Class AsyncStream

Namespace

VpnHood.Net.Toolkit.Streams

Assembly

VpnHood.Net.Toolkit.dll

Base Stream for async-only streams. It centralizes the repetitive plumbing: every synchronous I/O member throws NotSupportedException, and the legacy byte[]-based async overloads are routed to the Memory<T>-based core methods. Derived classes only implement the real I/O: ReadAsync(Memory<byte>, CancellationToken), WriteAsync(ReadOnlyMemory<byte>, CancellationToken), CanRead and CanWrite.

public abstract class AsyncStream : Stream, IAsyncDisposable, IDisposable

Inheritance

object

MarshalByRefObject

Stream

AsyncStream

Implements

IAsyncDisposable

IDisposable

Derived

AsyncStreamDecorator<T>

Inherited Members

Stream.Null

Stream.Close()

Stream.CopyTo(Stream)

Stream.CopyToAsync(Stream)

Stream.CopyToAsync(Stream, int)

Stream.CopyToAsync(Stream, int, CancellationToken)

Stream.CopyToAsync(Stream, CancellationToken)

Stream.CreateWaitHandle()

Stream.Dispose()

Stream.Dispose(bool)

Stream.DisposeAsync()

Stream.FlushAsync()

Stream.ObjectInvariant()

Stream.ReadAsync(byte[], int, int)

Stream.ReadAtLeast(Span<byte>, int, bool)

Stream.ReadAtLeastAsync(Memory<byte>, int, bool, CancellationToken)

Stream.ReadExactly(byte[], int, int)

Stream.ReadExactly(Span<byte>)

Stream.ReadExactlyAsync(byte[], int, int, CancellationToken)

Stream.ReadExactlyAsync(Memory<byte>, CancellationToken)

Stream.Synchronized(Stream)

Stream.ValidateBufferArguments(byte[], int, int)

Stream.ValidateCopyToArguments(Stream, int)

Stream.WriteAsync(byte[], int, int)

Stream.CanTimeout

Stream.ReadTimeout

Stream.WriteTimeout

MarshalByRefObject.GetLifetimeService()

MarshalByRefObject.InitializeLifetimeService()

MarshalByRefObject.MemberwiseClone(bool)

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

object.ToString()

Extension Methods

AsyncDisposableExtensions.TryDisposeAsync(IAsyncDisposable?, LogLevel)

AsyncDisposableExtensions.TryDisposeAsync(IAsyncDisposable?, TimeSpan, LogLevel)

DisposableExtensions.TryDispose(IDisposable?, LogLevel)

Properties

CanRead

When overridden in a derived class, gets a value indicating whether the current stream supports reading.

public override abstract bool CanRead { get; }

Property Value

bool

true if the stream supports reading; otherwise, false.

CanSeek

When overridden in a derived class, gets a value indicating whether the current stream supports seeking.

public override bool CanSeek { get; }

Property Value

bool

true if the stream supports seeking; otherwise, false.

Remarks

It is false here.

CanWrite

When overridden in a derived class, gets a value indicating whether the current stream supports writing.

public override abstract bool CanWrite { get; }

Property Value

bool

true if the stream supports writing; otherwise, false.

Length

When overridden in a derived class, gets the length in bytes of the stream.

public override long Length { get; }

Property Value

long

A long value representing the length of the stream in bytes.

Exceptions

NotSupportedException

A class derived from Stream does not support seeking and the length is unknown.

ObjectDisposedException

Methods were called after the stream was closed.

NotSupportedException

Always.

Position

When overridden in a derived class, gets or sets the position within the current stream.

public override long Position { get; set; }

Property Value

long

The current position within the stream.

Exceptions

IOException

An I/O error occurs.

NotSupportedException

The stream does not support seeking.

ObjectDisposedException

Methods were called after the stream was closed.

NotSupportedException

Always.

Methods

BeginRead(byte[], int, int, AsyncCallback?, object?)

Begins an asynchronous read operation. (Consider using ReadAsync(byte[], int, int) instead.)

public override sealed IAsyncResult BeginRead(byte[] buffer, int offset, int count, AsyncCallback? callback, object? state)

Parameters

buffer byte[]

The buffer to read the data into.

offset int

The byte offset in buffer at which to begin writing data read from the stream.

count int

The maximum number of bytes to read.

callback AsyncCallback

An optional asynchronous callback, to be called when the read is complete.

state object

A user-provided object that distinguishes this particular asynchronous read request from other requests.

Returns

IAsyncResult

An IAsyncResult that represents the asynchronous read, which could still be pending.

