aboutsummaryrefslogtreecommitdiffstats
path: root/plugins/mod_storage_sql.lua
blob: f0a8fee050d38ecb654abf26e3142bf8e4fbd6f8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771

-- luacheck: ignore 212/self

local cache = require "util.cache";
local json = require "util.json";
local sql = require "util.sql";
local xml_parse = require "util.xml".parse;
local uuid = require "util.uuid";
local resolve_relative_path = require "util.paths".resolve_relative_path;
local jid_join = require "util.jid".join;

local is_stanza = require"util.stanza".is_stanza;
local t_concat = table.concat;

local noop = function() end
local unpack = table.unpack or unpack; -- luacheck: ignore 113
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 = "SQLite3" };

local engine;

local function serialize(value)
	local t = type(value);
	if t == "string" or t == "boolean" or t == "number" then
		return t, tostring(value);
	elseif is_stanza(value) then
		return "xml", tostring(value);
	elseif t == "table" then
		local encoded,err = json.encode(value);
		if encoded then return "json", encoded; end
		return nil, err;
	end
	return nil, "Unhandled value type: "..t;
end
local function deserialize(t, value)
	if t == "string" then return value;
	elseif t == "boolean" then
		if value == "true" then return true;
		elseif value == "false" then return false; end
		return nil, "invalid-boolean";
	elseif t == "number" then
		value = tonumber(value);
		if value then return value; end
		return nil, "invalid-number";
	elseif t == "json" then
		return json.decode(value);
	elseif t == "xml" then
		return xml_parse(value);
	end
	return nil, "Unhandled value type: "..t;
end

local host = module.host;
local user, store;

local function keyval_store_get()
	local haveany;
	local result = {};
	local select_sql = [[
	SELECT "key","type","value"
	FROM "prosody"
	WHERE "host"=? AND "user"=? AND "store"=?;
	]]
	for row in engine:select(select_sql, host, user or "", store) do
		haveany = true;
		local k = row[1];
		local v, e = deserialize(row[2], row[3]);
		assert(v ~= nil, e);
		if k and v then
			if k ~= "" then result[k] = v; elseif type(v) == "table" then
				for a,b in pairs(v) do
					result[a] = b;
				end
			end
		end
	end
	if haveany then
		return result;
	end
end
local function keyval_store_set(data)
	local delete_sql = [[
	DELETE FROM "prosody"
	WHERE "host"=? AND "user"=? AND "store"=?
	]];
	engine:delete(delete_sql, host, user or "", store);

	local insert_sql = [[
	INSERT INTO "prosody"
	("host","user","store","key","type","value")
	VALUES (?,?,?,?,?,?);
	]]
	if data and next(data) ~= nil then
		local extradata = {};
		for key, value in pairs(data) do
			if type(key) == "string" and key ~= "" then
				local t, encoded_value = assert(serialize(value));
				engine:insert(insert_sql, host, user or "", store, key, t, encoded_value);
			else
				extradata[key] = value;
			end
		end
		if next(extradata) ~= nil then
			local t, encoded_extradata = assert(serialize(extradata));
			engine:insert(insert_sql, host, user or "", store, "", t, encoded_extradata);
		end
	end
	return true;
end

--- Key/value store API (default store type)

local keyval_store = {};
keyval_store.__index = keyval_store;
function keyval_store:get(username)
	user, store = username, 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, username or "<host>", result);
		return nil, result;
	end
	return result;
end
function keyval_store:set(username, data)
	user,store = username,self.store;
	return engine:transaction(function()
		return keyval_store_set(data);
	end);
end
function keyval_store:users()
	local ok, result = engine:transaction(function()
		local select_sql = [[
		SELECT DISTINCT "user"
		FROM "prosody"
		WHERE "host"=? AND "store"=?;
		]];
		return engine:select(select_sql, host, self.store);
	end);
	if not ok then error(result); end
	return iterator(result);
end

--- Archive store API

local archive_item_limit = module:get_option_number("storage_archive_item_limit");
local archive_item_count_cache = cache.new(module:get_option("storage_archive_item_limit_cache_size", 1000));

