Files
ezic/src/ezic_db_ets.erl

150 lines
3.3 KiB
Erlang

-module(ezic_db_ets).
-include("include/ezic.hrl").
-include_lib("eunit/include/eunit.hrl").
-define(DB_FILENAME, "db.e2f").
-export([
init/0
, zones/1
, rules/1
, flatzones/1
, flatzone/2
%, insert/2
, get_all/1
, insert_all/1
, wipe/1
, implementation/0
]).
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% PUBLIC API
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
implementation() -> ?MODULE.
zones(TzName) ->
ets:select(zone, [{#zone{name=TzName, _='_'}, [], ['$_']}]).
rules(TzName) ->
ets:select(rule, [{#rule{name=TzName, _='_'}, [], ['$_']}]).
flatzones(TzName) ->
ets:select(flatzone, [{#flatzone{tzname=TzName, _='_'}, [], ['$_']}]).
flatzone(Date, TzName) ->
FlatZones= ets:select(flatzone, ezic_flatten:ms(Date, TzName)),
case length(FlatZones) of
1 ->
hd(FlatZones);
2 ->
{error, {ambiguous_zone, FlatZones}};
0 ->
{error, no_zone};
_ ->
{error, {should_not_happen, {FlatZones, Date, TzName}}}
end.
get_all(Tab) ->
try ets:lookup(Tab, Tab) of X -> X
catch error:X -> {error, X}
end.
insert_all(Records) ->
Zones= [ZI || ZI <- Records, ZI = #zone{}],
ets:insert(zone, Zones),
Rules= [RI || RI <- Records, RI = #rule{}],
ets:insert(rule, Rules),
FlatZones= [FZ || FZ <- Records, FZ = #flatzone{}],
ets:insert(flatzone, FlatZones).
%wipe() ->
% gen_server:call(?MODULE, {wipe}).
wipe(Tab) ->
ets:delete(Tab, Tab).
init() ->
{ok, DbDir}= application:get_env(db_dir),
Filename= filename:join(DbDir, ?DB_FILENAME),
case db_sane(Filename) of
true -> load_tabfile(Filename);
false -> create_tables(Filename)
end,
{ok, []}.
%%~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
%% Private functions for initializing ets
%%~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
%% -> true if table exists
db_sane(Filename) ->
%% @todo ensure data is present for each record type.
case ets:tabfile_info(Filename) of
{ok, _} -> true;
{error, _} -> false
end.
%% creates the dets table and populates it.
create_tables(Filename) ->
{ok, Zones, Rules, _, _} = ezic_record:separate(ezic_loader:load()),
ets:new(zone, [duplicate_bag, named_table]),
true = ets:insert(zone, Zones),
ets:new(rule, [duplicate_bag, named_table]),
true = ets:insert(rule, Rules),
ets:new(flatzone, [duplicate_bag, named_table]),
%% io:format("~p~n", [Rules]),
FlatZones = ezic_flatten:flatten(Zones, Rules),
true = ets:insert(flatzone, FlatZones),
% combine into one ets
Ets= ets:new(ezic_db_ets, [duplicate_bag]),
ets:insert(Ets, ets:lookup(zone, zone)),
ets:insert(Ets, ets:lookup(rule, rule)),
ets:insert(Ets, ets:lookup(flatzone, flatzone)),
% save to disk
ets:tab2file(Ets, Filename),
ets:delete(Ets),
ok.
%% loads or creates the dets table.
load_tabfile(Filename) ->
{ok, Ets}= ets:file2tab(Filename),
Zones= ets:lookup(Ets, zone),
ets:new(zone, [duplicate_bag, named_table]),
ets:insert(zone, Zones),
Rules= ets:lookup(Ets, rule),
ets:new(rule, [duplicate_bag, named_table]),
ets:insert(rule, Rules),
FlatZones= ets:lookup(Ets, flatzone),
ets:new(flatzone, [duplicate_bag, named_table]),
ets:insert(flatzone, FlatZones),
ets:delete(Ets),
ok.