Remarks

The legacy asynchronous pattern is not supported: use ReadAsync or WriteAsync.

Exceptions

IOException

Attempted an asynchronous read past the end of the stream, or a disk error occurs.

ArgumentException

One or more of the arguments is invalid.

ObjectDisposedException

Methods were called after the stream was closed.

NotSupportedException

The current Stream implementation does not support the read operation.

NotSupportedException

Always.

BeginWrite(byte[], int, int, AsyncCallback?, object?)

Begins an asynchronous write operation. (Consider using WriteAsync(byte[], int, int) instead.)

public override sealed IAsyncResult BeginWrite(byte[] buffer, int offset, int count, AsyncCallback? callback, object? state)

Parameters

buffer byte[]

The buffer to write data from.

offset int

The byte offset in buffer from which to begin writing.

count int

The maximum number of bytes to write.

callback AsyncCallback

An optional asynchronous callback, to be called when the write is complete.

state object

A user-provided object that distinguishes this particular asynchronous write request from other requests.

Returns

IAsyncResult

An IAsyncResult that represents the asynchronous write, which could still be pending.

Remarks

The legacy asynchronous pattern is not supported: use ReadAsync or WriteAsync.

Exceptions

IOException

Attempted an asynchronous write past the end of the stream, or a disk error occurs.

ArgumentException

One or more of the arguments is invalid.

ObjectDisposedException

Methods were called after the stream was closed.

NotSupportedException

The current Stream implementation does not support the write operation.

NotSupportedException

Always.

CopyTo(Stream, int)

Reads the bytes from the current stream and writes them to another stream, using a specified buffer size. Both streams positions are advanced by the number of bytes copied.

public override sealed void CopyTo(Stream destination, int bufferSize)

Parameters

destination Stream

The stream to which the contents of the current stream will be copied.

bufferSize int

The size of the buffer. This value must be greater than zero. The default size is 81920.

Remarks

Synchronous I/O is not supported: use the asynchronous members.

Exceptions

ArgumentNullException

destination is null.

ArgumentOutOfRangeException

bufferSize is negative or zero.

NotSupportedException

The current stream does not support reading.

-or-

destination does not support writing.

ObjectDisposedException

Either the current stream or destination were closed before the CopyTo(Stream) method was called.

IOException

An I/O error occurred.

NotSupportedException

Always.

EndRead(IAsyncResult)

Waits for the pending asynchronous read to complete. (Consider using ReadAsync(byte[], int, int) instead.)

public override sealed int EndRead(IAsyncResult asyncResult)

Parameters

asyncResult IAsyncResult

The reference to the pending asynchronous request to finish.

Returns

int

The number of bytes read from the stream, between zero (0) and the number of bytes requested. ReadAsync returns zero (0) only if zero bytes were requested or if no more bytes will be available because it's at the end of the stream; otherwise, read operations do not complete until at least one byte is available. If zero bytes are requested, read operations may complete immediately or may not complete until at least one byte is available (but without consuming any data).

Remarks

The legacy asynchronous pattern is not supported: use ReadAsync or WriteAsync.

Exceptions

ArgumentNullException

asyncResult is null.

ArgumentException

A handle to the pending read operation is not available.

-or-

The pending operation does not support reading.

InvalidOperationException

asyncResult did not originate from a BeginRead(byte[], int, int, AsyncCallback, object) method on the current stream.

IOException

The stream is closed or an internal error has occurred.

NotSupportedException

Always.

EndWrite(IAsyncResult)

Ends an asynchronous write operation. (Consider using WriteAsync(byte[], int, int) instead.)

public override sealed void EndWrite(IAsyncResult asyncResult)

Parameters

asyncResult IAsyncResult

A reference to the outstanding asynchronous I/O request.

Remarks

The legacy asynchronous pattern is not supported: use ReadAsync or WriteAsync.

Exceptions

ArgumentNullException

asyncResult is null.

ArgumentException

A handle to the pending write operation is not available.

-or-

The pending operation does not support writing.

InvalidOperationException

asyncResult did not originate from a BeginWrite(byte[], int, int, AsyncCallback, object) method on the current stream.

IOException

The stream is closed or an internal error has occurred.

NotSupportedException

Always.

Flush()

When overridden in a derived class, clears all buffers for this stream and causes any buffered data to be written to the underlying device.

public override sealed void Flush()

Remarks

Synchronous I/O is not supported: use the asynchronous members.

Exceptions

IOException

An I/O error occurs.

NotSupportedException

Always.

