602 lines
		
	
	
		
			14 KiB
		
	
	
	
		
			Go
		
	
	
	
			
		
		
	
	
			602 lines
		
	
	
		
			14 KiB
		
	
	
	
		
			Go
		
	
	
	
| // Copyright 2021 The Prometheus Authors
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| // Licensed under the Apache License, Version 2.0 (the "License");
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| // you may not use this file except in compliance with the License.
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| // You may obtain a copy of the License at
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| //
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| // http://www.apache.org/licenses/LICENSE-2.0
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| //
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| // Unless required by applicable law or agreed to in writing, software
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| // distributed under the License is distributed on an "AS IS" BASIS,
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| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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| // See the License for the specific language governing permissions and
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| // limitations under the License.
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| 
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| // The code in this file was largely written by Damian Gryski as part of
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| // https://github.com/dgryski/go-tsz and published under the license below.
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| // It was modified to accommodate reading from byte slices without modifying
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| // the underlying bytes, which would panic when reading from mmapped
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| // read-only byte slices.
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| package chunkenc
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| 
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| import (
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| 	"math"
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| 	"testing"
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| 
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| 	"github.com/stretchr/testify/require"
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| 
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| 	"github.com/prometheus/prometheus/model/histogram"
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| )
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| 
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| // Example of a span layout and resulting bucket indices (_idx_ is used in this
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| // histogram, others are shown just for context):
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| //
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| //   spans      : [offset: 0, length: 2]                [offset 1, length 1]
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| //   bucket idx : _0_                _1_      2         [3]                  4 ...
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| 
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| func TestBucketIterator(t *testing.T) {
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| 	type test struct {
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| 		spans []histogram.Span
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| 		idxs  []int
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| 	}
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| 	tests := []test{
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| 		{
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| 			spans: []histogram.Span{
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| 				{
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| 					Offset: 0,
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| 					Length: 1,
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| 				},
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| 			},
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| 			idxs: []int{0},
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| 		},
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| 		{
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| 			spans: []histogram.Span{
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| 				{
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| 					Offset: 0,
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| 					Length: 2,
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| 				},
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| 				{
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| 					Offset: 1,
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| 					Length: 1,
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| 				},
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| 			},
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| 			idxs: []int{0, 1, 3},
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| 		},
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| 		{
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| 			spans: []histogram.Span{
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| 				{
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| 					Offset: 100,
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| 					Length: 4,
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| 				},
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| 				{
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| 					Offset: 8,
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| 					Length: 7,
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| 				},
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| 				{
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| 					Offset: 0,
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| 					Length: 1,
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| 				},
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| 			},
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| 			idxs: []int{100, 101, 102, 103, 112, 113, 114, 115, 116, 117, 118, 119},
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| 		},
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| 		// The below 2 sets ore the ones described in expandSpansForward's comments.
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| 		{
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| 			spans: []histogram.Span{
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| 				{Offset: 0, Length: 2},
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| 				{Offset: 2, Length: 1},
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| 				{Offset: 3, Length: 2},
