aboutsummaryrefslogtreecommitdiffstats
path: root/lib/tv/src/tv_etsread.erl
diff options
context:
space:
mode:
Diffstat (limited to 'lib/tv/src/tv_etsread.erl')
-rw-r--r--lib/tv/src/tv_etsread.erl767
1 files changed, 767 insertions, 0 deletions
diff --git a/lib/tv/src/tv_etsread.erl b/lib/tv/src/tv_etsread.erl
new file mode 100644
index 0000000000..d3240ef513
--- /dev/null
+++ b/lib/tv/src/tv_etsread.erl
@@ -0,0 +1,767 @@
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 1997-2009. 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%
+%%%*********************************************************************
+%%%
+%%% Description: Module containing the interface towards ETS tables,
+%%% i.e., handling the polling and thereafter sending the
+%%% result to the database part of the table tool.
+%%%
+%%%*********************************************************************
+
+
+-module(tv_etsread).
+
+
+
+-export([etsread/2]).
+
+
+
+-include("tv_int_def.hrl").
+-include("tv_int_msg.hrl").
+
+
+
+
+
+
+%%%*********************************************************************
+%%% EXTERNAL FUNCTIONS
+%%%*********************************************************************
+
+
+
+
+etsread(MasterPid, ErrorMsgMode) ->
+ process_flag(trap_exit, true),
+ put(error_msg_mode, ErrorMsgMode),
+ blocked(MasterPid).
+
+
+
+
+
+%%%*********************************************************************
+%%% INTERNAL FUNCTIONS
+%%%*********************************************************************
+
+
+
+blocked(MasterPid) ->
+ receive
+ Msg ->
+ case Msg of
+
+ #etsread_deblock{} ->
+ deblock(Msg, MasterPid);
+
+ {'EXIT', Pid, Reason} ->
+ exit_signals({Pid, Reason}, MasterPid),
+ blocked(MasterPid);
+
+ {error_msg_mode, Mode} ->
+ put(error_msg_mode, Mode),
+ blocked(MasterPid);
+
+ _Other ->
+ %% io:format("Received signal ~p~n", [_Other]),
+ blocked(MasterPid)
+ end
+ end.
+
+
+
+
+
+
+
+deblock(Msg, MasterPid) ->
+ #etsread_deblock{dbs_pid = DbsPid,
+ table_type = KindOfTable,
+ node = Node,
+ local_node = LocalNode,
+ table_id = TableId,
+ poll_interval = PollInt} = Msg,
+ PollInterval = case PollInt of
+ infinity ->
+ PollInt;
+ _Other ->
+ PollInt * 1000
+ end,
+ %% Get table info!
+ case catch get_table_info(Node, LocalNode, TableId, KindOfTable) of
+ nodedown ->
+ MasterPid ! #pc_nodedown{sender = self(),
+ automatic_polling = false},
+ blocked(MasterPid);
+ no_table ->
+ MasterPid ! #pc_dead_table{sender = self(),
+ automatic_polling = false},
+ blocked(MasterPid);
+ mnesia_not_started ->
+ MasterPid ! #pc_dead_table{sender = self(),
+ automatic_polling = false},
+ blocked(MasterPid);
+ {unexpected_error,_Reason} ->
+ MasterPid ! #pc_dead_table{sender = self(),
+ automatic_polling = false},
+ blocked(MasterPid);
+ {Type, Pos, Protection} ->
+ MasterPid ! #etsread_deblock_cfm{sender = self(),
+ type = Type,
+ keypos = Pos,
+ protection = Protection
+ },
+
+ timer:sleep(500),
+ case catch read_table(Node, LocalNode, TableId, KindOfTable, DbsPid) of
+ nodedown ->
+ MasterPid ! #pc_nodedown{sender = self(),
+ automatic_polling = false},
+ blocked(MasterPid);
+ no_table ->
+ MasterPid ! #pc_dead_table{sender = self(),
+ automatic_polling = false},
+ blocked(MasterPid);
+ mnesia_not_started ->
+ MasterPid ! #pc_dead_table{sender = self(),
+ automatic_polling = false},
+ blocked(MasterPid);
+ {unexpected_error,_Reason} ->
+ MasterPid ! #pc_dead_table{sender = self(),
+ automatic_polling = false},
+ blocked(MasterPid);
+ _ElapsedTime ->
+ deblocked_loop(MasterPid, DbsPid, Node, LocalNode, TableId,
+ KindOfTable, PollInterval)
+ end
+ end.
