feat(api): broadcast events to ALL channels #28487

Problem:
`vim.rpcnotify(0)` and `rpcnotify(0)` are documented as follows:

    If {channel} is 0, the event is broadcast to all channels.

But that's not actually true. Channels must call `nvim_subscribe` to
receive "broadcast" events, so it's actually "multicast".

- Assuming there is a use-case for "broadcast", the current model adds
  an extra step for broadcasting: all channels need to "subscribe".
- The presence of `nvim_subscribe` is a source of confusion for users,
  because its name implies something more generally useful than what it
  does.

Presumably the use-case of `nvim_subscribe` is to avoid "noise" on RPC
channels not expected a broadcast notification, and potentially an error
if the channel client reports an unknown event.

Solution:
- Deprecate `nvim_subscribe`/`nvim_unsubscribe`.
  - If applications want to multicast, they can keep their own multicast
    list. Or they can use `nvim_list_chans()` and `nvim_get_chan_info()`
    to enumerate and filter the clients they want to target.
- Always send "broadcast" events to ALL channels. Don't require channels
  to "subscribe" to receive broadcasts. This matches the documented
  behavior of `rpcnotify()`.
This commit is contained in:
Justin M. Keyes
2024-05-17 07:37:39 -07:00
committed by GitHub
parent 42aa69b076
commit aec4938a21
9 changed files with 102 additions and 185 deletions

View File

@@ -1334,36 +1334,6 @@ void nvim_put(ArrayOf(String) lines, String type, Boolean after, Boolean follow,
});
}
/// Subscribes to event broadcasts.
///
/// @param channel_id Channel id (passed automatically by the dispatcher)
/// @param event Event type string
void nvim_subscribe(uint64_t channel_id, String event)
FUNC_API_SINCE(1) FUNC_API_REMOTE_ONLY
{
size_t length = (event.size < METHOD_MAXLEN ? event.size : METHOD_MAXLEN);
char e[METHOD_MAXLEN + 1];
memcpy(e, event.data, length);
e[length] = NUL;
rpc_subscribe(channel_id, e);
}
/// Unsubscribes to event broadcasts.
///
/// @param channel_id Channel id (passed automatically by the dispatcher)
/// @param event Event type string
void nvim_unsubscribe(uint64_t channel_id, String event)
FUNC_API_SINCE(1) FUNC_API_REMOTE_ONLY
{
size_t length = (event.size < METHOD_MAXLEN
? event.size
: METHOD_MAXLEN);
char e[METHOD_MAXLEN + 1];
memcpy(e, event.data, length);
e[length] = NUL;
rpc_unsubscribe(channel_id, e);
}
/// Returns the 24-bit RGB value of a |nvim_get_color_map()| color name or
/// "#rrggbb" hexadecimal string.
///