%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 1996-2010. All Rights Reserved.
%%
%% Licensed under the Apache License, Version 2.0 (the "License");
%% you may not use this file except in compliance with the License.
%% You may obtain a copy of the License at
%%
%% http://www.apache.org/licenses/LICENSE-2.0
%%
%% Unless required by applicable law or agreed to in writing, software
%% distributed under the License is distributed on an "AS IS" BASIS,
%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
%% See the License for the specific language governing permissions and
%% limitations under the License.
%%
%% %CopyrightEnd%
%%
%%
-module(mnesia_dbn_meters).
-export([
start/0,
local_start/0,
distr_start/1,
start/3
]).
-record(simple,{key,val=0}).
-define(key,1).
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% Configuration and start
start() ->
local_start(),
distr_start(nodes()).
local_start() ->
start(one_ram_only,[node()],some_meters()),
start(one_disc_only,[node()],some_meters()).
distr_start([]) ->
local_only;
distr_start(OtherNodes) when is_list(OtherNodes) ->
start(ram_and_ram,[node()|OtherNodes],some_meters()),
start(disc_and_disc,[node()|OtherNodes],some_meters()).
start(Config,Nodes,Meters) ->
Attrs = record_info(fields,simple),
Schema = [{name,simple},{type,set},{attributes,Attrs}] ++ config(Config,Nodes),
L = '====================',
io:format("~n~p dbn_meters: ~p ~p~nSchema = ~p.~n~n",[L,Config,L,Schema]),
ok = mnesia:delete_schema(Nodes),
ok = mnesia:create_schema(Nodes),
rpc:multicall(Nodes, mnesia, start, []),
{atomic,_} = mnesia:create_table(Schema),
lists:foreach(fun report_meter/1,Meters),
{atomic, ok} = mnesia:delete_table(simple),
rpc:multicall(Nodes, mnesia, stop, []),
ok.
config(one_ram_only,[Single|_]) ->
[{ram_copies,[Single]}];
config(ram_and_ram,[Master|[Slave|_]]) ->
[{ram_copies,[Master,Slave]}];
config(one_disc_only,[Single|_]) ->
[{disc_copies,[Single]}];
config(disc_and_disc,[Master|[Slave|_]]) ->
[{disc_copies,[Master,Slave]}];
config(Config,Nodes) ->
io:format("<ERROR> Config ~p not supported or too few nodes ~p given~n",[Config,Nodes]).
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% The various DBN meters
some_meters() ->
[create,
open_safe_read,
open_dirty_read,
get_int,
open_update,
put_int,
put_int_and_copy,
dirty_put_int_and_copy,
start_trans,
commit_one_update,
delete,
dirty_delete
].
report_meter(Meter) ->
Times = 100,
Micros = repeat_meter(Meter,{atomic,{0,ignore}},Times) div Times,
io:format("\t~-30w ~-10w nano seconds (mean of ~p repetitions)~n",[Meter,Micros,Times]).
repeat_meter(_Meter,{atomic,{Micros,_Result}},0) ->
Micros;
repeat_meter(Meter,{atomic,{Micros,_Result}},Times) when Times > 0 ->
repeat_meter(Meter,catch meter(Meter),Times-1) + Micros;
repeat_meter(Meter,{aborted,Reason},Times) when Times > 0 ->
io:format("<ERROR>\t~-20w\t,aborted, because ~p~n",[Meter,Reason]),
0;
repeat_meter(Meter,{'EXIT',Reason},Times) when Times > 0 ->
io:format("<ERROR>\t~-20w\tcrashed, because ~p~n",[Meter,Reason]),
0.
