[Haskell-cafe] Contributing to http-conduit

[Myles C. Maxfield]

1. The spec defines a grammar for the attributes. They're in uppercase.
2. Yes - 1.3 is the first version that lists DiffTime as an instance of
RealFrac (so I can use the 'floor' function to pull out the number of
seconds to render it)
3. I'll see what I can do.

--Myles

On Sat, Feb 4, 2012 at 9:06 PM, Michael Snoyman <michael at snoyman.com> wrote:

> Looks good, a few questions/requests:
>
> 1. Is there a reason to upper-case all the attributes?
> 2. Is the time >= 1.3 a requirements? Because that can cause a lot of
> trouble for people.
> 3. Can you send the patch as a Github pull request? It's easier to
> track that way.
>
> Michael
>
> On Sat, Feb 4, 2012 at 1:21 AM, Myles C. Maxfield
> <myles.maxfield at gmail.com> wrote:
> > Here is the patch to Web.Cookie. I didn't modify the tests at all because
> > they were already broken - they looked like they hadn't been updated
> since
> > SetCookie only had 5 parameters. I did verify by hand that the patch
> works,
> > though.
> >
> > Thanks,
> > Myles
> >
> >
> > On Thu, Feb 2, 2012 at 11:26 PM, Myles C. Maxfield
> > <myles.maxfield at gmail.com> wrote:
> >>
> >> Alright, I'll make a small patch that adds 2 fields to SetCookie:
> >> setCookieMaxAge :: Maybe DiffTime
> >> setCookieSecureOnly :: Bool
> >>
> >> I've also gotten started on those cookie functions. I'm currently
> writing
> >> tests for them.
> >>
> >> @Chris: The best advice I can give is that Chrome (what I'm using as a
> >> source on all this) has the data baked into a .cc file. However, they
> have
> >> directions in a README and a script which will parse the list and
> generate
> >> that source file. I recommend doing this. That way, the Haskell module
> would
> >> have 2 source files: one file that reads the list and generates the
> second
> >> file, which is a very large source file that contains each element in
> the
> >> list. The list should export `elem`-type queries. I'm not quite sure
> how to
> >> handle wildcards that appear in the list - that part is up to you.
> Thanks
> >> for helping out with this :]
> >>
> >> --Myles
> >>
> >>
> >> On Thu, Feb 2, 2012 at 10:53 PM, Michael Snoyman <michael at snoyman.com>
> >> wrote:
> >>>
> >>> Looks good to me too. I agree with Aristid: let's make the change to
> >>> cookie itself. Do you want to send a pull request? I'm also
> >>> considering making the SetCookie constructor hidden like we have for
> >>> Request, so that if in the future we realize we need to add some other
> >>> settings, it doesn't break the API.
> >>>
> >>> Chris: I would recommend compiling it into the module. Best bet would
> >>> likely being converting the source file to Haskell source.
> >>>
> >>> Michael
> >>>
> >>> On Fri, Feb 3, 2012 at 6:32 AM, Myles C. Maxfield
> >>> <myles.maxfield at gmail.com> wrote:
> >>> > Alright. After reading the spec, I have these questions / concerns:
> >>> >
> >>> > The spec supports the "Max-Age" cookie attribute, which Web.Cookies
> >>> > doesn't.
> >>> >
> >>> > I see two possible solutions to this. The first is to have
> >>> > parseSetCookie
> >>> > take a UTCTime as an argument which will represent the current time
> so
> >>> > it
> >>> > can populate the setCookieExpires field by adding the Max-Age
> attribute
> >>> > to
> >>> > the current time. Alternatively, that function can return an IO
> >>> > SetCookie so
> >>> > it can ask for the current time by itself (which I think is inferior
> to
> >>> > taking the current time as an argument). Note that the spec says to
> >>> > prefer
> >>> > Max-Age over Expires.