+
+
+
+
+
+
+get_table_info(Node, LocalNode, TableId, KindOfTable) ->
+ case KindOfTable of
+ ets ->
+ % Check whether table is 'bag' or 'set' type.
+ Type = tv_ets_rpc:info(Node, LocalNode, TableId, type),
+ % Get position for the key.
+ Pos = tv_ets_rpc:info(Node, LocalNode, TableId, keypos),
+ Protection = tv_ets_rpc:info(Node, LocalNode, TableId, protection),
+ {Type, Pos, Protection};
+ mnesia ->
+ Type = tv_mnesia_rpc:table_info(Node, LocalNode, TableId, type),
+ Pos = 2,
+ %% All Mnesia tables are regarded as being public!
+ {Type, Pos, public}
+ end.
+
+
+
+
+
+
+deblocked_loop(MasterPid,DbsPid,Node,LocalNode,TableId,KindOfTable,PollInterval) ->
+ receive
+ Msg ->
+
+ case Msg of
+
+ #etsread_poll_table{} ->
+ case catch read_table(Node, LocalNode, TableId, KindOfTable, DbsPid) of
+ %% No automatic polling here!
+ nodedown ->
+ MasterPid ! #pc_nodedown{sender = self(),
+ automatic_polling = false};
+ no_table ->
+ MasterPid ! #pc_dead_table{sender = self(),
+ automatic_polling = false};
+ mnesia_not_started ->
+ MasterPid ! #pc_dead_table{sender = self(),
+ automatic_polling = false};
+ {unexpected_error,_Reason} ->
+ MasterPid ! #pc_dead_table{sender = self(),
+ automatic_polling = false};
+ _ElapsedTime ->
+ done
+ end,
+ deblocked_loop(MasterPid, DbsPid, Node, LocalNode,
+ TableId, KindOfTable, PollInterval);
+
+
+ #etsread_set_poll_interval{interval = PollInt} ->
+ NewPollInterval = case PollInt of
+ infinity ->
+ PollInt;
+ _Other ->
+ PollInt * 1000
+ end,
+ deblocked_loop(MasterPid, DbsPid, Node, LocalNode,
+ TableId, KindOfTable, NewPollInterval);
+
+
+ #etsread_deblock{} ->
+ deblock(Msg, MasterPid);
+
+
+ #etsread_update_object{key_no=KeyNo, object=Obj, old_object=OldObj} ->
+ update_object(KindOfTable, Node, LocalNode, TableId, DbsPid,
+ KeyNo, Obj, OldObj, MasterPid, PollInterval),
+ deblocked_loop(MasterPid, DbsPid, Node, LocalNode, TableId, KindOfTable,
+ PollInterval);
+
+
+ #etsread_new_object{object=Obj} ->
+ new_object(KindOfTable, Node, LocalNode, TableId, DbsPid,
+ Obj, MasterPid, PollInterval),
+ deblocked_loop(MasterPid, DbsPid, Node, LocalNode, TableId, KindOfTable,
+ PollInterval);
+
+
+ #etsread_delete_object{object=Obj} ->
+ delete_object(KindOfTable, Node, LocalNode, TableId, DbsPid,
+ Obj, MasterPid, PollInterval),
+ deblocked_loop(MasterPid, DbsPid, Node, LocalNode, TableId, KindOfTable,
+ PollInterval);
+
+
+ #ip_dead_table{} ->
+ AutoPoll = case PollInterval of
+ infinity ->
+ false;
+ _Other ->
+ true
+ end,
+ MasterPid ! #pc_dead_table{sender = self(),
+ automatic_polling = AutoPoll},
+ deblocked_loop(MasterPid, DbsPid, Node, LocalNode, TableId,
+ KindOfTable, infinity);
+
+
+ #etsread_nodedown{} ->
+ AutoPoll = case PollInterval of
+ infinity ->
+ false;
+ _Other ->
+ true
+ end,
+ MasterPid ! #pc_nodedown{sender = self(),
+ automatic_polling = AutoPoll},
+ deblocked_loop(MasterPid, DbsPid, Node, LocalNode, TableId,
+ KindOfTable, infinity);
+
+
+ {error_msg_mode, Mode} ->
+ put(error_msg_mode, Mode),
+ deblocked_loop(MasterPid, DbsPid, Node, LocalNode, TableId, KindOfTable,
+ PollInterval);
+
+
+ {'EXIT', Pid, Reason} ->
+ exit_signals({Pid, Reason}, MasterPid),
+ deblocked_loop(MasterPid, DbsPid, Node, LocalNode,
+ TableId, KindOfTable, PollInterval)
+ end
+
+ after PollInterval ->
+ %% Automatic polling must be on, otherwise these
+ %% lines would never be executed!