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| 				{Offset: 3, Length: 1},
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| 				{Offset: 1, Length: 1},
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| 			},
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| 			idxs: []int{0, 1, 4, 8, 9, 13, 15},
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| 		},
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| 		{
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| 			spans: []histogram.Span{
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| 				{Offset: 0, Length: 3},
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| 				{Offset: 1, Length: 1},
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| 				{Offset: 1, Length: 4},
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| 				{Offset: 3, Length: 3},
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| 			},
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| 			idxs: []int{0, 1, 2, 4, 6, 7, 8, 9, 13, 14, 15},
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| 		},
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| 	}
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| 	for _, test := range tests {
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| 		b := newBucketIterator(test.spans)
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| 		var got []int
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| 		v, ok := b.Next()
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| 		for ok {
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| 			got = append(got, v)
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| 			v, ok = b.Next()
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| 		}
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| 		require.Equal(t, test.idxs, got)
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| 	}
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| }
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| 
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| func TestCompareSpansAndInsert(t *testing.T) {
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| 	scenarios := []struct {
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| 		description           string
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| 		spansA, spansB        []histogram.Span
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| 		fInserts, bInserts    []Insert
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| 		bucketsIn, bucketsOut []int64
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| 	}{
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| 		{
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| 			description: "single prepend at the beginning",
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| 			spansA: []histogram.Span{
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| 				{Offset: -10, Length: 3},
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| 			},
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| 			spansB: []histogram.Span{
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| 				{Offset: -11, Length: 4},
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| 			},
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| 			fInserts: []Insert{
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| 				{
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| 					pos: 0,
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| 					num: 1,
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| 				},
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| 			},
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| 			bucketsIn:  []int64{6, -3, 0},
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| 			bucketsOut: []int64{0, 6, -3, 0},
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| 		},
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| 		{
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| 			description: "single append at the end",
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| 			spansA: []histogram.Span{
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| 				{Offset: -10, Length: 3},
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| 			},
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| 			spansB: []histogram.Span{
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| 				{Offset: -10, Length: 4},
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| 			},
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| 			fInserts: []Insert{
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| 				{
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| 					pos: 3,
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| 					num: 1,
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| 				},
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| 			},
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| 			bucketsIn:  []int64{6, -3, 0},
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| 			bucketsOut: []int64{6, -3, 0, -3},
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| 		},
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| 		{
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| 			description: "double prepend at the beginning",
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| 			spansA: []histogram.Span{
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| 				{Offset: -10, Length: 3},
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| 			},
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| 			spansB: []histogram.Span{
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| 				{Offset: -12, Length: 5},
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| 			},
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| 			fInserts: []Insert{
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| 				{
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| 					pos: 0,
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| 					num: 2,
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| 				},
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| 			},
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| 			bucketsIn:  []int64{6, -3, 0},
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| 			bucketsOut: []int64{0, 0, 6, -3, 0},
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| 		},
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| 		{
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| 			description: "double append at the end",
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| 			spansA: []histogram.Span{
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| 				{Offset: -10, Length: 3},
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| 			},
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| 			spansB: []histogram.Span{
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| 				{Offset: -10, Length: 5},
