1 files changed, 399 insertions, 0 deletions
diff --git a/apps/couch/src/couch_server.erl b/apps/couch/src/couch_server.erl
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+++ b/apps/couch/src/couch_server.erl
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+% 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).
+-behaviour(gen_server).
+
+-export([open/2,create/2,delete/2,all_databases/0,get_version/0]).
+-export([init/1, handle_call/3,sup_start_link/0]).
+-export([handle_cast/2,code_change/3,handle_info/2,terminate/2]).
+-export([dev_start/0,is_admin/2,has_admins/0,get_stats/0]).
+
+-include("couch_db.hrl").
+
+-record(server,{
+    root_dir = [],
+    dbname_regexp,
+    max_dbs_open=100,
+    dbs_open=0,
+    start_time=""
+    }).
+
+dev_start() ->
+    couch:stop(),
+    up_to_date = make:all([load, debug_info]),
+    couch:start().
+
+get_version() ->
+    Apps = application:loaded_applications(),
+    case lists:keysearch(couch, 1, Apps) of
+    {value, {_, _, Vsn}} ->
+        Vsn;
+    false ->
+        "0.0.0"
+    end.
+
+get_stats() ->
+    {ok, #server{start_time=Time,dbs_open=Open}} =
+            gen_server:call(couch_server, get_server),
+    [{start_time, ?l2b(Time)}, {dbs_open, Open}].
+
+sup_start_link() ->
+    gen_server:start_link({local, couch_server}, couch_server, [], []).
+
+open(DbName, Options) ->
+    case gen_server:call(couch_server, {open, DbName, Options}, infinity) of
+    {ok, Db} ->
+        Ctx = couch_util:get_value(user_ctx, Options, #user_ctx{}),
+        {ok, Db#db{user_ctx=Ctx}};
+    Error ->
+        Error
+    end.
+
+create(DbName, Options) ->
+    case gen_server:call(couch_server, {create, DbName, Options}, infinity) of
+    {ok, Db} ->
+        Ctx = couch_util:get_value(user_ctx, Options, #user_ctx{}),
+        {ok, Db#db{user_ctx=Ctx}};
+    Error ->
+        Error
+    end.
+
+delete(DbName, Options) ->
+    gen_server:call(couch_server, {delete, DbName, Options}, infinity).
+
+check_dbname(#server{dbname_regexp=RegExp}, DbName) ->
+    case re:run(DbName, RegExp, [{capture, none}]) of
+    nomatch ->
+        case DbName of
+            "_users" -> ok;
+            _Else ->
+                {error, illegal_database_name}
+            end;
+    match ->
+        ok
+    end.
+
+is_admin(User, ClearPwd) ->
+    case couch_config:get("admins", User) of
+    "-hashed-" ++ HashedPwdAndSalt ->
+        [HashedPwd, Salt] = string:tokens(HashedPwdAndSalt, ","),
+        couch_util:to_hex(crypto:sha(ClearPwd ++ Salt)) == HashedPwd;
+    _Else ->
+        false
+    end.
+
+has_admins() ->
+    couch_config:get("admins") /= [].
+
+get_full_filename(Server, DbName) ->
+    filename:join([Server#server.root_dir, "./" ++ DbName ++ ".couch"]).
+
+hash_admin_passwords() ->
+    hash_admin_passwords(true).
+
+hash_admin_passwords(Persist) ->
+    lists:foreach(
+        fun({_User, "-hashed-" ++ _}) ->
+            ok; % already hashed
+        ({User, ClearPassword}) ->
+            Salt = ?b2l(couch_uuids:random()),
+            Hashed = couch_util:to_hex(crypto:sha(ClearPassword ++ Salt)),
+            couch_config:set("admins",
+                User, "-hashed-" ++ Hashed ++ "," ++ Salt, Persist)
+        end, couch_config:get("admins")).
+
+init([]) ->
+    % read config and register for configuration changes
+
+    % just stop if one of the config settings change. couch_server_sup
+    % will restart us and then we will pick up the new settings.
+
+    RootDir = couch_config:get("couchdb", "database_dir", "."),
+    MaxDbsOpen = list_to_integer(
+            couch_config:get("couchdb", "max_dbs_open")),
+    Self = self(),
+    ok = couch_config:register(
+        fun("couchdb", "database_dir") ->
+            exit(Self, config_change)
+        end),
+    ok = couch_config:register(
+        fun("couchdb", "max_dbs_open", Max) ->
+            gen_server:call(couch_server,
+                    {set_max_dbs_open, list_to_integer(Max)})
+        end),
+    ok = couch_file:init_delete_dir(RootDir),
+    hash_admin_passwords(),
+    ok = couch_config:register(
+        fun("admins", _Key, _Value, Persist) ->
+            % spawn here so couch_config doesn't try to call itself
+            spawn(fun() -> hash_admin_passwords(Persist) end)
+        end, false),
+    {ok, RegExp} = re:compile("^[a-z][a-z0-9\\_\\$()\\+\\-\\/]*$"),
+    ets:new(couch_dbs_by_name, [set, private, named_table]),
+    ets:new(couch_dbs_by_pid, [set, private, named_table]),
+    ets:new(couch_dbs_by_lru, [ordered_set, private, named_table]),
+    ets:new(couch_sys_dbs, [set, private, named_table]),
+    process_flag(trap_exit, true),
+    {ok, #server{root_dir=RootDir,
+                dbname_regexp=RegExp,
+                max_dbs_open=MaxDbsOpen,
+                start_time=httpd_util:rfc1123_date()}}.