+ NewPollInterval =
+ case catch read_table(Node,LocalNode,TableId,KindOfTable,DbsPid) of
+ nodedown ->
+ MasterPid ! #pc_nodedown{sender = self(),
+ automatic_polling = true},
+ infinity;
+ no_table ->
+ MasterPid ! #pc_dead_table{sender = self(),
+ automatic_polling = true},
+ infinity;
+ mnesia_not_started ->
+ MasterPid ! #pc_dead_table{sender = self(),
+ automatic_polling = true},
+ infinity;
+ {unexpected_error,_Reason} ->
+ MasterPid ! #pc_dead_table{sender = self(),
+ automatic_polling = true},
+ infinity;
+ ElapsedMilliseconds ->
+ if
+ (ElapsedMilliseconds * 1000) >= PollInterval ->
+ infinity;
+ true ->
+ PollInterval
+ end
+ end,
+ deblocked_loop(MasterPid, DbsPid, Node, LocalNode,
+ TableId, KindOfTable, NewPollInterval)
+ end.
+
+
+
+
+
+exit_signals(ExitInfo, MasterPid) ->
+ case ExitInfo of
+ {MasterPid, _Reason} ->
+ exit(normal);
+ _Other ->
+ done
+ end.
+
+
+
+
+update_object(KindOfTable, Node, LocalNode, TableId, DbsPid, KeyNo, Obj, OldObj, MasterPid, PollInterval) ->
+ AutoPoll =
+ case PollInterval of
+ infinity ->
+ false;
+ _Other ->
+ true
+ end,
+ case check_record_format(KindOfTable, Node, LocalNode, TableId, Obj) of
+ bad_format ->
+ DbsPid ! #etsread_update_object_cfm{sender = self(),
+ success = false};
+ ok ->
+ %% Check that we are allowed to edit the table!
+ case catch update_object2(KindOfTable, Node, LocalNode, TableId, DbsPid, KeyNo,
+ Obj, OldObj) of
+
+ nodedown ->
+ DbsPid ! #etsread_update_object_cfm{sender = self(),
+ success = false},
+ MasterPid ! #pc_nodedown{sender = self(),
+ automatic_polling = AutoPoll};
+
+ no_table ->
+ DbsPid ! #etsread_update_object_cfm{sender = self(),
+ success = false},
+ MasterPid ! #pc_dead_table{sender = self(),
+ automatic_polling = AutoPoll};
+
+ mnesia_not_started ->
+ DbsPid ! #etsread_update_object_cfm{sender = self(),
+ success = false},
+ MasterPid ! #pc_dead_table{sender = self(),
+ automatic_polling = AutoPoll};
+
+
+ {unexpected_error,_Reason} ->
+ DbsPid ! #etsread_update_object_cfm{sender = self(),
+ success = false},
+ MasterPid ! #pc_dead_table{sender = self(),
+ automatic_polling = AutoPoll};
+
+ ok ->
+ DbsPid ! #etsread_update_object_cfm{sender = self(),
+ success = true}
+ end
+ end.
+
+
+
+
+
+update_object2(ets, Node, LocalNode, Tab, _DbsPid, KeyNo, Obj, OldObj) ->
+ %% We shall update a specific object! If the table is a 'set' table,
+ %% it is just to insert the altered object. However, if the table
+ %% is a 'bag', or a 'duplicate_bag', we first have to remove the
+ %% old object, and then insert the altered one.
+ %% But, we aren't finished with that... we also want to preserve
+ %% the time order, meaning we have to delete *ALL* objects having the
+ %% very same key, and then insert them again! (Actually we would have
+ %% to do this anyhow, due to limitations in the interface functions,
+ %% but this remark has to be noted!)
+ OldKey = element(KeyNo, OldObj),
+ InsertList =
+ case tv_ets_rpc:info(Node, LocalNode, Tab, type) of
+ set ->
+ %% Have to remove old object, because the key may be what's changed.
+ tv_ets_rpc:delete(Node, LocalNode, Tab, OldKey),
+ [Obj];
+ ordered_set ->
+ %% Have to remove old object, because the key may be what's changed.
