--- a/plugins/mod_storage_sql.lua	Thu Nov 05 22:27:17 2020 +0100
+++ b/plugins/mod_storage_sql.lua	Thu Nov 05 22:31:25 2020 +0100
@@ -1,17 +1,19 @@
 
 -- 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;
+local unpack = table.unpack or unpack; -- luacheck: ignore 113
 local function iterator(result)
 	return function(result_)
 		local row = result_();
@@ -148,7 +150,13 @@
 
 --- Archive store API
 
--- luacheck: ignore 512 431/user 431/store
+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));
+
+local item_count_cache_hit = module:measure("item_count_cache_hit", "rate");
+local item_count_cache_miss = module:measure("item_count_cache_miss", "rate")
+
+-- luacheck: ignore 512 431/user 431/store 431/err
 local map_store = {};
 map_store.__index = map_store;
 map_store.remove = {};
@@ -225,13 +233,91 @@
 	return result;
 end
 
+function map_store:get_all(key)
+	if type(key) ~= "string" or key == "" then
+		return nil, "get_all only supports non-empty string keys";
+	end
+	local ok, result = engine:transaction(function()
+		local query = [[
+		SELECT "user", "type", "value"
+		FROM "prosody"
+		WHERE "host"=? AND "store"=? AND "key"=?
+		]];
+
+		local data;
+		for row in engine:select(query, host, self.store, key) do
+			local key_data, err = deserialize(row[2], row[3]);
+			assert(key_data ~= nil, err);
+			if data == nil then
+				data = {};
+			end
+			data[row[1]] = key_data;
+		end
+
+		return data;
+
+	end);
+	if not ok then return nil, result; end
+	return result;
+end
+
+function map_store:delete_all(key)
+	if type(key) ~= "string" or key == "" then
+		return nil, "delete_all only supports non-empty string keys";
+	end
+	local ok, result = engine:transaction(function()
+		local delete_sql = [[
+		DELETE FROM "prosody"
+		WHERE "host"=? AND "store"=? AND "key"=?;
+		]];
+		engine:delete(delete_sql, host, self.store, key);
+		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
+		item_count_cache_miss();
+		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);
+	else
+		item_count_cache_hit();
+	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()
@@ -245,12 +331,16 @@
 		VALUES (?,?,?,?,?,?,?,?);
 		]];
 		if key then
-			engine:delete(delete_sql, host, user or "", store, key);
+			local result = 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
@@ -287,45 +377,48 @@
 	end
 end
 local function archive_where_id_range(query, args, where)
-	local args_len = #args
 	-- Before or after specific item, exclusive
+	local id_lookup_sql = [[
+	SELECT "sort_id"
+	FROM "prosodyarchive"
+	WHERE "key" = ? AND "host" = ? AND "user" = ? AND "store" = ?
+	LIMIT 1;
+	]];
 	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
+		local after_id = nil;
+		for row in engine:select(id_lookup_sql, query.after, args[1], args[2], args[3]) do
+			after_id = row[1];
+		end
+		if not after_id then
+			return nil, "item-not-found";
+		end
+		where[#where+1] = '"sort_id" > ?';
+		args[#args+1] = after_id;
 	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];
+		local before_id = nil;
+		for row in engine:select(id_lookup_sql, query.before, args[1], args[2], args[3]) do
+			before_id = row[1];
+		end
+		if not before_id then
+			return nil, "item-not-found";
+		end
+		where[#where+1] = '"sort_id" < ?';
+		args[#args+1] = before_id;
 	end
+	return true;
 end
 
 function archive_store:find(username, query)
 	query = query or {};
 	local user,store = username,self.store;
-	local total;
-	local ok, result = engine:transaction(function()
+	local cache_key = jid_join(username, host, self.store);
+	local total = archive_item_count_cache:get(cache_key);
+	(total and item_count_cache_hit or item_count_cache_miss)();
+	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, err = engine:transaction(function()
 		local sql_query = [[
 		SELECT "key", "type", "value", "when", "with"
 		FROM "prosodyarchive"
@@ -346,11 +439,53 @@
 					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
 
+		local ok, err = archive_where_id_range(query, args, where);
+		if not ok then return ok, err; end
+
+		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
+	if not result then return nil, err; 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(*), MIN("when"), MAX("when")
+		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
@@ -362,14 +497,19 @@
 		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;
+	local counts = {};
+	local earliest, latest = {}, {};
+	for row in result do
+		local with, count = row[1], row[2];
+		counts[with] = count;
+		earliest[with] = row[3];
+		latest[with] = row[4];
+	end
+	return {
+		counts = counts;
+		earliest = earliest;
+		latest = latest;
+	};
 end
 
 function archive_store:delete(username, query)
@@ -384,7 +524,8 @@
 			table.remove(where, 2);
 		end
 		archive_where(query, args, where);
-		archive_where_id_range(query, args, where);
+		local ok, err = archive_where_id_range(query, args, where);
+		if not ok then return ok, err; end
 		if query.truncate == nil then
 			sql_query = sql_query:format(t_concat(where, " AND "));
 		else
@@ -423,9 +564,24 @@
 		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;
@@ -610,9 +766,10 @@
 	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)];
+	local db_uri = sql.db2uri(params);
+	engine = engines[db_uri];
 	if not engine then
-		module:log("debug", "Creating new engine");
+		module:log("debug", "Creating new engine %s", db_uri);
 		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)