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| 			},
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| 			fInserts: []Insert{
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| 				{
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| 					pos: 3,
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| 					num: 2,
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| 				},
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| 			},
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| 			bucketsIn:  []int64{6, -3, 0},
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| 			bucketsOut: []int64{6, -3, 0, -3, 0},
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| 		},
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| 		{
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| 			description: "double prepond at the beginning and double append at the end",
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| 			spansA: []histogram.Span{
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| 				{Offset: -10, Length: 3},
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| 			},
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| 			spansB: []histogram.Span{
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| 				{Offset: -12, Length: 7},
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| 			},
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| 			fInserts: []Insert{
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| 				{
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| 					pos: 0,
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| 					num: 2,
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| 				},
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| 				{
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| 					pos: 3,
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| 					num: 2,
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| 				},
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| 			},
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| 			bucketsIn:  []int64{6, -3, 0},
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| 			bucketsOut: []int64{0, 0, 6, -3, 0, -3, 0},
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| 		},
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| 		{
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| 			description: "single removal of bucket at the start",
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| 			spansA: []histogram.Span{
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| 				{Offset: -10, Length: 4},
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| 			},
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| 			spansB: []histogram.Span{
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| 				{Offset: -9, Length: 3},
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| 			},
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| 			bInserts: []Insert{
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| 				{pos: 0, num: 1},
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| 			},
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| 		},
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| 		{
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| 			description: "single removal of bucket in the middle",
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| 			spansA: []histogram.Span{
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| 				{Offset: -10, Length: 4},
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| 			},
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| 			spansB: []histogram.Span{
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| 				{Offset: -10, Length: 2},
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| 				{Offset: 1, Length: 1},
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| 			},
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| 			bInserts: []Insert{
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| 				{pos: 2, num: 1},
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| 			},
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| 		},
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| 		{
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| 			description: "single removal of bucket at the end",
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| 			spansA: []histogram.Span{
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| 				{Offset: -10, Length: 4},
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| 			},
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| 			spansB: []histogram.Span{
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| 				{Offset: -10, Length: 3},
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| 			},
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| 			bInserts: []Insert{
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| 				{pos: 3, num: 1},
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| 			},
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| 		},
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| 		{
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| 			description: "as described in doc comment",
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| 			spansA: []histogram.Span{
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| 				{Offset: 0, Length: 2},
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| 				{Offset: 2, Length: 1},
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| 				{Offset: 3, Length: 2},
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| 				{Offset: 3, Length: 1},
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| 				{Offset: 1, Length: 1},
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| 			},
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| 			spansB: []histogram.Span{
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| 				{Offset: 0, Length: 3},
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| 				{Offset: 1, Length: 1},
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| 				{Offset: 1, Length: 4},
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| 				{Offset: 3, Length: 3},
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| 			},
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| 			fInserts: []Insert{
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| 				{
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| 					pos: 2,
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| 					num: 1,
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| 				},
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| 				{
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| 					pos: 3,
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| 					num: 2,
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| 				},
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| 				{
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| 					pos: 6,