+ tv_ets_rpc:delete(Node, LocalNode, Tab, OldKey),
+ [Obj];
+ _Other -> %% 'bag' or 'duplicate_bag'
+ OldList = tv_ets_rpc:lookup(Node, LocalNode, Tab, OldKey),
+ tv_ets_rpc:delete(Node, LocalNode, Tab, OldKey),
+ %% Have to beware of duplicate_bag tables,
+ %% i.e., the same object may occur more than
+ %% once, but we only want to replace it once!
+ {_Replaced, TmpList} =
+ lists:foldl(
+ fun(Data, {Replaced,Acc}) when Data =/= OldObj ->
+ {Replaced, [Data | Acc]};
+ (_Data, {Replaced,Acc}) when not Replaced ->
+ {true, [Obj | Acc]};
+ (Data, {Replaced,Acc}) ->
+ {Replaced, [Data | Acc]}
+ end,
+ {false, []},
+ OldList),
+ lists:reverse(TmpList)
+ end,
+ lists:foreach(fun(H) ->
+ tv_ets_rpc:insert(Node, LocalNode, Tab, H)
+ end,
+ InsertList),
+ ok;
+update_object2(mnesia, Node, LocalNode, Tab, _DbsPid, KeyNo, Obj, OldObj) ->
+ OldKey = element(KeyNo, OldObj),
+ InsertList =
+ case tv_mnesia_rpc:table_info(Node, LocalNode, Tab, type) of
+ set ->
+ tv_mnesia_rpc:transaction(
+ Node,
+ LocalNode,
+ fun() ->
+ mnesia:delete(Tab,OldKey,write)
+ end),
+ [Obj];
+ ordered_set ->
+ tv_mnesia_rpc:transaction(
+ Node,
+ LocalNode,
+ fun() ->
+ mnesia:delete(Tab,OldKey,write)
+ end),
+ [Obj];
+ _Other -> %% 'bag' or 'duplicate_bag'
+ {atomic, OldList} =
+ tv_mnesia_rpc:transaction(
+ Node,
+ LocalNode,
+ fun() ->
+ mnesia:read(Tab,OldKey,read)
+ end),
+ %% We can't use mnesia:delete_object here, because
+ %% time order wouldn't be preserved then!!!
+ tv_mnesia_rpc:transaction(
+ Node,
+ LocalNode,
+ fun() ->
+ mnesia:delete(Tab,OldKey,write)
+ end),
+ ChangeFun =
+ fun(H) when H =:= OldObj ->
+ Obj;
+ (H) ->
+ H
+ end,
+ [ChangeFun(X) || X <- OldList]
+ end,
+ lists:foreach(fun(H) ->
+ tv_mnesia_rpc:transaction(
+ Node,
+ LocalNode,
+ fun() ->
+ %% This mnesia call shall not be distributed,
+ %% since the transaction sees to that it is
+ %% executed on the right node!!!
+ mnesia:write(Tab,H,write)
+ end)
+ end,
+ InsertList),
+ ok.
+
+
+
+
+
+
+delete_object(KindOfTable, Node, LocalNode, TableId, DbsPid, Obj, MasterPid, PollInterval) ->
+ AutoPoll =
+ case PollInterval of
+ infinity ->
+ false;
+ _Other ->
+ true
+ end,
+ case catch delete_object2(KindOfTable, Node, LocalNode, TableId, DbsPid, Obj) of
+
+ nodedown ->
+ DbsPid ! #etsread_delete_object_cfm{sender = self(),
+ success = false},
+ MasterPid ! #pc_nodedown{sender = self(),
+ automatic_polling = AutoPoll};
+
+ no_table ->
+ DbsPid ! #etsread_delete_object_cfm{sender = self(),
+ success = false},
+ MasterPid ! #pc_dead_table{sender = self(),
+ automatic_polling = AutoPoll};
+
+ mnesia_not_started ->
+ DbsPid ! #etsread_delete_object_cfm{sender = self(),
+ success = false},
+ MasterPid ! #pc_dead_table{sender = self(),
+ automatic_polling = AutoPoll};
+
+ {unexpected_error,_Reason} ->
+ DbsPid ! #etsread_delete_object_cfm{sender = self(),
+ success = false},
+ MasterPid ! #pc_dead_table{sender = self(),
+ automatic_polling = AutoPoll};
+
+ ok ->
+ DbsPid ! #etsread_delete_object_cfm{sender = self(),
+ success = true}
+ end.
