mirror of https://github.com/dahall/Vanara.git
Updated ComStream to support IStream implementation
dahall
parent
e47f7c883c
commit
ce5e582d25
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@ -1,157 +1,515 @@
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using System;
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using System.IO;
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using System.Runtime.InteropServices;
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using System.Runtime.InteropServices.ComTypes;
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using STATSTG = System.Runtime.InteropServices.ComTypes.STATSTG;
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namespace Vanara.InteropServices
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{
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/// <summary>Implements a .NET stream over a COM IStream instance.</summary>
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/// <summary>Implements a .NET stream derivation and a COM IStream instance.</summary>
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/// <seealso cref="System.IO.Stream"/>
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public class ComStream : Stream
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/// <seealso cref="System.Runtime.InteropServices.ComTypes.IStream"/>
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/// <seealso cref="System.IDisposable"/>
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public class ComStream : Stream, IStream, IDisposable
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{
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/// <summary>Initializes a new instance of the <see cref="ComStream"/> class.</summary>
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/// <param name="stream">The supporting COM <see cref="IStream"/> instance.</param>
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/// <exception cref="System.ArgumentNullException">stream</exception>
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public ComStream(IStream stream) => IStream = stream ?? throw new ArgumentNullException(nameof(stream));
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private readonly IStream comStream = null;
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private readonly Stream netStream = null;
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/// <summary>Gets a value indicating whether the current stream supports reading.</summary>
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public override bool CanRead => true;
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/// <summary>Initializes a new instance of the ComStream class.</summary>
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/// <param name="stream">An IO.Stream</param>
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/// <exception cref="System.ArgumentNullException">stream - Stream cannot be null</exception>
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/// <exception cref="ArgumentNullException">Stream cannot be null</exception>
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public ComStream(Stream stream)
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{
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if (stream is null)
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throw new ArgumentNullException(nameof(stream), "Stream cannot be null");
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/// <summary>Gets a value indicating whether the current stream supports seeking.</summary>
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public override bool CanSeek => true;
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netStream = stream;
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}
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/// <summary>Gets a value indicating whether the current stream supports writing.</summary>
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public override bool CanWrite => true;
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/// <summary>Initializes a new instance of the ComStream class.</summary>
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/// <param name="stream">A ComTypes.IStream</param>
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/// <exception cref="System.ArgumentNullException">stream - IStream cannot be null</exception>
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/// <exception cref="ArgumentNullException">Stream cannot be null</exception>
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public ComStream(IStream stream)
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{
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if (stream is null)
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throw new ArgumentNullException(nameof(stream), "IStream cannot be null");
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/// <summary>Gets the underlying stream.</summary>
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/// <value>The underlying stream.</value>
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public IStream IStream { get; private set; }
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comStream = stream;
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}
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/// <summary>Gets the length in bytes of the stream.</summary>
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/// <exception cref="System.ObjectDisposedException">iComStream</exception>
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// Default constructor. Should not be used to create an ComStream object.
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private ComStream()
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{
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}
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/// <summary>Finalizes an instance of the <see cref="ComStream"/> class.</summary>
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~ComStream()
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{
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netStream?.Close();
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}
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/// <summary>When overridden in a derived class, gets the length in bytes of the stream.</summary>
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public override long Length
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{
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get
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{
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if (IStream is null)
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throw new ObjectDisposedException(nameof(IStream));
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IStream.Stat(out var statstg, 1 /* STATSFLAG_NONAME*/ );
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return statstg.cbSize;
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if (comStream is not null)
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{
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// Call IStream.Stat to retrieve info about the stream, which includes the length. STATFLAG_NONAME means that we don't
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// care about the name (STATSTG.pwcsName), so there is no need for the method to allocate memory for the string.
