diff options
Diffstat (limited to 'src/couchdb/couch_server.erl')
| -rw-r--r-- | src/couchdb/couch_server.erl | 252 |
1 files changed, 148 insertions, 104 deletions
diff --git a/src/couchdb/couch_server.erl b/src/couchdb/couch_server.erl index bb3617b2..86cdb2f8 100644 --- a/src/couchdb/couch_server.erl +++ b/src/couchdb/couch_server.erl @@ -15,7 +15,7 @@ -behaviour(application). -export([start/0,start/1,start/2,stop/0,stop/1]). --export([open/1,create/2,delete/1,all_databases/0,get_version/0]). +-export([open/2,create/2,delete/1,all_databases/0,get_version/0]). -export([init/1, handle_call/3,sup_start_link/2]). -export([handle_cast/2,code_change/3,handle_info/2,terminate/2]). -export([dev_start/0,remote_restart/0]). @@ -25,7 +25,9 @@ -record(server,{ root_dir = [], dbname_regexp, - options=[] + remote_restart=[], + max_dbs_open=100, + current_dbs_open=0 }). start() -> @@ -64,33 +66,41 @@ get_version() -> sup_start_link(RootDir, Options) -> gen_server:start_link({local, couch_server}, couch_server, {RootDir, Options}, []). -open(Filename) -> - gen_server:call(couch_server, {open, Filename}). +open(DbName, Options) -> + gen_server:call(couch_server, {open, DbName, Options}). -create(Filename, Options) -> - gen_server:call(couch_server, {create, Filename, Options}). +create(DbName, Options) -> + gen_server:call(couch_server, {create, DbName, Options}). -delete(Filename) -> - gen_server:call(couch_server, {delete, Filename}). +delete(DbName) -> + gen_server:call(couch_server, {delete, DbName}). remote_restart() -> gen_server:call(couch_server, remote_restart). -init({RootDir, Options}) -> - {ok, RegExp} = regexp:parse("^[a-z][a-z0-9\\_\\$()\\+\\-\\/]*$"), - {ok, #server{root_dir=RootDir, dbname_regexp=RegExp, options=Options}}. - -check_filename(#server{dbname_regexp=RegExp}, Filename) -> - case regexp:match(Filename, RegExp) of +check_dbname(#server{dbname_regexp=RegExp}, DbName) -> + case regexp:match(DbName, RegExp) of nomatch -> {error, illegal_database_name}; _Match -> ok end. -get_full_filename(Server, Filename) -> - filename:join([Server#server.root_dir, "./" ++ Filename ++ ".couch"]). +get_full_filename(Server, DbName) -> + filename:join([Server#server.root_dir, "./" ++ DbName ++ ".couch"]). +init({RootDir, Options}) -> + {ok, RegExp} = regexp:parse("^[a-z][a-z0-9\\_\\$()\\+\\-\\/]*$"), + ets:new(couch_dbs_by_name, [set, private, named_table]), + ets:new(couch_dbs_by_pid, [set, private, named_table]), + ets:new(couch_dbs_by_lru, [ordered_set, private, named_table]), + process_flag(trap_exit, true), + MaxDbsOpen = proplists:get_value(max_dbs_open, Options), + RemoteRestart = proplists:get_value(remote_restart, Options), + {ok, #server{root_dir=RootDir, + dbname_regexp=RegExp, + max_dbs_open=MaxDbsOpen, + remote_restart=RemoteRestart}}. terminate(_Reason, _Server) -> ok. @@ -109,107 +119,141 @@ all_databases() -> {ok, Filenames}. +maybe_close_lru_db(#server{current_dbs_open=NumOpen, max_dbs_open=MaxOpen}=Server) + when NumOpen < MaxOpen -> + {ok, Server}; +maybe_close_lru_db(#server{current_dbs_open=NumOpen}=Server) -> + % must free up the lru db. + case try_close_lru(now()) of + ok -> {ok, Server#server{current_dbs_open=NumOpen-1}}; + Error -> Error + end. + +try_close_lru(StartTime) -> + LruTime = ets:first(couch_dbs_by_lru), + if LruTime > StartTime -> + % this means we've looped through all our opened dbs and found them + % all in