Merge pull request #3243 from urbit/lf/lib-hooks-docs

lib-hooks: document with comments
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matildepark 2020-09-05 16:18:17 -04:00 committed by GitHub
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@ -1,3 +1,23 @@
:: lib/pull-hook: helper for creating a push hook
::
:: lib/pull-hook is a helper for automatically pulling data from a
:: corresponding push-hook to a store.
::
:: ## Interfacing notes:
::
:: The inner door may interact with the library by producing cards.
:: Do not pass any cards on a wire beginning with /helper as these
:: wires are reserved by this library. Any watches/pokes/peeks not
:: listed below will be routed to the inner door.
::
:: ## Subscription paths
::
:: /tracking: The set of resources we are pulling
::
:: ## Pokes
::
:: %pull-hook-action: Add/remove a resource from pulling.
::
/- *pull-hook
/+ default-agent, resource
::
@ -5,12 +25,24 @@
|%
+$ card card:agent:gall
::
:: $config: configuration for the pull hook
::
:: .store-name: name of the store to send subscription updates to.
:: .update-mark: mark that updates will be tagged with
:: .push-hook-name: name of the corresponding push-hook
::
+$ config
$: store-name=term
update=mold
update-mark=term
push-hook-name=term
==
::
:: $state-0: state for the pull hook
::
:: .tracking: a map of resources we are pulling, and the ships that
:: we are pulling them from.
:: .inner-state: state given to internal door
::
+$ state-0
$: %0
@ -37,7 +69,29 @@
|* config
$_ ^|
|_ bowl:gall
:: +on-pull-nack: handle failed pull subscription
::
:: This arm is called when a pull subscription fails. lib/pull-hook
:: will automatically delete the resource from .tracking by the
:: time this arm is called.
::
++ on-pull-nack
|~ [resource tang]
*[(list card) _^|(..on-init)]
:: +on-pull-kick: produce any additional resubscribe path
::
:: If non-null, the produced path is appended to the original
:: subscription path. This should be used to encode extra
:: information onto the path in order to reduce the payload of a
:: kick and resubscribe.
::
:: If null, a resubscribe is not attempted
::
++ on-pull-kick
|~ resource
*(unit path)
::
:: from agent:gall
++ on-init
*[(list card) _^|(..on-init)]
::
@ -75,26 +129,6 @@
++ on-fail
|~ [term tang]
*[(list card) _^|(..on-init)]
:: +on-pull-nack: handle failed pull subscription
::
:: This arm is called when a pull subscription fails.
::
++ on-pull-nack
|~ [resource tang]
*[(list card) _^|(..on-init)]
:: +on-pull-kick: produce any additional resubscribe path
::
:: If non-null, the produced path is appended to the original
:: subscription path. This should be used to encode extra
:: information onto the path in order to reduce the payload of a
:: kick and resubscribe.
::
:: If null, a resubscribe is not attempted
::
++ on-pull-kick
|~ resource
*(unit path)
:: ::
--
++ agent
|* =config
@ -209,7 +243,10 @@
=^ cards pull-hook
(on-fail:og term tang)
[cards this]
++ on-peek on-peek:def
++ on-peek
|= =path
^- (unit (unit cage))
(on-peek:og path)
--
|_ =bowl:gall
+* og ~(. pull-hook bowl)

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@ -1,8 +1,41 @@
:: lib/push-hook: helper for creating a push hook
::
:: lib/push-hook is a helper for automatically pushing data from a
:: local store to the corresponding pull-hook on remote ships. It also
:: proxies remote pokes to the store.
::
:: ## Interfacing notes:
::
:: The inner door may interact with the library by producing cards.
:: Do not pass any cards on a wire beginning with /helper as these
:: wires are reserved by this library. Any watches/pokes/peeks not
:: listed below will be routed to the inner door.
::
:: ## Subscription paths
::
:: /resource/[resource]: Receive initial state and updates to
:: .resource. .resource should be encoded with en-path:resource from
:: /lib/resource. Facts on this path will be of mark
:: update-mark.config
::
:: ## Pokes
::
:: %push-hook-action: Add/remove a resource from pushing.
:: [update-mark.config]: A poke to proxy to the local store
::
/- *push-hook
/+ default-agent, resource
|%
+$ card card:agent:gall
::
:: $config: configuration for the push hook
::
:: .store-name: name of the store to proxy pokes and
:: subscriptions to
:: .store-path: subscription path to receive updates on
:: .update-mark: mark that updates will be tagged with
:: .pull-hook-name: name of the corresponding pull-hook
::
+$ config
$: store-name=term
store-path=path
@ -10,6 +43,12 @@
update-mark=term
pull-hook-name=term
==
::
:: $state-0: state for the push hook
::
:: .sharing: resources that the push hook is proxying
:: .inner-state: state given to internal door
::
+$ state-0
$: %0
sharing=(set resource)
@ -21,6 +60,48 @@
$_ ^|
|_ bowl:gall
::
:: +resource-for-update: get affected resource from an update
::
:: Given a vase of the update, the mark of which is
:: update-mark.config, produce the affected resource, if any.
::
++ resource-for-update
|~ vase
*(unit resource)
::
:: +take-update: handle update from store
::
:: Given an update from the store, do other things after proxying
:: the update
::
++ take-update
|~ vase
*[(list card) _^|(..on-init)]
:: +should-proxy-update: should forward update to store
::
:: If %.y is produced, then the update is forwarded to the local
:: store. If %.n is produced then the update is not forwarded and
:: the poke fails.
::
++ should-proxy-update
|~ vase
*?
:: +initial-watch: produce initial state for a subscription
::
:: .resource is the resource being subscribed to.
:: .path is any additional information in the subscription wire.
:: This would typically be used to encode state that the subscriber
:: already has. For example, a chat client might encode
:: the number of messages that it already has, or the date it last
:: received an update.
::
:: If +initial-watch crashes, the subscription fails.
::
++ initial-watch
|~ [path resource]
*vase
:: from agent:gall
::
++ on-init
*[(list card) _^|(..on-init)]
::
@ -58,35 +139,6 @@
++ on-fail
|~ [term tang]
*[(list card) _^|(..on-init)]
:: +resource-for-update: get affected resource from an update
++ resource-for-update
|~ vase
*(unit resource)
::
:: +on-update: handle update from store
::
:: Do extra stuff on store update
++ take-update
|~ vase
*[(list card) _^|(..on-init)]
:: +should-proxy-update: should forward update to store
::
:: If %.y is produced, then the update is forwarded to the local
:: store. If %.n is produced then the update is not forwarded and
:: the poke fails.
::
++ should-proxy-update
|~ vase
*?
:: +initial-watch: produce initial state for a subscription
::
:: .resource is the resource being subscribed to.
:: .path is any additional information in the subscription wire
::
++ initial-watch
|~ [path resource]
*vase
::
--
++ agent
|* =config