%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 1996-2012. All Rights Reserved.
%%
%% The contents of this file are subject to the Erlang Public License,
%% Version 1.1, (the "License"); you may not use this file except in
%% compliance with the License. You should have received a copy of the
%% Erlang Public License along with this software. If not, it can be
%% retrieved online at http://www.erlang.org/.
%%
%% Software distributed under the License is distributed on an "AS IS"
%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
%% the License for the specific language governing rights and limitations
%% under the License.
%%
%% %CopyrightEnd%
%%
-module(snmpa_local_db).
-include_lib("kernel/include/file.hrl").
-include("snmpa_internal.hrl").
-include("snmp_types.hrl").
-include("STANDARD-MIB.hrl").
%% -define(VMODULE, "LDB").
-include("snmp_verbosity.hrl").
%% External exports
-export([start_link/3, start_link/4, stop/0, info/0, verbosity/1]).
-export([dump/0, backup/1,
register_notify_client/2, unregister_notify_client/1]).
-export([table_func/2, table_func/4,
variable_get/1, variable_set/2, variable_delete/1, variable_inc/2,
table_create/1, table_exists/1, table_delete/1,
table_create_row/3, table_create_row/4, table_construct_row/4,
table_delete_row/2,
table_get_row/2,
table_get_element/3, table_get_elements/4,
table_set_elements/3, table_set_status/7,
table_next/2,
table_max_col/2,
table_get/1]).
-export([get_elements/2]).
-export([match/2]).
%% Debug exports
-export([print/0, print/1, print/2]).
%% Internal exports
-export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2,
code_change/3]).
-define(BACKUP_TAB, snmpa_local_backup).
-define(DETS_TAB, snmpa_local_db1).
-define(ETS_TAB, snmpa_local_db2).
-define(SERVER, ?MODULE).
-record(state, {dets, ets, notify_clients = [], backup}).
-record(dets, {tab, shadow}).
%% -define(snmp_debug,true).
-include("snmp_debug.hrl").
-ifdef(snmp_debug).
-define(GS_START_LINK(Prio, Dir, DbInitError, Opts),
gen_server:start_link({local, ?SERVER}, ?MODULE,
[Prio, Dir, DbInitError, Opts],
[{debug,[trace]}])).
-else.
-define(GS_START_LINK(Prio, Dir, DbInitError, Opts),
gen_server:start_link({local, ?SERVER}, ?MODULE,
[Prio, Dir, DbInitError, Opts],
[])).
-endif.
%%%-----------------------------------------------------------------
%%% Implements a general database in which its possible
%%% to store variables and tables. Provide functions for
%%% tableaccess by row or by element, and for next.
%%%
%%% Opts = [Opt]
%%% Opt = {auto_repair, false | true | true_verbose} |
%%% {verbosity,silence | log | debug}
%%%-----------------------------------------------------------------
start_link(Prio, DbDir, Opts) when is_list(Opts) ->
start_link(Prio, DbDir, terminate, Opts).
start_link(Prio, DbDir, DbInitError, Opts) when is_list(Opts) ->
?d("start_link -> entry with"
"~n Prio: ~p"
"~n DbDir: ~p"
"~n DbInitError: ~p"
"~n Opts: ~p", [Prio, DbDir, DbInitError, Opts]),
?GS_START_LINK(Prio, DbDir, DbInitError, Opts).
stop() ->
call(stop).
register_notify_client(Client,Module) ->
call({register_notify_client,Client,Module}).
unregister_notify_client(Client) ->
call({unregister_notify_client,Client}).
backup(BackupDir) ->
call({backup, BackupDir}).
dump() ->
call(dump).
info() ->
call(info).
verbosity(Verbosity) ->
cast({verbosity,Verbosity}).
%%%-----------------------------------------------------------------
init([Prio, DbDir, DbInitError, Opts]) ->
?d("init -> entry with"
"~n Prio: ~p"
"~n DbDir: ~p"
"~n DbInitError: ~p"
"~n Opts: ~p", [Prio, DbDir, DbInitError, Opts]),
case (catch do_init(Prio, DbDir, DbInitError, Opts)) of
{ok, State} ->
?vdebug("started",[]),
{ok, State};
{error, Reason} ->
config_err("failed starting local-db: ~n~p", [Reason]),
{stop, {error, Reason}};
Error ->
config_err("failed starting local-db: ~n~p", [Error]),
{stop, {error, Error}}
end.
do_init(Prio, DbDir, DbInitError, Opts) ->
process_flag(priority, Prio),
process_flag(trap_exit, true),
put(sname,ldb),
put(verbosity,get_opt(verbosity, Opts, ?default_verbosity)),
?vlog("starting",[]),
Dets = dets_open(DbDir, DbInitError, Opts),
Ets = ets:new(?ETS_TAB, [set, protected]),
?vdebug("started",[]),
{ok, #state{dets = Dets, ets = Ets}}.