-- luacheck: ignore 512 431/user 431/store
local map_store = {};
map_store.__index = map_store;
map_store.remove = {};
function map_store:get(username, key)
	local ok, result = engine:transaction(function()
		local query = [[
		SELECT "type", "value"
		FROM "prosody"
		WHERE "host"=? AND "user"=? AND "store"=? AND "key"=?
		LIMIT 1
		]];
		local data, err;
		if type(key) == "string" and key ~= "" then
			for row in engine:select(query, host, username or "", self.store, key) do
				data, err = deserialize(row[1], row[2]);
				assert(data ~= nil, err);
			end
			return data;
		else
			for row in engine:select(query, host, username or "", self.store, "") do
				data, err = deserialize(row[1], row[2]);
				assert(data ~= nil, err);
			end
			return data and data[key] or nil;
		end
	end);
	if not ok then return nil, result; end
	return result;
end
function map_store:set(username, key, data)
	if data == nil then data = self.remove; end
	return self:set_keys(username, { [key] = data });
end
function map_store:set_keys(username, keydatas)
	local ok, result = engine:transaction(function()
		local delete_sql = [[
		DELETE FROM "prosody"
		WHERE "host"=? AND "user"=? AND "store"=? AND "key"=?;
		]];
		local insert_sql = [[
		INSERT INTO "prosody"
		("host","user","store","key","type","value")
		VALUES (?,?,?,?,?,?);
		]];
		local select_extradata_sql = [[
		SELECT "type", "value"
		FROM "prosody"
		WHERE "host"=? AND "user"=? AND "store"=? AND "key"=?
		LIMIT 1;
		]];
		for key, data in pairs(keydatas) do
			if type(key) == "string" and key ~= "" then
				engine:delete(delete_sql,
					host, username or "", self.store, key);
				if data ~= self.remove then
					local t, value = assert(serialize(data));
					engine:insert(insert_sql, host, username or "", self.store, key, t, value);
				end
			else
				local extradata, err = {};
				for row in engine:select(select_extradata_sql, host, username or "", self.store, "") do
					extradata, err = deserialize(row[1], row[2]);
					assert(extradata ~= nil, err);
				end
				engine:delete(delete_sql, host, username or "", self.store, "");
				extradata[key] = data;
				local t, value = assert(serialize(extradata));
				engine:insert(insert_sql, host, username or "", self.store, "", t, value);
			end
		end
		return true;
	end);
	if not ok then return nil, result; end
	return result;
end

local archive_store = {}
archive_store.caps = {
	total = true;
	quota = archive_item_limit;
	truncate = true;
};
archive_store.__index = archive_store
function archive_store:append(username, key, value, when, with)
	local user,store = username,self.store;
	local cache_key = jid_join(username, host, store);
	local item_count = archive_item_count_cache:get(cache_key);
	if not item_count then
		local ok, ret = engine:transaction(function()
			local count_sql = [[
			SELECT COUNT(*) FROM "prosodyarchive"
			WHERE "host"=? AND "user"=? AND "store"=?;
			]];
			local result = engine:select(count_sql, host, user, store);
			if result then
				for row in result do
					item_count = row[1];
				end
			end
		end);
		if not ok or not item_count then
			module:log("error", "Failed while checking quota for %s: %s", username, ret);
			return nil, "Failure while checking quota";
		end
		archive_item_count_cache:set(cache_key, item_count);
	end

	if archive_item_limit then
		module:log("debug", "%s has %d items out of %d limit", username, item_count, archive_item_limit);
		if item_count >= archive_item_limit then
			return nil, "quota-limit";
		end
	end

	when = when or os.time();
	with = with or "";
	local ok, ret = engine:transaction(function()
		local delete_sql = [[
		DELETE FROM "prosodyarchive"
		WHERE "host"=? AND "user"=? AND "store"=? AND "key"=?;
		]];
		local insert_sql = [[
		INSERT INTO "prosodyarchive"
		("host", "user", "store", "when", "with", "key", "type", "value")
		VALUES (?,?,?,?,?,?,?,?);
		]];
		if key then
			local result, err = engine:delete(delete_sql, host, user or "", store, key);
			if result then
				item_count = item_count - result:affected();
			end
		else
			key = uuid.generate();
		end
		local t, encoded_value = assert(serialize(value));
		engine:insert(insert_sql, host, user or "", store, when, with, key, t, encoded_value);
		archive_item_count_cache:set(cache_key, item_count+1);
		return key;
	end);
	if not ok then return ok, ret; end
	return ret; -- the key
end