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| 					num: 1,
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| 				},
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| 			},
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| 			bucketsIn:  []int64{6, -3, 0, -1, 2, 1, -4},
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| 			bucketsOut: []int64{6, -3, -3, 3, -3, 0, 2, 2, 1, -5, 1},
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| 		},
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| 		{
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| 			description: "both forward and backward inserts, complex case",
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| 			spansA: []histogram.Span{
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| 				{Offset: 0, Length: 2},
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| 				{Offset: 2, Length: 1},
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| 				{Offset: 3, Length: 2},
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| 				{Offset: 3, Length: 1},
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| 				{Offset: 1, Length: 1},
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| 			},
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| 			spansB: []histogram.Span{
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| 				{Offset: 1, Length: 2},
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| 				{Offset: 1, Length: 1},
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| 				{Offset: 1, Length: 2},
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| 				{Offset: 1, Length: 1},
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| 				{Offset: 4, Length: 1},
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| 			},
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| 			fInserts: []Insert{
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| 				{
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| 					pos: 2,
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| 					num: 1,
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| 				},
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| 				{
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| 					pos: 3,
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| 					num: 2,
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| 				},
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| 				{
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| 					pos: 6,
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| 					num: 1,
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| 				},
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| 			},
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| 			bInserts: []Insert{
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| 				{
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| 					pos: 0,
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| 					num: 1,
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| 				},
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| 				{
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| 					pos: 5,
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| 					num: 1,
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| 				},
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| 				{
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| 					pos: 6,
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| 					num: 1,
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| 				},
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| 				{
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| 					pos: 7,
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| 					num: 1,
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| 				},
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| 			},
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| 		},
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| 	}
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| 
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| 	for _, s := range scenarios {
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| 		t.Run(s.description, func(t *testing.T) {
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| 			if len(s.bInserts) > 0 {
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| 				fInserts, bInserts, _ := expandSpansBothWays(s.spansA, s.spansB)
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| 				require.Equal(t, s.fInserts, fInserts)
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| 				require.Equal(t, s.bInserts, bInserts)
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| 			}
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| 
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| 			inserts, valid := expandSpansForward(s.spansA, s.spansB)
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| 			if len(s.bInserts) > 0 {
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| 				require.False(t, valid, "compareScan unexpectedly returned true")
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| 				return
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| 			}
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| 			require.True(t, valid, "compareScan unexpectedly returned false")
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| 			require.Equal(t, s.fInserts, inserts)
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| 
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| 			gotBuckets := make([]int64, len(s.bucketsOut))
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| 			insert(s.bucketsIn, gotBuckets, inserts, true)
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| 			require.Equal(t, s.bucketsOut, gotBuckets)
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| 
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| 			floatBucketsIn := make([]float64, len(s.bucketsIn))
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| 			last := s.bucketsIn[0]
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| 			floatBucketsIn[0] = float64(last)
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| 			for i := 1; i < len(floatBucketsIn); i++ {
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| 				last += s.bucketsIn[i]
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| 				floatBucketsIn[i] = float64(last)
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| 			}
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| 			floatBucketsOut := make([]float64, len(s.bucketsOut))
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| 			last = s.bucketsOut[0]
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| 			floatBucketsOut[0] = float64(last)
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| 			for i := 1; i < len(floatBucketsOut); i++ {
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| 				last += s.bucketsOut[i]
