From 31b06641f692641f82c489069584220609e1e840 Mon Sep 17 00:00:00 2001 From: Micael Karlberg Date: Tue, 21 May 2013 11:17:44 +0200 Subject: [snmp/agent] backup --- lib/snmp/src/agent/snmpa_mib_storage_dets.erl | 298 ++++++++++++++++++++++++++ 1 file changed, 298 insertions(+) create mode 100644 lib/snmp/src/agent/snmpa_mib_storage_dets.erl (limited to 'lib/snmp/src/agent/snmpa_mib_storage_dets.erl') diff --git a/lib/snmp/src/agent/snmpa_mib_storage_dets.erl b/lib/snmp/src/agent/snmpa_mib_storage_dets.erl new file mode 100644 index 0000000000..6062f4327e --- /dev/null +++ b/lib/snmp/src/agent/snmpa_mib_storage_dets.erl @@ -0,0 +1,298 @@ +%% +%% %CopyrightBegin% +%% +%% Copyright Ericsson AB 2013-2013. 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_mib_storage_dets). + +-behaviour(snmpa_mib_storage). + + +%%%----------------------------------------------------------------- +%%% This module implements the snmpa_mib_storage behaviour. +%%% It uses dets for storage. +%%%----------------------------------------------------------------- + +-export([ + open/5, + close/1, + read/2, + write/2, + delete/1, + delete/2, + sync/1, + backup/2, + match_object/2, + match_delete/2, + tab2list/1, + info/1 + ]). + + +-define(VMODULE, "MS-DETS"). +-include("snmp_verbosity.hrl"). + +-record(tab, {id}). + + +%% --------------------------------------------------------------- +%% open +%% +%% Open or create a mib-storage (dets) table. +%% +%% Opts - A list of implementation dependent options +%% dets_open_options() = [dets_open_option()] +%% dets_open_option() = {dir, filename()} | +%% {action, keep | clear} | +%% {auto_save, default | pos_integer()} | +%% {repair, force | boolean()} +%% +%% --------------------------------------------------------------- + +open(Name, _RecName, _Fields, Type, Opts) -> + Dir = snmp_misc:get_option(dir, Opts), + Action = snmp_misc:get_option(action, Opts, keep), + AutoSave = snmp_misc:get_option(auto_save, Opts, default), + Repair = snmp_misc:get_option(repair, Opts, false), + File = dets_filename(Name, Dir), + OpenOpts = [{file, File}, + {type, Type}, + {keypos, 2}, + {repair, Repair}] ++ + case AutoSave of + default -> + []; + _ -> + [{auto_save, AutoSave}] + end, + case dets:open_file(Name, OpenOpts) of + {ok, ID} when (Action =:= keep) -> + {ok, #tab{id = ID}}; + {ok, ID} when (Action =:= clear) -> + dets:match_delete(ID, '_'), + {ok, #tab{id = ID}}; + {error, Reason} -> + {error, {dets_open, Reason}} + end. + +dets_filename(Name, Dir) -> + Dir1 = dets_filename1(Dir), + Dir2 = string:strip(Dir1, right, $/), + io_lib:format("~s/~p.dat", [Dir2, Name]). + +dets_filename1([]) -> "."; +dets_filename1(Dir) -> Dir. + + +%% --------------------------------------------------------------- +%% close +%% +%% Close the table. +%% --------------------------------------------------------------- + +close(#tab{id = ID}) -> + ?vtrace("close database ~p", [ID]), + dets:close(ID). + + +%% --------------------------------------------------------------- +%% read +%% +%% Retrieve a record from the database table. +%% --------------------------------------------------------------- + +read(#tab{id = ID}, Key) -> + ?vtrace("read from table ~p: ~p", [ID, Key]), + case dets:lookup(ID, Key) of + [Rec|_] -> {value, Rec}; + _ -> false + end. + + +%% --------------------------------------------------------------- +%% write +%% +%% Write a record to the database table. +%% --------------------------------------------------------------- + +write(#tab{id = ID}, Rec) -> + ?vtrace("write to table ~p", [ID]), + dets:insert(ID, Rec). + + +%% --------------------------------------------------------------- +%% delete +%% +%% Delete the database table. +%% --------------------------------------------------------------- + +delete(#tab{id = ID}) -> + ?vtrace("delete database ~p", [ID]), + File = dets:info(ID, filename), + case dets:close(ID) of + ok -> + file:delete(File); + Error -> + Error + end. + + +%% --------------------------------------------------------------- +%% delete +%% +%% Delete a record from the database table. +%% --------------------------------------------------------------- + +delete(#tab{id = ID}, Key) -> + ?vtrace("delete from table ~p: ~p", [ID, Key]), + dets:delete(ID, Key). + + +%% --------------------------------------------------------------- +%% match_object +%% +%% Search the database table for records witch matches the pattern. +%% --------------------------------------------------------------- + +match_object(#tab{id = ID}, Pattern) -> + ?vtrace("match_object in ~p of ~p", [ID, Pattern]), + dets:match_object(ID, Pattern). + + +%% --------------------------------------------------------------- +%% match_delete +%% +%% Search the database table for records witch matches the +%% pattern and deletes them from the database table. +%% --------------------------------------------------------------- + +match_delete(#tab{id = ID}, Pattern) -> + ?vtrace("match_delete in ~p with pattern ~p", [ID, Pattern]), + Recs = dets:match_object(ID, Pattern), + dets:match_delete(ID, Pattern), + Recs. + + +%% --------------------------------------------------------------- +%% tab2list +%% +%% Return all records in the table in the form of a list. +%% --------------------------------------------------------------- + +tab2list(#tab{id = ID} = Tab) -> + ?vtrace("tab2list -> list of ~p", [ID]), + match_object(Tab, '_'). + + +%% --------------------------------------------------------------- +%% info +%% +%% Retrieve implementation dependent mib-storage table +%% information. +%% --------------------------------------------------------------- + +info(#tab{id = ID}) -> + ?vtrace("info -> info of ~p", [ID]), + dets:info(ID). + + +%% --------------------------------------------------------------- +%% sync +%% +%% Dump mib-storage table to disc (if it has a disk component) +%% --------------------------------------------------------------- + +sync(#tab{id = ID}) -> + ?vtrace("sync -> sync ~p", [ID]), + dets:sync(ID). + + +%% --------------------------------------------------------------- +%% backup +%% +%% Make a backup copy of the mib-storage table. +%% --------------------------------------------------------------- + +backup(#tab{id = ID}, BackupDir) -> + ?vtrace("backup -> backup of ~p to ~p", [ID, BackupDir]), + case dets:info(ID, filename) of + undefined -> + {error, no_file}; + Filename -> + case filename:dirname(Filename) of + BackupDir -> + {error, db_dir}; + _ -> + Type = dets:info(ID, type), + KP = dets:info(ID, keypos), + dets_backup(ID, + filename:basename(Filename), + BackupDir, Type, KP) + end + end. + + +dets_backup(ID, Filename, BackupDir, Type, KP) -> + ?vtrace("dets_backup -> entry with" + "~n ID: ~p" + "~n Filename: ~p" + "~n BackupDir: ~p" + "~n Type: ~p" + "~n KP: ~p", [ID, Filename, BackupDir, Type, KP]), + BackupFile = filename:join(BackupDir, Filename), + ?vtrace("dets_backup -> " + "~n BackupFile: ~p", [BackupFile]), + Backup = list_to_atom(atom_to_list(ID) ++ "_backup"), + Opts = [{file, BackupFile}, {type, Type}, {keypos, KP}], + case dets:open_file(Backup, Opts) of + {ok, B} -> + ?vtrace("dets_backup -> create fun", []), + F = fun(Arg) -> + dets_backup(Arg, start, ID, B) + end, + dets:safe_fixtable(ID, true), + Res = dets:init_table(Backup, F, [{format, bchunk}]), + dets:safe_fixtable(ID, false), + ?vtrace("dets_backup -> Res: ~p", [Res]), + Res; + Error -> + ?vinfo("dets_backup -> open_file failed: " + "~n ~p", [Error]), + Error + end. + +dets_backup(close, _Cont, _ID, B) -> + dets:close(B), + ok; +dets_backup(read, Cont1, ID, B) -> + case dets:bchunk(ID, Cont1) of + {Cont2, Data} -> + F = fun(Arg) -> + dets_backup(Arg, Cont2, ID, B) + end, + {Data, F}; + '$end_of_table' -> + dets:close(B), + end_of_input; + Error -> + Error + end. + + +%%---------------------------------------------------------------------- + +%% user_err(F, A) -> +%% snmpa_error:user_err(F, A). -- cgit v1.2.3