+
+
+
+
+delete_object2(ets, Node, LocalNode, Tab, _DbsPid, Obj) ->
+ KeyNo = tv_ets_rpc:info(Node, LocalNode, Tab, keypos),
+ Key = element(KeyNo, Obj),
+ InsertList =
+ case tv_ets_rpc:info(Node, LocalNode, Tab, type) of
+ set ->
+ %% Have to remove old object, because the key may be what's changed.
+ tv_ets_rpc:delete(Node, LocalNode, Tab, Key),
+ [];
+ ordered_set ->
+ %% Have to remove old object, because the key may be what's changed.
+ tv_ets_rpc:delete(Node, LocalNode, Tab, Key),
+ [];
+ _Other -> %% 'bag' or 'duplicate_bag'
+ OldList = tv_ets_rpc:lookup(Node, LocalNode, Tab, Key),
+ tv_ets_rpc:delete(Node, LocalNode, Tab, Key),
+ OldList -- [Obj]
+ end,
+
+ lists:foreach(fun(H) ->
+ tv_ets_rpc:insert(Node, LocalNode, Tab, H)
+ end,
+ InsertList),
+ ok;
+delete_object2(mnesia, Node, LocalNode, Tab, _DbsPid, Obj) ->
+ tv_mnesia_rpc:transaction(
+ Node,
+ LocalNode,
+ fun() ->
+ %% This mnesia call shall not be distributed,
+ %% since the transaction sees to that it is
+ %% executed on the right node!!!
+ mnesia:delete_object(Tab,Obj,write)
+ end),
+ ok.
+
+
+
+
+
+new_object(KindOfTable, Node, LocalNode, TableId, DbsPid, Obj, MasterPid, PollInterval) ->
+ AutoPoll =
+ case PollInterval of
+ infinity ->
+ false;
+ _Other ->
+ true
+ end,
+ case check_record_format(KindOfTable, Node, LocalNode, TableId, Obj) of
+ bad_format ->
+ DbsPid ! #etsread_new_object_cfm{sender = self(),
+ success = false};
+ ok ->
+ %% Check that we are allowed to edit the table!
+ case catch new_object2(KindOfTable, Node, LocalNode, TableId, DbsPid, Obj) of
+
+ nodedown ->
+ DbsPid ! #etsread_new_object_cfm{sender = self(),
+ success = false},
+ MasterPid ! #pc_nodedown{sender = self(),
+ automatic_polling = AutoPoll};
+
+ no_table ->
+ DbsPid ! #etsread_new_object_cfm{sender = self(),
+ success = false},
+ MasterPid ! #pc_dead_table{sender = self(),
+ automatic_polling = AutoPoll};
+
+ mnesia_not_started ->
+ DbsPid ! #etsread_new_object_cfm{sender = self(),
+ success = false},
+ MasterPid ! #pc_dead_table{sender = self(),
+ automatic_polling = AutoPoll};
+
+ {unexpected_error,_Reason} ->
+ DbsPid ! #etsread_new_object_cfm{sender = self(),
+ success = false},
+ MasterPid ! #pc_dead_table{sender = self(),
+ automatic_polling = AutoPoll};
+
+ ok ->
+ DbsPid ! #etsread_new_object_cfm{sender = self(),
+ success = true}
+ end
+ end.
+
+
+
+
+
+new_object2(ets, Node, LocalNode, Tab, _DbsPid, Obj) ->
+ tv_ets_rpc:insert(Node, LocalNode, Tab, Obj),
+ ok;
+new_object2(mnesia, Node, LocalNode, Tab, _DbsPid, Obj) ->
+ tv_mnesia_rpc:transaction(
+ Node,
+ LocalNode,
+ fun() ->
+ %% This mnesia call shall not be distributed,
+ %% since the transaction sees to that it is
+ %% executed on the right node!!!
+ mnesia:write(Tab,Obj,write)
+ end),
+ ok.
+
+
+
+
+
+check_record_format(mnesia, Node, LocalNode, Tab, Obj) ->
+ Arity = tv_mnesia_rpc:table_info(Node, LocalNode, Tab, arity),
+ case size(Obj) of
+ Arity ->
+ ok;
+ _Other ->
+ gs:window(etsreadwin, gs:start(), []),
+ case get(error_msg_mode) of
+ normal ->
+ tv_utils:notify(etsreadwin, "TV Notification",
+ ["The record is not complete,",
+ "too few fields are specified!"]);
+ haiku ->
+ tv_utils:notify(etsreadwin, "TV Notification",
+ ["The attempt to change",
+ "The specified record size",
+ "Is simply ignored."])