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comStream.Stat(out var statstg, 1);
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return statstg.cbSize;
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}
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else
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{
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return netStream.Length;
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}
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}
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}
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/// <summary>Gets or sets the position within the current stream.</summary>
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/// <summary>Gets or sets the position.</summary>
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/// <value>The position.</value>
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public override long Position
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{
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get => Seek(0, SeekOrigin.Current);
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set => Seek(value, SeekOrigin.Begin);
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get => comStream is not null ? Seek(0, SeekOrigin.Current) : netStream.Position;
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set
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{
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if (comStream is not null)
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{
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Seek(value, SeekOrigin.Begin);
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}
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else
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{
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netStream.Position = value;
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}
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}
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}
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/// <summary>Gets a value indicating whether this instance can read.</summary>
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/// <value><see langword="true"/> if this instance can read; otherwise, <see langword="false"/>.</value>
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public override bool CanRead => comStream is not null || netStream.CanRead;
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/// <summary>Gets a value indicating whether this instance can seek.</summary>
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/// <value><see langword="true"/> if this instance can seek; otherwise, <see langword="false"/>.</value>
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public override bool CanSeek => comStream is not null || netStream.CanSeek;
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/// <summary>Gets a value indicating whether this instance can timeout.</summary>
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/// <value><see langword="true"/> if this instance can timeout; otherwise, <see langword="false"/>.</value>
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public override bool CanTimeout => comStream is null && netStream.CanTimeout;
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/// <summary>Gets a value indicating whether this instance can write.</summary>
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/// <value><see langword="true"/> if this instance can write; otherwise, <see langword="false"/>.</value>
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public override bool CanWrite => comStream is not null || netStream.CanWrite;
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/// <summary>Gets the <see cref="IStream"/> instance from the <paramref name="stream"/> value, if possible.</summary>
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/// <param name="stream">The stream.</param>
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/// <returns>An <see cref="IStream"/> instance or <see langword="null"/> if not available.</returns>
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public static IStream ToIStream(object stream) => stream is Stream ? new ComStream(stream as Stream) : stream is IStream ? stream as IStream : null;
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/// <summary>Gets the <see cref="Stream"/> instance from the <paramref name="stream"/> value, if possible.</summary>
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/// <param name="stream">The stream.</param>
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/// <returns>An <see cref="Stream"/> instance or <see langword="null"/> if not available.</returns>
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public static Stream ToStream(object stream) => stream is Stream ? stream as Stream : stream is IStream ? new ComStream(stream as IStream) : null;
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/// <summary>Creates a new stream object with its own seek pointer that references the same bytes as the original stream.</summary>
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/// <param name="ppstm">When successful, pointer to the location of an IStream pointer to the new stream object.</param>
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/// <returns></returns>
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/// <exception cref="NotSupportedException">The IO.Streamtream cannot be cloned.</exception>
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/// <remarks>This method is not used and always throws the exception.</remarks>
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void IStream.Clone(out IStream ppstm)
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{
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if (netStream is not null)
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throw new NotSupportedException("A System.IO.Stream instance cannot be cloned.");
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comStream.Clone(out ppstm);
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}
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/// <summary>Closes the current stream and releases any resources (such as the Stream) associated with the current IStream.</summary>
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/// <returns></returns>
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/// <remarks>This method is not a member in IStream.</remarks>
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public override void Close()
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{
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if (netStream is not null)
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{
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netStream.Close();
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}
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else
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{
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comStream.Commit(0 /*STGC_DEFAULT*/);
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// Marshal.ReleaseComObject(TheIStream); // Investigate this because we cannot release an IStream to the stash file
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}
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GC.SuppressFinalize(this);
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}
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/// <summary>Ensures that any changes made to an stream object that is open in transacted mode are reflected in the parent storage.</summary>
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/// <param name="grfCommitFlags">
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/// Controls how the changes for the stream object are committed. See the STGC enumeration for a definition of these values.
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/// </param>
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/// <returns></returns>
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/// <exception cref="IOException">An I/O error occurs.</exception>
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/// <remarks>The <paramref name="grfCommitFlags"/> parameter is not used and this method only does Stream.Flush()</remarks>
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void IStream.Commit(int grfCommitFlags)
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{
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// Clears all buffers for this stream and causes any buffered data to be written to the underlying device.
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if (netStream is not null)
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{
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netStream.Flush();
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}
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else
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{
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comStream.Commit(grfCommitFlags);
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}
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}
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/// <summary>
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/// Closes the current stream and releases any resources (such as sockets and file handles) associated with the current stream.
