From 5ae49d3c49790e1390a9bba790980e516974f8bd Mon Sep 17 00:00:00 2001
From: alemi <me@alemi.dev>
Date: Thu, 26 Sep 2024 05:40:58 +0200
Subject: [PATCH] feat: improved async poller for events

now, when :abort() is available, it properly cancels promises so that we
dont get dangling references
---
 lua/codemp/utils.lua     | 44 ++++++++++++++++++++++++++++++++--------
 lua/codemp/workspace.lua | 28 +++++++++++++++++++++----
 2 files changed, 59 insertions(+), 13 deletions(-)

diff --git a/lua/codemp/utils.lua b/lua/codemp/utils.lua
index 827b1d0..78afccb 100644
--- a/lua/codemp/utils.lua
+++ b/lua/codemp/utils.lua
@@ -29,18 +29,44 @@ local function color(name)
 	}
 end
 
+---@class AsyncPoller
+---@field promise WorkspaceEventPromise | nil
+---@field timer luv.Timer
+---@field generator fun(): WorkspaceEventPromise
+---@field callback fun(e: WorkspaceEvent)
+---@field stop fun(self: AsyncPoller)
+
+---@return AsyncPoller
 local function async_poller(generator, callback)
-	local promise = nil
-	local timer = vim.loop.new_timer()
-	timer:start(500, 500, function()
-		if promise == nil then promise = generator() end
-		if promise.ready then
-			local res = promise:await()
-			vim.schedule(function() callback(res) end)
-			promise = nil
+	---@type AsyncPoller
+	local poller = {
+		promise = nil,
+		generator = generator,
+		callback = callback,
+		timer = vim.uv.new_timer(),
+		stop = function (this)
+			print("stopping async poller")
+			if this.promise ~= nil then
+				-- TODO the :abort() change still hasnt been merged, so check for its presence!
+				if this.promise.abort ~= nil then
+					this.promise:abort()
+				end
+			end
+			this.timer:stop()
+			this.timer:close()
+		end
+	}
+	poller.timer:start(500, 500, function()
+		print("ticking poller")
+		if poller.promise == nil then poller.promise = poller.generator() end
+		if poller.promise.ready then
+			print("spawning callback")
+			local res = poller.promise:await()
+			vim.schedule(function() poller.callback(res) end)
+			poller.promise = nil
 		end
 	end)
-
+	return poller
 end
 
 ---@param first integer
diff --git a/lua/codemp/workspace.lua b/lua/codemp/workspace.lua
index 12ded21..6bc626e 100644
--- a/lua/codemp/workspace.lua
+++ b/lua/codemp/workspace.lua
@@ -150,6 +150,8 @@ local function register_cursor_handler(controller)
 	controller:callback(function (_controller) async:send() end)
 end
 
+local events_poller = nil
+
 ---@param workspace string workspace name to join
 ---join a workspace and register event handlers
 local function join(workspace)
@@ -169,8 +171,14 @@ local function join(workspace)
 			}
 		end
 		require('codemp.window').update()
-		utils.poller(
-			function() return ws:event() end,
+		local ws_name = ws.name
+		events_poller = utils.poller(
+			function()
+				if CODEMP.client == nil then return nil end
+				local wspace = CODEMP.client:get_workspace(ws_name)
+				if wspace == nil then return nil end
+				return wspace:event()
+			end,
 			function(event)
 				if event.type == "leave" then
 					if buffers.users[event.value] ~= nil then
@@ -198,9 +206,21 @@ local function join(workspace)
 end
 
 local function leave()
-	CODEMP.client:leave_workspace(CODEMP.workspace.name)
-	print(" -- left workspace")
+	local name = CODEMP.workspace.name
 	CODEMP.workspace = nil
+	if events_poller ~= nil then
+		events_poller:stop()
+		events_poller = nil
+	end
+	if not CODEMP.client:leave_workspace(name) then
+		collectgarbage("collect")
+		-- TODO codemp disconnects when all references to its objects are dropped. since it
+		-- hands out Arc<> of things, all references still not garbage collected in Lua will
+		-- prevent it from disconnecting. while running a full cycle may be a bit slow, this
+		-- only happens when manually requested, and it's not like the extra garbage collection
+		-- is an effort for nothing... still it would be more elegant to not need this!!
+	end
+	print(" -- left workspace " .. name)
 	require('codemp.window').update()
 end