dets_open(DbDir, DbInitError, Opts) ->
Name = ?DETS_TAB,
Filename = dets_filename(Name, DbDir),
case file:read_file_info(Filename) of
{ok, _} ->
%% File exists
case do_dets_open(Name, Filename, Opts) of
{ok, Dets} ->
?vdebug("dets open done",[]),
Shadow = ets:new(snmp_local_db1_shadow, [set, protected]),
dets:to_ets(Dets, Shadow),
?vtrace("shadow table created and populated",[]),
#dets{tab = Dets, shadow = Shadow};
{error, Reason1} ->
user_err("Corrupt local database: ~p", [Filename]),
case DbInitError of
terminate ->
throw({error, {failed_open_dets, Reason1}});
_ ->
Saved = Filename ++ ".saved",
file:rename(Filename, Saved),
case do_dets_open(Name, Filename, Opts) of
{ok, Dets} ->
Shadow = ets:new(snmp_local_db1_shadow,
[set, protected]),
#dets{tab = Dets, shadow = Shadow};
{error, Reason2} ->
user_err("Could not create local "
"database: ~p"
"~n ~p"
"~n ~p",
[Filename, Reason1, Reason2]),
throw({error, {failed_open_dets, Reason2}})
end
end
end;
_ ->
case do_dets_open(Name, Filename, Opts) of
{ok, Dets} ->
?vdebug("dets open done",[]),
Shadow = ets:new(snmp_local_db1_shadow, [set, protected]),
?vtrace("shadow table created",[]),
#dets{tab = Dets, shadow = Shadow};
{error, Reason} ->
user_err("Could not create local database ~p"
"~n ~p", [Filename, Reason]),
throw({error, {failed_open_dets, Reason}})
end
end.
do_dets_open(Name, Filename, Opts) ->
Repair = get_opt(repair, Opts, true),
AutoSave = get_opt(auto_save, Opts, 5000),
Args = [{auto_save, AutoSave},
{file, Filename},
{repair, Repair}],
dets:open_file(Name, Args).
dets_filename(Name, Dir) when is_atom(Name) ->
dets_filename(atom_to_list(Name), Dir);
dets_filename(Name, Dir) ->
filename:join(dets_filename1(Dir), Name).
dets_filename1([]) -> ".";
dets_filename1(Dir) -> Dir.
%%-----------------------------------------------------------------
%% Interface functions.
%%-----------------------------------------------------------------
%%-----------------------------------------------------------------
%% Functions for debugging.
%%-----------------------------------------------------------------
print() -> call(print).
print(Table) -> call({print,Table,volatile}).
print(Table, Db) -> call({print,Table,Db}).
variable_get({Name, Db}) ->
call({variable_get, Name, Db});
variable_get(Name) ->
call({variable_get, Name, volatile}).
variable_set({Name, Db}, Val) ->
call({variable_set, Name, Db, Val});
variable_set(Name, Val) ->
call({variable_set, Name, volatile, Val}).
variable_inc({Name, Db}, N) ->
cast({variable_inc, Name, Db, N});
variable_inc(Name, N) ->
cast({variable_inc, Name, volatile, N}).
variable_delete({Name, Db}) ->
call({variable_delete, Name, Db});
variable_delete(Name) ->
call({variable_delete, Name, volatile}).
table_create({Name, Db}) ->
call({table_create, Name, Db});
table_create(Name) ->
call({table_create, Name, volatile}).
table_exists({Name, Db}) ->
call({table_exists, Name, Db});
table_exists(Name) ->
call({table_exists, Name, volatile}).
table_delete({Name, Db}) ->
call({table_delete, Name, Db});
table_delete(Name) ->
call({table_delete, Name, volatile}).
table_delete_row({Name, Db}, RowIndex) ->
call({table_delete_row, Name, Db, RowIndex});
table_delete_row(Name, RowIndex) ->
call({table_delete_row, Name, volatile, RowIndex}).
table_get_row({Name, Db}, RowIndex) ->
call({table_get_row, Name, Db, RowIndex});
table_get_row(Name, RowIndex) ->
call({table_get_row, Name, volatile, RowIndex}).
table_get_element({Name, Db}, RowIndex, Col) ->
call({table_get_element, Name, Db, RowIndex, Col});
table_get_element(Name, RowIndex, Col) ->
call({table_get_element, Name, volatile, RowIndex, Col}).
table_set_elements({Name, Db}, RowIndex, Cols) ->
call({table_set_elements, Name, Db, RowIndex, Cols});
table_set_elements(Name, RowIndex, Cols) ->
call({table_set_elements, Name, volatile, RowIndex, Cols}).
table_next({Name, Db}, RestOid) ->
call({table_next, Name, Db, RestOid});
table_next(Name, RestOid) ->
call({table_next, Name, volatile, RestOid}).
table_max_col({Name, Db}, Col) ->
call({table_max_col, Name, Db, Col});
table_max_col(Name, Col) ->
call({table_max_col, Name, volatile, Col}).
table_create_row({Name, Db}, RowIndex, Row) ->
call({table_create_row, Name, Db,RowIndex, Row});
table_create_row(Name, RowIndex, Row) ->
call({table_create_row, Name, volatile, RowIndex, Row}).
table_create_row(NameDb, RowIndex, Status, Cols) ->
Row = table_construct_row(NameDb, RowIndex, Status, Cols),
table_create_row(NameDb, RowIndex, Row).
match({Name, Db}, Pattern) ->
call({match, Name, Db, Pattern});
match(Name, Pattern) ->
call({match, Name, volatile, Pattern}).
table_get(Table) ->
table_get(Table, [], []).
table_get(Table, Idx, Acc) ->
case table_next(Table, Idx) of
endOfTable ->
lists:reverse(Acc);
NextIdx ->
case table_get_row(Table, NextIdx) of
undefined ->
{error, {failed_get_row, NextIdx, lists:reverse(Acc)}};
Row ->
NewAcc = [{NextIdx, Row}|Acc],
table_get(Table, NextIdx, NewAcc)
end
end.