FlushAsync(CancellationToken)

Asynchronously clears all buffers for this stream, causes any buffered data to be written to the underlying device, and monitors cancellation requests.

public override Task FlushAsync(CancellationToken cancellationToken)

Parameters

cancellationToken CancellationToken

The token to monitor for cancellation requests. The default value is None.

Returns

Task

A task that represents the asynchronous flush operation.

Remarks

It does nothing here.

Exceptions

ObjectDisposedException

The stream has been disposed.

OperationCanceledException

The cancellation token was canceled. This exception is stored into the returned task.

Read(byte[], int, int)

When overridden in a derived class, reads a sequence of bytes from the current stream and advances the position within the stream by the number of bytes read.

public override sealed int Read(byte[] buffer, int offset, int count)

Parameters

buffer byte[]

An array of bytes. When this method returns, the buffer contains the specified byte array with the values between offset and (offset + count - 1) replaced by the bytes read from the current source.

offset int

The zero-based byte offset in buffer at which to begin storing the data read from the current stream.

count int

The maximum number of bytes to be read from the current stream.

Returns

int

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 currently available, or zero (0) if count is 0 or the end of the stream has been reached.

Remarks

Synchronous I/O is not supported: use the asynchronous members.

Exceptions

ArgumentException

The sum of offset and count is larger than the buffer length.

ArgumentNullException

buffer is null.

ArgumentOutOfRangeException

offset or count is negative.

IOException

An I/O error occurs.

NotSupportedException

The stream does not support reading.

ObjectDisposedException

Methods were called after the stream was closed.

NotSupportedException

Always.

Read(Span<byte>)

When overridden in a derived class, reads a sequence of bytes from the current stream and advances the position within the stream by the number of bytes read.

public override sealed int Read(Span<byte> buffer)

Parameters

buffer Span<byte>

A region of memory. When this method returns, the contents of this region are replaced by the bytes read from the current source.

Returns

int

The total number of bytes read into the buffer. This can be less than the size of the buffer if that many bytes are not currently available, or zero (0) if the buffer's length is zero or the end of the stream has been reached.

Remarks

Synchronous I/O is not supported: use the asynchronous members.

Exceptions

NotSupportedException

Always.

ReadAsync(byte[], int, int, CancellationToken)

Asynchronously reads a sequence of bytes from the current stream, advances the position within the stream by the number of bytes read, and monitors cancellation requests.

public override sealed Task<int> ReadAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)

Parameters

buffer byte[]

The buffer to write the data into.

offset int

The byte offset in buffer at which to begin writing data from the stream.

count int

The maximum number of bytes to read.

cancellationToken CancellationToken

The token to monitor for cancellation requests. The default value is None.

Returns

Task<int>

A task that represents the asynchronous read operation. The value of the TResult parameter contains the total number of bytes read into the buffer. The result value can be less than the number of bytes requested if the number of bytes currently available is less than the requested number, or it can be 0 (zero) if count is 0 or if the end of the stream has been reached.

Remarks

It calls the Memory<T> overload.

Exceptions

ArgumentNullException

buffer is null.

ArgumentOutOfRangeException

offset or count is negative.

ArgumentException

The sum of offset and count is larger than the buffer length.

NotSupportedException

The stream does not support reading.

ObjectDisposedException

The stream has been disposed.

InvalidOperationException

The stream is currently in use by a previous read operation.

OperationCanceledException

The cancellation token was canceled. This exception is stored into the returned task.

ReadAsync(Memory<byte>, CancellationToken)

Asynchronously reads a sequence of bytes from the current stream, advances the position within the stream by the number of bytes read, and monitors cancellation requests.

public override abstract ValueTask<int> ReadAsync(Memory<byte> buffer, CancellationToken cancellationToken = default)

Parameters

buffer Memory<byte>

The region of memory to write the data into.

cancellationToken CancellationToken

The token to monitor for cancellation requests. The default value is None.

Returns

ValueTask<int>

A task that represents the asynchronous read operation. The value of its Result property contains the total number of bytes read into the buffer. The result value can be less than the length of the buffer if that many bytes are not currently available, or it can be 0 (zero) if the length of the buffer is 0 or if the end of the stream has been reached.

Exceptions

OperationCanceledException

The cancellation token was canceled. This exception is stored into the returned task.

ReadByte()

Reads a byte from the stream and advances the position within the stream by one byte, or returns -1 if at the end of the stream.

public override sealed int ReadByte()

Returns

int

The unsigned byte cast to an int, or -1 if at the end of the stream.

Remarks

Synchronous I/O is not supported: use the asynchronous members.

Exceptions

NotSupportedException

The stream does not support reading.

ObjectDisposedException

Methods were called after the stream was closed.