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| 				floatBucketsOut[i] = float64(last)
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| 			}
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| 			gotFloatBuckets := make([]float64, len(floatBucketsOut))
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| 			insert(floatBucketsIn, gotFloatBuckets, inserts, false)
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| 			require.Equal(t, floatBucketsOut, gotFloatBuckets)
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| 		})
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| 	}
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| }
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| 
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| func TestWriteReadHistogramChunkLayout(t *testing.T) {
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| 	layouts := []struct {
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| 		schema                       int32
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| 		zeroThreshold                float64
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| 		positiveSpans, negativeSpans []histogram.Span
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| 		customValues                 []float64
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| 	}{
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| 		{
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| 			schema:        3,
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| 			zeroThreshold: 0,
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| 			positiveSpans: []histogram.Span{{Offset: -4, Length: 3}, {Offset: 2, Length: 42}},
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| 			negativeSpans: nil,
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| 		},
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| 		{
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| 			schema:        -2,
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| 			zeroThreshold: 2.938735877055719e-39, // Default value in client_golang.
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| 			positiveSpans: nil,
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| 			negativeSpans: []histogram.Span{{Offset: 2, Length: 5}, {Offset: 1, Length: 34}},
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| 		},
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| 		{
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| 			schema:        6,
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| 			zeroThreshold: 1024, // The largest power of two we can encode in one byte.
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| 			positiveSpans: nil,
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| 			negativeSpans: nil,
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| 		},
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| 		{
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| 			schema:        6,
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| 			zeroThreshold: 1025,
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| 			positiveSpans: []histogram.Span{{Offset: 2, Length: 5}, {Offset: 1, Length: 34}, {Offset: 0, Length: 0}}, // Weird span.
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| 			negativeSpans: []histogram.Span{{Offset: -345, Length: 4545}, {Offset: 53645665, Length: 345}, {Offset: 945995, Length: 85848}},
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| 		},
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| 		{
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| 			schema:        6,
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| 			zeroThreshold: 2048,
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| 			positiveSpans: nil,
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| 			negativeSpans: nil,
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| 		},
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| 		{
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| 			schema:        0,
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| 			zeroThreshold: math.Ldexp(0.5, -242), // The smallest power of two we can encode in one byte.
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| 			positiveSpans: []histogram.Span{{Offset: -4, Length: 3}},
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| 			negativeSpans: []histogram.Span{{Offset: 2, Length: 5}, {Offset: 1, Length: 34}},
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| 		},
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| 		{
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| 			schema:        0,
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| 			zeroThreshold: math.Ldexp(0.5, -243),
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| 			positiveSpans: []histogram.Span{{Offset: -4, Length: 3}},
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| 			negativeSpans: []histogram.Span{{Offset: 2, Length: 5}, {Offset: 1, Length: 34}},
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| 		},
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| 		{
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| 			schema:        4,
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| 			zeroThreshold: 42, // Not a power of two.
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| 			positiveSpans: nil,
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| 			negativeSpans: nil,
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| 		},
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| 		{
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| 			schema:        histogram.CustomBucketsSchema,
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| 			positiveSpans: []histogram.Span{{Offset: -4, Length: 3}, {Offset: 2, Length: 42}},
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| 			negativeSpans: nil,
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| 			customValues:  []float64{-5, -2.5, 0, 0.1, 0.25, 0.5, 1, 2, 5, 10, 25, 50, 100, 255, 500, 1000, 50000, 1e7},
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| 		},
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| 		{
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| 			schema:        histogram.CustomBucketsSchema,
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| 			positiveSpans: []histogram.Span{{Offset: -4, Length: 3}, {Offset: 2, Length: 42}},
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| 			negativeSpans: nil,
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| 			customValues:  []float64{0.005, 0.01, 0.025, 0.05, 0.1, 0.25, 0.5, 1.0, 2.5, 5.0, 10.0, 25.0, 50.0, 100.0},
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| 		},
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| 		{
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| 			schema:        histogram.CustomBucketsSchema,
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| 			positiveSpans: []histogram.Span{{Offset: -4, Length: 3}, {Offset: 2, Length: 42}},