> >>> > Add a field to SetCookie of type Maybe DiffTime which represents the
> >>> > Max-Age
> >>> > attribute
> >>> >
> >>> > Cookie code should be aware of the Public Suffix List as a part of
> its
> >>> > domain verification. The cookie code only needs to be able to tell
> if a
> >>> > specific string is in the list (W.Ascii -> Bool)
> >>> >
> >>> > I propose making an entirely unrelated package, public-suffix-list,
> >>> > with a
> >>> > module Network.PublicSuffixList, which will expose this function, as
> >>> > well as
> >>> > functions about parsing the list itself. Thoughts?
> >>> >
> >>> > Web.Cookie doesn't have a "secure-only" attribute. Adding one in is
> >>> > straightforward enough.
> >>> > The spec describes cookies as a property of HTTP, not of the World
> Wide
> >>> > Web.
> >>> > Perhaps "Web.Cookie" should be renamed? Just a thought; it doesn't
> >>> > really
> >>> > matter to me.
> >>> >
> >>> > As for Network.HTTP.Conduit.Cookie, the spec describes in section 5.3
> >>> > "Storage Model" what fields a Cookie has. Here is my proposal for the
> >>> > functions it will expose:
> >>> >
> >>> > receiveSetCookie :: SetCookie -> Req.Request m -> UTCTime -> Bool ->
> >>> > CookieJar -> CookieJar
> >>> >
> >>> > Runs the algorithm described in section 5.3 "Storage Model"
> >>> > The UTCTime is the current-time, the Bool is whether or not the
> caller
> >>> > is an
> >>> > HTTP-based API (as opposed to JavaScript or anything else)
> >>> >
> >>> > updateCookieJar :: Res.Response a -> Req.Request m -> UTCTime ->
> >>> > CookieJar
> >>> > -> (CookieJar, Res.Response a)
> >>> >
> >>> > Applies "receiveSetCookie" to a Response. The output CookieJar is
> >>> > stripped
> >>> > of any Set-Cookie headers.
> >>> > Specifies "True" for the Bool in receiveSetCookie
> >>> >
> >>> > computeCookieString :: Req.Request m -> CookieJar -> UTCTime -> Bool
> ->
> >>> > (W.Ascii, CookieJar)
> >>> >
> >>> > Runs the algorithm described in section 5.4 "The Cookie Header"
> >>> > The UTCTime and Bool are the same as in receiveSetCookie
> >>> >
> >>> > insertCookiesIntoRequest :: Req.Request m -> CookieJar -> UTCTime ->
> >>> > (Req.Request m, CookieJar)
> >>> >
> >>> > Applies "computeCookieString" to a Request. The output cookie jar has
> >>> > updated last-accessed-times.
> >>> > Specifies "True" for the Bool in computeCookieString
> >>> >
> >>> > evictExpiredCookies :: CookieJar -> UTCTime -> CookieJar
> >>> >
> >>> > Runs the algorithm described in the last part of section 5.3 "Storage
> >>> > Model"
> >>> >
> >>> > This will make the relevant part of 'http' look like:
> >>> >
> >>> >     go count req'' cookie_jar'' = do
> >>> >         now <- liftIO $ getCurrentTime
> >>> >         let (req', cookie_jar') = insertCookiesIntoRequest req''
> >>> > (evictExpiredCookies cookie_jar'' now) now
> >>> >         res' <- httpRaw req' manager
> >>> >         let (cookie_jar, res) = updateCookieJar res' req' now
> >>> > cookie_jar'
> >>> >         case getRedirectedRequest req' (responseHeaders res)
> >>> > (W.statusCode
> >>> > (statusCode res)) of
> >>> >             Just req -> go (count - 1) req cookie_jar
> >>> >             Nothing -> return res
> >>> >
> >>> > I plan to not allow for a user-supplied cookieFilter function. If
> they
> >>> > want
> >>> > that functionality, they can re-implement the redirection-following
> >>> > logic.
> >>> >
> >>> > Any thoughts on any of this?
