non_blocking_io_wrapper

Description:

non_blocking_io_wrapper.NonBlockingReader is a wrapper class to build a non blocking stream from any read stream. It can be used for example to wrap the stdout pipe of a subprocess in a non blocking way.

It is a true io.RawIOBase subclass. Because of that, any method valid on an input byte stream should work seamlessly. Yet, a line access (readline, or iterator) will raise an OSError if no data is available at call time (you can use the select method to test/wait for that condition). If some data is available a line will be returned, or a partial one if no newline is available in the buffer.

If no data is present, a read will return None instead of blocking.

Additional methods

drain(timeout=None)

Waits for the underlying stream to reach its end of file.

If timeout is given and is not None it is the maximum time in seconds to wait.

Returns True if it succeeded or False on timeout.

It is intended to force a blocking wait after signaling an end of communication to a peer.

select(timeout=None)

Waits for data to become available.

If timeout is given and is not None it is the maximum time in seconds to wait.

Returns True if it succeeded or False on timeout

It is intended to allow to wait for availability of some data.

Installation

From PyPI

Released version are normally available from PyPI. Just user pip to install the last one:

pip install non_blocking_io_wrapper

From GitHUB

You can also clone the main repository from GitHUB:

git clone https://github.com/s-ball/non_blocking_io_wrapper.git

Contribution - development

A test package (97% coverage as of 0.5) is included in the GitHUB repository and in the source packages on PyPI.

Special processing for version.py

Versioning file is not included in the GitHUB repository because it is generated with setuptools_scm. It is of course included in PyPI packages so you should make sure to have a true git repository, or to get the sources from PyPI. The symptom is that you get a version number of 0.0.0 ...

Disclaimer: beta quality

It is fully functional and pass tests for Python 3.6 to 3.9 on Travis-CI. Yet it could have a better documentation, and has not been extensively tested.

License

This work is licenced under a MIT Licence. See LICENSE.txt