github.com/dolthub/dolt/go@v0.40.5-0.20240520175717-68db7794bea6/store/prolly/tree/stats_test.go (about)

     1  // Copyright 2023 Dolthub, Inc.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package tree
    16  
    17  import (
    18  	"context"
    19  	"fmt"
    20  	"testing"
    21  
    22  	"github.com/stretchr/testify/require"
    23  
    24  	"github.com/dolthub/dolt/go/store/val"
    25  )
    26  
    27  func TestStatsLevel(t *testing.T) {
    28  	ctx := context.Background()
    29  
    30  	tests := []struct {
    31  		count int
    32  		level int
    33  	}{
    34  		{
    35  			count: 10,
    36  			level: 0,
    37  		},
    38  		{
    39  			count: 1e3,
    40  			level: 0,
    41  		},
    42  		{
    43  			count: 1e6,
    44  			level: 1,
    45  		},
    46  	}
    47  	lowBucketCnt := 20
    48  	hashFanout := 200
    49  	highBucketCnt := lowBucketCnt * hashFanout
    50  	for _, tt := range tests {
    51  		t.Run(fmt.Sprintf("stats histogram level test count: %d", tt.count), func(t *testing.T) {
    52  			root, _, ns := randomTree(t, tt.count*2)
    53  			m := StaticMap[val.Tuple, val.Tuple, val.TupleDesc]{
    54  				Root:      root,
    55  				NodeStore: ns,
    56  				Order:     keyDesc,
    57  			}
    58  			levelNodes, err := GetHistogramLevel(ctx, m, lowBucketCnt)
    59  			require.NoError(t, err)
    60  
    61  			require.Equal(t, tt.level, levelNodes[0].Level())
    62  
    63  			if root.level == 0 {
    64  				require.Equal(t, 1, len(levelNodes))
    65  			} else if root.level == 1 {
    66  				require.Equal(t, root.Count(), len(levelNodes))
    67  			} else {
    68  				if len(levelNodes) < lowBucketCnt || len(levelNodes) >= highBucketCnt {
    69  					t.Errorf("expected histogram bucket level to be in range: [%d,%d); found: %d", lowBucketCnt, highBucketCnt, len(levelNodes))
    70  				}
    71  			}
    72  			require.Equal(t, tt.count, histLevelCount(t, levelNodes))
    73  		})
    74  	}
    75  }
    76  
    77  func histLevelCount(t *testing.T, nodes []Node) int {
    78  	cnt := 0
    79  	for _, n := range nodes {
    80  		switch n.level {
    81  		case 0:
    82  			cnt += n.Count()
    83  		default:
    84  			n, err := n.loadSubtrees()
    85  			require.NoError(t, err)
    86  			for i := 0; i < n.Count(); i++ {
    87  				subCnt, err := n.getSubtreeCount(i)
    88  				require.NoError(t, err)
    89  				cnt += int(subCnt)
    90  			}
    91  		}
    92  	}
    93  	return cnt
    94  }