%%-----------------------------------------------------------------
%% Implements the variable functions.
%%-----------------------------------------------------------------
handle_call({variable_get, Name, Db}, _From, State) ->
?vlog("variable get: ~p [~p]",[Name, Db]),
{reply, lookup(Db, Name, State), State};
handle_call({variable_set, Name, Db, Val}, _From, State) ->
?vlog("variable ~p set [~p]: "
"~n Val: ~p",[Name, Db, Val]),
{reply, insert(Db, Name, Val, State), State};
handle_call({variable_delete, Name, Db}, _From, State) ->
?vlog("variable delete: ~p [~p]",[Name, Db]),
{reply, delete(Db, Name, State), State};
%%-----------------------------------------------------------------
%% Implements the table functions.
%%-----------------------------------------------------------------
%% Entry in ets for a tablerow:
%% Key = {<tableName>, <(flat) list of indexes>}
%% Val = {{Row}, <Prev>, <Next>}
%% Where Prev and Next = <list of indexes>; "pointer to prev/next"
%% Each table is a double linked list, with a head-element, with
%% direct access to each individual element.
%% Head-el: Key = {<tableName>, first}
%% Operations:
%% table_create_row(<tableName>, <list of indexes>, <row>) O(n)
%% table_delete_row(<tableName>, <list of indexes>) O(1)
%% get(<tableName>, <list of indexes>, Col) O(1)
%% set(<tableName>, <list of indexes>, Col, Val) O(1)
%% next(<tableName>, <list of indexes>) if Row exist O(1), else O(n)
%%-----------------------------------------------------------------
handle_call({table_create, Name, Db}, _From, State) ->
?vlog("table create: ~p [~p]",[Name, Db]),
catch handle_delete(Db, Name, State),
{reply, insert(Db, {Name, first}, {undef, first, first}, State), State};
handle_call({table_exists, Name, Db}, _From, State) ->
?vlog("table exist: ~p [~p]",[Name, Db]),
Res =
case lookup(Db, {Name, first}, State) of
{value, _} -> true;
undefined -> false
end,
?vdebug("table exist result: "
"~n ~p",[Res]),
{reply, Res, State};
handle_call({table_delete, Name, Db}, _From, State) ->
?vlog("table delete: ~p [~p]",[Name, Db]),
catch handle_delete(Db, Name, State),
{reply, true, State};
handle_call({table_create_row, Name, Db, Indexes, Row}, _From, State) ->
?vlog("table create row [~p]: "
"~n Name: ~p"
"~n Indexes: ~p"
"~n Row: ~p",[Db, Name, Indexes, Row]),
Res =
case catch handle_create_row(Db, Name, Indexes, Row, State) of
{'EXIT', _} -> false;
_ -> true
end,
?vdebug("table create row result: "
"~n ~p",[Res]),
{reply, Res, State};
handle_call({table_delete_row, Name, Db, Indexes}, _From, State) ->
?vlog("table delete row [~p]: "
"~n Name: ~p"
"~n Indexes: ~p", [Db, Name, Indexes]),
Res =
case catch handle_delete_row(Db, Name, Indexes, State) of
{'EXIT', _} -> false;
_ -> true
end,
?vdebug("table delete row result: "
"~n ~p",[Res]),
{reply, Res, State};
handle_call({table_get_row, Name, Db, Indexes}, _From, State) ->
?vlog("table get row [~p]: "
"~n Name: ~p"
"~n Indexes: ~p",[Db, Name, Indexes]),
Res = case lookup(Db, {Name, Indexes}, State) of
undefined ->
undefined;
{value, {Row, _Prev, _Next}} ->
Row
end,
?vdebug("table get row result: "
"~n ~p",[Res]),
{reply, Res, State};
handle_call({table_get_element, Name, Db, Indexes, Col}, _From, State) ->
?vlog("table ~p get element [~p]: "
"~n Indexes: ~p"
"~n Col: ~p", [Name, Db, Indexes, Col]),
Res = case lookup(Db, {Name, Indexes}, State) of
undefined -> undefined;
{value, {Row, _Prev, _Next}} -> {value, element(Col, Row)}
end,
?vdebug("table get element result: "
"~n ~p",[Res]),
{reply, Res, State};
handle_call({table_set_elements, Name, Db, Indexes, Cols}, _From, State) ->
?vlog("table ~p set element [~p]: "
"~n Indexes: ~p"
"~n Cols: ~p", [Name, Db, Indexes, Cols]),
Res =
case catch handle_set_elements(Db, Name, Indexes, Cols, State) of
{'EXIT', _} -> false;
_ -> true
end,
?vdebug("table set element result: "
"~n ~p",[Res]),
{reply, Res, State};
handle_call({table_next, Name, Db, []}, From, State) ->
?vlog("table next: ~p [~p]",[Name, Db]),
handle_call({table_next, Name, Db, first}, From, State);
handle_call({table_next, Name, Db, Indexes}, _From, State) ->
?vlog("table ~p next [~p]: "
"~n Indexes: ~p",[Name, Db, Indexes]),
Res = case lookup(Db, {Name, Indexes}, State) of
{value, {_Row, _Prev, Next}} ->
if
Next =:= first -> endOfTable;
true -> Next
end;
undefined ->
table_search_next(Db, Name, Indexes, State)
end,
?vdebug("table next result: "
"~n ~p",[Res]),
{reply, Res, State};
handle_call({table_max_col, Name, Db, Col}, _From, State) ->
?vlog("table ~p max col [~p]: "
"~n Col: ~p",[Name, Db, Col]),
Res = table_max_col(Db, Name, Col, 0, first, State),
?vdebug("table max col result: "
"~n ~p",[Res]),
{reply, Res, State};
handle_call({match, Name, Db, Pattern}, _From, State) ->
?vlog("match ~p [~p]:"
"~n Pat: ~p", [Name, Db, Pattern]),
L1 = match(Db, Name, Pattern, State),
{reply, lists:delete([undef], L1), State};
%% This check (that there is no backup already in progress) is also
%% done in the master agent process, but just in case a user issues
%% a backup call to this process directly, we add a similar check here.