> >>> >
> >>> > Thanks,
> >>> > Myles
> >>> >
> >>> > On Wed, Feb 1, 2012 at 5:19 PM, Myles C. Maxfield
> >>> > <myles.maxfield at gmail.com>
> >>> > wrote:
> >>> >>
> >>> >> Nope. I'm not. The RFC is very explicit about how to handle cookies.
> >>> >> As
> >>> >> soon as I'm finished making sense of it (in terms of Haskell) I'll
> >>> >> send
> >>> >> another proposal email.
> >>> >>
> >>> >> On Feb 1, 2012 3:25 AM, "Michael Snoyman" <michael at snoyman.com>
> wrote:
> >>> >>>
> >>> >>> You mean you're *not* making this proposal?
> >>> >>>
> >>> >>> On Wed, Feb 1, 2012 at 7:30 AM, Myles C. Maxfield
> >>> >>> <myles.maxfield at gmail.com> wrote:
> >>> >>> > Well, this is embarrassing. Please disregard my previous email. I
> >>> >>> > should
> >>> >>> > learn to read the RFC *before* submitting proposals.
> >>> >>> >
> >>> >>> > --Myles
> >>> >>> >
> >>> >>> >
> >>> >>> > On Tue, Jan 31, 2012 at 6:37 PM, Myles C. Maxfield
> >>> >>> > <myles.maxfield at gmail.com> wrote:
> >>> >>> >>
> >>> >>> >> Here are my initial ideas about supporting cookies. Note that
> I'm
> >>> >>> >> using
> >>> >>> >> Chrome for ideas since it's open source.
> >>> >>> >>
> >>> >>> >> Network/HTTP/Conduit/Cookies.hs file
> >>> >>> >> Exporting the following symbols:
> >>> >>> >>
> >>> >>> >> type StuffedCookie = SetCookie
> >>> >>> >>
> >>> >>> >> A regular SetCookie can have Nothing for its Domain and Path
> >>> >>> >> attributes. A
> >>> >>> >> StuffedCookie has to have these fields set.
> >>> >>> >>
> >>> >>> >> type CookieJar = [StuffedCookie]
> >>> >>> >>
> >>> >>> >> Chrome's cookie jar is implemented as (the C++ equivalent of)
> Map
> >>> >>> >> W.Ascii
> >>> >>> >> StuffedCookie. The key is the "eTLD+1" of the domain, so lookups
> >>> >>> >> for
> >>> >>> >> all
> >>> >>> >> cookies for a given domain are fast.
> >>> >>> >> I think I'll stay with just a list of StuffedCookies just to
> keep
> >>> >>> >> it
> >>> >>> >> simple. Perhaps a later revision can implement the faster map.
> >>> >>> >>
> >>> >>> >> getRelevantCookies :: Request m -> CookieJar -> UTCTime ->
> >>> >>> >> (CookieJar,
> >>> >>> >> Cookies)
> >>> >>> >>
> >>> >>> >> Gets all the cookies from the cookie jar that should be set for
> >>> >>> >> the
> >>> >>> >> given
> >>> >>> >> Request.
> >>> >>> >> The time argument is whatever "now" is (it's pulled out of the
> >>> >>> >> function so
> >>> >>> >> the function can remain pure and easily testable)
> >>> >>> >> The function will also remove expired cookies from the cookie
> jar
> >>> >>> >> (given
> >>> >>> >> what "now" is) and return the filtered cookie jar
> >>> >>> >>
> >>> >>> >> putRelevantCookies :: Request m -> CookieJar -> [StuffedCookie]
> ->
> >>> >>> >> CookieJar
> >>> >>> >>
> >>> >>> >> Insert cookies from a server response into the cookie jar.
