--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mod_storage_muconference_readonly/README.markdown	Thu Jun 30 05:22:12 2016 +0100
@@ -0,0 +1,45 @@
+---
+labels:
+- 'Type-Storage'
+- 'Stage-Alpha'
+summary: MU-Conference SQL Read-only Storage Module
+...
+
+Introduction
+============
+
+This is a storage backend using MU-Conference’s SQL storage. It depends
+on [LuaDBI](https://prosody.im/doc/depends#luadbi)
+
+This module only works in read-only, and was made to be used by
+[mod\_migrate](https://modules.prosody.im/mod_migrate.html) to migrate
+from MU-Conference’s SQL storage.
+
+You may need to convert your 'rooms' and 'rooms\_lists' tables to
+utf8mb4 before running that script, in order not to end up with
+mojibake.  Note that MySQL doesn’t support having more than
+191 characters in the jid field in this case, so you may have to change
+the table schema as well.
+
+Configuration
+=============
+
+Copy the module to the prosody modules/plugins directory.
+
+In Prosody's configuration file, set:
+
+    storage = "muconference_readonly"
+
+MUConferenceSQL options are the same as the
+[https://prosody.im/doc/modules/mod\_storage\_sql](SQL ones):
+
+Compatibility
+=============
+
+  ------- ---------------------------
+  trunk   Works
+  ------- ---------------------------
+  0.10    Untested, but should work
+  ------- ---------------------------
+  0.9     Does not work
+  ------- ---------------------------

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mod_storage_muconference_readonly/mod_storage_muconference_readonly.lua	Thu Jun 30 05:22:12 2016 +0100
@@ -0,0 +1,155 @@
+
+-- luacheck: ignore 212/self
+
+local sql = require "util.sql";
+local xml_parse = require "util.xml".parse;
+local resolve_relative_path = require "util.paths".resolve_relative_path;
+local stanza_preserialize = require "util.stanza".preserialize;
+
+local unpack = unpack
+local function iterator(result)
+	return function(result_)
+		local row = result_();
+		if row ~= nil then
+			return unpack(row);
+		end
+	end, result, nil;
+end
+
+local default_params = { driver = "MySQL" };
+
+local engine;
+
+local host = module.host;
+local room, store;
+
+local function get_best_affiliation(a, b)
+	if a == 'owner' or b == 'owner' then
+		return 'owner';
+	elseif a == 'administrator' or b == 'administrator' then
+		return 'administrator';
+	elseif a == 'outcast' or b == 'outcast' then
+		return 'outcast';
+	elseif a == 'member' or b == 'member' then
+		return 'member';
+	end
+	assert(false);
+end
+
+local function keyval_store_get()
+	if store == "muc" then
+		local room_jid = room.."@"..host;
+		local result;
+		for row in engine:select("SELECT `name`,`desc`,`topic`,`public`,`secret` FROM `rooms` WHERE `jid`=? LIMIT 1", room_jid or "") do result = row end
+		local name = result[1];
+		local desc = result[2];
+		local subject = result[3];
+		local public = result[4];
+		local hidden = public == 0 and true or nil;
+		local secret = result[5];
+		if secret == '' then secret = nil end
+		local affiliations = {};
+		for row in engine:select("SELECT `jid_user`,`affil` FROM `rooms_lists` WHERE `jid_room`=?", room_jid or "") do
+			local jid_user = row[1];
+			local affil = row[2];
+			-- mu-conference has a bug where full JIDs get stored…
+			local bare_jid = jid_user:gsub('/.*', '');
+			local old_affil = affiliations[bare_jid];
+			-- mu-conference has a bug where it can record multiple affiliations…
+			if old_affil ~= nil and old_affil ~= affil then
+				affil = get_best_affiliation(old_affil, affil);
+			end
+			-- terminology is clearly “admin”, not “administrator”.
+			if affil == 'administrator' then
+				affil = 'admin';
+			end
+			affiliations[bare_jid] = affil;
+		end
+		return {
+			jid = room_jid,
+			_data = {
+				persistent = true,
+				name = name,
+				subject = subject,
+				password = secret,
+				hidden = hidden,
+			},
+			_affiliations = affiliations,
+		};
+	end
+end
+
+--- Key/value store API (default store type)
+
+local keyval_store = {};
+keyval_store.__index = keyval_store;
+function keyval_store:get(roomname)
+	room, store = roomname, self.store;
+	local ok, result = engine:transaction(keyval_store_get);
+	if not ok then
+		module:log("error", "Unable to read from database %s store for %s: %s", store, roomname or "<host>", result);
+		return nil, result;
+	end
+	return result;
+end
+
+function keyval_store:users()
+	local host_length = host:len() + 1;
+	local ok, result = engine:transaction(function()
+		return engine:select("SELECT SUBSTRING_INDEX(jid, '@', 1) FROM `rooms`");
+	end);
+	if not ok then return ok, result end
+	return iterator(result);
+end
+
+local stores = {
+	keyval = keyval_store;
+};
+
+--- Implement storage driver API
+
+-- FIXME: Some of these operations need to operate on the archive store(s) too
+
+local driver = {};
+
+function driver:open(store, typ)
+	local store_mt = stores[typ or "keyval"];
+	if store_mt then
+		return setmetatable({ store = store }, store_mt);
+	end
+	return nil, "unsupported-store";
+end
+
+function driver:stores(roomname)
+	local query = "SELECT 'config'";
+	if roomname == true or not roomname then
+		roomname = "";
+	end
+	local ok, result = engine:transaction(function()
+		return engine:select(query, host, roomname);
+	end);
+	if not ok then return ok, result end
+	return iterator(result);
+end
+
+--- Initialization
+
+
+local function normalize_params(params)
+	assert(params.driver and params.database, "Configuration error: Both the SQL driver and the database need to be specified");
+	return params;
+end
+
+function module.load()
+	if prosody.prosodyctl then return; end
+	local engines = module:shared("/*/sql/connections");
+	local params = normalize_params(module:get_option("sql", default_params));
+	engine = engines[sql.db2uri(params)];
+	if not engine then
+		module:log("debug", "Creating new engine");
+		engine = sql:create_engine(params);
+		engines[sql.db2uri(params)] = engine;
+	end
+
+	module:provides("storage", driver);
+end