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feat(queue): update docs

This commit is contained in:
Ilya Averyanov 2024-07-10 19:31:40 +03:00
parent f213569460
commit 8705956cdc
2 changed files with 16 additions and 8 deletions
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1
apps/emqx_ds_shared_sub/README.md
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@ -13,7 +13,6 @@ On the code level, the application is organized in the following way:
* The nesting reflects nesting/ownership of entity states.
* The bold arrow represent the [most complex interaction](https://github.com/emqx/eip/blob/main/active/0028-durable-shared-subscriptions.md#shared-subscription-session-handler), between session-side group subscription state machine (**GroupSM**) and the shared subscription leader (**Leader**).
# Contributing
Please see our [contributing.md](../../CONTRIBUTING.md).

23
apps/emqx_ds_shared_sub/src/emqx_ds_shared_sub_agent.erl
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@ -54,14 +54,23 @@
session_id := emqx_persistent_session_ds:id()
}.
%% Techinically, group_id and share_topic_filter are the same.
%% However, we speak in the terms of share_topic_filter in the API,
%% which is known to the shared subscription handler of persistent session.
%% We speak in the terms of share_topic_filter in the module API
%% which is consumed by persistent session.
%%
%% And we speak in the terms of group_id internally:
%% * we keep group_sm's in the state by group_id
%% * we use group_id to address group_sm's, e.g. when sending messages to them
%% from leader or from themselves.
%% We speak in the terms of group_id internally:
%% * to identfy shared subscription's group_sm in the state;
%% * to addres agent's group_sm while communicating with leader.
%% * to identify the leader itself.
%%
%% share_topic_filter should be uniquely determined by group_id. See MQTT 5.0 spec:
%%
%% > Note that "$share/consumer1//finance" and "$share/consumer1/sport/tennis/+"
%% > are distinct shared subscriptions, even though they have the same ShareName.
%% > While they might be related in some way, no specific relationship between them
%% > is implied by them having the same ShareName.
%%
%% So we just use the full share_topic_filter record as group_id.
-define(group_id(ShareTopicFilter), ShareTopicFilter).
-define(share_topic_filter(GroupId), GroupId).