src/couch/test/couch_server_tests.erl - couchdb - Git at Google

 % Licensed under the Apache License, Version 2.0 (the "License"); you may not
 % use this file except in compliance with the License. You may obtain a copy of
 % the License at
 %
 %   http://www.apache.org/licenses/LICENSE-2.0
 %
 % Unless required by applicable law or agreed to in writing, software
 % distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 % WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 % License for the specific language governing permissions and limitations under
 % the License.

 -module(couch_server_tests).

 -include_lib("couch/include/couch_eunit.hrl").
 -include_lib("couch/include/couch_db.hrl").
 -include("../src/couch_server_int.hrl").

 start() ->
     Ctx = test_util:start_couch(),
     config:set("log", "include_sasl", "false", false),
     Ctx.

 setup() ->
     DbName = ?tempdb(),
     {ok, Db} = couch_db:create(DbName, []),
     Db.

 setup(rename) ->
     config:set("couchdb", "enable_database_recovery", "true", false),
     setup();
 setup(_) ->
     setup().

 teardown(Db) ->
     FilePath = couch_db:get_filepath(Db),
     (catch couch_db:close(Db)),
     (catch file:delete(FilePath)).

 teardown(rename, Db) ->
     config:set("couchdb", "enable_database_recovery", "false", false),
     teardown(Db);
 teardown(_, Db) ->
     teardown(Db).


 delete_db_test_() ->
     {
         "Test for proper deletion of db file",
         {
             setup,
             fun start/0, fun test_util:stop/1,
             [
                 make_test_case(rename, [fun should_rename_on_delete/2]),
                 make_test_case(delete, [fun should_delete/2])
             ]
         }
     }.

 make_test_case(Mod, Funs) ->
     {
         lists:flatten(io_lib:format("~s", [Mod])),
         {foreachx, fun setup/1, fun teardown/2, [{Mod, Fun} || Fun <- Funs]}
     }.

 should_rename_on_delete(_, Db) ->
     DbName = couch_db:name(Db),
     Origin = couch_db:get_filepath(Db),
     ?_test(begin
         ?assert(filelib:is_regular(Origin)),
         ?assertMatch(ok, couch_server:delete(DbName, [])),
         ?assertNot(filelib:is_regular(Origin)),
         DeletedFiles = deleted_files(Origin),
         ?assertMatch([_], DeletedFiles),
         [Renamed] = DeletedFiles,
         ?assertEqual(
             filename:extension(Origin), filename:extension(Renamed)),
         ?assert(filelib:is_regular(Renamed))
     end).

 should_delete(_, Db) ->
     DbName = couch_db:name(Db),
     Origin = couch_db:get_filepath(Db),
     ?_test(begin
         ?assert(filelib:is_regular(Origin)),
         ?assertMatch(ok, couch_server:delete(DbName, [])),
         ?assertNot(filelib:is_regular(Origin)),
         ?assertMatch([], deleted_files(Origin))
     end).

 deleted_files(ViewFile) ->
     filelib:wildcard(filename:rootname(ViewFile) ++ "*.deleted.*").


 bad_engine_option_test_() ->
     {
         setup,
         fun start/0,
         fun test_util:stop/1,
         [
             fun t_bad_engine_option/0
         ]
     }.


 t_bad_engine_option() ->
     Resp = couch_server:create(?tempdb(), [{engine, <<"cowabunga!">>}]),
     ?assertEqual(Resp, {error, {invalid_engine_extension, <<"cowabunga!">>}}).


 get_engine_path_test_() ->
     {
         setup,
         fun start/0, fun test_util:stop/1,
         {
             foreach,
             fun setup/0, fun teardown/1,
             [
                 fun should_return_engine_path/1,
                 fun should_return_invalid_engine_error/1
             ]
         }
     }.