> >>> >>> >> The first argument is only used for checking to see which
> cookies
> >>> >>> >> are
> >>> >>> >> valid (which cookies match the requested domain, etc, so
> site1.com
> >>> >>> >> can't set
> >>> >>> >> a cookie for site2.com)
> >>> >>> >>
> >>> >>> >> stuffCookie :: Request m -> SetCookie -> StuffedCookie
> >>> >>> >>
> >>> >>> >> If the SetCookie's fields are Nothing, fill them in given the
> >>> >>> >> Request
> >>> >>> >> from
> >>> >>> >> which it originated
> >>> >>> >>
> >>> >>> >> getCookies :: Response a -> ([SetCookie], Response a)
> >>> >>> >>
> >>> >>> >> Pull cookies out of a server response. Return the response with
> >>> >>> >> the
> >>> >>> >> Set-Cookie headers filtered out
> >>> >>> >>
> >>> >>> >> putCookies :: Request a -> Cookies -> Request a
> >>> >>> >>
> >>> >>> >> A wrapper around renderCookies. Inserts some cookies into a
> >>> >>> >> request.
> >>> >>> >> Doesn't overwrite cookies that are already set in the request
> >>> >>> >>
> >>> >>> >> These functions will be exported from Network.HTTP.Conduit as
> >>> >>> >> well, so
> >>> >>> >> callers can use them to re-implement redirection chains
> >>> >>> >> I won't implement a cookie filtering function (like what
> >>> >>> >> Network.Browser
> >>> >>> >> has)
> >>> >>> >>
> >>> >>> >> If you want to have arbitrary handling of cookies, re-implement
> >>> >>> >> redirection following. It's not very difficult if you use the
> API
> >>> >>> >> provided,
> >>> >>> >> and the 'http' function is open source so you can use that as a
> >>> >>> >> reference.
> >>> >>> >>
> >>> >>> >> I will implement the functions according to RFC 6265
> >>> >>> >> I will also need to write the following functions. Should they
> >>> >>> >> also be
> >>> >>> >> exported?
> >>> >>> >>
> >>> >>> >> canonicalizeDomain :: W.Ascii -> W.Ascii
> >>> >>> >>
> >>> >>> >> turns "..a.b.c..d.com..." to "a.b.c.d.com"
> >>> >>> >> Technically necessary for domain matching (Chrome does it)
> >>> >>> >> Perhaps unnecessary for a first pass? Perhaps we can trust users
> >>> >>> >> for
> >>> >>> >> now?
> >>> >>> >>
> >>> >>> >> domainMatches :: W.Ascii -> W.Ascii -> Maybe W.Ascii
> >>> >>> >>
> >>> >>> >> Does the first domain match against the second domain?
> >>> >>> >> If so, return the prefix of the first that isn't in the second
> >>> >>> >>
> >>> >>> >> pathMatches :: W.Ascii -> W.Ascii -> Bool
> >>> >>> >>
> >>> >>> >> Do the paths match?
> >>> >>> >>
> >>> >>> >> In order to implement domain matching, I have to have knowledge
> of
> >>> >>> >> the Public Suffix List so I know that sub1.sub2.pvt.k12.wy.uscan
> >>> >>> >> set
> >>> >>> >> a
> >>> >>> >> cookie for sub2.pvt.k12.wy.us but not for k12.wy.us (because
> >>> >>> >> pvt.k12.wy.us
> >>> >>> >> is a "suffix"). There are a variety of ways to implement this.
> >>> >>> >>
> >>> >>> >> As far as I can tell, Chrome does it by using a script (which a
> >>> >>> >> human
> >>> >>> >> periodically runs) which parses the list at creates a .cc file
> >>> >>> >> that is
> >>> >>> >> included in the build.
> >>> >>> >>
> >>> >>> >> I might be wrong about the execution of the script; it might be
> a
> >>> >>> >> build
> >>> >>> >> step. If it is a build step, however, it is suspicious that a
> >>> >>> >> build
> >>> >>> >> target
> >>> >>> >> would try to download a file...
> >>> >>> >>
> >>> >>> >> Any more elegant ideas?
