Slow hgweb.cgi

[Dominik Psenner]

> Then, the last thing I can think of is to instrument the hgweb
> CGI/WSGI to gather and dump profiling information, just like the
> --profile command line option.  The code for such option is at:
> 
>     http://selenic.com/hg/file/b032bec2c0a6/mercurial/dispatch.py#l613
> 
> From line 613.  Unfortunately, I don't fully understand how it works
> to give you any advice.  Maybe even there is a sample CGI/WSGI script
> already configured for profiling.

If it's not documented anywhere, from now on it is. I hacked:

#!/usr/bin/env python
def main():
  # Path to repo or hgweb config to serve (see 'hg help hgweb')
  config = "/var/hg/hgweb.config"

  # let the output be UTF-8
  import os;
  os.environ["HGENCODING"] = "UTF-8"

  # Uncomment and adjust if Mercurial is not installed system-wide:
  #import sys; sys.path.insert(0, "/path/to/python/lib")

  # Uncomment to send python tracebacks to the browser if an error occurs:
  #import cgitb; cgitb.enable()

  from mercurial import demandimport; demandimport.enable()
  from mercurial.hgweb import hgweb, wsgicgi
  application = hgweb(config)
  wsgicgi.launch(application)
import profile;
profile.run("main()")

And then executed on the server:

$ export SCRIPT_NAME="hgweb.cgi"
$ ./hgweb.profile.cgi

Hooray!

PS: this story feels a lot like hacking ;-)