use. + {error, all_dbs_active}; + true -> + [{_, DbName}] = ets:lookup(couch_dbs_by_lru, LruTime), + [{_, {MainPid, LruTime}}] = ets:lookup(couch_dbs_by_name, DbName), + case couch_db:num_refs(MainPid) of + 0 -> + exit(MainPid, kill), + receive {'EXIT', MainPid, _Reason} -> ok end, + true = ets:delete(couch_dbs_by_lru, LruTime), + true = ets:delete(couch_dbs_by_name, DbName), + true = ets:delete(couch_dbs_by_pid, MainPid), + ok; + _NumRefs -> + % this still has referrers. Go ahead and give it a current lru time + % and try the next one in the table. + NewLruTime = now(), + true = ets:insert(couch_dbs_by_name, {DbName, {MainPid, NewLruTime}}), + true = ets:insert(couch_dbs_by_pid, {MainPid, DbName}), + true = ets:delete(couch_dbs_by_lru, LruTime), + true = ets:insert(couch_dbs_by_lru, {NewLruTime, DbName}), + try_close_lru(StartTime) + end + end. + + handle_call(get_root, _From, #server{root_dir=Root}=Server) -> {reply, {ok, Root}, Server}; -handle_call({open, Filename}, From, Server) -> - case check_filename(Server, Filename) of - {error, Error} -> - {reply, {error, Error}, Server}; - ok -> - Filepath = get_full_filename(Server, Filename), - Result = supervisor:start_child(couch_server_sup, - {Filename, - {couch_db, open, [Filename, Filepath]}, - transient , - infinity, - supervisor, - [couch_db]}), - case Result of - {ok, Db} -> - {reply, {ok, Db}, Server}; - {error, already_present} -> - ok = supervisor:delete_child(couch_server_sup, Filename), - % call self recursively - handle_call({open, Filename}, From, Server); - {error, {already_started, Db}} -> - {reply, {ok, Db}, Server}; - {error, {not_found, _}} -> - {reply, not_found, Server}; - {error, {Error, _}} -> - {reply, {error, Error}, Server} - end +handle_call({open, DbName, Options}, {FromPid,_}, Server) -> + Filepath = get_full_filename(Server, DbName), + LruTime = now(), + case ets:lookup(couch_dbs_by_name, DbName) of + [] -> + case maybe_close_lru_db(Server) of + {ok, Server2} -> + case couch_db:start_link(DbName, Filepath, Options) of + {ok, MainPid} -> + true = ets:insert(couch_dbs_by_name, {DbName, {MainPid, LruTime}}), + true = ets:insert(couch_dbs_by_pid, {MainPid, DbName}), + true = ets:insert(couch_dbs_by_lru, {LruTime, DbName}), + DbsOpen = Server2#server.current_dbs_open + 1, + {reply, + couch_db:open_ref_counted(MainPid, FromPid), + Server2#server{current_dbs_open=DbsOpen}}; + CloseError -> + {reply, CloseError, Server2} + end; + Error -> + {reply, Error, Server} + end; + [{_, {MainPid, PrevLruTime}}] -> + true = ets:insert(couch_dbs_by_name, {DbName, {MainPid, LruTime}}), + true = ets:delete(couch_dbs_by_lru, PrevLruTime), + true = ets:insert(couch_dbs_by_lru, {LruTime, DbName}), + {reply, couch_db:open_ref_counted(MainPid, FromPid), Server} end; -handle_call({create, Filename, Options}, _From, Server) -> - case check_filename(Server, Filename) of - {error, Error} -> - {reply, {error, Error}, Server}; +handle_call({create, DbName, Options}, {FromPid,_}, Server) -> + case check_dbname(Server, DbName) of ok -> - Filepath = get_full_filename(Server, Filename), - ChildSpec = {Filename, - {couch_db, create, [Filename, Filepath, Options]}, - transient, - infinity, - supervisor, - [couch_db]}, - Result = - case supervisor:delete_child(couch_server_sup, Filename) of - ok -> - sup_start_child(couch_server_sup, ChildSpec); - {error, not_found} -> - sup_start_child(couch_server_sup, ChildSpec); - {error, running} -> - % a