[snmp/agent] backup

1 files changed, 298 insertions, 0 deletions

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
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+++ 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).