> >>> >>> >>
> >>> >>> >> Feedback on any/all of the above would be very helpful before I
> go
> >>> >>> >> off
> >>> >>> >> into the weeds on this project.
> >>> >>> >>
> >>> >>> >> Thanks,
> >>> >>> >> Myles C. Maxfield
> >>> >>> >>
> >>> >>> >> On Sat, Jan 28, 2012 at 8:17 PM, Michael Snoyman
> >>> >>> >> <michael at snoyman.com>
> >>> >>> >> wrote:
> >>> >>> >>>
> >>> >>> >>> Thanks, looks great! I've merged it into the Github tree.
> >>> >>> >>>
> >>> >>> >>> On Sat, Jan 28, 2012 at 8:36 PM, Myles C. Maxfield
> >>> >>> >>> <myles.maxfield at gmail.com> wrote:
> >>> >>> >>> > Ah, yes, you're completely right. I completely agree that
> >>> >>> >>> > moving
> >>> >>> >>> > the
> >>> >>> >>> > function into the Maybe monad increases readability. This
> kind
> >>> >>> >>> > of
> >>> >>> >>> > function
> >>> >>> >>> > is what the Maybe monad was designed for.
> >>> >>> >>> >
> >>> >>> >>> > Here is a revised patch.
> >>> >>> >>> >
> >>> >>> >>> >
> >>> >>> >>> > On Sat, Jan 28, 2012 at 8:28 AM, Michael Snoyman
> >>> >>> >>> > <michael at snoyman.com>
> >>> >>> >>> > wrote:
> >>> >>> >>> >>
> >>> >>> >>> >> On Sat, Jan 28, 2012 at 1:20 AM, Myles C. Maxfield
> >>> >>> >>> >> <myles.maxfield at gmail.com> wrote:
> >>> >>> >>> >> > the fromJust should never fail, beceause of the guard
> >>> >>> >>> >> > statement:
> >>> >>> >>> >> >
> >>> >>> >>> >> >     | 300 <= code && code < 400 && isJust l'' && isJust
> l' =
> >>> >>> >>> >> > Just $
> >>> >>> >>> >> > req
> >>> >>> >>> >> >
> >>> >>> >>> >> > Because of the order of the && operators, it will only
> >>> >>> >>> >> > evaluate
> >>> >>> >>> >> > fromJust
> >>> >>> >>> >> > after it makes sure that the argument isJust. That
> function
> >>> >>> >>> >> > in
> >>> >>> >>> >> > particular
> >>> >>> >>> >> > shouldn't throw any exceptions - it should only return
> >>> >>> >>> >> > Nothing.
> >>> >>> >>> >> >
> >>> >>> >>> >> > Knowing that, I don't quite think I understand what your
> >>> >>> >>> >> > concern
> >>> >>> >>> >> > is.
> >>> >>> >>> >> > Can
> >>> >>> >>> >> > you
> >>> >>> >>> >> > elaborate?
> >>> >>> >>> >>
> >>> >>> >>> >> You're right, but I had to squint really hard to prove to
> >>> >>> >>> >> myself
> >>> >>> >>> >> that
> >>> >>> >>> >> you're right. That's the kind of code that could easily be
> >>> >>> >>> >> broken
> >>> >>> >>> >> in
> >>> >>> >>> >> future updates by an unwitting maintainer (e.g., me). To
> >>> >>> >>> >> protect
> >>> >>> >>> >> the
> >>> >>> >>> >> world from me, I'd prefer if the code didn't have the
> >>> >>> >>> >> fromJust.
> >>> >>> >>> >> This
> >>> >>> >>> >> might be a good place to leverage the Monad instance of
> Maybe.
> >>> >>> >>> >>
> >>> >>> >>> >> Michael
> >>> >>> >>> >
> >>> >>> >>> >
> >>> >>> >>
> >>> >>> >>
> >>> >>> >
> >>> >
> >>> >
> >>
> >>
> >
>
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