NotSupportedException

Always.

Seek(long, SeekOrigin)

When overridden in a derived class, sets the position within the current stream.

public override long Seek(long offset, SeekOrigin origin)

Parameters

offset long

A byte offset relative to the origin parameter.

origin SeekOrigin

A value of type SeekOrigin indicating the reference point used to obtain the new position.

Returns

long

The new position within the current stream.

Exceptions

IOException

An I/O error occurs.

NotSupportedException

The stream does not support seeking, such as if the stream is constructed from a pipe or console output.

ObjectDisposedException

Methods were called after the stream was closed.

NotSupportedException

Always.

SetLength(long)

When overridden in a derived class, sets the length of the current stream.

public override void SetLength(long value)

Parameters

value long

The desired length of the current stream in bytes.

Exceptions

IOException

An I/O error occurs.

NotSupportedException

The stream does not support both writing and seeking, such as if the stream is constructed from a pipe or console output.

ObjectDisposedException

Methods were called after the stream was closed.

NotSupportedException

Always.

Write(byte[], int, int)

When overridden in a derived class, writes a sequence of bytes to the current stream and advances the current position within this stream by the number of bytes written.

public override sealed void Write(byte[] buffer, int offset, int count)

Parameters

buffer byte[]

An array of bytes. This method copies count bytes from buffer to the current stream.

offset int

The zero-based byte offset in buffer at which to begin copying bytes to the current stream.

count int

The number of bytes to be written to the current stream.

Remarks

Synchronous I/O is not supported: use the asynchronous members.

Exceptions

ArgumentException

The sum of offset and count is greater than the buffer length.

ArgumentNullException

buffer is null.

ArgumentOutOfRangeException

offset or count is negative.

IOException

An I/O error occurred, such as the specified file cannot be found.

NotSupportedException

The stream does not support writing.

ObjectDisposedException

Write(byte[], int, int) was called after the stream was closed.

NotSupportedException

Always.

Write(ReadOnlySpan<byte>)

When overridden in a derived class, writes a sequence of bytes to the current stream and advances the current position within this stream by the number of bytes written.

public override sealed void Write(ReadOnlySpan<byte> buffer)

Parameters

buffer ReadOnlySpan<byte>

A region of memory. This method copies the contents of this region to the current stream.

Remarks

Synchronous I/O is not supported: use the asynchronous members.

Exceptions

NotSupportedException

Always.

WriteAsync(byte[], int, int, CancellationToken)

Asynchronously writes a sequence of bytes to the current stream, advances the current position within this stream by the number of bytes written, and monitors cancellation requests.

public override sealed Task WriteAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)

Parameters

buffer byte[]

The buffer to write data from.

offset int

The zero-based byte offset in buffer from which to begin copying bytes to the stream.

count int

The maximum number of bytes to write.

cancellationToken CancellationToken

The token to monitor for cancellation requests. The default value is None.

Returns

Task

A task that represents the asynchronous write operation.

Remarks

It calls the ReadOnlyMemory<T> overload.

Exceptions

ArgumentNullException

buffer is null.

ArgumentOutOfRangeException

offset or count is negative.

ArgumentException

The sum of offset and count is larger than the buffer length.

NotSupportedException

The stream does not support writing.

ObjectDisposedException

The stream has been disposed.

InvalidOperationException

The stream is currently in use by a previous write operation.

OperationCanceledException

The cancellation token was canceled. This exception is stored into the returned task.

WriteAsync(ReadOnlyMemory<byte>, CancellationToken)

Asynchronously writes a sequence of bytes to the current stream, advances the current position within this stream by the number of bytes written, and monitors cancellation requests.

public override abstract ValueTask WriteAsync(ReadOnlyMemory<byte> buffer, CancellationToken cancellationToken = default)

Parameters

buffer ReadOnlyMemory<byte>

The region of memory to write data from.

cancellationToken CancellationToken

The token to monitor for cancellation requests. The default value is None.

Returns

ValueTask

A task that represents the asynchronous write operation.

Exceptions

OperationCanceledException

The cancellation token was canceled. This exception is stored into the returned task.

WriteByte(byte)

Writes a byte to the current position in the stream and advances the position within the stream by one byte.

public override sealed void WriteByte(byte value)

Parameters

value byte

The byte to write to the stream.

Remarks

Synchronous I/O is not supported: use the asynchronous members.

Exceptions

IOException

An I/O error occurs.

NotSupportedException

The stream does not support writing, or the stream is already closed.

ObjectDisposedException

Methods were called after the stream was closed.

NotSupportedException

Always.