 should_return_engine_path(Db) ->
     DbName = couch_db:name(Db),
     Engine = couch_db_engine:get_engine(Db),
     Resp = couch_server:get_engine_path(DbName, Engine),
     FilePath = couch_db:get_filepath(Db),
     ?_assertMatch({ok, FilePath}, Resp).


 should_return_invalid_engine_error(Db) ->
     DbName = couch_db:name(Db),
     Engine = fake_engine,
     Resp = couch_server:get_engine_path(DbName, Engine),
     ?_assertMatch({error, {invalid_engine, Engine}}, Resp).


 interleaved_requests_test_() ->
     {
         setup,
         fun start_interleaved/0,
         fun stop_interleaved/1,
         fun make_interleaved_requests/1
     }.


 start_interleaved() ->
     TestDbName = ?tempdb(),
     meck:new(couch_db, [passthrough]),
     meck:expect(couch_db, start_link, fun(Engine, DbName, Filename, Options) ->
         case DbName of
             TestDbName ->
                 receive
                     go -> ok
                 end,
                 Res = meck:passthrough([Engine, DbName, Filename, Options]),
                 % We're unlinking and sending a delayed
                 % EXIT signal so that we can mimic a specific
                 % message order in couch_server. On a test machine
                 % this is a big race condition which affects the
                 % ability to induce the bug.
                 case Res of
                     {ok, Db} ->
                         DbPid = couch_db:get_pid(Db),
                         unlink(DbPid),
                         Msg = {'EXIT', DbPid, killed},
                         erlang:send_after(2000, whereis(couch_server), Msg);
                     _ ->
                         ok
                 end,
                 Res;
             _ ->
                 meck:passthrough([Engine, DbName, Filename, Options])
         end
     end),
     {test_util:start_couch(), TestDbName}.


 stop_interleaved({Ctx, TestDbName}) ->
     couch_server:delete(TestDbName, [?ADMIN_CTX]),
     meck:unload(),
     test_util:stop_couch(Ctx).


 make_interleaved_requests({_, TestDbName}) ->
     [
         fun() -> t_interleaved_create_delete_open(TestDbName) end
     ].


 t_interleaved_create_delete_open(DbName) ->
     {CrtRef, DelRef, OpenRef} = {make_ref(), make_ref(), make_ref()},
     CrtMsg = {'$gen_call', {self(), CrtRef}, {create, DbName, [?ADMIN_CTX]}},
     DelMsg = {'$gen_call', {self(), DelRef}, {delete, DbName, [?ADMIN_CTX]}},
     OpenMsg = {'$gen_call', {self(), OpenRef}, {open, DbName, [?ADMIN_CTX]}},

     % Get the current couch_server pid so we're sure
     % to not end up messaging two different pids
     CouchServer = whereis(couch_server),

     % Start our first instance that will succeed in
     % an invalid state. Notice that the opener pid
     % spawned by couch_server:open_async/5 will halt
     % in our meck expect function waiting for a message.
     %
     % We're using raw message passing here so that we don't
     % have to coordinate multiple processes for this test.
     CouchServer ! CrtMsg,
     {ok, Opener} = get_opener_pid(DbName),

     % We have to suspend couch_server so that we can enqueue
     % our next requests and let the opener finish processing.
     erlang:suspend_process(CouchServer),

     % Since couch_server is suspend, this delete request won't
     % be processed until after the opener has sent its
     % successful open response via gen_server:call/3
     CouchServer ! DelMsg,

     % This open request will be in the queue after the
     % delete request but before the gen_server:call/3
     % message which will establish the mixed up state
     % in the couch_dbs ets table
     CouchServer ! OpenMsg,

     % First release the opener pid so it can continue
     % working while we tweak meck
     Opener ! go,

     % Replace our expect call to meck so that the OpenMsg
     % isn't blocked on the receive
     meck:expect(couch_db, start_link, fun(Engine, DbName1, Filename, Options) ->
         meck:passthrough([Engine, DbName1, Filename, Options])
     end),

     % Wait for the '$gen_call' message from OpenerPid to arrive
     % in couch_server's mailbox
     ok = wait_for_open_async_result(CouchServer, Opener),

