97 lines
3.2 KiB
C#
97 lines
3.2 KiB
C#
namespace PerfectNumbers.Core;
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/// <summary>
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/// Provides thread-safe file writing for both text and binary data.
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/// </summary>
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public sealed class TextFileWriter : IDisposable
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{
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private readonly FileStream _stream;
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private StreamWriter? _textWriter;
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private BinaryWriter? _binaryWriter;
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private readonly object _lock = new();
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public TextFileWriter(string path, FileMode mode)
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{
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var options = new FileStreamOptions
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{
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Access = FileAccess.Write,
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Mode = mode,
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Share = FileShare.Read
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};
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_stream = new FileStream(path, options);
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}
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public long Position
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{
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get
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{
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// TODO: Surface a lock-free position snapshot (for example via Interlocked.Read on a cached long)
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// so the high-frequency status probes measured in the writer throughput profiling stop contending on
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// the flush lock while runs follow the buffered pipeline planned for the scanner fast path.
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lock (_lock)
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{
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return _stream.Position;
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}
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}
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}
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private StreamWriter TextWriter => _textWriter ??= new StreamWriter(_stream, leaveOpen: true);
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private BinaryWriter BinaryWriter => _binaryWriter ??= new BinaryWriter(_stream, System.Text.Encoding.UTF8, leaveOpen: true);
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/// <summary>
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/// Clears the file by truncating it to zero length.
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/// </summary>
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public void Clear()
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{
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lock (_lock)
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{
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// TODO: Use the pooled writer buffers planned for the TextFileWriter fast path so truncation flushes
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// reuse the span caches identified alongside the Mod10_8_5_3Benchmarks instead of forcing synchronous
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// SetLength/Flush work on every restart.
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_stream.SetLength(0);
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_stream.Position = 0;
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_textWriter?.Flush();
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_binaryWriter?.Flush();
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}
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}
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/// <summary>
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/// Writes a line of text to the file.
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/// </summary>
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public void WriteLine(string line)
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{
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lock (_lock)
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{
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// TODO: Buffer these writes through an ArrayPool-backed accumulator so we only flush when the
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// batch is full; flushing per line shows up as a serialization bottleneck once the scanner emits
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// millions of candidate summaries.
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TextWriter.WriteLine(line);
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TextWriter.Flush();
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}
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}
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/// <summary>
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/// Executes a binary writing action within the internal lock.
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/// </summary>
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public void WriteBinary(Action<BinaryWriter> action)
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{
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lock (_lock)
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{
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// TODO: Buffer binary writes with the same ArrayPool-backed accumulator planned for text so GPU result
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// dumps can batch disk flushes instead of flushing on every invocation.
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action(BinaryWriter);
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BinaryWriter.Flush();
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}
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}
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public void Dispose()
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{
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// TODO: Return the writers to a pooled wrapper once the buffered pipeline lands so disposing the
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// TextFileWriter mirrors the zero-allocation strategy validated by the Mod10_8_5_3Benchmarks helpers.
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_binaryWriter?.Dispose();
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_textWriter?.Dispose();
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_stream.Dispose();
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}
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}
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