[Tilecache] PATCH: X-SendFile and Expires headers
Christopher Schmidt
crschmidt at metacarta.com
Wed Oct 7 10:15:54 EDT 2009
On Tue, Oct 06, 2009 at 11:02:56AM -0400, mdeneen+tiles at saucontech.com wrote:
> Chris,
>
> I've attached another patch. This one adds a bit of documentation, support for the cgi handler and a bug fix to my previous patch. It will only send the X-SendFile and Expires if the content type is not text/xml. If text/xml is returned, the output should be identical to what it would be if one were not using X-SendFile.
>
> The patch is against TileCache 2.10, so you don't need to apply the previous patch first.
Applied, with a couple changes:
* expires is in seconds
* It checks for image/, rather than for text/xml, since KML is also
not-cached and served via the KML service.
* mod_python support added.
Commit was r396. I'll try and push a release with this and other bugfixes
relatively soon.
Thanks for the patch.
-- Chris
> Best Regards,
> Mark Deneen
> Saucon Technologies
>
> ----- "Christopher Schmidt" <crschmidt at metacarta.com> wrote:
>
> > On Tue, Oct 06, 2009 at 10:02:56AM -0400, Mark Deneen wrote:
> > > Where do you want the documentation for the new options? They are
> > options for the Disk cache and the only documented options I see are
> > for the layers. Should I just write up a description in
> > docs/Caches.txt?
> >
> > That'd be great. And no need to write the patch for the other
> > hanlders;
> > just mention in the docs what handlers the options work for.
> >
> > Don't worry too much about formatting; just get the text together, and
> >
> > I can fix any formatting issues.
> >
> > Regards,
> > --
> > Christopher Schmidt
> > MetaCarta
> diff -ru tilecache-2.10/docs/Caches.txt ../tilecache.mod/docs/Caches.txt
> --- tilecache-2.10/docs/Caches.txt 2008-12-14 09:59:49.000000000 -0500
> +++ ../tilecache.mod/docs/Caches.txt 2009-10-06 10:55:08.000000000 -0400
> @@ -12,9 +12,24 @@
> type=Disk
> base=/var/lib/tilecache
> umask=002
> + sendfile=yes
> + expire=24
>
> Dependencies: None
>
> +The sendfile=yes option instructs TileCache to send an X-SendFile header to
> +the web server rather than the contents of the image.
> +
> +See http://blog.lighttpd.net/articles/2006/07/02/x-sendfile and
> +http://tn123.ath.cx/mod_xsendfile/
> +
> +The expire=n option instructs TileCache to send an Expires header, with the
> +date set 'n' hours into the future.
> +
> +Both the sendfile and expire options are currently only supported with the cgi
> +and wsgi handlers. With minor changes, other handlers could easily be
> +supported.
> +
> GoogleDisk
> ----
> Example Configuration::
> diff -ru tilecache-2.10/TileCache/Caches/Disk.py ../tilecache.mod/TileCache/Caches/Disk.py
> --- tilecache-2.10/TileCache/Caches/Disk.py 2008-12-14 09:32:29.000000000 -0500
> +++ ../tilecache.mod/TileCache/Caches/Disk.py 2009-10-05 15:50:57.000000000 -0400
> @@ -4,11 +4,14 @@
> import sys, os, time, warnings
>
> class Disk (Cache):
> - def __init__ (self, base = None, umask = '002', **kwargs):
> + def __init__ (self, base = None, sendfile = False, expire = False, umask = '002', **kwargs):
> Cache.__init__(self, **kwargs)
> self.basedir = base
> self.umask = int(umask, 0)
> -
> + self.sendfile = sendfile and sendfile.lower() in ["yes", "y", "t", "true"]
> + self.expire = expire
> + if expire != False:
> + self.expire = long(expire) * 3600
> if sys.platform.startswith("java"):
> from java.io import File
> self.file_module = File
> @@ -64,8 +67,11 @@
> def get (self, tile):
> filename = self.getKey(tile)
> if self.access(filename, 'read'):
> - tile.data = file(filename, "rb").read()
> - return tile.data
> + if self.sendfile:
> + return filename
> + else:
> + tile.data = file(filename, "rb").read()
> + return tile.data
> else:
> return None
>
> diff -ru tilecache-2.10/TileCache/Service.py ../tilecache.mod/TileCache/Service.py
> --- tilecache-2.10/TileCache/Service.py 2009-01-18 21:11:52.000000000 -0500
> +++ ../tilecache.mod/TileCache/Service.py 2009-10-06 10:47:46.000000000 -0400
> @@ -4,7 +4,7 @@
>
> class TileCacheException(Exception): pass
>
> -import sys, cgi, time, os, traceback, ConfigParser
> +import sys, cgi, time, os, traceback, email, ConfigParser
> import Cache, Caches
> import Layer, Layers
>
> @@ -291,8 +291,18 @@
> fields = parse_formvars(environ)
>
> format, image = service.dispatchRequest( fields, path_info, req_method, host )
> - start_response("200 OK", [('Content-Type',format)])
> - return [image]
> + headers = [('Content-Type',format)]
> + if format != "text/xml":
> + if service.cache.sendfile:
> + headers.append(('X-SendFile', image))
> + if service.cache.expire:
> + headers.append(('Expires', email.Utils.formatdate(time.time() + service.cache.expire, False, True)))
> +
> + start_response("200 OK", headers)
> + if service.cache.sendfile and format != "text/xml":
> + return []
> + else:
> + return [image]
>
> except TileCacheException, E:
> start_response("404 Tile Not Found", [('Content-Type','text/plain')])
> @@ -321,12 +331,18 @@
> host += os.environ["SCRIPT_NAME"]
> req_method = os.environ["REQUEST_METHOD"]
> format, image = service.dispatchRequest( params, path_info, req_method, host )
> - print "Content-type: %s\n" % format
> -
> - if sys.platform == "win32":
> - binaryPrint(image)
> - else:
> - print image
> + print "Content-type: %s" % format
> + if format != "text/xml":
> + if service.cache.sendfile:
> + print "X-SendFile: %s" % image
> + if service.cache.expire:
> + print "Expires: %s" % email.Utils.formatdate(time.time() + service.cache.expire, False, True)
> + print "\n"
> + if (not service.cache.sendfile) or (format == "text/xml"):
> + if sys.platform == "win32":
> + binaryPrint(image)
> + else:
> + print image
> except TileCacheException, E:
> print "Cache-Control: max-age=10, must-revalidate" # make the client reload
> print "Content-type: text/plain\n"
--
Christopher Schmidt
MetaCarta
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