73 lines
2.3 KiB
C#
73 lines
2.3 KiB
C#
using System.Globalization;
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using System.Text;
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namespace MareSynchronosStaticFilesServer.Utils;
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public sealed class BlockFileDataSubstream : IDisposable
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{
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private readonly MemoryStream _headerStream;
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private readonly FileStream _dataStream;
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private int _headerPosition = 0;
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private long _dataPosition = 0;
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private bool _disposed = false;
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private long RemainingHeaderLength => _headerStream.Length - _headerPosition;
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private long RemainingDataLength => _dataStream.Length - _dataPosition;
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public BlockFileDataSubstream(FileStream dataStream)
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{
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_headerStream = new MemoryStream();
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var headerStreamWriter = new BinaryWriter(_headerStream);
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headerStreamWriter.Write(Encoding.ASCII.GetBytes("#" + new FileInfo(dataStream.Name).Name + ":" + dataStream.Length.ToString(CultureInfo.InvariantCulture) + "#"));
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headerStreamWriter.Flush();
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_headerStream.Position = 0;
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_dataStream = dataStream;
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}
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public int Read(byte[] inputBuffer, int offset, int count)
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{
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int currentOffset = offset;
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int currentCount = count;
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int readHeaderBytes = 0;
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if (RemainingHeaderLength > 0)
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{
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bool readOnlyHeader = currentCount <= RemainingHeaderLength;
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byte[] readHeaderBuffer = new byte[Math.Min(currentCount, RemainingHeaderLength)];
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readHeaderBytes = _headerStream.Read(readHeaderBuffer, 0, readHeaderBuffer.Length);
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_headerPosition += readHeaderBytes;
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Buffer.BlockCopy(readHeaderBuffer, 0, inputBuffer, currentOffset, readHeaderBytes);
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if (readOnlyHeader)
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{
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return readHeaderBytes;
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}
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currentOffset += readHeaderBytes;
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currentCount -= readHeaderBytes;
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}
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if (RemainingDataLength > 0)
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{
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byte[] readDataBuffer = new byte[currentCount];
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var readDataBytes = _dataStream.Read(readDataBuffer, 0, readDataBuffer.Length);
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_dataPosition += readDataBytes;
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Buffer.BlockCopy(readDataBuffer, 0, inputBuffer, currentOffset, readDataBytes);
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return readDataBytes + readHeaderBytes;
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}
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return 0;
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}
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public void Dispose()
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{
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if (_disposed) return;
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_headerStream.Dispose();
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_dataStream.Dispose();
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_disposed = true;
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}
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} |