VictoriaMetrics/app/vmalert/datasource/vm_prom_api_test.go
Roman Khavronenko 4f0525852f
app/vmalert/datasource: reduce number of allocations when parsing instant responses (#6272)
Allocations are reduced by implementing custom json parser via fastjson
lib.
The change also re-uses `promInstant` object in attempt to reduce number
of
allocations when parsing big responses, as usually happens with heavy
recording rules.

```
name                                old allocs/op  new allocs/op  delta
ParsePrometheusResponse/Instant-10     9.65k ± 0%     5.60k ± 0%   ~     (p=1.000 n=1+1)

```

Signed-off-by: hagen1778 <roman@victoriametrics.com>

---------

Signed-off-by: hagen1778 <roman@victoriametrics.com>
2024-05-15 15:18:33 +02:00

74 lines
2.0 KiB
Go

package datasource
import (
"reflect"
"testing"
)
func TestPromInstant_UnmarshalPositive(t *testing.T) {
f := func(data string, exp []Metric) {
t.Helper()
var pi promInstant
err := pi.Unmarshal([]byte(data))
if err != nil {
t.Fatalf("unexpected unmarshal err %v; \n %v", err, string(data))
}
got, _ := pi.metrics()
if !reflect.DeepEqual(got, exp) {
t.Fatalf("expected to get:\n%v\ngot instead:\n%v", exp, got)
}
}
f(`[{"metric":{"__name__":"up"},"value":[1583780000,"42"]}]`, []Metric{
{
Labels: []Label{{Name: "__name__", Value: "up"}},
Timestamps: []int64{1583780000},
Values: []float64{42},
},
})
f(`[
{"metric":{"__name__":"up"},"value":[1583780000,"42"]},
{"metric":{"__name__":"foo"},"value":[1583780001,"7"]},
{"metric":{"__name__":"baz", "instance":"bar"},"value":[1583780002,"8"]}]`, []Metric{
{
Labels: []Label{{Name: "__name__", Value: "up"}},
Timestamps: []int64{1583780000},
Values: []float64{42},
},
{
Labels: []Label{{Name: "__name__", Value: "foo"}},
Timestamps: []int64{1583780001},
Values: []float64{7},
},
{
Labels: []Label{{Name: "__name__", Value: "baz"}, {Name: "instance", Value: "bar"}},
Timestamps: []int64{1583780002},
Values: []float64{8},
},
})
}
func TestPromInstant_UnmarshalNegative(t *testing.T) {
f := func(data string) {
t.Helper()
var pi promInstant
err := pi.Unmarshal([]byte(data))
if err == nil {
t.Fatalf("expected to get an error; got nil instead")
}
}
f(``)
f(`foo`)
f(`[{"metric":{"__name__":"up"},"value":[1583780000,"42"]},`)
f(`[{"metric":{"__name__"},"value":[1583780000,"42"]},`)
// no `metric` object
f(`[{"value":[1583780000,"42"]}]`)
// no `value` object
f(`[{"metric":{"__name__":"up"}}]`)
// less than 2 values in `value` object
f(`[{"metric":{"__name__":"up"},"value":["42"]}]`)
f(`[{"metric":{"__name__":"up"},"value":[1583780000]}]`)
// non-numeric sample value
f(`[{"metric":{"__name__":"up"},"value":[1583780000,"foo"]}]`)
}