server process for this database already started. Maybe kill it - case lists:member(overwrite, Options) of - true -> - supervisor:terminate_child(couch_server_sup, Filename), - ok = supervisor:delete_child(couch_server_sup, Filename), - sup_start_child(couch_server_sup, ChildSpec); - false -> - {error, database_already_exists} - end - end, - case Result of - {ok, _Db} -> couch_db_update_notifier:notify({created, Filename}); - _ -> ok - end, - {reply, Result, Server} + Filepath = get_full_filename(Server, DbName), + + case ets:lookup(couch_dbs_by_name, DbName) of + [] -> + case couch_db:start_link(DbName, Filepath, [create|Options]) of + {ok, MainPid} -> + LruTime = now(), + true = ets:insert(couch_dbs_by_name, {DbName, {MainPid, LruTime}}), + true = ets:insert(couch_dbs_by_pid, {MainPid, DbName}), + true = ets:insert(couch_dbs_by_lru, {LruTime, DbName}), + DbsOpen = Server#server.current_dbs_open + 1, + {reply, + couch_db:open_ref_counted(MainPid, FromPid), + Server#server{current_dbs_open=DbsOpen}}; + Error -> + {reply, Error, Server} + end; + [_AlreadyRunningDb] -> + {reply, {error, file_exists}, Server} + end; + Error -> + {reply, Error, Server} end; -handle_call({delete, Filename}, _From, Server) -> - FullFilepath = get_full_filename(Server, Filename), - supervisor:terminate_child(couch_server_sup, Filename), - supervisor:delete_child(couch_server_sup, Filename), +handle_call({delete, DbName}, _From, Server) -> + FullFilepath = get_full_filename(Server, DbName), + Server2 = + case ets:lookup(couch_dbs_by_name, DbName) of + [] -> Server; + [{_, {Pid, LruTime}}] -> + exit(Pid, kill), + receive {'EXIT', Pid, _Reason} -> ok end, + true = ets:delete(couch_dbs_by_name, DbName), + true = ets:delete(couch_dbs_by_pid, Pid), + true = ets:delete(couch_dbs_by_lru, LruTime), + DbsOpen = Server#server.current_dbs_open - 1, + Server#server{current_dbs_open=DbsOpen} + end, case file:delete(FullFilepath) of ok -> - couch_db_update_notifier:notify({deleted, Filename}), - {reply, ok, Server}; + couch_db_update_notifier:notify({deleted, DbName}), + {reply, ok, Server2}; {error, enoent} -> - {reply, not_found, Server}; + {reply, not_found, Server2}; Else -> - {reply, Else, Server} + {reply, Else, Server2} end; -handle_call(remote_restart, _From, #server{options=Options}=Server) -> - case proplists:get_value(remote_restart, Options) of - true -> - exit(self(), restart); - _ -> - ok - end, +handle_call(remote_restart, _From, #server{remote_restart=false}=Server) -> + {reply, ok, Server}; +handle_call(remote_restart, _From, #server{remote_restart=true}=Server) -> + exit(couch_server_sup, restart), {reply, ok, Server}. -% this function is just to strip out the child spec error stuff if hit -sup_start_child(couch_server_sup, ChildSpec) -> - case supervisor:start_child(couch_server_sup, ChildSpec) of - {error, {Error, _ChildInfo}} -> - {error, Error}; - Else -> - Else - end. - -handle_cast(_Msg, State) -> - {noreply,State}. +handle_cast(Msg, _Server) -> + exit({unknown_cast_message, Msg}). code_change(_OldVsn, State, _Extra) -> {ok, State}. -handle_info(_Info, State) -> - {noreply, State}. +handle_info({'EXIT', Pid, _Reason}, Server) -> + [{Pid, DbName}] = ets:lookup(couch_dbs_by_pid, Pid), + true = ets:delete(couch_dbs_by_pid, Pid), + true = ets:delete(couch_dbs_by_name, DbName), + {noreply, Server}; +handle_info(Info, _Server) -> + exit({unknown_message, Info}). |