./ct_report/coverage/mongoose_instrument_prometheus.COVER.html

1 -module(mongoose_instrument_prometheus).
2
3 -behaviour(mongoose_instrument).
4
5 -export([set_up/3, handle_event/4]).
6
7 -spec set_up(mongoose_instrument:event_name(), mongoose_instrument:labels(),
8 mongoose_instrument:config()) -> boolean().
9 set_up(EventName, Labels, #{metrics := Metrics}) ->
10 1486 LabelKeys = labels_to_keys(Labels),
11 1486 maps:foreach(fun(MetricName, MetricType) ->
12 2350 set_up_metric(EventName, LabelKeys, MetricName, MetricType)
13 end, Metrics),
14 1486 true;
15 set_up(_EventName, _Labels, #{}) ->
16 
:-(
 false.
17
18 -spec handle_event(mongoose_instrument:event_name(), mongoose_instrument:labels(),
19 mongoose_instrument:config(), mongoose_instrument:measurements()) -> ok.
20 handle_event(EventName, Labels, #{metrics := Metrics}, Measurements) ->
21 14567 LabelValues = labels_to_values(Labels),
22 14567 maps:foreach(fun(MetricName, MetricType) ->
23 31362 handle_metric_event(EventName, LabelValues, MetricName, MetricType, Measurements)
24 end, Metrics).
25
26 set_up_metric(EventName, LabelKeys, MetricName, MetricType) ->
27 2350 MetricSpec = metric_spec(EventName, LabelKeys, MetricName),
28 2350 declare_metric(MetricSpec, MetricType).
29
30 declare_metric(MetricSpec, spiral) ->
31 1622 prometheus_counter:declare(MetricSpec);
32 declare_metric(MetricSpec, histogram) ->
33 728 prometheus_histogram:declare([{buckets, histogram_buckets()} | MetricSpec]).
34
35 metric_spec(EventName, LabelKeys, MetricName) ->
36 2350 [{name, full_metric_name(EventName, MetricName)},
37 {help, metric_help(EventName, MetricName)},
38 {labels, LabelKeys}].
39
40 histogram_buckets() ->
41 728 histogram_buckets([], 1 bsl 30). % ~1.07 * 10^9
42
43 histogram_buckets(AccBuckets, Val) when Val > 0 ->
44 22568 histogram_buckets([Val | AccBuckets], Val bsr 1);
45 histogram_buckets(AccBuckets, _Val) ->
46 728 AccBuckets.
47
48 handle_metric_event(EventName, LabelValues, MetricName, MetricType, Measurements) ->
49 31362 case Measurements of
50 #{MetricName := MetricValue} ->
51 30377 FullName = full_metric_name(EventName, MetricName),
52 30377 update_metric(FullName, LabelValues, MetricType, MetricValue);
53 #{} ->
54 985 ok
55 end.
56
57 metric_help(EventName, MetricName) ->
58 2350 lists:flatten(io_lib:format("Event: ~p, Metric: ~p", [EventName, MetricName])).
59
60 full_metric_name(EventName, MetricName) ->
61 32727 list_to_atom(atom_to_list(EventName) ++ "_" ++ atom_to_list(MetricName)).
62
63 labels_to_keys(Labels) ->
64 1486 lists:sort(maps:keys(Labels)).
65
66 labels_to_values(Labels) ->
67 14567 [V || {_K, V} <- lists:keysort(1, maps:to_list(Labels))].
68
69 update_metric(Name, Labels, spiral, Value) when is_integer(Value), Value >= 0 ->
70 14716 prometheus_counter:inc(Name, Labels, Value);
71 update_metric(Name, Labels, histogram, Value) when is_integer(Value) ->
72 15661 prometheus_histogram:observe(Name, Labels, Value).
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