-- Helpers for building the WHERE clause
local function archive_where(query, args, where)
	-- Time range, inclusive
	if query.start then
		args[#args+1] = query.start
		where[#where+1] = "\"when\" >= ?"
	end

	if query["end"] then
		args[#args+1] = query["end"];
		if query.start then
			where[#where] = "\"when\" BETWEEN ? AND ?" -- is this inclusive?
		else
			where[#where+1] = "\"when\" <= ?"
		end
	end

	-- Related name
	if query.with then
		where[#where+1] = "\"with\" = ?";
		args[#args+1] = query.with
	end

	-- Unique id
	if query.key then
		where[#where+1] = "\"key\" = ?";
		args[#args+1] = query.key
	end
end
local function archive_where_id_range(query, args, where)
	local args_len = #args
	-- Before or after specific item, exclusive
	if query.after then  -- keys better be unique!
		where[#where+1] = [[
		"sort_id" > COALESCE(
			(
				SELECT "sort_id"
				FROM "prosodyarchive"
				WHERE "key" = ? AND "host" = ? AND "user" = ? AND "store" = ?
				LIMIT 1
			), 0)
		]];
		args[args_len+1], args[args_len+2], args[args_len+3], args[args_len+4] = query.after, args[1], args[2], args[3];
		args_len = args_len + 4
	end
	if query.before then
		where[#where+1] = [[
		"sort_id" < COALESCE(
			(
				SELECT "sort_id"
				FROM "prosodyarchive"
				WHERE "key" = ? AND "host" = ? AND "user" = ? AND "store" = ?
				LIMIT 1
			),
			(
				SELECT MAX("sort_id")+1
				FROM "prosodyarchive"
			)
		)
		]]
		args[args_len+1], args[args_len+2], args[args_len+3], args[args_len+4] = query.before, args[1], args[2], args[3];
	end
end

function archive_store:find(username, query)
	query = query or {};
	local user,store = username,self.store;
	local cache_key = jid_join(username, host, self.store);
	local total = archive_item_count_cache:get(cache_key);
	if total ~= nil and query.limit == 0 and query.start == nil and query.with == nil and query["end"] == nil and query.key == nil then
		return noop, total;
	end
	local ok, result = engine:transaction(function()
		local sql_query = [[
		SELECT "key", "type", "value", "when", "with"
		FROM "prosodyarchive"
		WHERE %s
		ORDER BY "sort_id" %s%s;
		]];
		local args = { host, user or "", store, };
		local where = { "\"host\" = ?", "\"user\" = ?", "\"store\" = ?", };

		archive_where(query, args, where);

		-- Total matching
		if query.total then
			local stats = engine:select("SELECT COUNT(*) FROM \"prosodyarchive\" WHERE "
				.. t_concat(where, " AND "), unpack(args));
			if stats then
				for row in stats do
					total = row[1];
				end
			end
			if query.start == nil and query.with == nil and query["end"] == nil and query.key == nil then
				archive_item_count_cache:set(cache_key, total);
			end
			if query.limit == 0 then -- Skip the real query
				return noop, total;
			end
		end

		archive_where_id_range(query, args, where);

		if query.limit then
			args[#args+1] = query.limit;
		end

		sql_query = sql_query:format(t_concat(where, " AND "), query.reverse
			and "DESC" or "ASC", query.limit and " LIMIT ?" or "");
		return engine:select(sql_query, unpack(args));
	end);
	if not ok then return ok, result end
	return function()
		local row = result();
		if row ~= nil then
			local value, err = deserialize(row[2], row[3]);
			assert(value ~= nil, err);
			return row[1], value, row[4], row[5];
		end
	end, total;
end