meter(create) ->
Key = 1,
mnesia:transaction(fun() -> mnesia:delete({simple,Key}) end),
Fun = fun() ->
BeforeT = erlang:monotonic_time(),
R = mnesia:write(#simple{key=Key}),
AfterT = erlang:monotonic_time(),
elapsed_time(BeforeT,AfterT,R)
end,
mnesia:transaction(Fun);
meter(open_safe_read) ->
Key = 2,
mnesia:transaction(fun() -> mnesia:write(#simple{key=Key}) end),
Fun = fun() ->
BeforeT = erlang:monotonic_time(),
R = mnesia:read({simple,Key}),
AfterT = erlang:monotonic_time(),
elapsed_time(BeforeT,AfterT,R)
end,
mnesia:transaction(Fun);
meter(open_dirty_read) ->
Key = 21,
mnesia:transaction(fun() -> mnesia:write(#simple{key=Key}) end),
Fun = fun() ->
BeforeT = erlang:monotonic_time(),
R = mnesia:dirty_read({simple,Key}),
AfterT = erlang:monotonic_time(),
elapsed_time(BeforeT,AfterT,R)
end,
mnesia:transaction(Fun);
meter(get_int) ->
Key = 3,
mnesia:transaction(fun() -> mnesia:write(#simple{key=Key}) end),
Fun = fun() ->
[Simple] = mnesia:read({simple,Key}),
BeforeT = erlang:monotonic_time(),
Int = Simple#simple.val,
AfterT = erlang:monotonic_time(),
elapsed_time(BeforeT,AfterT,Int)
end,
mnesia:transaction(Fun);
meter(open_update) ->
Key = 3,
mnesia:transaction(fun() -> mnesia:write(#simple{key=Key}) end),
Fun = fun() ->
BeforeT = erlang:monotonic_time(),
R = mnesia:wread({simple,Key}),
AfterT = erlang:monotonic_time(),
elapsed_time(BeforeT,AfterT,R)
end,
mnesia:transaction(Fun);
meter(put_int) ->
Key = 4,
mnesia:transaction(fun() -> mnesia:write(#simple{key=Key}) end),
Fun = fun() ->
[Simple] = mnesia:wread({simple,Key}),
BeforeT = erlang:monotonic_time(),
R = Simple#simple{val=7},
AfterT = erlang:monotonic_time(),
elapsed_time(BeforeT,AfterT,R)
end,
mnesia:transaction(Fun);
meter(put_int_and_copy) ->
Key = 5,
mnesia:transaction(fun() -> mnesia:write(#simple{key=Key}) end),
Fun = fun() ->
[Simple] = mnesia:wread({simple,Key}),
BeforeT = erlang:monotonic_time(),
Simple2 = Simple#simple{val=17},
R = mnesia:write(Simple2),
AfterT = erlang:monotonic_time(),
elapsed_time(BeforeT,AfterT,R)
end,
mnesia:transaction(Fun);
meter(dirty_put_int_and_copy) ->
Key = 55,
mnesia:dirty_write(#simple{key=Key}),
[Simple] = mnesia:dirty_read({simple,Key}),
BeforeT = erlang:monotonic_time(),
Simple2 = Simple#simple{val=17},
R = mnesia:dirty_write(Simple2),
AfterT = erlang:monotonic_time(),
{atomic,elapsed_time(BeforeT,AfterT,R)};
meter(start_trans) ->
BeforeT = erlang:monotonic_time(),
{atomic,AfterT} = mnesia:transaction(fun() -> erlang:monotonic_time() end),
{atomic,elapsed_time(BeforeT,AfterT,ok)};
meter(commit_one_update) ->
Key = 6,
mnesia:transaction(fun() -> mnesia:write(#simple{key=Key}) end),
Fun = fun() ->
[Simple] = mnesia:wread({simple,Key}),
Simple2 = Simple#simple{val=27},
_R = mnesia:write(Simple2),
erlang:monotonic_time()
end,
{atomic,BeforeT} = mnesia:transaction(Fun),
AfterT = erlang:monotonic_time(),
{atomic,elapsed_time(BeforeT,AfterT,ok)};
meter(delete) ->
Key = 7,
mnesia:transaction(fun() -> mnesia:write(#simple{key=Key}) end),
Fun = fun() ->
BeforeT = erlang:monotonic_time(),
R = mnesia:delete({simple,Key}),
AfterT = erlang:monotonic_time(),
elapsed_time(BeforeT,AfterT,R)
end,
mnesia:transaction(Fun);
meter(dirty_delete) ->
Key = 75,
mnesia:dirty_write(#simple{key=Key}),
BeforeT = erlang:monotonic_time(),
R = mnesia:dirty_delete({simple,Key}),
AfterT = erlang:monotonic_time(),
{atomic, elapsed_time(BeforeT,AfterT,R)}.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% Calculate the elapsed time
elapsed_time(BeforeT,AfterT,Result) ->
{erlang:convert_time_unit(AfterT-BeforeT, native, nano_seconds),Result}.