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/// Copies a specified number of bytes from the current seek pointer in the stream to the current seek pointer in another stream.
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/// </summary>
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public override void Close()
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/// <param name="pstm">The destination stream. The pstm stream can be a new stream or a clone of the source stream.</param>
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/// <param name="cb">The number of bytes to copy from the source stream.</param>
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/// <param name="pcbRead">
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/// The actual number of bytes read from the source. It can be set to IntPtr.Zero. In this case, this method does not provide the
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/// actual number of bytes read.
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/// </param>
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/// <param name="pcbWritten">
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/// The actual number of bytes written to the destination. It can be set this to IntPtr.Zero. In this case, this method does not
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/// provide the actual number of bytes written.
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/// </param>
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/// <returns>
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/// The actual number of bytes read ( <paramref name="pcbRead"/>) and written ( <paramref name="pcbWritten"/>) from the source.
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/// </returns>
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/// <exception cref="ArgumentException">The sum of offset and count is larger than the buffer length.</exception>
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/// <exception cref="ArgumentNullException">buffer is a null reference.</exception>
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/// <exception cref="ArgumentOutOfRangeException">offset or count is negative.</exception>
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/// <exception cref="IOException">An I/O error occurs.</exception>
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/// <exception cref="NotSupportedException">The stream does not support reading.</exception>
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/// <exception cref="ObjectDisposedException">Methods were called after the stream was closed.</exception>
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void IStream.CopyTo(IStream pstm, long cb, IntPtr pcbRead, IntPtr pcbWritten)
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{
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if (IStream is null) return;
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IStream.Commit(0);
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IStream = null;
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if (netStream is not null)
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{
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var sourceBytes = new byte[cb];
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long totalBytesRead = 0;
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long totalBytesWritten = 0;
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IntPtr bw = Marshal.AllocHGlobal(Marshal.SizeOf(typeof(int)));
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Marshal.WriteInt32(bw, 0);
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while (totalBytesWritten < cb)
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{
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var currentBytesRead = netStream.Read(sourceBytes, 0, (int)(cb - totalBytesWritten));
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// Has the end of the stream been reached?
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if (currentBytesRead == 0) break;
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totalBytesRead += currentBytesRead;
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pstm.Write(sourceBytes, currentBytesRead, bw);
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var currentBytesWritten = Marshal.ReadInt32(bw);
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if (currentBytesWritten != currentBytesRead)
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{
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System.Diagnostics.Debug.WriteLine("ERROR!: The IStream Write is not writing all the bytes needed!");
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}
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totalBytesWritten += currentBytesWritten;
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}
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Marshal.FreeHGlobal(bw);
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if (pcbRead != IntPtr.Zero) Marshal.WriteInt64(pcbRead, totalBytesRead);
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if (pcbWritten != IntPtr.Zero) Marshal.WriteInt64(pcbWritten, totalBytesWritten);
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}
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else
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{
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comStream.CopyTo(pstm, cb, pcbRead, pcbWritten);
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}
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}
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/// <summary>Clears all buffers for this stream and causes any buffered data to be written to the underlying device.</summary>
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public override void Flush() => IStream?.Commit(0);
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/// <returns></returns>
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public override void Flush() => ((IStream)this).Commit(0 /*STGC_DEFAULT*/);
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/// <summary>Restricts access to a specified range of bytes in the stream.</summary>
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/// <param name="libOffset">Integer that specifies the byte offset for the beginning of the range.</param>
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/// <param name="cb">Integer that specifies the length of the range, in bytes, to be restricted.</param>
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/// <param name="dwLockType">Specifies the restrictions being requested on accessing the range.</param>
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/// <returns></returns>
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/// <exception cref="NotSupportedException">The IO.Stream does not support locking.</exception>
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/// <remarks>This method is not used and always throws the exception.</remarks>
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void IStream.LockRegion(long libOffset, long cb, int dwLockType)
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{
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if (netStream is not null)
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throw new NotSupportedException("Stream does not support locking.");
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comStream.LockRegion(libOffset, cb, dwLockType);
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}
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/// <summary>
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/// Reads a sequence of bytes from the current stream and advances the position within the stream by the number of bytes read.