     % Now monitor and resume the couch_server and assert that
     % couch_server does not crash while processing OpenMsg
     CSRef = erlang:monitor(process, CouchServer),
     erlang:resume_process(CouchServer),
     check_monitor_not_triggered(CSRef),

     % The create response is expected to return not_found
     % due to the delete request canceling the async opener
     % pid and sending not_found to all waiters unconditionally
     ?assertEqual({CrtRef, not_found}, get_next_message()),

     % Our delete request was processed normally
     ?assertEqual({DelRef, ok}, get_next_message()),

     % The db was deleted thus it should be not found
     % when we try and open it.
     ?assertMatch({OpenRef, {not_found, no_db_file}}, get_next_message()),

     % And finally assert that couch_server is still
     % alive.
     ?assert(is_process_alive(CouchServer)),
     check_monitor_not_triggered(CSRef).


 get_opener_pid(DbName) ->
     WaitFun = fun() ->
         case ets:lookup(couch_dbs, DbName) of
             [#entry{pid = Pid}] ->
                 {ok, Pid};
             [] ->
                 wait
         end
     end,
     test_util:wait(WaitFun).


 wait_for_open_async_result(CouchServer, Opener) ->
     WaitFun = fun() ->
         {_, Messages} = erlang:process_info(CouchServer, messages),
         Found = lists:foldl(fun(Msg, Acc) ->
             case Msg of
                 {'$gen_call', {Opener, _}, {open_result, _, _, {ok, _}}} ->
                     true;
                 _ ->
                     Acc
             end
         end, false, Messages),
         if Found -> ok; true -> wait end
     end,
     test_util:wait(WaitFun).


 check_monitor_not_triggered(Ref) ->
     receive
         {'DOWN', Ref, _, _, Reason0} ->
             erlang:error({monitor_triggered, Reason0})
     after 100 ->
         ok
     end.


 get_next_message() ->
     receive
         Msg ->
             Msg
     after 5000 ->
         erlang:error(timeout)
     end.
	% Licensed under the Apache License, Version 2.0 (the "License"); you may not
	% use this file except in compliance with the License. You may obtain a copy of
	% the License at
	%
	% http://www.apache.org/licenses/LICENSE-2.0
	%
	% Unless required by applicable law or agreed to in writing, software
	% distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
	% WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
	% License for the specific language governing permissions and limitations under
	% the License.

	-module(couch_server_tests).

	-include_lib("couch/include/couch_eunit.hrl").
	-include_lib("couch/include/couch_db.hrl").
	-include("../src/couch_server_int.hrl").

	start() ->
	Ctx = test_util:start_couch(),
	config:set("log", "include_sasl", "false", false),
	Ctx.

	setup() ->
	DbName = ?tempdb(),
	{ok, Db} = couch_db:create(DbName, []),
	Db.

	setup(rename) ->
	config:set("couchdb", "enable_database_recovery", "true", false),
	setup();
	setup(_) ->
	setup().

	teardown(Db) ->
	FilePath = couch_db:get_filepath(Db),
	(catch couch_db:close(Db)),
	(catch file:delete(FilePath)).

	teardown(rename, Db) ->
	config:set("couchdb", "enable_database_recovery", "false", false),
	teardown(Db);
	teardown(_, Db) ->
	teardown(Db).


	delete_db_test_() ->
	{
	"Test for proper deletion of db file",
	{
	setup,
	fun start/0, fun test_util:stop/1,
	[
	make_test_case(rename, [fun should_rename_on_delete/2]),
	make_test_case(delete, [fun should_delete/2])
	]
	}
	}.

	make_test_case(Mod, Funs) ->
	{
	lists:flatten(io_lib:format("~s", [Mod])),
	{foreachx, fun setup/1, fun teardown/2, [{Mod, Fun} \|\| Fun <- Funs]}
	}.