+
+terminate(_Reason, _Srv) ->
+    [couch_util:shutdown_sync(Pid) || {_, {Pid, _LruTime}} <-
+            ets:tab2list(couch_dbs_by_name)],
+    ok.
+
+all_databases() ->
+    {ok, #server{root_dir=Root}} = gen_server:call(couch_server, get_server),
+    NormRoot = couch_util:normpath(Root),
+    Filenames =
+    filelib:fold_files(Root, "^[a-z0-9\\_\\$()\\+\\-]*[\\.]couch$", true,
+        fun(Filename, AccIn) ->
+            NormFilename = couch_util:normpath(Filename),
+            case NormFilename -- NormRoot of
+            [$/ | RelativeFilename] -> ok;
+            RelativeFilename -> ok
+            end,
+            [list_to_binary(filename:rootname(RelativeFilename, ".couch")) | AccIn]
+        end, []),
+    {ok, Filenames}.
+
+
+maybe_close_lru_db(#server{dbs_open=NumOpen, max_dbs_open=MaxOpen}=Server)
+        when NumOpen < MaxOpen ->
+    {ok, Server};
+maybe_close_lru_db(#server{dbs_open=NumOpen}=Server) ->
+    % must free up the lru db.
+    case try_close_lru(now()) of
+    ok ->
+        {ok, Server#server{dbs_open=NumOpen - 1}};
+    Error -> Error
+    end.
+
+try_close_lru(StartTime) ->
+    LruTime = get_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),
+        [{_, {opened, MainPid, LruTime}}] = ets:lookup(couch_dbs_by_name, DbName),
+        case couch_db:is_idle(MainPid) of
+        true ->
+            couch_util:shutdown_sync(MainPid),
+            true = ets:delete(couch_dbs_by_lru, LruTime),
+            true = ets:delete(couch_dbs_by_name, DbName),
+            true = ets:delete(couch_dbs_by_pid, MainPid),
+            true = ets:delete(couch_sys_dbs, DbName),
+            ok;
+        false ->
+            % 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, {opened, 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.
+
+get_lru() ->
+    get_lru(ets:first(couch_dbs_by_lru)).
+
+get_lru(LruTime) ->
+    [{LruTime, DbName}] = ets:lookup(couch_dbs_by_lru, LruTime),
+    case ets:member(couch_sys_dbs, DbName) of
+    false ->
+        LruTime;
+    true ->
+        [{_, {opened, MainPid, _}}] = ets:lookup(couch_dbs_by_name, DbName),
+        case couch_db:is_idle(MainPid) of
+        true ->
+            LruTime;
+        false ->
+            get_lru(ets:next(couch_dbs_by_lru, LruTime))
+        end
+    end.
+
+open_async(Server, From, DbName, Filepath, Options) ->
+    Parent = self(),
+    Opener = spawn_link(fun() ->
+            Res = couch_db:start_link(DbName, Filepath, Options),
+            gen_server:call(
+                Parent, {open_result, DbName, Res, Options}, infinity
+            ),
+            unlink(Parent),
+            case Res of
+            {ok, DbReader} ->
+                unlink(DbReader);
+            _ ->
+                ok
+            end
+        end),
+    true = ets:insert(couch_dbs_by_name, {DbName, {opening, Opener, [From]}}),
+    true = ets:insert(couch_dbs_by_pid, {Opener, DbName}),
+    DbsOpen = case lists:member(sys_db, Options) of
+    true ->
+        true = ets:insert(couch_sys_dbs, {DbName, true}),
+        Server#server.dbs_open;
+    false ->
+        Server#server.dbs_open + 1
+    end,
+    Server#server{dbs_open = DbsOpen}.
