"""
This simple module demonstrates how to use the content handler
to send gzipped files to the remote browser (if it is supported)
To use this handler, simple turn it on via:

SnakeContentHandler   mod_snake_gzip_content.content_handler

You can enable and disable gzipping certain regions of your website by
also adding a:
SnakeVarSet gzip_content off|on

And to change the compression level (6 default), use:
SnakeVarSet gzip_level <0-9>

XXX -- This module should change once 2.0 supports IO filtering.
"""

import gzip
import mod_snake
import string
import sys

def content_handler(per_dir, per_svr, r):
    if per_dir.has_key('gzip_content') and per_dir['gzip_content'] == 'off':
        return mod_snake.DECLINED
    
    if not r.headers_in.has_key('Accept-Encoding'):
        return mod_snake.DECLINED
    
    if string.find(r.headers_in['Accept-Encoding'], 'gzip') == -1:
        return mod_snake.DECLINED
    
    try:
        x = open(r.filename, 'r')
        data = x.read()
        r.content_encoding  = 'gzip'
        r.send_http_header()
        gzip_level = 6
        if per_dir.has_key('gzip_level'):
            try:
                gzip_level = int(per_dir['gzip_level'])
            except:
                pass
            
        if gzip_level < 0:
            gzip_level = 0
        elif gzip_level > 9:
            gzip_level = 9
            
        x = gzip.GzipFile(None, 'w', gzip_level, r.connection)
        x.write(data)
        x.close()
        return mod_snake.OK
    except IOError:
        # XXX -- Is this correct?  if we don't know anything about it,
        # simply pass it on?
        return mod_snake.DECLINED
    except:
        # XXX -- Log a traceback
        return mod_snake.HTTP_INTERNAL_SERVER_ERROR