hfutils.utils.binary_proxy

BinaryProxyIO module provides a proxy implementation for binary I/O operations.

This module defines a class that wraps a binary stream and implements the BinaryIO interface, primarily focusing on write operations while providing stubs for other operations. It can be used as a base class for implementing custom binary I/O handlers that need to intercept or modify write operations.

BinaryProxyIO

class hfutils.utils.binary_proxy.BinaryProxyIO(stream: BinaryIO)

A proxy class that implements the BinaryIO interface, wrapping another binary stream.

This class primarily supports write operations, while other operations raise io.UnsupportedOperation exceptions by default. It can be extended by overriding the _on_write and _after_close methods to implement custom behavior.

Parameters:

stream (BinaryIO) – The binary stream to wrap

__enter__()

Enter the runtime context related to this object.

Returns:

Self

Return type:

BinaryProxyIO

Raises:

ValueError – If the file is already closed

__exit__(_BinaryProxyIO__t, _BinaryProxyIO__value, _BinaryProxyIO__traceback)

Exit the runtime context related to this object.

Parameters:

• __t – Exception type

• __value – Exception value

• __traceback – Exception traceback

__iter__()

Return self as an iterator.

Returns:

Self

Return type:

BinaryProxyIO

Raises:

ValueError – If the file is closed

close()

Close the file.

This method sets the internal closed flag to True and calls _after_close.

fileno()

Return the underlying file descriptor.

Raises:

UnsupportedOperation – Always, as this operation is not supported

flush()

Flush the write buffers.

Raises:

• ValueError – If the file is closed

• UnsupportedOperation – Always, as this operation is not supported

isatty()

Return whether this is an ‘interactive’ stream.

Returns:

Always False

Return type:

bool

Raises:

ValueError – If the file is closed

read(_BinaryProxyIO__n=Ellipsis)

Read up to n bytes from the object and return them.

Parameters:

__n (int, optional) – Number of bytes to read

Raises:

• ValueError – If the file is closed

• UnsupportedOperation – Always, as this operation is not supported

readable()

Return whether the file is readable.

Returns:

Always False

Return type:

bool

Raises:

ValueError – If the file is closed

readline(_BinaryProxyIO__limit=Ellipsis)

Read and return one line from the stream.

Parameters:

__limit (int, optional) – Maximum number of bytes to read

Raises:

• ValueError – If the file is closed

• UnsupportedOperation – Always, as this operation is not supported

readlines(_BinaryProxyIO__hint=Ellipsis)

Return a list of lines from the stream.

Parameters:

__hint (int, optional) – Maximum number of bytes to read

Raises:

• ValueError – If the file is closed

• UnsupportedOperation – Always, as this operation is not supported

seek(_BinaryProxyIO__offset, _BinaryProxyIO__whence=Ellipsis)

Change the stream position.

Parameters:

• __offset (int) – Offset relative to position indicated by whence

• __whence (int, optional) – Position from which offset is applied

Raises:

• ValueError – If the file is closed

• UnsupportedOperation – Always, as this operation is not supported

seekable()

Return whether the file supports seeking.

Returns:

Always False

Return type:

bool

Raises:

ValueError – If the file is closed

tell()

Return the current stream position.

Returns:

Current position in the file

Return type:

int

Raises:

ValueError – If the file is closed

truncate(_BinaryProxyIO__size=Ellipsis)

Truncate the file to at most size bytes.

Parameters:

__size (int, optional) – Size to truncate to

Raises:

• ValueError – If the file is closed

• UnsupportedOperation – Always, as this operation is not supported

writable()

Return whether the file is writable.

Returns:

Always True

Return type:

bool

Raises:

ValueError – If the file is closed

write(_BinaryProxyIO__s)

Write bytes to the file.

This method writes the bytes to the wrapped stream, updates the position, calls the _on_write hook, and returns the number of bytes written.

Parameters:

__s (bytes) – Bytes to write

Returns:

Number of bytes written

Return type:

int

Raises:

ValueError – If the file is closed

writelines(_BinaryProxyIO__lines)

Write a list of lines to the file.

Parameters:

__lines (list[bytes]) – List of byte strings to write

Raises:

ValueError – If the file is closed