handle_call({backup, BackupDir}, From,
#state{backup = undefined, dets = Dets} = State) ->
?vlog("backup: ~p",[BackupDir]),
Pid = self(),
V = get(verbosity),
case file:read_file_info(BackupDir) of
{ok, #file_info{type = directory}} ->
BackupServer =
erlang:spawn_link(
fun() ->
put(sname, albs),
put(verbosity, V),
Dir = filename:join([BackupDir]),
#dets{tab = Tab} = Dets,
Reply = handle_backup(Tab, Dir),
Pid ! {backup_done, Reply},
unlink(Pid)
end),
?vtrace("backup server: ~p", [BackupServer]),
{noreply, State#state{backup = {BackupServer, From}}};
{ok, _} ->
{reply, {error, not_a_directory}, State};
Error ->
{reply, Error, State}
end;
handle_call({backup, _BackupDir}, _From, #state{backup = Backup} = S) ->
?vinfo("backup already in progress: ~p", [Backup]),
{reply, {error, backup_in_progress}, S};
handle_call(dump, _From, #state{dets = Dets} = State) ->
?vlog("dump",[]),
dets_sync(Dets),
{reply, ok, State};
handle_call(info, _From, #state{dets = Dets, ets = Ets} = State) ->
?vlog("info",[]),
Info = get_info(Dets, Ets),
{reply, Info, State};
handle_call(print, _From, #state{dets = Dets, ets = Ets} = State) ->
?vlog("print",[]),
L1 = ets:tab2list(Ets),
L2 = dets_match_object(Dets, '_'),
{reply, {{ets, L1}, {dets, L2}}, State};
handle_call({print, Table, Db}, _From, State) ->
?vlog("print: ~p [~p]", [Table, Db]),
L = match(Db, Table, '$1', State),
{reply, lists:delete([undef], L), State};
handle_call({register_notify_client, Client, Module}, _From, State) ->
?vlog("register_notify_client: "
"~n Client: ~p"
"~n Module: ~p", [Client, Module]),
Nc = State#state.notify_clients,
case lists:keysearch(Client,1,Nc) of
{value,{Client,Mod}} ->
?vlog("register_notify_client: already registered to: ~p",
[Module]),
{reply, {error,{already_registered,Mod}}, State};
false ->
{reply, ok, State#state{notify_clients = [{Client,Module}|Nc]}}
end;
handle_call({unregister_notify_client, Client}, _From, State) ->
?vlog("unregister_notify_client: ~p",[Client]),
Nc = State#state.notify_clients,
case lists:keysearch(Client,1,Nc) of
{value,{Client,_Module}} ->
Nc1 = lists:keydelete(Client,1,Nc),
{reply, ok, State#state{notify_clients = Nc1}};
false ->
?vlog("unregister_notify_client: not registered",[]),
{reply, {error,not_registered}, State}
end;
handle_call(stop, _From, State) ->
?vlog("stop",[]),
{stop, normal, stopped, State};
handle_call(Req, _From, State) ->
warning_msg("received unknown request: ~n~p", [Req]),
Reply = {error, {unknown, Req}},
{reply, Reply, State}.
handle_cast({variable_inc, Name, Db, N}, State) ->
?vlog("variable ~p inc"
"~n N: ~p", [Name, N]),
M = case lookup(Db, Name, State) of
{value, Val} -> Val;
_ -> 0
end,
insert(Db, Name, M+N rem 4294967296, State),
{noreply, State};
handle_cast({verbosity,Verbosity}, State) ->
?vlog("verbosity: ~p -> ~p",[get(verbosity),Verbosity]),
put(verbosity,?vvalidate(Verbosity)),
{noreply, State};
handle_cast(Msg, State) ->
warning_msg("received unknown message: ~n~p", [Msg]),
{noreply, State}.
handle_info({'EXIT', Pid, Reason}, #state{backup = {Pid, From}} = S) ->
?vlog("backup server (~p) exited for reason ~n~p", [Pid, Reason]),
gen_server:reply(From, {error, Reason}),
{noreply, S#state{backup = undefined}};
handle_info({'EXIT', Pid, Reason}, S) ->
%% The only other processes we should be linked to are
%% either the master agent or our supervisor, so die...
{stop, {received_exit, Pid, Reason}, S};
handle_info({backup_done, Reply}, #state{backup = {_, From}} = S) ->
?vlog("backup done:"
"~n Reply: ~p", [Reply]),
gen_server:reply(From, Reply),
{noreply, S#state{backup = undefined}};
handle_info(Info, State) ->
warning_msg("received unknown info: ~n~p", [Info]),
{noreply, State}.
terminate(Reason, State) ->
?vlog("terminate: ~p",[Reason]),
close(State).
