From e1f84a756eaffb0c4aba4334b93cd9906cc4a3a8 Mon Sep 17 00:00:00 2001
From: Lohikar <lohikar@protonmail.com>
Date: Sat, 2 Sep 2017 13:35:03 -0500
Subject: [PATCH] experimental caching performance tweaks (#3364)

Changes the asset cache's on-connect cache to use a ticking subsystem instead of sleeps and timers to slowly send assets to clients.
---
 code/controllers/subsystems/assets.dm | 52 ++++++++++++++++++++++++---
 code/modules/client/asset_cache.dm    | 17 ++-------
 code/modules/client/client procs.dm   |  5 ++-
 3 files changed, 53 insertions(+), 21 deletions(-)

diff --git a/code/controllers/subsystems/assets.dm b/code/controllers/subsystems/assets.dm
index 06673355a66..7111f0738ee 100644
--- a/code/controllers/subsystems/assets.dm
+++ b/code/controllers/subsystems/assets.dm
@@ -1,20 +1,64 @@
-
 /var/datum/controller/subsystem/assets/SSassets
 
 /datum/controller/subsystem/assets
 	name = "Assets"
 	init_order = SS_INIT_MISC_FIRST
-	flags = SS_NO_FIRE
+	flags = SS_BACKGROUND | SS_FIRE_IN_LOBBY
+	wait = 1
 	var/list/cache = list()
+	var/list/target_clients = list()
+	var/list/currentrun
 
 /datum/controller/subsystem/assets/New()
 	NEW_SS_GLOBAL(SSassets)
 
+/datum/controller/subsystem/assets/stat_entry()
+	..("C:[target_clients.len]")
+
 /datum/controller/subsystem/assets/Initialize(timeofday)
 	for(var/type in typesof(/datum/asset) - list(/datum/asset, /datum/asset/simple))
 		var/datum/asset/A = new type()
 		A.register()
+		CHECK_TICK
 
-	for(var/client/C in global.clients)
-		addtimer(CALLBACK(GLOBAL_PROC, .proc/getFilesSlow, C, cache, FALSE), 10)
+	for (var/client/C in global.clients)
+		handle_connect(C)
 	..()
+
+/datum/controller/subsystem/assets/proc/handle_disconnect(client/C)
+	target_clients -= C
+	if (currentrun)
+		currentrun -= C
+
+/datum/controller/subsystem/assets/proc/handle_connect(client/C)
+	if (!C)
+		CRASH("Client is missing.")
+
+	target_clients[C] = cache.Copy()
+	if (suspended)
+		wake()
+
+/datum/controller/subsystem/assets/fire(resumed = 0)
+	if (!resumed)
+		currentrun = target_clients.Copy()
+
+	if (!target_clients.len)
+		suspend()
+
+	while (currentrun.len)
+		var/client/C = currentrun[currentrun.len]
+		currentrun.len--
+
+		if (!C)
+			continue
+
+		var/list/c_files = target_clients[C]
+
+		if (!c_files.len)
+			target_clients -= C
+		else
+			send_asset(C, c_files[1], FALSE)
+			c_files.Cut(1, 2)
+
+		if (MC_TICK_CHECK)
+			return
diff --git a/code/modules/client/asset_cache.dm b/code/modules/client/asset_cache.dm
index 1b9fe21661d..d4550557871 100644
--- a/code/modules/client/asset_cache.dm
+++ b/code/modules/client/asset_cache.dm
@@ -25,7 +25,7 @@ You can set verify to TRUE if you want send() to sleep until the client has the
 
 //This proc sends the asset to the client, but only if it needs it.
 //This proc blocks(sleeps) unless verify is set to false
-/proc/send_asset(var/client/client, var/asset_name, var/verify = TRUE)
+/proc/send_asset(client/client, asset_name, verify = TRUE)
 	if(!istype(client))
 		if(ismob(client))
 			var/mob/M = client
@@ -72,7 +72,7 @@ You can set verify to TRUE if you want send() to sleep until the client has the
 	return 1
 
 //This proc blocks(sleeps) unless verify is set to false
-/proc/send_asset_list(var/client/client, var/list/asset_list, var/verify = TRUE)
+/proc/send_asset_list(client/client, list/asset_list, verify = TRUE)
 	if(!istype(client))
 		if(ismob(client))
 			var/mob/M = client
@@ -122,20 +122,9 @@ You can set verify to TRUE if you want send() to sleep until the client has the
 
 	return 1
 
-//This proc will download the files without clogging up the browse() queue, used for passively sending files on connection start.
-//The proc calls procs that sleep for long times.
-/proc/getFilesSlow(var/client/client, var/list/files, var/register_asset = TRUE)
-	for(var/file in files)
-		if (!client)
-			break
-		if (register_asset)
-			register_asset(file,files[file])
-		send_asset(client,file)
-		sleep(0) //queuing calls like this too quickly can cause issues in some client versions
-
 //This proc "registers" an asset, it adds it to the cache for further use, you cannot touch it from this point on or you'll fuck things up.
 //if it's an icon or something be careful, you'll have to copy it before further use.
-/proc/register_asset(var/asset_name, var/asset)
+/proc/register_asset(asset_name, asset)
 	SSassets.cache[asset_name] = asset
 
 //These datums are used to populate the asset cache, the proc "register()" does this.
diff --git a/code/modules/client/client procs.dm b/code/modules/client/client procs.dm
index 236e5804eff..2f378566afe 100644
--- a/code/modules/client/client procs.dm	
+++ b/code/modules/client/client procs.dm	
@@ -380,6 +380,7 @@
 		admins -= src
 	directory -= ckey
 	clients -= src
+	SSassets.handle_disconnect(src)
 	return ..()
 
 
@@ -491,9 +492,7 @@
 
 //send resources to the client. It's here in its own proc so we can move it around easiliy if need be
 /client/proc/send_resources()
-	spawn (10) //removing this spawn causes all clients to not get verbs.
-		//Precache the client with all other assets slowly, so as to not block other browse() calls
-		getFilesSlow(src, SSassets.cache, register_asset = FALSE)
+	SSassets.handle_connect(src)
 
 /mob/proc/MayRespawn()
 	return 0