guv 0.33.2

About

guv is a fast networking library and WSGI server for Python >= 3.2 and pypy3

The event loop backend is pyuv_cffi, which aims to be fully compatible with the pyuv interface. pyuv_cffi is fully supported on CPython and pypy3, but is still experimental and in heavy development. libuv >= 1.0.0 is required

Asynchronous DNS queries are supported via dnspython3 if available (pip install dnspython3). To forcefully disable greendns, set the environment variable GUV_NO_GREENDNS to any value.

Currently only runs on POSIX-compliant operating systems (no Windows), but Windows support is not far off and can be added in the near future if there is a demand for this.

This project is under heavy, active development and any help is appreciated.

Installing

Since guv is in very heavy, active development, it is currently highly recommended to pull often and install manually:

git clone https://github.com/veegee/guv.git
cd guv
python setup.py install

You’ll need the latest version (>= 1.0.0) of libuv which isn’t available on most package managers yet, so visit their project page to see how to intall it.

While you’re there, you can run some examples:

cd examples
pip install requests
python3 crawler.py

Install using pip:

pip install guv

Examples

• examples/crawler.py: using requests to crawl the web (both HTTP and HTTPS)

• examples/wsgi_app.py: serving a WSGI application (any WSGI application is fully supported, since the current WSGI server implementation is heavily based on gevent’s server).

• examples/guv_simple_server.py: a low-level example showing how to create very fast TCP servers which can easily handle 10,000+ connections.

With any of these examples, you can use wrk to get an idea of guv’s performance in terms of open connections and requests/sec.

Compatibility

guv aims to be compatible with all libraries which are compatible with the gevent/eventlet-patched standard library. Out of the box, the provided examples show how easy it is to use guv.

pyuv_cffi Status

• Currently implemented handles: Loop, Handle, Idle, Prepare, Timer, Signal, Poll

• The remaining handles are trivial to implement, and will be implemented after high priority goals are completed.

To do

High and medium priority tasks are in the issue tracker.

Low priority:

• Optimize the WSGI server by using http-parser and removing the dependency of socket.makefile(), which seems to be slow on Python 3.

• Speed up importing and monkey-patching. The initial delay may be caused by CFFI compiling/verifying and the patcher module.

• Implement the asyncio interface

• When we drop Python 3.2 support, we can greatly simplify I/O exceptions by using BlockingIOError rather than socket.error and checking for args[0]. It would be a good idea to patch BlockingIOError now to ease the transition to drop Python 3.2 support later.