	should_rename_on_delete(_, Db) ->
	DbName = couch_db:name(Db),
	Origin = couch_db:get_filepath(Db),
	?_test(begin
	?assert(filelib:is_regular(Origin)),
	?assertMatch(ok, couch_server:delete(DbName, [])),
	?assertNot(filelib:is_regular(Origin)),
	DeletedFiles = deleted_files(Origin),
	?assertMatch([_], DeletedFiles),
	[Renamed] = DeletedFiles,
	?assertEqual(
	filename:extension(Origin), filename:extension(Renamed)),
	?assert(filelib:is_regular(Renamed))
	end).

	should_delete(_, Db) ->
	DbName = couch_db:name(Db),
	Origin = couch_db:get_filepath(Db),
	?_test(begin
	?assert(filelib:is_regular(Origin)),
	?assertMatch(ok, couch_server:delete(DbName, [])),
	?assertNot(filelib:is_regular(Origin)),
	?assertMatch([], deleted_files(Origin))
	end).

	deleted_files(ViewFile) ->
	filelib:wildcard(filename:rootname(ViewFile) ++ ".deleted.").


	bad_engine_option_test_() ->
	{
	setup,
	fun start/0,
	fun test_util:stop/1,
	[
	fun t_bad_engine_option/0
	]
	}.


	t_bad_engine_option() ->
	Resp = couch_server:create(?tempdb(), [{engine, <<"cowabunga!">>}]),
	?assertEqual(Resp, {error, {invalid_engine_extension, <<"cowabunga!">>}}).


	get_engine_path_test_() ->
	{
	setup,
	fun start/0, fun test_util:stop/1,
	{
	foreach,
	fun setup/0, fun teardown/1,
	[
	fun should_return_engine_path/1,
	fun should_return_invalid_engine_error/1
	]
	}
	}.


	should_return_engine_path(Db) ->
	DbName = couch_db:name(Db),
	Engine = couch_db_engine:get_engine(Db),
	Resp = couch_server:get_engine_path(DbName, Engine),
	FilePath = couch_db:get_filepath(Db),
	?_assertMatch({ok, FilePath}, Resp).


	should_return_invalid_engine_error(Db) ->
	DbName = couch_db:name(Db),
	Engine = fake_engine,
	Resp = couch_server:get_engine_path(DbName, Engine),
	?_assertMatch({error, {invalid_engine, Engine}}, Resp).


	interleaved_requests_test_() ->
	{
	setup,
	fun start_interleaved/0,
	fun stop_interleaved/1,
	fun make_interleaved_requests/1
	}.


	start_interleaved() ->
	TestDbName = ?tempdb(),
	meck:new(couch_db, [passthrough]),
	meck:expect(couch_db, start_link, fun(Engine, DbName, Filename, Options) ->
	case DbName of
	TestDbName ->
	receive
	go -> ok
	end,
	Res = meck:passthrough([Engine, DbName, Filename, Options]),
	% We're unlinking and sending a delayed
	% EXIT signal so that we can mimic a specific
	% message order in couch_server. On a test machine
	% this is a big race condition which affects the
	% ability to induce the bug.
	case Res of
	{ok, Db} ->
	DbPid = couch_db:get_pid(Db),
	unlink(DbPid),
	Msg = {'EXIT', DbPid, killed},
	erlang:send_after(2000, whereis(couch_server), Msg);
	_ ->
	ok
	end,
	Res;
	_ ->
	meck:passthrough([Engine, DbName, Filename, Options])
	end
	end),
	{test_util:start_couch(), TestDbName}.


	stop_interleaved({Ctx, TestDbName}) ->
	couch_server:delete(TestDbName, [?ADMIN_CTX]),
	meck:unload(),
	test_util:stop_couch(Ctx).


	make_interleaved_requests({_, TestDbName}) ->
	[
	fun() -> t_interleaved_create_delete_open(TestDbName) end
	].


