urbit/pkg/arvo/app/eth-watcher.hoon
Fang 5c6c75c7ea
eth: move existing chain requests into ethio
To avoid reimplementing these (on top of ethio) every time. This seems
like a good place to centralize chain request logic going forward.
2019-11-04 18:59:30 +01:00

324 lines
9.3 KiB
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:: eth-watcher: ethereum event log collector
::
/- *eth-watcher
/+ tapp, stdio, ethio
=, ethereum-types
=, able:jael
::
=> |%
++ refresh-rate ~m5
--
::
=> |%
+$ app-state
$: %0
dogs=(map path watchdog)
==
::
+$ context [=path dog=watchdog]
+$ watchdog
$: config
=number:block
=pending-logs
=history
blocks=(list block)
==
::
:: history: newest block first, oldest event first
+$ history (list loglist)
+$ pending-logs (map number:block loglist)
::
+$ peek-data
[%atom =next-block=number:block]
+$ in-poke-data
$: %eth-watcher-poke
poke
==
+$ out-poke-data ~
+$ in-peer-data ~
+$ out-peer-data
$: %eth-watcher-diff
diff
==
++ tapp
%: ^tapp
app-state
peek-data
in-poke-data
out-poke-data
in-peer-data
out-peer-data
==
++ tapp-async tapp-async:tapp
++ stdio (^stdio out-poke-data out-peer-data)
++ ethio (^ethio out-poke-data out-peer-data)
--
::
:: Async helpers
::
=> |%
++ send-logs
|= [=path =loglist]
=/ m (async:stdio ,~)
|- ^- form:m
=* loop $
?~ loglist
(pure:m ~)
;< ~ bind:m (send-update path %log i.loglist)
loop(loglist t.loglist)
::
++ send-update
|= [=path =diff]
=/ m (async:stdio ,~)
^- form:m
=. path [%logs path]
(give-result:stdio path %eth-watcher-diff diff)
--
::
:: Main loop
::
=> |%
::
:: Update watchdog configuration, then look for updates
::
++ configure
|= [context =config]
=/ m (async:stdio ,watchdog)
^- form:m
%+ get-updates path
%_ dog
- config
number from.config
==
::
:: Get updates since last checked
::
++ get-updates
|= context
=/ m (async:stdio ,watchdog)
^- form:m
;< =latest=block bind:m (get-latest-block:ethio url.dog)
;< dog=watchdog bind:m (zoom [path dog] number.id.latest-block)
|- ^- form:m
=* loop $
?: (gth number.dog number.id.latest-block)
(pure:m dog)
;< =block bind:m (get-block-by-number:ethio url.dog number.dog)
;< dog=watchdog bind:m
(take-block [path dog] block)
loop(dog dog)
::
:: Process a block, detecting and handling reorgs
::
++ take-block
|= [context =block]
=/ m (async:stdio ,watchdog)
^- form:m
:: if this next block isn't direct descendant of our logs, reorg happened
?: &(?=(^ blocks.dog) !=(parent-hash.block hash.id.i.blocks.dog))
(rewind [path dog] block)
;< [=new=pending-logs =released=loglist] bind:m
(release-old-events path pending-logs.dog number.id.block)
;< =new=loglist bind:m :: oldest first
(get-logs-by-hash:ethio url.dog hash.id.block contracts.dog topics.dog)
=. new-pending-logs
(~(put by new-pending-logs) number.id.block new-loglist)
%- pure:m
%_ dog
number +(number.id.block)
pending-logs new-pending-logs
history [released-loglist history.dog]
blocks [block blocks.dog]
==
::
:: Release events if they're more than 30 blocks ago
::
++ release-old-events
|= [=path =pending-logs =number:block]
=/ m (async:stdio ,[^pending-logs loglist])
^- form:m
?: (lth number 30) (pure:m pending-logs ~)
=/ rel-number (sub number 30)
=/ =loglist (~(get ja pending-logs) rel-number)
;< ~ bind:m (send-logs path loglist)
(pure:m (~(del by pending-logs) rel-number) loglist)
::
:: Reorg detected, so rewind until we're back in sync
::
++ rewind
:: block: wants to be head of blocks.dog, but might not match
|= [context =block]
=/ m (async:stdio ,watchdog)
=* blocks blocks.dog
|- ^- form:m
=* loop $
:: if we have no further history to rewind, we're done
?~ blocks
(pure:m dog(blocks [block blocks]))
:: if target block is directly after "latest", we're done
?: =(parent-hash.block hash.id.i.blocks)
(pure:m dog(blocks [block blocks]))
:: next-block: the new target block
;< =next=^block bind:m
(get-block-by-number:ethio url.dog number.id.i.blocks)
:: remove from either pending-logs or history
?: =(~ pending-logs.dog)
:: if no more pending logs, start deleting from history instead
::NOTE this assumes there's one history entry per item in blocks.