+
+handle_call({set_max_dbs_open, Max}, _From, Server) ->
+    {reply, ok, Server#server{max_dbs_open=Max}};
+handle_call(get_server, _From, Server) ->
+    {reply, {ok, Server}, Server};
+handle_call({open_result, DbName, {ok, OpenedDbPid}, Options}, _From, Server) ->
+    link(OpenedDbPid),
+    [{DbName, {opening,Opener,Froms}}] = ets:lookup(couch_dbs_by_name, DbName),
+    lists:foreach(fun({FromPid,_}=From) ->
+        gen_server:reply(From,
+                catch couch_db:open_ref_counted(OpenedDbPid, FromPid))
+    end, Froms),
+    LruTime = now(),
+    true = ets:insert(couch_dbs_by_name,
+            {DbName, {opened, OpenedDbPid, LruTime}}),
+    true = ets:delete(couch_dbs_by_pid, Opener),
+    true = ets:insert(couch_dbs_by_pid, {OpenedDbPid, DbName}),
+    true = ets:insert(couch_dbs_by_lru, {LruTime, DbName}),
+    case lists:member(create, Options) of
+    true ->
+        couch_db_update_notifier:notify({created, DbName});
+    false ->
+        ok
+    end,
+    {reply, ok, Server};
+handle_call({open_result, DbName, Error, Options}, _From, Server) ->
+    [{DbName, {opening,Opener,Froms}}] = ets:lookup(couch_dbs_by_name, DbName),
+    lists:foreach(fun(From) ->
+        gen_server:reply(From, Error)
+    end, Froms),
+    true = ets:delete(couch_dbs_by_name, DbName),
+    true = ets:delete(couch_dbs_by_pid, Opener),
+    DbsOpen = case lists:member(sys_db, Options) of
+    true ->
+        true = ets:delete(couch_sys_dbs, DbName),
+        Server#server.dbs_open;
+    false ->
+        Server#server.dbs_open - 1
+    end,
+    {reply, ok, Server#server{dbs_open = DbsOpen}};
+handle_call({open, DbName, Options}, {FromPid,_}=From, Server) ->
+    LruTime = now(),
+    case ets:lookup(couch_dbs_by_name, DbName) of
+    [] ->
+        open_db(DbName, Server, Options, From);
+    [{_, {opening, Opener, Froms}}] ->
+        true = ets:insert(couch_dbs_by_name, {DbName, {opening, Opener, [From|Froms]}}),
+        {noreply, Server};
+    [{_, {opened, MainPid, PrevLruTime}}] ->
+        true = ets:insert(couch_dbs_by_name, {DbName, {opened, 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, DbName, Options}, From, Server) ->
+    case ets:lookup(couch_dbs_by_name, DbName) of
+    [] ->
+        open_db(DbName, Server, [create | Options], From);
+    [_AlreadyRunningDb] ->
+        {reply, file_exists, Server}
+    end;
+handle_call({delete, DbName, _Options}, _From, Server) ->
+    DbNameList = binary_to_list(DbName),
+    case check_dbname(Server, DbNameList) of
+    ok ->
+        FullFilepath = get_full_filename(Server, DbNameList),
+        UpdateState =
+        case ets:lookup(couch_dbs_by_name, DbName) of
+        [] -> false;
+        [{_, {opening, Pid, Froms}}] ->
+            couch_util:shutdown_sync(Pid),
+            true = ets:delete(couch_dbs_by_name, DbName),
+            true = ets:delete(couch_dbs_by_pid, Pid),
+            [gen_server:send_result(F, not_found) || F <- Froms],
+            true;
+        [{_, {opened, Pid, LruTime}}] ->
+            couch_util:shutdown_sync(Pid),
+            true = ets:delete(couch_dbs_by_name, DbName),
+            true = ets:delete(couch_dbs_by_pid, Pid),
+            true = ets:delete(couch_dbs_by_lru, LruTime),
+            true
+        end,
+        Server2 = case UpdateState of
+        true ->
+            DbsOpen = case ets:member(couch_sys_dbs, DbName) of
+            true ->
+                true = ets:delete(couch_sys_dbs, DbName),
+                Server#server.dbs_open;
+            false ->
+                Server#server.dbs_open - 1
+            end,
+            Server#server{dbs_open = DbsOpen};
+        false ->
+            Server
+        end,
+
+        %% Delete any leftover .compact files.  If we don't do this a subsequent
+        %% request for this DB will try to open the .compact file and use it.
+        couch_file:delete(Server#server.root_dir, FullFilepath ++ ".compact"),
+
+        case couch_file:delete(Server#server.root_dir, FullFilepath) of
+        ok ->
+            couch_db_update_notifier:notify({deleted, DbName}),
+            {reply, ok, Server2};
+        {error, enoent} ->
+            {reply, not_found, Server2};
+        Else ->
+            {reply, Else, Server2}
+        end;
+    Error ->
+        {reply, Error, Server}
+    end.
+
+handle_cast(Msg, _Server) ->
+    exit({unknown_cast_message, Msg}).
+
+code_change(_OldVsn, State, _Extra) ->
+    {ok, State}.
+    
+handle_info({'EXIT', _Pid, config_change}, Server) ->
+    {noreply, shutdown, Server};
+handle_info(Error, _Server) ->
+    ?LOG_ERROR("Unexpected message, restarting couch_server: ~p", [Error]),
+    exit(kill).
+
+open_db(DbName, Server, Options, From) ->
+    DbNameList = binary_to_list(DbName),
+    case check_dbname(Server, DbNameList) of
+    ok ->
+        Filepath = get_full_filename(Server, DbNameList),
+        case lists:member(sys_db, Options) of
+        true ->
+            {noreply, open_async(Server, From, DbName, Filepath, Options)};
+        false ->
+            case maybe_close_lru_db(Server) of
+            {ok, Server2} ->
+                {noreply, open_async(Server2, From, DbName, Filepath, Options)};
+            CloseError ->
+                {reply, CloseError, Server}
+            end
+        end;
+     Error ->
+        {reply, Error, Server}
+     end.