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| 			negativeSpans: nil,
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| 			customValues:  []float64{0.001, 0.002, 0.004, 0.008, 0.016, 0.032, 0.064, 0.128, 0.256, 0.512, 1.024, 2.048, 4.096, 8.192},
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| 		},
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| 		{
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| 			schema:        histogram.CustomBucketsSchema,
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| 			positiveSpans: []histogram.Span{{Offset: -4, Length: 3}, {Offset: 2, Length: 42}},
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| 			negativeSpans: nil,
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| 			customValues:  []float64{1.001, 1.023, 2.01, 4.007, 4.095, 8.001, 8.19, 16.24},
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| 		},
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| 	}
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| 
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| 	bs := bstream{}
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| 
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| 	for _, l := range layouts {
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| 		writeHistogramChunkLayout(&bs, l.schema, l.zeroThreshold, l.positiveSpans, l.negativeSpans, l.customValues)
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| 	}
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| 
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| 	bsr := newBReader(bs.bytes())
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| 
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| 	for _, want := range layouts {
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| 		gotSchema, gotZeroThreshold, gotPositiveSpans, gotNegativeSpans, gotCustomBounds, err := readHistogramChunkLayout(&bsr)
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| 		require.NoError(t, err)
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| 		require.Equal(t, want.schema, gotSchema)
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| 		require.Equal(t, want.zeroThreshold, gotZeroThreshold)
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| 		require.Equal(t, want.positiveSpans, gotPositiveSpans)
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| 		require.Equal(t, want.negativeSpans, gotNegativeSpans)
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| 		require.Equal(t, want.customValues, gotCustomBounds)
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| 	}
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| }
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| 
 | |
| func TestSpansFromBidirectionalCompareSpans(t *testing.T) {
 | |
| 	cases := []struct {
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| 		s1, s2, exp []histogram.Span
 | |
| 	}{
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| 		{ // All empty.
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| 			s1: []histogram.Span{},
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| 			s2: []histogram.Span{},
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| 		},
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| 		{ // Same spans.
 | |
| 			s1: []histogram.Span{},
 | |
| 			s2: []histogram.Span{},
 | |
| 		},
 | |
| 		{
 | |
| 			// Has the cases of
 | |
| 			// 1.  |----|        (partial overlap)
 | |
| 			//        |----|
 | |
| 			//
 | |
| 			// 2.       |-----|  (no gap but no overlap as well)
 | |
| 			//     |---|
 | |
| 			//
 | |
| 			// 3.  |----|        (complete overlap)
 | |
| 			//     |----|
 | |
| 			s1: []histogram.Span{
 | |
| 				{Offset: 0, Length: 3},
 | |
| 				{Offset: 3, Length: 3},
 | |
| 				{Offset: 5, Length: 3},
 | |
| 			},
 | |
| 			s2: []histogram.Span{
 | |
| 				{Offset: 0, Length: 2},
 | |
| 				{Offset: 2, Length: 2},
 | |
| 				{Offset: 2, Length: 3},
 | |
| 				{Offset: 3, Length: 3},
 | |
| 			},
 | |
| 			exp: []histogram.Span{
 | |
| 				{Offset: 0, Length: 3},
 | |
| 				{Offset: 1, Length: 7},
 | |
| 				{Offset: 3, Length: 3},
 | |
| 			},
 | |
| 		},
 | |
| 		{
 | |
| 			// s1 is superset of s2.
 | |
| 			s1: []histogram.Span{
 | |
| 				{Offset: 0, Length: 3},
 | |
| 				{Offset: 3, Length: 5},
 | |
| 				{Offset: 3, Length: 3},
 | |
| 			},
 | |
| 			s2: []histogram.Span{
 | |
| 				{Offset: 0, Length: 2},
 | |
| 				{Offset: 5, Length: 3},
 | |
| 				{Offset: 4, Length: 3},
 | |
| 			},
 | |
| 			exp: []histogram.Span{
 | |
| 				{Offset: 0, Length: 3},
 | |
| 				{Offset: 3, Length: 5},
 | |
| 				{Offset: 3, Length: 3},
 | |
| 			},
 | |
| 		},
 | |
| 		{
 | |
| 			// No overlaps but one span is side by side.
 | |
| 			s1: []histogram.Span{
 | |
| 				{Offset: 0, Length: 3},
 | |
| 				{Offset: 3, Length: 3},
 | |
| 				{Offset: 5, Length: 3},
 | |
| 			},
 | |
| 			s2: []histogram.Span{
 | |
| 				{Offset: 3, Length: 3},
 | |
| 				{Offset: 4, Length: 2},
 | |
| 			},
 | |
| 			exp: []histogram.Span{
 | |
| 				{Offset: 0, Length: 9},
 | |
| 				{Offset: 1, Length: 2},
 | |
| 				{Offset: 2, Length: 3},
 | |
| 			},
 | |
| 		},
 | |
| 		{
 | |
| 			// No buckets in one of them.
 | |
| 			s1: []histogram.Span{
 | |
| 				{Offset: 0, Length: 3},
 | |
| 				{Offset: 3, Length: 3},
 | |
| 				{Offset: 5, Length: 3},
 | |
| 			},
 | |
| 			s2: []histogram.Span{},
 | |
| 			exp: []histogram.Span{
 | |
| 				{Offset: 0, Length: 3},
 | |
| 				{Offset: 3, Length: 3},
 | |
| 				{Offset: 5, Length: 3},
 | |
| 			},
 | |
| 		},
 | |
| 		{ // Zero length spans.
 | |
| 			s1: []histogram.Span{
 | |
| 				{Offset: -5, Length: 0},
 | |
| 				{Offset: 2, Length: 0},
 | |
| 				{Offset: 3, Length: 3},
 | |
| 				{Offset: 1, Length: 0},
 | |
| 				{Offset: 2, Length: 3},
 | |
| 				{Offset: 2, Length: 0},
 | |
| 				{Offset: 2, Length: 0},
 | |
| 				{Offset: 1, Length: 3},
 | |
| 				{Offset: 4, Length: 0},
 | |
| 				{Offset: 5, Length: 0},
 | |
| 			},
 | |
| 			s2: []histogram.Span{
 | |
| 				{Offset: 0, Length: 2},
 | |
| 				{Offset: 2, Length: 2},
 | |
| 				{Offset: 1, Length: 0},
 | |
| 				{Offset: 1, Length: 3},
 | |
| 				{Offset: 3, Length: 3},
 | |
| 			},
 | |
| 			exp: []histogram.Span{
 | |
| 				{Offset: 0, Length: 3},
 | |
| 				{Offset: 1, Length: 7},
 | |
| 				{Offset: 3, Length: 3},
 | |
| 			},
 | |
| 		},
 | |
| 	}
 | |
| 
 | |
| 	for _, c := range cases {
 | |
| 		s1c := make([]histogram.Span, len(c.s1))
 | |
| 		s2c := make([]histogram.Span, len(c.s2))
 | |
| 		copy(s1c, c.s1)
 | |
| 		copy(s2c, c.s2)
 | |
| 
 | |
| 		_, _, act := expandSpansBothWays(c.s1, c.s2)
 | |
| 		require.Equal(t, c.exp, act)
 | |
| 		// Check that s1 and s2 are not modified.
 | |
| 		require.Equal(t, s1c, c.s1)
 | |
| 		require.Equal(t, s2c, c.s2)
 | |
| 		_, _, act = expandSpansBothWays(c.s2, c.s1)
 | |
| 		require.Equal(t, c.exp, act)
 | |
| 	}
 | |
| }
 |