* but WITHOUT ANY WARRANTY; without even the implied warranty of -* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the -* GNU Affero General Public License for more details. -* -* You should have received a copy of the GNU Affero General Public License -* along with this program. If not, see https://www.gnu.org/licenses/. -*/ - -using System; -using System.IO; -using System.Text; -using System.Collections.Generic; -using System.Security.Cryptography; - -using VNLib.Utils; -using VNLib.Utils.IO; -using VNLib.Utils.Memory; -using VNLib.Utils.Extensions; - - -namespace VNLib.Net.Messaging.FBM -{ - /// <summary> - /// Contains FBM library helper methods - /// </summary> - public static class Helpers - { - /// <summary> - /// The message-id of a connection control frame / out of band message - /// </summary> - public const int CONTROL_FRAME_MID = -500; - - public static readonly Encoding DefaultEncoding = Encoding.UTF8; - public static readonly ReadOnlyMemory<byte> Termination = new byte[] { 0xFF, 0xF1 }; - - /// <summary> - /// Parses the header line for a message-id - /// </summary> - /// <param name="line">A sequence of bytes that make up a header line</param> - /// <returns>The message-id if parsed, -1 if message-id is not valid</returns> - public static int GetMessageId(ReadOnlySpan<byte> line) - { - //Make sure the message line is large enough to contain a message-id - if (line.Length < 1 + sizeof(int)) - { - return -1; - } - //The first byte should be the header id - HeaderCommand headerId = (HeaderCommand)line[0]; - //Make sure the headerid is set - if (headerId != HeaderCommand.MessageId) - { - return -2; - } - //Get the messageid after the header byte - ReadOnlySpan<byte> messageIdSegment = line.Slice(1, sizeof(int)); - //get the messageid from the messageid segment - return BitConverter.ToInt32(messageIdSegment); - } - - /// <summary> - /// Alloctes a random integer to use as a message id - /// </summary> - public static int RandomMessageId => RandomNumberGenerator.GetInt32(1, int.MaxValue); - /// <summary> - /// Gets the remaining data after the current position of the stream. - /// </summary> - /// <param name="response">The stream to segment</param> - /// <returns>The remaining data segment</returns> - public static ReadOnlySpan<byte> GetRemainingData(VnMemoryStream response) - { - return response.AsSpan()[(int)response.Position..]; - } - - /// <summary> - /// Reads the next available line from the response message - /// </summary> - /// <param name="response"></param> - /// <returns>The read line</returns> - public static ReadOnlySpan<byte> ReadLine(VnMemoryStream response) - { - //Get the span from the current stream position to end of the stream - ReadOnlySpan<byte> line = GetRemainingData(response); - //Search for next line termination - int index = line.IndexOf(Termination.Span); - if (index == -1) - { - return ReadOnlySpan<byte>.Empty; - } - //Update stream position to end of termination - response.Seek(index + Termination.Length, SeekOrigin.Current); - //slice up line and exclude the termination - return line[..index]; - } - /// <summary> - /// Parses headers from the request stream, stores headers from the buffer into the - /// header collection - /// </summary> - /// <param name="vms">The FBM packet buffer</param> - /// <param name="buffer">The header character buffer to write headers to</param> - /// <param name="headers">The collection to store headers in</param> - /// <param name="encoding">The encoding type used to deocde header values</param> - /// <returns>The results of the parse operation</returns> - public static HeaderParseError ParseHeaders(VnMemoryStream vms, char[] buffer, ICollection<KeyValuePair<HeaderCommand, ReadOnlyMemory<char>>> headers, Encoding encoding) - { - HeaderParseError status = HeaderParseError.None; - //sliding window - Memory<char> currentWindow = buffer; - //Accumulate headers - while (true) - { - //Read the next line from the current stream - ReadOnlySpan<byte> line = ReadLine(vms); - if (line.IsEmpty) - { - //Done reading headers - break; - } - HeaderCommand cmd = GetHeaderCommand(line); - //Get header value - ERRNO charsRead = GetHeaderValue(line, currentWindow.Span, encoding); - if (charsRead < 0) - { - //Out of buffer space - status |= HeaderParseError.HeaderOutOfMem; - break; - } - else if (!charsRead) - { - //Invalid header - status |= HeaderParseError.InvalidHeaderRead; - } - else - { - //Store header as a read-only sequence - headers.Add(new(cmd, currentWindow[..