%%----------------------------------------------------------
%% Code change
%%----------------------------------------------------------
%% downgrade
%%
code_change({down, _Vsn}, S1, downgrade_to_pre_4_11) ->
#state{dets = D} = S1,
#dets{tab = Dets, shadow = Shadow} = D,
ets:delete(Shadow),
S2 = S1#state{dets = Dets},
{ok, S2};
%% upgrade
%%
code_change(_Vsn, S1, upgrade_from_pre_4_11) ->
#state{dets = D} = S1,
Shadow = ets:new(snmp_local_db1_shadow, [set, protected]),
dets:to_ets(D, Shadow),
Dets = #dets{tab = D, shadow = Shadow},
S2 = S1#state{dets = Dets},
{ok, S2};
code_change(_Vsn, State, _Extra) ->
{ok, State}.
%%----------------------------------------------------------
%% Backup
%%----------------------------------------------------------
handle_backup(D, BackupDir) ->
%% First check that we do not wrote to the corrent db-dir...
?vtrace("handle_backup -> entry with"
"~n D: ~p"
"~n BackupDir: ~p", [D, BackupDir]),
case dets:info(D, filename) of
undefined ->
?vinfo("handle_backup -> no file to backup", []),
{error, no_file};
Filename ->
?vinfo("handle_backup -> file to backup: ~n ~p", [Filename]),
case filename:dirname(Filename) of
BackupDir ->
?vinfo("handle_backup -> backup dir and db dir the same",
[]),
{error, db_dir};
_ ->
case file:read_file_info(BackupDir) of
{ok, #file_info{type = directory}} ->
?vdebug("handle_backup -> backup dir ok", []),
%% All well so far...
Type = dets:info(D, type),
KP = dets:info(D, keypos),
dets_backup(D,
filename:basename(Filename),
BackupDir, Type, KP);
{ok, _} ->
?vinfo("handle_backup -> backup dir not a dir",
[]),
{error, not_a_directory};
Error ->
?vinfo("handle_backup -> Error: ~p", [Error]),
Error
end
end
end.
dets_backup(D, Filename, BackupDir, Type, KP) ->
?vtrace("dets_backup -> entry with"
"~n D: ~p"
"~n Filename: ~p"
"~n BackupDir: ~p", [D, Filename, BackupDir]),
BackupFile = filename:join(BackupDir, Filename),
?vtrace("dets_backup -> "
"~n BackupFile: ~p", [BackupFile]),
Opts = [{file, BackupFile}, {type, Type}, {keypos, KP}],
case dets:open_file(?BACKUP_TAB, Opts) of
{ok, B} ->
F = fun(Arg) ->
dets_backup(Arg, start, D, B)
end,
?vtrace("dets_backup -> fix table", []),
dets:safe_fixtable(D, true),
?vtrace("dets_backup -> copy table", []),
Res = dets:init_table(?BACKUP_TAB, F, [{format, bchunk}]),
?vtrace("dets_backup -> unfix table", []),
dets:safe_fixtable(D, false),
?vtrace("dets_backup -> Res: ~p", [Res]),
Res;
Error ->
?vinfo("dets_backup -> open_file failed: "
"~n ~p", [Error]),
Error
end.
dets_backup(close, _Cont, _D, B) ->
dets:close(B),
ok;
dets_backup(read, Cont1, D, B) ->
case dets:bchunk(D, Cont1) of
{Cont2, Data} ->
F = fun(Arg) ->
dets_backup(Arg, Cont2, D, B)
end,
{Data, F};
'$end_of_table' ->
dets:close(B),
end_of_input;
Error ->
Error
end.
%%-----------------------------------------------------------------
%% All handle_ functions exists so we can catch the call to
%% them, because we don't want to crash the server if a user
%% forgets to call e.g. table_create.
%%-----------------------------------------------------------------
%% Find larger element and insert before.
handle_create_row(Db, Name, Indexes, Row, State) ->
case table_find_first_after_maybe_same(Db, Name, Indexes, State) of
{{Name, Next}, {NRow, NPrev, NNext}} ->
{value, {PRow, PPrev, _PNext}} = lookup(Db, {Name, NPrev}, State),
if
Next =:= NPrev ->
% Insert before first
insert(Db, {Name, NPrev}, {PRow, Indexes, Indexes}, State);
true ->
insert(Db, {Name, NPrev}, {PRow, PPrev, Indexes}, State),
insert(Db, {Name, Next}, {NRow, Indexes, NNext}, State)
end,
insert(Db, {Name, Indexes}, {Row, NPrev, Next}, State);
{same_row, {Prev, Next}} ->
insert(Db, {Name, Indexes}, {Row, Prev, Next}, State)
end.
handle_delete_row(Db, Name, Indexes, State) ->
{value, {_, Prev, Next}} = lookup(Db, {Name, Indexes}, State),
{value, {PRow, PPrev, Indexes}} = lookup(Db, {Name, Prev}, State),
insert(Db, {Name, Prev}, {PRow, PPrev, Next}, State),
{value, {NRow, Indexes, NNext}} = lookup(Db, {Name, Next}, State),
insert(Db, {Name, Next}, {NRow, Prev, NNext}, State),
delete(Db, {Name, Indexes}, State).
handle_set_elements(Db, Name, Indexes, Cols, State) ->
{value, {Row, Prev, Next}} = lookup(Db, {Name, Indexes}, State),
NewRow = set_new_row(Cols, Row),
insert(Db, {Name, Indexes}, {NewRow, Prev, Next}, State).
set_new_row([{Col, Val} | Cols], Row) ->
set_new_row(Cols, setelement(Col, Row, Val));
set_new_row([], Row) ->
Row.
handle_delete(Db, Name, State) ->
{value, {_, _, Next}} = lookup(Db, {Name, first}, State),
delete(Db, {Name, first}, State),
handle_delete(Db, Name, Next, State).
handle_delete(_Db, _Name, first, _State) -> true;
handle_delete(Db, Name, Indexes, State) ->
{value, {_, _, Next}} = lookup(Db, {Name, Indexes}, State),
delete(Db, {Name, Indexes}, State),
handle_delete(Db, Name, Next, State).