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/// </summary>
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/// <param name="buffer">
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/// An array of bytes. When this method returns, the buffer contains the specified byte array with the values between
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/// <paramref name="offset"/> and ( <paramref name="offset"/> + <paramref name="count"/> - 1) replaced by the bytes read from the
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/// current source.
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/// </param>
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/// <param name="offset">
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/// The zero-based byte offset in <paramref name="buffer"/> at which to begin storing the data read from the current stream.
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/// An array of bytes. When this method returns, the buffer contains the specified byte array with the values between offset and
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/// (offset + count - 1) replaced by the bytes read from the current source.
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/// </param>
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/// <param name="offset">The zero-based byte offset in buffer at which to begin storing the data read from the current stream.</param>
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/// <param name="count">The maximum number of bytes to be read from the current stream.</param>
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/// <returns>
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/// The total number of bytes read into the buffer. This can be less than the number of bytes requested if that many bytes are not
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/// currently available, or zero (0) if the end of the stream has been reached.
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/// </returns>
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/// <exception cref="System.ObjectDisposedException">iComStream</exception>
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/// <exception cref="System.NotSupportedException">Offsets other than zero are not supported.</exception>
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/// <exception cref="NotSupportedException">Only a zero offset is supported.</exception>
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public override int Read(byte[] buffer, int offset, int count)
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{
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if (IStream is null)
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throw new ObjectDisposedException(nameof(IStream));
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if (comStream is not null)
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{
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var rdBuf = buffer;
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if (offset != 0)
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#if NETCOREAPP3_0_OR_GREATER || NET5_0_OR_GREATER || NETSTANDARD2_1_OR_GREATER
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rdBuf = buffer[offset..];
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#else
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throw new InvalidOperationException("Offsets cannot be handled by IStream.");
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#endif
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unsafe
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{
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int bytesRead = 0;
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comStream.Read(rdBuf, count, (IntPtr)(void*)&bytesRead);
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return bytesRead;
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}
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}
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else
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{
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return netStream.Read(buffer, offset, count);
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}
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}
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if (offset != 0)
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throw new NotSupportedException("Offsets other than zero are not supported.");
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/// <summary>Reads a specified number of bytes from the stream object into memory starting at the current seek pointer.</summary>
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/// <param name="pv">The buffer which the stream data is read into.</param>
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/// <param name="cb">The number of bytes of data to read from the stream object.</param>
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/// <param name="pcbRead">
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/// A pointer to a ULONG variable that receives the actual number of bytes read from the stream object. It can be set to
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/// IntPtr.Zero. In this case, this method does not return the number of bytes read.
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/// </param>
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/// <returns>The actual number of bytes read ( <paramref name="pcbRead"/>) from the source.</returns>
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/// <exception cref="ArgumentException">The sum of offset and count is larger than the buffer length.</exception>
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/// <exception cref="ArgumentNullException">buffer is a null reference.</exception>
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/// <exception cref="ArgumentOutOfRangeException">offset or count is negative.</exception>
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/// <exception cref="IOException">An I/O error occurs.</exception>
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/// <exception cref="NotSupportedException">The stream does not support reading.</exception>
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/// <exception cref="ObjectDisposedException">Methods were called after the stream was closed.</exception>
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void IStream.Read(byte[] pv, int cb, IntPtr pcbRead)
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{
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if (netStream is not null)
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{
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var bytesRead = netStream.Read(pv, 0, cb);
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if (pcbRead != IntPtr.Zero)
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Marshal.WriteInt32(pcbRead, bytesRead);
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}
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else
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{
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comStream.Read(pv, cb, pcbRead);
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}
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}
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var bytesRead = 0;
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using (var address = new PinnedObject(bytesRead))
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IStream.Read(buffer, count, address);
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return bytesRead;
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/// <summary>Discards all changes that have been made to a transacted stream since the last stream.Commit call</summary>
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/// <returns></returns>
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/// <exception cref="NotSupportedException">The IO.Stream does not support reverting.</exception>
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/// <remarks>This method is not used and always throws the exception.</remarks>
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void IStream.Revert()
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{
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if (netStream is not null)
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throw new NotSupportedException("Stream does not support reverting.");
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comStream.Revert();
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}
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/// <summary>Sets the position within the current stream.</summary>
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/// <param name="offset">A byte offset relative to the <paramref name="origin"/> parameter.</param>
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/// <param name="origin">
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/// A value of type <see cref="T:System.IO.SeekOrigin"/> indicating the reference point used to obtain the new position.