	t_interleaved_create_delete_open(DbName) ->
	{CrtRef, DelRef, OpenRef} = {make_ref(), make_ref(), make_ref()},
	CrtMsg = {'$gen_call', {self(), CrtRef}, {create, DbName, [?ADMIN_CTX]}},
	DelMsg = {'$gen_call', {self(), DelRef}, {delete, DbName, [?ADMIN_CTX]}},
	OpenMsg = {'$gen_call', {self(), OpenRef}, {open, DbName, [?ADMIN_CTX]}},

	% Get the current couch_server pid so we're sure
	% to not end up messaging two different pids
	CouchServer = whereis(couch_server),

	% Start our first instance that will succeed in
	% an invalid state. Notice that the opener pid
	% spawned by couch_server:open_async/5 will halt
	% in our meck expect function waiting for a message.
	%
	% We're using raw message passing here so that we don't
	% have to coordinate multiple processes for this test.
	CouchServer ! CrtMsg,
	{ok, Opener} = get_opener_pid(DbName),

	% We have to suspend couch_server so that we can enqueue
	% our next requests and let the opener finish processing.
	erlang:suspend_process(CouchServer),

	% Since couch_server is suspend, this delete request won't
	% be processed until after the opener has sent its
	% successful open response via gen_server:call/3
	CouchServer ! DelMsg,

	% This open request will be in the queue after the
	% delete request but before the gen_server:call/3
	% message which will establish the mixed up state
	% in the couch_dbs ets table
	CouchServer ! OpenMsg,

	% First release the opener pid so it can continue
	% working while we tweak meck
	Opener ! go,

	% Replace our expect call to meck so that the OpenMsg
	% isn't blocked on the receive
	meck:expect(couch_db, start_link, fun(Engine, DbName1, Filename, Options) ->
	meck:passthrough([Engine, DbName1, Filename, Options])
	end),

	% Wait for the '$gen_call' message from OpenerPid to arrive
	% in couch_server's mailbox
	ok = wait_for_open_async_result(CouchServer, Opener),

	% Now monitor and resume the couch_server and assert that
	% couch_server does not crash while processing OpenMsg
	CSRef = erlang:monitor(process, CouchServer),
	erlang:resume_process(CouchServer),
	check_monitor_not_triggered(CSRef),

	% The create response is expected to return not_found
	% due to the delete request canceling the async opener
	% pid and sending not_found to all waiters unconditionally
	?assertEqual({CrtRef, not_found}, get_next_message()),

	% Our delete request was processed normally
	?assertEqual({DelRef, ok}, get_next_message()),

	% The db was deleted thus it should be not found
	% when we try and open it.
	?assertMatch({OpenRef, {not_found, no_db_file}}, get_next_message()),

	% And finally assert that couch_server is still
	% alive.
	?assert(is_process_alive(CouchServer)),
	check_monitor_not_triggered(CSRef).


	get_opener_pid(DbName) ->
	WaitFun = fun() ->
	case ets:lookup(couch_dbs, DbName) of
	[#entry{pid = Pid}] ->
	{ok, Pid};
	[] ->
	wait
	end
	end,
	test_util:wait(WaitFun).


	wait_for_open_async_result(CouchServer, Opener) ->
	WaitFun = fun() ->
	{_, Messages} = erlang:process_info(CouchServer, messages),
	Found = lists:foldl(fun(Msg, Acc) ->
	case Msg of
	{'$gen_call', {Opener, _}, {open_result, _, _, {ok, _}}} ->
	true;
	_ ->
	Acc
	end
	end, false, Messages),
	if Found -> ok; true -> wait end
	end,
	test_util:wait(WaitFun).


	check_monitor_not_triggered(Ref) ->
	receive
	{'DOWN', Ref, _, _, Reason0} ->
	erlang:error({monitor_triggered, Reason0})
	after 100 ->
	ok
	end.


	get_next_message() ->
	receive
	Msg ->
	Msg
	after 5000 ->
	erlang:error(timeout)
	end.