urbit/pkg/base-dev/lib/sole.hoon
fang 3120681b2b
sole: properly support multiple sessions
We update the sole protocol to more cleanly support multiple sessions.

Primarily, the "sole id" is updated to be a [@p @ta] instead of a @ta,
and it is now generated based off the connected dill session, rather
than statically.

This change ripples out to applications that support the sole protocol:
the subscription path becomes /sole/[ship]/[session] (as opposed to
/sole/[per-ship-constant]), and %sole-action pokes include the new id as
well.
For shoe agents, this means (at the very least) updating the function
signatures of the shoe arms.

/lib/sole has been updated to include helper functions for parsing a
sole-id from a subscription path, and turning a sole-id into its
corresponding path. It also has a function to aid in migrating old
sole-ids.

Existing sole agents are made to kick any known open sessions, forcing a
resubscribe by drum, so that they may use exclusively the new format
going forward. Third-party agents are recommended to do the same.

Note that some functionality, such as |link, still operates exclusively
on the default session. Improvements in this area to follow soon.
2022-02-20 17:19:03 -06:00

164 lines
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::
:::: /hoon/sole/lib
::
/? 310
/- *sole
::::
::
|_ sole-share :: shared-state engine
++ abet +<
++ apply
|= ted=sole-edit
^+ +>
?- -.ted
%del +>.$(buf (weld (scag p.ted buf) (slag +(p.ted) buf)))
%ins +>.$(buf (weld (scag p.ted buf) `_buf`[q.ted (slag p.ted buf)]))
%mor |- ^+ +>.^$
?~ p.ted
+>.^$
$(p.ted t.p.ted, +>.^$ ^$(ted i.p.ted))
%nop +>.$
%set +>.$(buf p.ted)
==
::
::::
:: ++transmute: symmetric operational transformation.
::
:: for any sole state +>, obeys
::
:: =+ [x=(transmute a b) y=(transmute b a)]
:: .= (apply:(apply a) x)
:: (apply:(apply b) y)
::
++ transmute :: dex as after sin
|= [sin=sole-edit dex=sole-edit]
~| [%transmute sin dex]
^- sole-edit
?: ?=(%mor -.sin)
|- ^- sole-edit
?~ p.sin dex
$(p.sin t.p.sin, dex ^$(sin i.p.sin))
::
?: ?=(%mor -.dex)
:- %mor
|- ^- (list sole-edit)
?~ p.dex ~
[^$(dex i.p.dex) $(p.dex t.p.dex)]
::
?: |(?=(%nop -.sin) ?=(%nop -.dex)) dex
?: ?=(%set -.sin) [%nop ~]
?: ?=(%set -.dex) dex
::
?- -.sin
%del
?- -.dex
%del ?: =(p.sin p.dex) [%nop ~]
?:((lth p.sin p.dex) dex(p (dec p.dex)) dex)
%ins ?:((lth p.sin p.dex) dex(p (dec p.dex)) dex)
==
::
%ins
?- -.dex
%del ?:((lte p.sin p.dex) dex(p +(p.dex)) dex)
%ins ?: =(p.sin p.dex)
?:((lth q.sin q.dex) dex dex(p +(p.dex)))
?:((lte p.sin p.dex) dex(p +(p.dex)) dex)
==
==
::
++ commit :: local change
|= ted=sole-edit
^- sole-share
abet:(apply(own.ven +(own.ven), leg [ted leg]) ted)
::
::::
:: ++inverse: inverse of change in context.
::
:: for any sole state +>, obeys
::
:: =(+> (apply:(apply a) (inverse a)))
::
++ inverse :: relative inverse
|= ted=sole-edit
^- sole-edit
=. ted ?.(?=([%mor * ~] ted) ted i.p.ted)
?- -.ted
%del [%ins p.ted (snag p.ted buf)]
%ins [%del p.ted]
%mor :- %mor
%- flop
|- ^- (list sole-edit)
?~ p.ted ~
:- ^$(ted i.p.ted)
$(p.ted t.p.ted, +>.^$ (apply i.p.ted))
%nop [%nop ~]
%set [%set buf]
==
::
++ receive :: naturalize event
|= sole-change
^- [sole-edit sole-share]
?. &(=(his.ler his.ven) (lte own.ler own.ven))
~| [%receive-sync his+[his.ler his.ven] own+[own.ler own.ven]]
!!
?> &(=(his.ler his.ven) (lte own.ler own.ven))
?> |(!=(own.ler own.ven) =(`@`0 haw) =(haw (sham buf)))
=. leg (scag (sub own.ven own.ler) leg)
:: ~? !=(own.ler own.ven) [%miss-leg leg]
=+ dat=(transmute [%mor leg] ted)
:: ~? !=(~ leg) [%transmute from+ted to+dat ~]
[dat abet:(apply(his.ven +(his.ven)) dat)]
::
++ remit :: conditional accept
|= [cal=sole-change ask=$-((list @c) ?)]
^- [(unit sole-change) sole-share]
=+ old=buf
=^ dat +>+<.$ (receive cal)
?: (ask buf)
[~ +>+<.$]
=^ lic +>+<.$ (transmit (inverse(buf old) dat))
[`lic +>+<.$]
::
++ transmit :: outgoing change
|= ted=sole-edit
^- [sole-change sole-share]
[[[his.ven own.ven] (sham buf) ted] (commit ted)]
::
++ transceive :: receive and invert
|= sole-change
^- [sole-edit sole-share]
=+ old=buf
=^ dat +>+<.$ (receive +<.$)
[(inverse(buf old) dat) +>+<.$]
::
++ transpose :: adjust position
|= pos=@ud
=+ dat=(transmute [%mor leg] [%ins pos `@c`0])
?> ?=(%ins -.dat)
p.dat
::
::
++ path-to-id
|= =path
^- (unit sole-id)
?. ?=([%sole @ ?(~ [@ ~])] path) ~
?~ who=(slaw %p i.t.path) ~
`[u.who ?~(t.t.path %$ i.t.t.path)]
::
++ id-to-path
|= sole-id
^- path
::TODO this whole "no empty path ending" business feels icky.
:: do we want default session to be ~.~ ?
:: concern here is that outsiders cannot subscribe to the default
:: session, because /sole/~zod/ isn't a valid path...
[%sole (scot %p who) ?~(ses ~ /[ses])]
::
++ upgrade-id
|= old=@ta
^- (unit sole-id)
%+ rush old
%+ cook (late %$)
;~(pfix (jest 'drum_~') fed:ag)
--