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/// </param>
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/// <param name="offset">A byte offset relative to the origin parameter.</param>
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/// <param name="origin">A value of type SeekOrigin indicating the reference point used to obtain the new position.</param>
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/// <returns>The new position within the current stream.</returns>
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/// <exception cref="System.ObjectDisposedException">iComStream</exception>
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public override long Seek(long offset, SeekOrigin origin)
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{
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if (IStream is null)
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throw new ObjectDisposedException(nameof(IStream));
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if (comStream is not null)
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{
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unsafe
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{
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long position = 0;
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// The enum values of SeekOrigin match the enum values of STREAM_SEEK, so we can just cast the origin to an integer.
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comStream.Seek(offset, (int)origin, (IntPtr)(void*)&position);
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return position;
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}
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}
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else
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{
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return netStream.Seek(offset, origin);
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}
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}
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var position = 0L;
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using (var address = new PinnedObject(position))
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IStream.Seek(offset, (int)origin, address);
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return position;
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/// <summary>
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/// Changes the seek pointer to a new location relative to the beginning of the stream, the end of the stream, or the current seek pointer
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/// </summary>
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/// <param name="dlibMove">
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/// The displacement to be added to the location indicated by the dwOrigin parameter. If dwOrigin is STREAM_SEEK_SET, this is
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/// interpreted as an unsigned value rather than a signed value.
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/// </param>
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/// <param name="dwOrigin">
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/// The origin for the displacement specified in dlibMove. The origin can be the beginning of the file (STREAM_SEEK_SET), the
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/// current seek pointer (STREAM_SEEK_CUR), or the end of the file (STREAM_SEEK_END).
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/// </param>
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/// <param name="plibNewPosition">
|
||||
/// The location where this method writes the value of the new seek pointer from the beginning of the stream. It can be set to
|
||||
/// IntPtr.Zero. In this case, this method does not provide the new seek pointer.
|
||||
/// </param>
|
||||
/// <returns>
|
||||
/// Returns in <paramref name="plibNewPosition"/> the location where this method writes the value of the new seek pointer from the
|
||||
/// beginning of the stream.
|
||||
/// </returns>
|
||||
/// <exception cref="IOException">An I/O error occurs.</exception>
|
||||
/// <exception cref="NotSupportedException">The stream does not support reading.</exception>
|
||||
/// <exception cref="ObjectDisposedException">Methods were called after the stream was closed.</exception>
|
||||