%%-----------------------------------------------------------------
%% Implementation of next.
%%-----------------------------------------------------------------
table_search_next(Db, Name, Indexes, State) ->
case catch table_find_first_after(Db, Name, Indexes, State) of
{{Name, Key}, {_, _, _Next}} ->
case Key of
first -> endOfTable;
_ -> Key
end;
{'EXIT', _} -> endOfTable
end.
table_find_first_after(Db, Name, Indexes, State) ->
{value, {_Row, _Prev, Next}} = lookup(Db, {Name, first}, State),
table_loop(Db, Name, Indexes, Next, State).
table_loop(Db, Name, _Indexes, first, State) ->
{value, FirstVal} = lookup(Db, {Name, first}, State),
{{Name, first}, FirstVal};
table_loop(Db, Name, Indexes, Cur, State) ->
{value, {Row, Prev, Next}} = lookup(Db, {Name, Cur}, State),
if
Cur > Indexes ->
{{Name, Cur}, {Row, Prev, Next}};
true ->
table_loop(Db, Name, Indexes, Next, State)
end.
table_find_first_after_maybe_same(Db, Name, Indexes, State) ->
{value, {_Row, _Prev, Next}} = lookup(Db, {Name, first}, State),
table_loop2(Db, Name, Indexes, Next, State).
table_loop2(Db, Name, _Indexes, first, State) ->
{value, FirstVal} = lookup(Db, {Name, first}, State),
{{Name, first}, FirstVal};
table_loop2(Db, Name, Indexes, Cur, State) ->
{value, {Row, Prev, Next}} = lookup(Db, {Name, Cur}, State),
if
Cur > Indexes ->
{{Name, Cur}, {Row, Prev, Next}};
Cur =:= Indexes ->
{same_row, {Prev, Next}};
true ->
table_loop2(Db, Name, Indexes, Next, State)
end.
%%-----------------------------------------------------------------
%% Implementation of max.
%% The value in a column could be noinit or undefined,
%% so we must check only those with an integer.
%%-----------------------------------------------------------------
table_max_col(Db, Name, Col, Max, Indexes, State) ->
case lookup(Db, {Name, Indexes}, State) of
{value, {Row, _Prev, Next}} ->
if
Next =:= first ->
if
is_integer(element(Col, Row)) andalso
(element(Col, Row) > Max) ->
element(Col, Row);
true ->
Max
end;
is_integer(element(Col, Row)) andalso
(element(Col, Row) > Max) ->
table_max_col(Db,Name, Col,element(Col, Row),Next, State);
true ->
table_max_col(Db, Name, Col, Max, Next, State)
end;
undefined -> table_search_next(Db, Name, Indexes, State)
end.
%%-----------------------------------------------------------------
%% Interface to Pets.
%%-----------------------------------------------------------------
insert(volatile, Key, Val, #state{ets = Ets}) ->
?vtrace("insert(volatile) -> entry with"
"~n Key: ~p"
"~n Val: ~p",
[Key,Val]),
ets:insert(Ets, {Key, Val}),
true;
insert(persistent, Key, Val, #state{dets = Dets, notify_clients = NC}) ->
?vtrace("insert(persistent) -> entry with"
"~n Key: ~p"
"~n Val: ~p",
[Key,Val]),
case dets_insert(Dets, {Key, Val}) of
ok ->
notify_clients(insert,NC),
true;
{error, Reason} ->
error_msg("DETS (persistent) insert failed for {~w,~w}: ~n~w",
[Key, Val, Reason]),
false
end;
insert(permanent, Key, Val, #state{dets = Dets, notify_clients = NC}) ->
?vtrace("insert(permanent) -> entry with"
"~n Key: ~p"
"~n Val: ~p",
[Key,Val]),
case dets_insert(Dets, {Key, Val}) of
ok ->
notify_clients(insert,NC),
true;
{error, Reason} ->
error_msg("DETS (permanent) insert failed for {~w,~w}: ~n~w",
[Key, Val, Reason]),
false
end;
insert(UnknownDb, Key, Val, _) ->
error_msg("Tried to insert ~w = ~w into unknown db ~w",
[Key, Val, UnknownDb]),
false.
delete(volatile, Key, State) ->
ets:delete(State#state.ets, Key),
true;
delete(persistent, Key, #state{dets = Dets, notify_clients = NC}) ->
case dets_delete(Dets, Key) of
ok ->
notify_clients(delete,NC),
true;
{error, Reason} ->
error_msg("DETS (persistent) delete failed for ~w: ~n~w",
[Key, Reason]),
false
end;
delete(permanent, Key, #state{dets = Dets, notify_clients = NC}) ->
case dets_delete(Dets, Key) of
ok ->
notify_clients(delete,NC),
true;
{error, Reason} ->
error_msg("DETS (permanent) delete failed for ~w: ~n~w",
[Key, Reason]),
false
end;
delete(UnknownDb, Key, _) ->
error_msg("Tried to delete ~w from unknown db ~w",
[Key, UnknownDb]),
false.