function archive_store:summary(username, query)
	query = query or {};
	local user,store = username,self.store;
	local ok, result = engine:transaction(function()
		local sql_query = [[
		SELECT DISTINCT "with", COUNT(*)
		FROM "prosodyarchive"
		WHERE %s
		GROUP BY "with"
		ORDER BY "sort_id" %s%s;
		]];
		local args = { host, user or "", store, };
		local where = { "\"host\" = ?", "\"user\" = ?", "\"store\" = ?", };

		archive_where(query, args, where);

		archive_where_id_range(query, args, where);

		if query.limit then
			args[#args+1] = query.limit;
		end

		sql_query = sql_query:format(t_concat(where, " AND "), query.reverse
			and "DESC" or "ASC", query.limit and " LIMIT ?" or "");
		return engine:select(sql_query, unpack(args));
	end);
	if not ok then return ok, result end
	local summary = {};
	for row in result do
		local with, count = row[1], row[2];
		summary[with] = count;
	end
	return summary;
end

function archive_store:delete(username, query)
	query = query or {};
	local user,store = username,self.store;
	local ok, stmt = engine:transaction(function()
		local sql_query = "DELETE FROM \"prosodyarchive\" WHERE %s;";
		local args = { host, user or "", store, };
		local where = { "\"host\" = ?", "\"user\" = ?", "\"store\" = ?", };
		if user == true then
			table.remove(args, 2);
			table.remove(where, 2);
		end
		archive_where(query, args, where);
		archive_where_id_range(query, args, where);
		if query.truncate == nil then
			sql_query = sql_query:format(t_concat(where, " AND "));
		else
			args[#args+1] = query.truncate;
			local unlimited = "ALL";
			sql_query = [[
			DELETE FROM "prosodyarchive"
			WHERE "sort_id" IN (
				SELECT "sort_id" FROM "prosodyarchive"
				WHERE %s
				ORDER BY "sort_id" %s
				LIMIT %s OFFSET ?
			);]];
			if engine.params.driver == "SQLite3" then
				if engine._have_delete_limit then
					sql_query = [[
					DELETE FROM "prosodyarchive"
					WHERE %s
					ORDER BY "sort_id" %s
					LIMIT %s OFFSET ?;
					]];
				end
				unlimited = "-1";
			elseif engine.params.driver == "MySQL" then
				sql_query = [[
				DELETE result FROM prosodyarchive AS result JOIN (
					SELECT sort_id FROM prosodyarchive
					WHERE %s
					ORDER BY "sort_id" %s
					LIMIT %s OFFSET ?
				) AS limiter on result.sort_id = limiter.sort_id;]];
				unlimited = "18446744073709551615";
			end
			sql_query = string.format(sql_query, t_concat(where, " AND "),
				query.reverse and "ASC" or "DESC", unlimited);
		end
		return engine:delete(sql_query, unpack(args));
	end);
	local cache_key = jid_join(username, host, self.store);
	archive_item_count_cache:set(cache_key, nil);
	return ok and stmt:affected(), stmt;
end

function archive_store:users()
	local ok, result = engine:transaction(function()
		local select_sql = [[
		SELECT DISTINCT "user"
		FROM "prosodyarchive"
		WHERE "host"=? AND "store"=?;
		]];
		return engine:select(select_sql, host, self.store);
	end);
	if not ok then error(result); end
	return iterator(result);
end

local stores = {
	keyval = keyval_store;
	map = map_store;
	archive = archive_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(username)
	local query = "SELECT DISTINCT \"store\" FROM \"prosody\" WHERE \"host\"=? AND \"user\"" ..
		(username == true and "!=?" or "=?");
	if username == true or not username then
		username = "";
	end
	local ok, result = engine:transaction(function()
		return engine:select(query, host, username);
	end);
	if not ok then return ok, result end
	return iterator(result);
end

function driver:purge(username)
	return engine:transaction(function()
		engine:delete("DELETE FROM \"prosody\" WHERE \"host\"=? AND \"user\"=?", host, username);
		engine:delete("DELETE FROM \"prosodyarchive\" WHERE \"host\"=? AND \"user\"=?", host, username);
	end);
end