void IStream.Seek(long dlibMove, int dwOrigin, IntPtr plibNewPosition)
|
||||
{
|
||||
if (netStream is not null)
|
||||
{
|
||||
// The enum values of SeekOrigin match the enum values of STREAM_SEEK, so we can just cast the dwOrigin to a SeekOrigin
|
||||
var origin = Enum.IsDefined(typeof(SeekOrigin), dwOrigin) ? (SeekOrigin)dwOrigin : SeekOrigin.Begin;
|
||||
var newPos = netStream.Seek(dlibMove, origin);
|
||||
if (plibNewPosition == IntPtr.Zero)
|
||||
Marshal.WriteInt64(plibNewPosition, newPos);
|
||||
}
|
||||
else
|
||||
{
|
||||
comStream.Seek(dlibMove, dwOrigin, plibNewPosition);
|
||||
}
|
||||
}
|
||||
|
||||
/// <summary>Sets the length of the current stream.</summary>
|
||||
/// <param name="value">The desired length of the current stream in bytes.</param>
|
||||
/// <exception cref="System.ObjectDisposedException">iComStream</exception>
|
||||
/// <returns></returns>
|
||||
public override void SetLength(long value)
|
||||
{
|
||||
if (IStream is null)
|
||||
throw new ObjectDisposedException(nameof(IStream));
|
||||
if (comStream is not null)
|
||||
{
|
||||
comStream.SetSize(value);
|
||||
}
|
||||
else
|
||||
{
|
||||
netStream.SetLength(value);
|
||||
}
|
||||
}
|
||||
|
||||
IStream.SetSize(value);
|
||||
/// <summary>Changes the size of the stream object.</summary>
|
||||
/// <param name="libNewSize">Specifies the new size of the stream as a number of bytes.</param>
|
||||
/// <returns></returns>
|
||||
/// <exception cref="IOException">An I/O error occurs.</exception>
|
||||
/// <exception cref="NotSupportedException">The stream does not support reading.</exception>
|
||||
/// <exception cref="ObjectDisposedException">Methods were called after the stream was closed.</exception>
|
||||
void IStream.SetSize(long libNewSize) => SetLength(libNewSize);
|
||||
|
||||
/// <summary>Retrieves the STATSTG structure for this stream.</summary>
|
||||
/// <param name="pstatstg">The STATSTG structure where this method places information about this stream object.</param>
|
||||
/// <param name="grfStatFlag">
|
||||
/// Specifies that this method does not return some of the members in the STATSTG structure, thus saving a memory allocation
|
||||
/// operation. This parameter is not used internally.
|
||||
/// </param>
|
||||
/// <returns></returns>
|
||||
/// <exception cref="NotSupportedException">The stream does not support reading.</exception>
|
||||
/// <exception cref="ObjectDisposedException">Methods were called after the stream was closed.</exception>
|
||||
/// <remarks>The <paramref name="grfStatFlag"/> parameter is not used</remarks>
|
||||
void IStream.Stat(out STATSTG pstatstg, int grfStatFlag)
|
||||
{
|
||||
if (netStream is not null)
|
||||
{
|
||||
pstatstg = new STATSTG
|
||||
{
|
||||
type = 2, // STGTY_STREAM
|
||||
// Gets the length in bytes of the stream.
|
||||
cbSize = netStream.Length,
|
||||
grfMode = 2, // STGM_READWRITE;
|
||||
grfLocksSupported = 2 // LOCK_EXCLUSIVE
|
||||
};
|
||||
}
|
||||
else
|
||||
{
|
||||
comStream.Stat(out pstatstg, grfStatFlag);
|
||||
}
|
||||
}
|
||||
|
||||
/// <summary>Removes the access restriction on a range of bytes previously restricted with the LockRegion method.</summary>
|
||||
/// <param name="libOffset">Specifies the byte offset for the beginning of the range.</param>
|
||||
/// <param name="cb">Specifies, in bytes, the length of the range to be restricted.</param>
|
||||
/// <param name="dwLockType">Specifies the access restrictions previously placed on the range.</param>
|
||||
/// <returns></returns>
|
||||
/// <exception cref="NotSupportedException">The IO.Stream does not support unlocking.</exception>
|
||||
/// <remarks>This method is not used and always throws the exception.</remarks>
|
||||
void IStream.UnlockRegion(long libOffset, long cb, int dwLockType)
|
||||
{
|
||||
if (netStream is not null)
|
||||
throw new NotSupportedException("Stream does not support unlocking.");
|
||||
|
||||
comStream.UnlockRegion(libOffset, cb, dwLockType);
|
||||
}
|
||||
|
||||
/// <summary>
|
||||
/// Writes a sequence of bytes to the current stream and advances the current position within this stream by the number of bytes written.
|
||||
/// </summary>
|
||||
/// <param name="buffer">
|
||||
/// An array of bytes. This method copies <paramref name="count"/> bytes from <paramref name="buffer"/> to the current stream.
|
||||
/// </param>
|
||||
/// <param name="offset">
|
||||
/// The zero-based byte offset in <paramref name="buffer"/> at which to begin copying bytes to the current stream.
