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Diffstat (limited to 'Utils/src/IO/VnStreamReader.cs')
| -rw-r--r-- | Utils/src/IO/VnStreamReader.cs | 180 |
1 files changed, 0 insertions, 180 deletions
diff --git a/Utils/src/IO/VnStreamReader.cs b/Utils/src/IO/VnStreamReader.cs deleted file mode 100644 index 70b9734..0000000 --- a/Utils/src/IO/VnStreamReader.cs +++ /dev/null @@ -1,180 +0,0 @@ -/* -* Copyright (c) 2022 Vaughn Nugent -* -* Library: VNLib -* Package: VNLib.Utils -* File: VnStreamReader.cs -* -* VnStreamReader.cs is part of VNLib.Utils which is part of the larger -* VNLib collection of libraries and utilities. -* -* VNLib.Utils is free software: you can redistribute it and/or modify -* it under the terms of the GNU General Public License as published -* by the Free Software Foundation, either version 2 of the License, -* or (at your option) any later version. -* -* VNLib.Utils 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 -* General Public License for more details. -* -* You should have received a copy of the GNU General Public License -* along with VNLib.Utils. If not, see http://www.gnu.org/licenses/. -*/ - -using System; -using System.IO; -using System.Text; -using System.Buffers; -using System.Threading; -using System.Threading.Tasks; - -using VNLib.Utils.Extensions; - -namespace VNLib.Utils.IO -{ - /// <summary> - /// Binary based buffered text reader, optimized for reading network streams - /// </summary> - public class VnStreamReader : TextReader, IVnTextReader - { - private bool disposedValue; - - private readonly ISlindingWindowBuffer<byte> _buffer; - ///<inheritdoc/> - public virtual Stream BaseStream { get; } - ///<inheritdoc/> - public Encoding Encoding { get; } - - /// <summary> - /// Number of available bytes of buffered data within the current buffer window - /// </summary> - public int Available => _buffer.AccumulatedSize; - /// <summary> - /// Gets or sets the line termination used to deliminate a line of data - /// </summary> - public ReadOnlyMemory<byte> LineTermination { get; set; } - Span<byte> IVnTextReader.BufferedDataWindow => _buffer.Accumulated; - - /// <summary> - /// Creates a new <see cref="TextReader"/> that reads encoded data from the base. - /// Internal buffers will be alloced from <see cref="ArrayPool{T}.Shared"/> - /// </summary> - /// <param name="baseStream">The underlying stream to read data from</param> - /// <param name="enc">The <see cref="Encoding"/> to use when reading from the stream</param> - /// <param name="bufferSize">The size of the internal binary buffer</param> - public VnStreamReader(Stream baseStream, Encoding enc, int bufferSize) - { - BaseStream = baseStream; - Encoding = enc; - //Init a new buffer - _buffer = InitializeBuffer(bufferSize); - } - - /// <summary> - /// Invoked by the constuctor method to allocte the internal buffer with the specified buffer size. - /// </summary> - /// <param name="bufferSize">The requested size of the buffer to alloc</param> - /// <remarks>By default requests the buffer from the <see cref="ArrayPool{T}.Shared"/> instance</remarks> - protected virtual ISlindingWindowBuffer<byte> InitializeBuffer(int bufferSize) => new ArrayPoolStreamBuffer<byte>(ArrayPool<byte>.Shared, bufferSize); - - ///<inheritdoc/> - public override async Task<string?> ReadLineAsync() - { - //If buffered data is available, check for line termination - if (Available > 0) - { - //Get current buffer window - Memory<byte> buffered = _buffer.AccumulatedBuffer; - //search for line termination in current buffer - int term = buffered.IndexOf(LineTermination); - //Termination found in buffer window - if (term > -1) - { - //Capture the line from the begining of the window to the termination - Memory<byte> line = buffered[..term]; - //Shift the window to the end of the line (excluding the termination) - _buffer.AdvanceStart(term + LineTermination.Length); - //Decode the line to a string - return Encoding.GetString(line.Span); - } - //Termination not found - } - //Compact the buffer window and see if space is avialble to buffer more data - if (_buffer.CompactBufferWindow()) - { - //There is room, so buffer more data - await _buffer.AccumulateDataAsync(BaseStream, CancellationToken.None); - //Check again to see if more data is buffered - if (Available <= 0) - { - //No string found - return null; - } - //Get current buffer window - Memory<byte> buffered = _buffer.AccumulatedBuffer; - //search for line termination in current buffer - int term = buffered.IndexOf(LineTermination); - //Termination found in buffer window - if (term > -1) - { - //Capture the line from the begining of the window to the termination - Memory<byte> line = buffered[..term]; - //Shift the window to the end of the line (excluding the termination) - _buffer.AdvanceStart(term + LineTermination.Length); - //Decode the line to a string - return Encoding.GetString(line.Span); - } - } - //Termination not found within the entire buffer, so buffer space has been exhausted - - //OOM is raised in the TextReader base class, the standard is preserved -#pragma warning disable CA2201 // Do not raise reserved exception types - throw new OutOfMemoryException("A line termination was not found within the buffer"); -#pragma warning restore CA2201 // Do not raise reserved exception types - } - - ///<inheritdoc/> - public override int Read(char[] buffer, int index, int count) => Read(buffer.AsSpan(index, count)); - ///<inheritdoc/> - public override int Read(Span<char> buffer) - { - if (Available <= 0) - { - return 0; - } - //Get current buffer window - Span<byte> buffered = _buffer.Accumulated; - //Convert all avialable data - int encoded = Encoding.GetChars(buffered, buffer); - //Shift buffer window to the end of the converted data - _buffer.AdvanceStart(encoded); - //return the number of chars written - return Encoding.GetCharCount(buffered); - } - ///<inheritdoc/> - public override void Close() => _buffer.Close(); - ///<inheritdoc/> - protected override void Dispose(bool disposing) - { - if (!disposedValue) - { - Close(); - disposedValue = true; - } - base.Dispose(disposing); - } - - /// <summary> - /// Resets the internal buffer window - /// </summary> - protected void ClearBuffer() - { - _buffer.Reset(); - } - - void IVnTextReader.Advance(int count) => _buffer.AdvanceStart(count); - void IVnTextReader.FillBuffer() => _buffer.AccumulateData(BaseStream); - ERRNO IVnTextReader.CompactBufferWindow() => _buffer.CompactBufferWindow(); - } -}
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