--- Initialization


local function create_table(engine) -- luacheck: ignore 431/engine
	local Table, Column, Index = sql.Table, sql.Column, sql.Index;

	local ProsodyTable = Table {
		name = "prosody";
		Column { name="host", type="TEXT", nullable=false };
		Column { name="user", type="TEXT", nullable=false };
		Column { name="store", type="TEXT", nullable=false };
		Column { name="key", type="TEXT", nullable=false };
		Column { name="type", type="TEXT", nullable=false };
		Column { name="value", type="MEDIUMTEXT", nullable=false };
		Index { name="prosody_index", "host", "user", "store", "key" };
	};
	engine:transaction(function()
		ProsodyTable:create(engine);
	end);

	local ProsodyArchiveTable = Table {
		name="prosodyarchive";
		Column { name="sort_id", type="INTEGER", primary_key=true, auto_increment=true };
		Column { name="host", type="TEXT", nullable=false };
		Column { name="user", type="TEXT", nullable=false };
		Column { name="store", type="TEXT", nullable=false };
		Column { name="key", type="TEXT", nullable=false }; -- item id
		Column { name="when", type="INTEGER", nullable=false }; -- timestamp
		Column { name="with", type="TEXT", nullable=false }; -- related id
		Column { name="type", type="TEXT", nullable=false };
		Column { name="value", type="MEDIUMTEXT", nullable=false };
		Index { name="prosodyarchive_index", unique = engine.params.driver ~= "MySQL", "host", "user", "store", "key" };
		Index { name="prosodyarchive_with_when", "host", "user", "store", "with", "when" };
		Index { name="prosodyarchive_when", "host", "user", "store", "when" };
	};
	engine:transaction(function()
		ProsodyArchiveTable:create(engine);
	end);
end

local function upgrade_table(engine, params, apply_changes) -- luacheck: ignore 431/engine
	local changes = false;
	if params.driver == "MySQL" then
		local success,err = engine:transaction(function()
			do
				local result = assert(engine:execute("SHOW COLUMNS FROM \"prosody\" WHERE \"Field\"='value' and \"Type\"='text'"));
				if result:rowcount() > 0 then
					changes = true;
					if apply_changes then
						module:log("info", "Upgrading database schema (value column size)...");
						assert(engine:execute("ALTER TABLE \"prosody\" MODIFY COLUMN \"value\" MEDIUMTEXT"));
						module:log("info", "Database table automatically upgraded");
					end
				end
			end

			do
				-- Ensure index is not unique (issue #1073)
				local result = assert(engine:execute([[SHOW INDEX FROM prosodyarchive WHERE key_name='prosodyarchive_index' and non_unique=0]]));
				if result:rowcount() > 0 then
					changes = true;
					if apply_changes then
						module:log("info", "Upgrading database schema (prosodyarchive_index)...");
						assert(engine:execute[[ALTER TABLE "prosodyarchive" DROP INDEX prosodyarchive_index;]]);
						local new_index = sql.Index { table = "prosodyarchive", name="prosodyarchive_index", "host", "user", "store", "key" };
						assert(engine:_create_index(new_index));
						module:log("info", "Database table automatically upgraded");
					end
				end
			end
			return true;
		end);
		if not success then
			module:log("error", "Failed to check/upgrade database schema (%s), please see "
				.."https://prosody.im/doc/mysql for help",
				err or "unknown error");
			return false;
		end

