Re: content processing modules ready for experimentation

I just fetched the branch, and it looks great Robert.

We'll have questions for you shortly....

Robert Collins wrote:

> The rbcollins_filters branch now has a interface to filters that has
> passed the changing-minute-by-minute phase.
>
> Note: I've called it content processing, because filters do not need
> to alter the data to be useful: for example calculating the checksum
> for signed digest responses is a perfect filter that won't alter
> the data and shold only be in the request chain when needed.
>
> Second Note: As I started adding the fourth! set of module code to
> squid (fs/repl/auth/filters) I figured that maybe it was time to make
> generic modules that register with squid for the tasks they are
> able to be used for. Thus eliminating the need for a fifth set of
> identical configure options, modules.sh etc. So this branch has the
> beginings of a generic module framework. This doesn't affect the
> stability of the filters code, and if/when I start looking at bring
> the fs/repl/auth modules into the generic framework, I will branch
> off HEAD and port over the relevant bits beforehand. It's into
> there that I am considering working on dynamic modules.. anyone
> think that dynamic modules are a good thing/bad thing?
>
> So Joe & Moez, it's ready to be experimented with by you guys.
>
> Features: new squid.conf options: http_reply_access ->this isn't
> strictly speaking a filter feature, it was a 'freebie' that occured
> to me while building the reply_filter_access code. filter_add
filter_config
>

> reply_filter_access ->These combined to create an instance of a
> filter, configure the filter, and apply it to a reply.
>
> new acl type: acl foo rep_mime_type [-i] regex ->is a regex acl used
> to determine whether to apply a filter to a reply body.
>
> My sample filter (yes the code is garbage there, but I needed
> something to test with) called textreplace should act as a fairly
comprehensive
> template.
>
> There's still a long list of things I need to do to call this
> stable, such as * tidy up the boundary conditions for failed
> connections, aborted or dropped network connections etc. * flesh
> out the filter framework with some functions for common code
> patterns. * perhaps add a rep_status acl type?
>
> Writing filters: make a new directory in src/modules with the name
> of your module. Copy over the makefile.in from
> src/modules/textreplace & edit the Module line at the top and the
> list of objects. drop your source code into the same directory.
>
> Add a function of type MOD_INSTALL called mod_install_modulename to
> your source code.
>
> For filters, the install routine should call filterRegisterModule
> with the namestr passed to it upon install, and static pointers to it's
> filterAddInstance and filterRemInstance functions. Then implement
> all the functions contained in the FILTER_instance & FILTER_list
> structs. Voila, have a champagne.
>
> Rob

                                   --
                      Joe Cooper <joe@swelltech.com>
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Received on Tue Jan 30 2001 - 14:36:46 MST