match(volatile, Name, Pattern, #state{ets = Ets}) ->
ets:match(Ets, {{Name,'_'},{Pattern,'_','_'}});
match(persistent, Name, Pattern, #state{dets = Dets}) ->
dets_match(Dets, {{Name,'_'},{Pattern,'_','_'}});
match(permanent, Name, Pattern, #state{dets = Dets}) ->
dets_match(Dets, {{Name,'_'},{Pattern,'_','_'}});
match(UnknownDb, Name, Pattern, _) ->
error_msg("Tried to match [~p,~p] from unknown db ~w",
[Name, Pattern, UnknownDb]),
[].
lookup(volatile, Key, #state{ets = Ets}) ->
case ets:lookup(Ets, Key) of
[{_, Val}] ->
{value, Val};
[] ->
undefined
end;
lookup(persistent, Key, #state{dets = Dets}) ->
case dets_lookup(Dets, Key) of
[{_, Val}] ->
{value, Val};
[] ->
undefined
end;
lookup(permanent, Key, #state{dets = Dets}) ->
case dets_lookup(Dets, Key) of
[{_, Val}] ->
{value, Val};
[] ->
undefined
end;
lookup(UnknownDb, Key, _) ->
error_msg("Tried to lookup ~w in unknown db ~w", [Key, UnknownDb]),
false.
close(#state{dets = Dets, ets = Ets}) ->
ets:delete(Ets),
dets_close(Dets).
%%-----------------------------------------------------------------
%% Notify clients interface
%%-----------------------------------------------------------------
notify_clients(Event, Clients) ->
F = fun(Client) -> notify_client(Client, Event) end,
lists:foreach(F, Clients).
notify_client({Client,Module}, Event) ->
(catch Module:notify(Client,Event)).
%%------------------------------------------------------------------
%% Constructs a row with first elements the own part of RowIndex,
%% and last element RowStatus. All values are stored "as is", i.e.
%% dynamic key values are stored without length first.
%% RowIndex is a list of the
%% first elements. RowStatus is needed, because the
%% provided value may not be stored, e.g. createAndGo
%% should be active.
%% Returns a tuple of values for the row. If a value
%% isn't specified in the Col list, then the
%% corresponding value will be noinit.
%%------------------------------------------------------------------
table_construct_row(Name, RowIndex, Status, Cols) ->
#table_info{nbr_of_cols = LastCol, index_types = Indexes,
defvals = Defs, status_col = StatusCol,
first_own_index = FirstOwnIndex, not_accessible = NoAccs} =
snmp_generic:table_info(Name),
Keys = snmp_generic:split_index_to_keys(Indexes, RowIndex),
OwnKeys = snmp_generic:get_own_indexes(FirstOwnIndex, Keys),
Row = OwnKeys ++ snmp_generic:table_create_rest(length(OwnKeys) + 1,
LastCol, StatusCol,
Status, Cols, NoAccs),
L = snmp_generic:init_defaults(Defs, Row),
list_to_tuple(L).
table_get_elements(NameDb, RowIndex, Cols, _FirstOwnIndex) ->
get_elements(Cols, table_get_row(NameDb, RowIndex)).
get_elements(_Cols, undefined) ->
undefined;
get_elements([Col | Cols], Row) when is_tuple(Row) and (size(Row) >= Col) ->
[element(Col, Row) | get_elements(Cols, Row)];
get_elements([], _Row) ->
[];
get_elements(Cols, Row) ->
erlang:error({bad_arguments, Cols, Row}).
%%----------------------------------------------------------------------
%% This should/could be a generic function, but since Mnesia implements
%% its own and this version still is local_db dependent, it's not generic yet.
%%----------------------------------------------------------------------
%% createAndGo
table_set_status(NameDb, RowIndex, ?'RowStatus_createAndGo', StatusCol, Cols,
ChangedStatusFunc, _ConsFunc) ->
case table_create_row(NameDb, RowIndex, ?'RowStatus_active', Cols) of
true -> snmp_generic:try_apply(ChangedStatusFunc,
[NameDb, ?'RowStatus_createAndGo',
RowIndex, Cols]);
_ -> {commitFailed, StatusCol}
end;
%%------------------------------------------------------------------
%% createAndWait - set status to notReady, and try to
%% make row consistent.
%%------------------------------------------------------------------
table_set_status(NameDb, RowIndex, ?'RowStatus_createAndWait', StatusCol, Cols,
ChangedStatusFunc, ConsFunc) ->
case table_create_row(NameDb, RowIndex, ?'RowStatus_notReady', Cols) of
true ->
case snmp_generic:try_apply(ConsFunc, [NameDb, RowIndex, Cols]) of
{noError, 0} ->
snmp_generic:try_apply(ChangedStatusFunc,
[NameDb, ?'RowStatus_createAndWait',
RowIndex, Cols]);
Error -> Error
end;
_ -> {commitFailed, StatusCol}
end;
%% destroy
table_set_status(NameDb, RowIndex, ?'RowStatus_destroy', _StatusCol, Cols,
ChangedStatusFunc, _ConsFunc) ->
case snmp_generic:try_apply(ChangedStatusFunc,
[NameDb, ?'RowStatus_destroy',
RowIndex, Cols]) of
{noError, 0} ->
table_delete_row(NameDb, RowIndex),
{noError, 0};
Error -> Error
end;
%% Otherwise, active or notInService
table_set_status(NameDb, RowIndex, Val, _StatusCol, Cols,
ChangedStatusFunc, ConsFunc) ->
snmp_generic:table_set_cols(NameDb, RowIndex, Cols, ConsFunc),
snmp_generic:try_apply(ChangedStatusFunc, [NameDb, Val, RowIndex, Cols]).