		-- COMPAT w/pre-0.10: Upgrade table to UTF-8 if not already
		local check_encoding_query = [[
		SELECT "COLUMN_NAME","COLUMN_TYPE","TABLE_NAME"
		FROM "information_schema"."columns"
		WHERE "TABLE_NAME" LIKE 'prosody%%'
		AND "TABLE_SCHEMA" = ?
		AND ( "CHARACTER_SET_NAME"!=? OR "COLLATION_NAME"!=?);
		]];
		-- FIXME Is it ok to ignore the return values from this?
		engine:transaction(function()
			local result = assert(engine:execute(check_encoding_query, params.database, engine.charset, engine.charset.."_bin"));
			local n_bad_columns = result:rowcount();
			if n_bad_columns > 0 then
				changes = true;
				if apply_changes then
					module:log("warn", "Found %d columns in prosody table requiring encoding change, updating now...", n_bad_columns);
					local fix_column_query1 = "ALTER TABLE \"%s\" CHANGE \"%s\" \"%s\" BLOB;";
					local fix_column_query2 = "ALTER TABLE \"%s\" CHANGE \"%s\" \"%s\" %s CHARACTER SET '%s' COLLATE '%s_bin';";
					for row in result:rows() do
						local column_name, column_type, table_name  = unpack(row);
						module:log("debug", "Fixing column %s in table %s", column_name, table_name);
						engine:execute(fix_column_query1:format(table_name, column_name, column_name));
						engine:execute(fix_column_query2:format(table_name, column_name, column_name, column_type, engine.charset, engine.charset));
					end
					module:log("info", "Database encoding upgrade complete!");
				end
			end
		end);
		success,err = engine:transaction(function()
			return engine:execute(check_encoding_query, params.database,
				engine.charset, engine.charset.."_bin");
		end);
		if not success then
			module:log("error", "Failed to check/upgrade database encoding: %s", err or "unknown error");
			return false;
		end
	end
	return changes;
end

local function normalize_database(driver, database) -- luacheck: ignore 431/driver
	if driver == "SQLite3" and database ~= ":memory:" then
		return resolve_relative_path(prosody.paths.data or ".", database or "prosody.sqlite");
	end
	return database;
end

local function normalize_params(params)
	return {
		driver = assert(params.driver,
			"Configuration error: Both the SQL driver and the database need to be specified");
		database = assert(normalize_database(params.driver, params.database),
			"Configuration error: Both the SQL driver and the database need to be specified");
		username = params.username;
		password = params.password;
		host = params.host;
		port = params.port;
	};
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, function (engine) -- luacheck: ignore 431/engine
			if module:get_option("sql_manage_tables", true) then
				-- Automatically create table, ignore failure (table probably already exists)
				-- FIXME: we should check in information_schema, etc.
				create_table(engine);
				-- Check whether the table needs upgrading
				if upgrade_table(engine, params, false) then
					module:log("error", "Old database format detected. Please run: prosodyctl mod_%s upgrade", module.name);
					return false, "database upgrade needed";
				end
				if engine.params.driver == "SQLite3" then
					for row in engine:select("PRAGMA compile_options") do
						if row[1] == "ENABLE_UPDATE_DELETE_LIMIT" then
							engine._have_delete_limit = true;
						end
					end
				end
			end
		end);
		engines[sql.db2uri(params)] = engine;
	end

	module:provides("storage", driver);
end

function module.command(arg)
	local config = require "core.configmanager";
	local prosodyctl = require "util.prosodyctl";
	local command = table.remove(arg, 1);
	if command == "upgrade" then
		-- We need to find every unique dburi in the config
		local uris = {};
		for host in pairs(prosody.hosts) do -- luacheck: ignore 431/host
			local params = normalize_params(config.get(host, "sql") or default_params);
			uris[sql.db2uri(params)] = params;
		end
		print("We will check and upgrade the following databases:\n");
		for _, params in pairs(uris) do
			print("", "["..params.driver.."] "..params.database..(params.host and " on "..params.host or ""));
		end
		print("");
		print("Ensure you have working backups of the above databases before continuing! ");
		if not prosodyctl.show_yesno("Continue with the database upgrade? [yN]") then
			print("Ok, no upgrade. But you do have backups, don't you? ...don't you?? :-)");
			return;
		end
		-- Upgrade each one
		for _, params in pairs(uris) do
			print("Checking "..params.database.."...");
			engine = sql:create_engine(params);
			upgrade_table(engine, params, true);
		end
		print("All done!");
	elseif command then
		print("Unknown command: "..command);
	else
		print("Available commands:");
		print("","upgrade - Perform database upgrade");
	end
end