histogram: expose bug in bucket key calculation

The current code doesn't work fork negative schemas if the observed
value should go into a bucket with a non-positive key.

Signed-off-by: beorn7 <beorn@grafana.com>
This commit is contained in:
beorn7 2023-05-25 13:58:22 +02:00
parent 297fea317b
commit 30948120dc
1 changed files with 5 additions and 2 deletions

View File

@ -500,23 +500,26 @@ func TestNativeHistogram(t *testing.T) {
{
name: "factor 4 results in schema -1",
observations: []float64{
0.0156251, 0.0625, // Bucket -2: (0.015625, 0.0625)
0.1, 0.25, // Bucket -1: (0.0625, 0.25]
0.5, 1, // Bucket 0: (0.25, 1]
1.5, 2, 3, 3.5, // Bucket 1: (1, 4]
5, 6, 7, // Bucket 2: (4, 16]
33.33, // Bucket 3: (16, 64]
},
factor: 4,
want: `sample_count:10 sample_sum:62.83 schema:-1 zero_threshold:2.938735877055719e-39 zero_count:0 positive_span:<offset:0 length:4 > positive_delta:2 positive_delta:2 positive_delta:-1 positive_delta:-2 `,
want: `sample_count:14 sample_sum:63.2581251 schema:-1 zero_threshold:2.938735877055719e-39 zero_count:0 positive_span:<offset:-2 length:6 > positive_delta:2 positive_delta:0 positive_delta:0 positive_delta:2 positive_delta:-1 positive_delta:-2 `,
},
{
name: "factor 17 results in schema -2",
observations: []float64{
0.0156251, 0.0625, 0.1, 0.25, // Bucket -1: (0.015625, 0.25]
0.5, 1, // Bucket 0: (0.0625, 1]
1.5, 2, 3, 3.5, 5, 6, 7, // Bucket 1: (1, 16]
33.33, // Bucket 2: (16, 256]
},
factor: 17,
want: `sample_count:10 sample_sum:62.83 schema:-2 zero_threshold:2.938735877055719e-39 zero_count:0 positive_span:<offset:0 length:3 > positive_delta:2 positive_delta:5 positive_delta:-6 `,
want: `sample_count:14 sample_sum:63.2581251 schema:-2 zero_threshold:2.938735877055719e-39 zero_count:0 positive_span:<offset:-1 length:4 > positive_delta:4 positive_delta:-2 positive_delta:5 positive_delta:-6 `,
},
{
name: "negative buckets",