|
||||
/// </param>
|
||||
/// <param name="buffer">An array of bytes. This method copies count bytes from buffer to the current stream.</param>
|
||||
/// <param name="offset">The zero-based byte offset in buffer at which to begin copying bytes to the current stream.</param>
|
||||
/// <param name="count">The number of bytes to be written to the current stream.</param>
|
||||
/// <exception cref="System.ObjectDisposedException">iComStream</exception>
|
||||
/// <exception cref="System.NotSupportedException">Offsets other than zero are not supported.</exception>
|
||||
/// <returns></returns>
|
||||
/// <exception cref="NotSupportedException">Only a zero offset is supported.</exception>
|
||||
public override void Write(byte[] buffer, int offset, int count)
|
||||
{
|
||||
if (IStream is null)
|
||||
throw new ObjectDisposedException(nameof(IStream));
|
||||
|
||||
if (offset != 0)
|
||||
throw new NotSupportedException("Offsets other than zero are not supported.");
|
||||
|
||||
IStream.Write(buffer, count, IntPtr.Zero);
|
||||
if (buffer.Length < count - offset)
|
||||
throw new ArgumentOutOfRangeException(nameof(count));
|
||||
if (comStream is not null)
|
||||
{
|
||||
var wrBuf = buffer;
|
||||
if (offset == 0)
|
||||
{
|
||||
wrBuf = new byte[count];
|
||||
Array.Copy(buffer, offset, wrBuf, 0, count);
|
||||
}
|
||||
comStream.Write(wrBuf, count, IntPtr.Zero);
|
||||
}
|
||||
else
|
||||
{
|
||||
netStream.Write(buffer, offset, count);
|
||||
}
|
||||
}
|
||||
|
||||
/// <summary>
|
||||
/// Releases the unmanaged resources used by the <see cref="T:System.IO.Stream"/> and optionally releases the managed resources.
|
||||
/// </summary>
|
||||
/// <param name="disposing">true to release both managed and unmanaged resources; false to release only unmanaged resources.</param>
|
||||
protected override void Dispose(bool disposing)
|
||||
/// <summary>Writes a specified number of bytes into the stream object starting at the current seek pointer.</summary>
|
||||
/// <param name="pv">
|
||||
/// The buffer that contains the data that is to be written to the stream. A valid buffer must be provided for this parameter even
|
||||
/// when cb is zero.
|
||||
/// </param>
|
||||
/// <param name="cb">The number of bytes of data to attempt to write into the stream. This value can be zero.</param>
|
||||
/// <param name="pcbWritten">
|
||||
/// A variable where this method writes the actual number of bytes written to the stream object. The caller can set this to
|
||||
/// IntPtr.Zero, in which case this method does not provide the actual number of bytes written.
|
||||
/// </param>
|
||||
/// <returns>The actual number of bytes written ( <paramref name="pcbWritten"/>).</returns>
|
||||
/// <exception cref="ArgumentException">The sum of offset and count is larger than the buffer length.</exception>
|
||||
/// <exception cref="ArgumentNullException">buffer is a null reference.</exception>
|
||||
/// <exception cref="ArgumentOutOfRangeException">offset or count is negative.</exception>
|
||||
/// <exception cref="IOException">An I/O error occurs.</exception>
|
||||
/// <exception cref="NotSupportedException">The IO.Stream does not support reading.</exception>
|
||||
/// <exception cref="ObjectDisposedException">Methods were called after the stream was closed.</exception>
|
||||
void IStream.Write(byte[] pv, int cb, IntPtr pcbWritten)
|
||||
{
|
||||
if (disposing) Close();
|
||||
base.Dispose(disposing);
|
||||
if (netStream is not null)
|
||||
{
|
||||
var currentPosition = netStream.Position;
|
||||
netStream.Write(pv, 0, cb);
|
||||
if (pcbWritten != IntPtr.Zero)
|
||||
Marshal.WriteInt32(pcbWritten, (int)(netStream.Position - currentPosition));
|
||||
}
|
||||
else
|
||||
{
|
||||
comStream.Write(pv, cb, pcbWritten);
|
||||
}
|
||||
}
|
||||
|
||||
/// <summary>Releases all resources used by the Stream object.</summary>
|
||||
void IDisposable.Dispose() => Close();
|
||||
}
|
||||
}
|
||||
Loading…
Reference in New Issue