mod_smacks: Switch storage for tracking resumption tokens

All that was a complicated way to limit the number of resumable
sessions. Let's control resource usage some other way.  This leaves the
essence of mapping resumption tokens to live sessions.

This keeps resumption state across reloads.

1 files changed, 5 insertions, 40 deletions

diff --git a/plugins/mod_smacks.lua b/plugins/mod_smacks.lua
index b4ac7ec5..4ca2b52d 100644
--- a/plugins/mod_smacks.lua
+++ b/plugins/mod_smacks.lua
@@ -18,7 +18,6 @@ local math_min = math.min;
 local os_time = os.time;
 local t_remove = table.remove;
 
-local cache = require "util.cache";
 local datetime = require "util.datetime";
 local add_filter = require "util.filters".add_filter;
 local jid = require "util.jid";
@@ -44,47 +43,13 @@ local s2s_resend = module:get_option_boolean("smacks_s2s_resend", false);
 local max_unacked_stanzas = module:get_option_number("smacks_max_unacked_stanzas", 0);
 local max_inactive_unacked_stanzas = module:get_option_number("smacks_max_inactive_unacked_stanzas", 256);
 local delayed_ack_timeout = module:get_option_number("smacks_max_ack_delay", 30);
-local max_hibernated_sessions = module:get_option_number("smacks_max_hibernated_sessions", 10);
-
-assert(max_hibernated_sessions > 0, "smacks_max_hibernated_sessions must be greater than 0");
 
 local c2s_sessions = module:shared("/*/c2s/sessions");
 
 local function format_h(h) if h then return string.format("%d", h) end end
 
-local function init_session_cache(max_entries, evict_callback)
-	-- use per user limited cache for prosody >= 0.10
-	local stores = {};
-	return {
-			get = function(user, key)
-				if not user then return nil; end
-				if not key then return nil; end
-				if not stores[user] then
-					stores[user] = cache.new(max_entries, evict_callback);
-				end
-				return stores[user]:get(key);
-			end;
-			set = function(user, key, value)
-				if not user then return nil; end
-				if not key then return nil; end
-				if not stores[user] then stores[user] = cache.new(max_entries, evict_callback); end
-				stores[user]:set(key, value);
-				-- remove empty caches completely
-				if stores[user]:count() == 0 then stores[user] = nil; end
-			end;
-		};
-end
 local old_session_registry = module:open_store("smacks_h", "map");
-local session_registry = init_session_cache(max_hibernated_sessions, function(resumption_token, session)
-	if session.destroyed then return true; end -- destroyed session can always be removed from cache
-	session.log("warn", "User has too much hibernated sessions, removing oldest session (token: %s)", resumption_token);
-	-- store old session's h values on force delete
-	-- save only actual h value and username/host (for security)
-	old_session_registry:set(session.username, resumption_token, {
-		h = session.handled_stanza_count,
-	});
-	return true; -- allow session to be removed from full cache to make room for new one
-end);
+local session_registry = module:shared "/*/smacks/resumption-tokens"; -- > user@host/resumption-token --> resource
 
 local function ack_delayed(session, stanza)
 	-- fire event only if configured to do so and our session is not already hibernated or destroyed
@@ -245,7 +210,7 @@ end
 module:hook("pre-session-close", function(event)
 	local session = event.session;
 	if session.resumption_token then
-		session_registry.set(session.username, session.resumption_token, nil);
+		session_registry[jid.join(session.username, session.host, session.resumption_token)] = nil;
 		old_session_registry:set(session.username, session.resumption_token, nil);
 		session.resumption_token = nil;
 	end
@@ -290,7 +255,7 @@ function handle_enable(session, stanza, xmlns_sm)
 	local resume = stanza.attr.resume;
 	if resume == "true" or resume == "1" then
 		resume_token = uuid_generate();
-		session_registry.set(session.username, resume_token, session);
+		session_registry[jid.join(session.username, session.host, resume_token)] = session;
 		session.resumption_token = resume_token;
 	end
 	(session.sends2s or session.send)(st.stanza("enabled", { xmlns = xmlns_sm, id = resume_token, resume = resume, max = tostring(resume_timeout) }));
@@ -489,7 +454,7 @@ module:hook("pre-resource-unbind", function (event)
 						return resume_timeout-(current_time-timeout_start); -- time left to wait
 					end
 					session.log("debug", "Destroying session for hibernating too long");
-					session_registry.set(session.username, session.resumption_token, nil);
+					session_registry[jid.join(session.username, session.host, session.resumption_token)] = nil;
 					-- save only actual h value and username/host (for security)
 					old_session_registry:set(session.username, session.resumption_token, {
 						h = session.handled_stanza_count,
@@ -541,7 +506,7 @@ function handle_resume(session, stanza, xmlns_sm)
 	end
 
 	local id = stanza.attr.previd;
-	local original_session = session_registry.get(session.username, id);
+	local original_session = session_registry[jid.join(session.username, session.host, id)];
 	if not original_session then
 		session.log("debug", "Tried to resume non-existent session with id %s", id);
 		local old_session = old_session_registry:get(session.username, id);