Class ReadOnlySubStream

Namespace

VpnHood.Net.Toolkit.Streams

Assembly

VpnHood.Net.Toolkit.dll

Provides a read-only, seekable window onto part of another stream: positions start at 0 at the window's start, and the window's end is the stream's end. It reads in place, with no copy, as for an uncompressed entry inside an Android package.

public class ReadOnlySubStream : Stream, IAsyncDisposable, IDisposable

Inheritance

object

MarshalByRefObject

Stream

ReadOnlySubStream

Implements

IAsyncDisposable

IDisposable

Inherited Members

Stream.Null

Stream.BeginRead(byte[], int, int, AsyncCallback, object)

Stream.BeginWrite(byte[], int, int, AsyncCallback, object)

Stream.Close()

Stream.CopyTo(Stream)

Stream.CopyTo(Stream, int)

Stream.CopyToAsync(Stream)

Stream.CopyToAsync(Stream, int)

Stream.CopyToAsync(Stream, int, CancellationToken)

Stream.CopyToAsync(Stream, CancellationToken)

Stream.CreateWaitHandle()

Stream.Dispose()

Stream.EndRead(IAsyncResult)

Stream.EndWrite(IAsyncResult)

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

Stream.WriteAsync(ReadOnlyMemory<byte>, CancellationToken)

Stream.WriteByte(byte)

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)

Remarks

Each nonempty read before the window's end positions the source first; seeking moves only the window's position. So one source must not serve two windows at once, and a window must not be read concurrently. Writing is never supported; reading, seeking and read timeouts are the source's.

Constructors

ReadOnlySubStream(Stream, long, long, bool)

Provides a read-only, seekable window onto part of another stream: positions start at 0 at the window's start, and the window's end is the stream's end. It reads in place, with no copy, as for an uncompressed entry inside an Android package.

public ReadOnlySubStream(Stream source, long start, long length, bool leaveOpen = false)

Parameters

source Stream

The source stream, which must read and seek.

start long

The window's start in the source.

length long

The window's length, which must end within the source.

leaveOpen bool

true to leave the source open when the window is disposed.

Remarks

Each nonempty read before the window's end positions the source first; seeking moves only the window's position. So one source must not serve two windows at once, and a window must not be read concurrently. Writing is never supported; reading, seeking and read timeouts are the source's.

Exceptions

ArgumentNullException

source is null.

ArgumentException

The source cannot read or seek.

ArgumentOutOfRangeException

start or length is negative, or the window ends past the source's end.

Properties

CanRead

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

public override bool CanRead { get; }

Property Value

bool

true if the stream supports reading; otherwise, false.

Remarks

The source's.

Exceptions

ArgumentNullException

source is null.

ArgumentException

The source cannot read or seek.

ArgumentOutOfRangeException

start or length is negative, or the window ends past the source's end.

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

The source's.

Exceptions

ArgumentNullException

source is null.

ArgumentException

The source cannot read or seek.

ArgumentOutOfRangeException

start or length is negative, or the window ends past the source's end.

CanTimeout

Gets a value that determines whether the current stream can time out.

public override bool CanTimeout { get; }

Property Value

bool

A value that determines whether the current stream can time out.

Remarks

The source's.

Exceptions

ArgumentNullException

source is null.

ArgumentException

The source cannot read or seek.

ArgumentOutOfRangeException

start or length is negative, or the window ends past the source's end.

CanWrite

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

public override bool CanWrite { get; }

Property Value

bool

true if the stream supports writing; otherwise, false.

Remarks

It is always false.

Exceptions

ArgumentNullException

source is null.

ArgumentException

The source cannot read or seek.

ArgumentOutOfRangeException

start or length is negative, or the window ends past the source's end.

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.

Remarks

The window's length.

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.

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.

Remarks

The position in the window; setting it seeks from the window's start.

Exceptions

IOException

An I/O error occurs.

NotSupportedException

The stream does not support seeking.

ObjectDisposedException

Methods were called after the stream was closed.

ReadTimeout

Gets or sets a value, in milliseconds, that determines how long the stream will attempt to read before timing out.

public override int ReadTimeout { get; set; }

Property Value

int

A value, in milliseconds, that determines how long the stream will attempt to read before timing out.

Remarks

The source's.

Exceptions

InvalidOperationException

The ReadTimeout method always throws an InvalidOperationException.

Methods

Dispose(bool)

Closes the source, once, unless left open, when disposing.

protected override void Dispose(bool disposing)

Parameters

disposing bool

true for the synchronous close.

Exceptions

ArgumentNullException

source is null.

ArgumentException

The source cannot read or seek.

ArgumentOutOfRangeException

start or length is negative, or the window ends past the source's end.

DisposeAsync()

Closes the source asynchronously, once, unless left open, then disposes the window.

public override ValueTask DisposeAsync()

Returns

ValueTask

A task that represents the asynchronous operation.

Exceptions

ArgumentNullException

source is null.

ArgumentException

The source cannot read or seek.

ArgumentOutOfRangeException

start or length is negative, or the window ends past the source's end.

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 void Flush()

Remarks

The source's.

Exceptions

IOException

An I/O error occurs.

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

The source's.

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 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.

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.

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 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

It reads no further than the window's end.

Exceptions

ArgumentNullException

source is null.

ArgumentException

The source cannot read or seek.

ArgumentOutOfRangeException

start or length is negative, or the window ends past the source's end.

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 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.

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 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.

Remarks

It reads no further than the window's end.

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 int ReadByte()

Returns

int

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

Exceptions

NotSupportedException

The stream does not support reading.

ObjectDisposedException

Methods were called after the stream was closed.

Seek(long, SeekOrigin)

Sets the position in the window; past its end is allowed, where a read returns 0.

public override long Seek(long position, SeekOrigin origin)

Parameters

position long

The offset from the origin.

origin SeekOrigin

The origin: the window's start, the current position, or the window's end.

Returns

long

The new position.

Exceptions

ArgumentOutOfRangeException

The position would be before the window's start, or the origin is not valid.

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 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.

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 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.

Exceptions

NotSupportedException

Always.