(int)charsRead])); - //Shift buffer window - currentWindow = currentWindow[(int)charsRead..]; - } - } - return status; - } - - /// <summary> - /// Gets a <see cref="HeaderCommand"/> enum from the first byte of the message - /// </summary> - /// <param name="line"></param> - /// <returns>The <see cref="HeaderCommand"/> enum value from hte first byte of the message</returns> - public static HeaderCommand GetHeaderCommand(ReadOnlySpan<byte> line) - { - return (HeaderCommand)line[0]; - } - /// <summary> - /// Gets the value of the header following the colon bytes in the specifed - /// data message data line - /// </summary> - /// <param name="line">The message header line to get the value of</param> - /// <param name="output">The output character buffer to write characters to</param> - /// <param name="encoding">The encoding to decode the specified data with</param> - /// <returns>The number of characters encoded</returns> - public static ERRNO GetHeaderValue(ReadOnlySpan<byte> line, Span<char> output, Encoding encoding) - { - //Get the data following the header byte - ReadOnlySpan<byte> value = line[1..]; - //Calculate the character account - int charCount = encoding.GetCharCount(value); - //Determine if the output buffer is large enough - if (charCount > output.Length) - { - return -1; - } - //Decode the characters and return the char count - _ = encoding.GetChars(value, output); - return charCount; - } - - /// <summary> - /// Appends an arbitrary header to the current request buffer - /// </summary> - /// <param name="buffer"></param> - /// <param name="header">The <see cref="HeaderCommand"/> of the header</param> - /// <param name="value">The value of the header</param> - /// <param name="encoding">Encoding to use when writing character message</param> - /// <exception cref="OutOfMemoryException"></exception> - public static void WriteHeader(ref this ForwardOnlyWriter<byte> buffer, byte header, ReadOnlySpan<char> value, Encoding encoding) - { - //get char count - int byteCount = encoding.GetByteCount(value); - //make sure there is enough room in the buffer - if (buffer.RemainingSize < byteCount) - { - throw new OutOfMemoryException(); - } - //Write header command enum value - buffer.Append(header); - //Convert the characters to binary and write to the buffer - encoding.GetBytes(value, ref buffer); - //Write termination (0) - buffer.WriteTermination(); - } - - /// <summary> - /// Ends the header section of the request and appends the message body to - /// the end of the request - /// </summary> - /// <param name="buffer"></param> - /// <param name="body">The message body to send with request</param> - /// <exception cref="OutOfMemoryException"></exception> - public static void WriteBody(ref this ForwardOnlyWriter<byte> buffer, ReadOnlySpan<byte> body) - { - //start with termination - buffer.WriteTermination(); - //Write the body - buffer.Append(body); - } - /// <summary> - /// Writes a line termination to the message buffer - /// </summary> - /// <param name="buffer"></param> - public static void WriteTermination(ref this ForwardOnlyWriter<byte> buffer) - { - //write termination - buffer.Append(Termination.Span); - } - - /// <summary> - /// Writes a line termination to the message buffer - /// </summary> - /// <param name="buffer"></param> - public static void WriteTermination(this IDataAccumulator<byte> buffer) - { - //write termination - buffer.Append(Termination.Span); - } - - /// <summary> - /// Appends an arbitrary header to the current request buffer - /// </summary> - /// <param name="buffer"></param> - /// <param name="header">The <see cref="HeaderCommand"/> of the header</param> - /// <param name="value">The value of the header</param> - /// <param name="encoding">Encoding to use when writing character message</param> - /// <exception cref="ArgumentException"></exception> - public static void WriteHeader(this IDataAccumulator<byte> buffer, byte header, ReadOnlySpan<char> value, Encoding encoding) - { - //Write header command enum value - buffer.Append(header); - //Convert the characters to binary and write to the buffer - int written = encoding.GetBytes(value, buffer.Remaining); - //Advance the buffer - buffer.Advance(written); - //Write termination (0) - buffer.WriteTermination(); - } - } -} |