table_func(new, NameDb) ->
case table_exists(NameDb) of
true -> ok;
_ -> table_create(NameDb)
end;
table_func(delete, _NameDb) ->
ok.
table_func(get, RowIndex, Cols, NameDb) ->
TableInfo = snmp_generic:table_info(NameDb),
snmp_generic:handle_table_get(NameDb, RowIndex, Cols,
TableInfo#table_info.first_own_index);
%%------------------------------------------------------------------
%% Returns: List of endOfTable | {NextOid, Value}.
%% Implements the next operation, with the function
%% handle_table_next. Next should return the next accessible
%% instance, which cannot be a key.
%%------------------------------------------------------------------
table_func(get_next, RowIndex, Cols, NameDb) ->
#table_info{first_accessible = FirstCol, first_own_index = FOI,
nbr_of_cols = LastCol} = snmp_generic:table_info(NameDb),
snmp_generic:handle_table_next(NameDb, RowIndex, Cols,
FirstCol, FOI, LastCol);
%%-----------------------------------------------------------------
%% This function must only be used by tables with a RowStatus col!
%% Other tables must check if row exist themselves.
%%-----------------------------------------------------------------
table_func(is_set_ok, RowIndex, Cols, NameDb) ->
snmp_generic:table_try_row(NameDb, nofunc, RowIndex, Cols);
%%------------------------------------------------------------------
%% Cols is here a list of {ColumnNumber, NewValue}
%% This function must only be used by tables with a RowStatus col!
%% Other tables should use table_set_cols/3,4.
%%------------------------------------------------------------------
table_func(set, RowIndex, Cols, NameDb) ->
snmp_generic:table_set_row(NameDb,
nofunc,
fun snmp_generic:table_try_make_consistent/3,
RowIndex,
Cols);
table_func(undo, _RowIndex, _Cols, _NameDb) ->
{noError, 0}.
%%------------------------------------------------------------------
%% This functions retrieves option values from the Options list.
%%------------------------------------------------------------------
get_opt(Key, Opts, Def) ->
snmp_misc:get_option(Key, Opts, Def).
%%------------------------------------------------------------------
get_info(Dets, Ets) ->
ProcSize = proc_mem(self()),
DetsSz = dets_size(Dets),
EtsSz = ets_size(Ets),
[{process_memory, ProcSize},
{db_memory, [{persistent, DetsSz}, {volatile, EtsSz}]}].
proc_mem(P) when is_pid(P) ->
case (catch erlang:process_info(P, memory)) of
{memory, Sz} ->
Sz;
_ ->
undefined
end.
%% proc_mem(_) ->
%% undefined.
dets_size(#dets{tab = Tab, shadow = Shadow}) ->
TabSz =
case (catch dets:info(Tab, file_size)) of
Sz when is_integer(Sz) ->
Sz;
_ ->
undefined
end,
ShadowSz = ets_size(Shadow),
[{tab, TabSz}, {shadow, ShadowSz}].
ets_size(T) ->
case (catch ets:info(T, memory)) of
Sz when is_integer(Sz) ->
Sz;
_ ->
undefined
end.
%%------------------------------------------------------------------
%% info_msg(F, A) ->
%% ?snmpa_info("Local DB server: " ++ F, A).
warning_msg(F, A) ->
?snmpa_warning("Local DB server: " ++ F, A).
error_msg(F, A) ->
?snmpa_error("Local DB server: " ++ F, A).
%% ---
user_err(F, A) ->
snmpa_error:user_err(F, A).
config_err(F, A) ->
snmpa_error:config_err(F, A).
%% ----------------------------------------------------------------
call(Req) ->
gen_server:call(?SERVER, Req, infinity).
cast(Msg) ->
gen_server:cast(?SERVER, Msg).
%% ----------------------------------------------------------------
%% DETS wrapper functions
%% The purpose of these fuctions is basically to hide the shadow
%% table.
%% Changes are made both in dets and in the shadow table.
%% Reads are made from the shadow table.
%% ----------------------------------------------------------------
dets_sync(#dets{tab = Dets}) ->
dets:sync(Dets).
dets_insert(#dets{tab = Tab, shadow = Shadow}, Data) ->
ets:insert(Shadow, Data),
dets:insert(Tab, Data).
dets_delete(#dets{tab = Tab, shadow = Shadow}, Key) ->
ets:delete(Shadow, Key),
dets:delete(Tab, Key).
dets_match(#dets{shadow = Shadow}, Pat) ->
ets:match(Shadow, Pat).
dets_match_object(#dets{shadow = Shadow}, Pat) ->
ets:match_object(Shadow, Pat).
dets_lookup(#dets{shadow = Shadow}, Key) ->
ets:lookup(Shadow, Key).
dets_close(#dets{tab = Tab, shadow = Shadow}) ->
ets:delete(Shadow),
dets:close(Tab).