+ end,
+ gs:destroy(etsreadwin),
+ bad_format
+ end;
+check_record_format(ets, _Node, _LocalNode, _Tab, _Obj) ->
+ ok.
+
+
+
+
+
+
+
+read_table(Node, LocalNode, Tab, KindOfTable, DbsPid) ->
+ T1 = time(),
+
+ {TableContent, ListOfKeys} =
+ case KindOfTable of
+ ets ->
+ {tv_ets_rpc:tab2list(Node, LocalNode, Tab),
+ [tv_ets_rpc:info(Node, LocalNode, Tab, keypos)]
+ };
+ mnesia ->
+ %% It may be tempting to use Mnesia event subscription,
+ %% but will this really save the day? The main drawback
+ %% is that we will then have to update the table copy we
+ %% store internally in two different ways: one for the
+ %% Mnesia tables, and one for the ETS tables. Also, if
+ %% the Mnesia tables are frequently updated, this will
+ %% cause TV to work all the time too (either updating the
+ %% table copy for each inserted/deleted object, or storing
+ %% these objects until polling is ordered). To make this
+ %% work smoothly requires a bit of work...
+ %% The second drawback is that it doesn't seem clear in all
+ %% circumstances how the subscription actually works - i.e.,
+ %% if we only use subscriptions, can we actually be sure that
+ %% the *real* state of the table is the same as the one kept
+ %% in TV? For example, imagine the scenario that Mnesia is
+ %% stopped, all Mnesia directories are removed (from the UNIX
+ %% shell), and then Mnesia once again is started. The first
+ %% problem is that we have to check for start/stop of Mnesia,
+ %% the second is that we then have to rescan the actual table.
+ %% The logic for this may require som effort to write!
+ %% Also, what will happen if the table is killed/dies?
+ %% Will we get messages for each element in the table?
+ %% (I havent't checked this last issue, this is just som thoughts.)
+ %% And generally, there is always a risk that a message is lost,
+ %% which will result in TV showing an erroneous table content.
+ %%
+ %% All in all, using Mnesia subscriptions *may* be a sub-optimization.
+ %% The current solution works fine, is also easy to control, and is
+ %% mainly the same for both ETS and Mnesia tables.
+ %% My suggestion is that it is used until someone actually complains
+ %% about the polling time being too long for huge tables! :-)
+ %% (However, it shall be emphasized that it is this module that
+ %% actually polls the Mnesia/ETS tables, meaning that it is
+ %% mainly this module that has to be modified, should the usage of
+ %% subscriptions be desired. The other module that has to be modified
+ %% is the one maintaining the internal copy of the table.)
+ WildPattern = tv_mnesia_rpc:table_info(Node,LocalNode,Tab,wild_pattern),
+ {atomic, Content} =
+ tv_mnesia_rpc:transaction(
+ Node,
+ LocalNode,
+ fun() ->
+ %% This mnesia call shall not be distributed,
+ %% since the transaction sees to that it is
+ %% executed on the right node!!!
+ mnesia:match_object(Tab, WildPattern, read)
+ end),
+ {Content, [2 | tv_mnesia_rpc:table_info(Node, LocalNode,Tab, index)]}
+ end,
+
+ T2 = time(),
+
+ ElapsedTime = compute_elapsed_seconds(T1, T2),
+
+ DbsPid ! #dbs_new_data{sender = self(),
+ data = TableContent,
+ keys = ListOfKeys,
+ time_to_read_table = ElapsedTime
+ },
+
+ ElapsedTime.
+
+
+
+
+
+
+
+compute_elapsed_seconds({H1, M1, S1}, {H2, M2, S2}) ->
+ ElapsedHours = get_time_diff(hours, H1, H2),
+ ElapsedMinutes = get_time_diff(minutes, M1, M2),
+ ElapsedSeconds = get_time_diff(seconds, S1, S2),
+ (ElapsedHours * 3600) + (ElapsedMinutes * 60) + ElapsedSeconds + 1.
+
+
+
+
+
+get_time_diff(_Type, T1, T2) when T1 =< T2 ->
+ T2 - T1;
+get_time_diff(hours, T1, T2) ->
+ T2 + 24 - T1;
+get_time_diff(minutes, T1, T2) ->
+ T2 + 60 - T1;
+get_time_diff(seconds, T1, T2) ->
+ T2 + 60 - T1.
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-25 11:44:26 +0000