:: while +zoom breaks that assumption by clearing blocks, we won't
:: run out of history before running out of blocks, allowing us to
:: skip the =(number.id.block number.id.i.i.history) check.
?~ history.dog
loop(block next-block, blocks t.blocks)
;< ~ bind:m
:: don't bother sending a disavow if there were no logs there
?~ i.history.dog (pure:(async:stdio ,~) ~)
(disavow path block)
loop(block next-block, blocks t.blocks, history.dog t.history.dog)
=. pending-logs.dog
(~(del by pending-logs.dog) number.id.block)
loop(block next-block, blocks t.blocks)
::
:: Tell subscribers there was a deep reorg
::
++ disavow
|= [=path =block]
=/ m (async:stdio ,~)
^- form:m
(send-update path %disavow id.block)
::
:: Zoom forward to near a given block number.
::
:: Zooming doesn't go forward one block at a time. As a
:: consequence, it cannot detect and handle reorgs. Only use it
:: at a safe distance -- 500 blocks ago is probably sufficient.
::
++ zoom
|= [context =latest=number:block]
=/ m (async:stdio ,watchdog)
^- form:m
=/ zoom-margin=number:block 100
?: (lth latest-number (add number.dog zoom-margin))
(pure:m dog)
=/ to-number=number:block (sub latest-number zoom-margin)
;< =loglist bind:m :: oldest first
%: get-logs-by-range:ethio
url.dog
contracts.dog
topics.dog
number.dog
to-number
==
;< ~ bind:m (send-logs path loglist)
=. number.dog +(to-number)
=. blocks.dog ~
=. history.dog [loglist history.dog]
(pure:m dog)
--
::
:: Main
::
=* default-tapp default-tapp:tapp
%- create-tapp-all:tapp
^- tapp-core-all:tapp
|_ [=bowl:gall state=app-state]
++ handle-init
=/ m tapp-async
^- form:m
:: start update timer loop
;< now=@da bind:m get-time:stdio
;< ~ bind:m (wait-effect:stdio (add now refresh-rate))
(pure:m state)
::
++ handle-diff handle-diff:default-tapp
::
++ handle-poke
|= in=in-poke-data
=/ m tapp-async
^- form:m
?- +<.in
%watch
:: fully restart the watchdog if it doesn't exist yet,
:: or if the new config changes more than just the url.
=/ restart=?
?| !(~(has by dogs.state) path.in)
?! .= ->:(~(got by dogs.state) path.in)
+.config.in
==
~? &((~(has by dogs.state) path.in) restart)
[dap.bowl 'overwriting existing watchdog on' path.in]
;< dog=watchdog bind:m
=/ dog=watchdog
?: restart *watchdog
(~(got by dogs.state) path.in)
(configure [path.in dog] config.in)
=. dogs.state (~(put by dogs.state) path.in dog)
(pure:m state)
::
%clear
=. dogs.state (~(del by dogs.state) path.in)
(pure:m state)
==
::
++ handle-take
|= =sign:tapp
=/ m tapp-async
^- form:m
?+ -.sign ~|([%strange-sign -.sign] !!)
%wake
;< ~ bind:m
;< now=@da bind:(async:tapp ,~) get-time:stdio
=/ next=@da (add now refresh-rate)
::NOTE we use +send-raw-card here to ensure we always set a new timer,
:: regardless of what happens further on in the flow.
(send-raw-card:stdio %wait /effect/(scot %da next) next)
::TODO ideally we'd process these in parallel. this seems possible,
:: but requires non-trivial work, as it deviates from tapp's flow.
:: (when making that change, take note of rpc request id's.)
=/ dogs=(list [=path dog=watchdog]) ~(tap by dogs.state)
|- ^- form:m
=* loop $
?~ dogs
(pure:m state)
=, i.dogs
;< dog=watchdog bind:m (get-updates path dog)
=. dogs.state (~(put by dogs.state) path dog)
loop(dogs t.dogs)
==
::
:: +handle-peer: subscribe & get initial subscription data
::
:: /logs/some-path:
::
++ handle-peer
|= =path
=/ m tapp-async
^- form:m
?. ?=([%logs ^] path)
~| [%invalid-subscription-path path]
!!
;< ~ bind:m
%+ send-effect-on-bone:stdio ost.bowl
:+ %diff %eth-watcher-diff
:- %history
^- loglist
%- zing
%- flop
=< history
(~(gut by dogs.state) t.path *watchdog)
(pure:m state)
::
:: +handle-peek: get diagnostics data
::
:: /block/some-path: get next block number to check for /some-path
::
++ handle-peek
|= =path
^- (unit (unit peek-data))
?. ?=([%x %block ^] path) ~
?. (~(has by dogs.state) t.t.path) ~
:+ ~ ~
:- %atom
number:(~(got by dogs.state) t.t.path)
--