Files
tidb/statistics/fmsketch_test.go

130 lines
4.1 KiB
Go

// Copyright 2017 PingCAP, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package statistics
import (
"testing"
"time"
"github.com/pingcap/errors"
"github.com/pingcap/tidb/sessionctx/stmtctx"
"github.com/pingcap/tidb/types"
"github.com/stretchr/testify/require"
)
// extractSampleItemsDatums is for test purpose only to extract Datum slice
// from SampleItem slice.
func extractSampleItemsDatums(items []*SampleItem) []types.Datum {
datums := make([]types.Datum, len(items))
for i, item := range items {
datums[i] = item.Value
}
return datums
}
func buildFMSketch(sc *stmtctx.StatementContext, values []types.Datum, maxSize int) (*FMSketch, int64, error) {
s := NewFMSketch(maxSize)
for _, value := range values {
err := s.InsertValue(sc, value)
if err != nil {
return nil, 0, errors.Trace(err)
}
}
return s, s.NDV(), nil
}
func SubTestSketch() func(*testing.T) {
return func(t *testing.T) {
s := createTestStatisticsSamples(t)
sc := &stmtctx.StatementContext{TimeZone: time.Local}
maxSize := 1000
sampleSketch, ndv, err := buildFMSketch(sc, extractSampleItemsDatums(s.samples), maxSize)
require.NoError(t, err)
require.Equal(t, int64(6232), ndv)
rcSketch, ndv, err := buildFMSketch(sc, s.rc.(*recordSet).data, maxSize)
require.NoError(t, err)
require.Equal(t, int64(73344), ndv)
pkSketch, ndv, err := buildFMSketch(sc, s.pk.(*recordSet).data, maxSize)
require.NoError(t, err)
require.Equal(t, int64(100480), ndv)
sampleSketch.MergeFMSketch(pkSketch)
sampleSketch.MergeFMSketch(rcSketch)
require.Equal(t, int64(100480), sampleSketch.NDV())
maxSize = 2
sketch := NewFMSketch(maxSize)
sketch.insertHashValue(1)
sketch.insertHashValue(2)
require.Equal(t, maxSize, len(sketch.hashset))
sketch.insertHashValue(4)
require.LessOrEqual(t, maxSize, len(sketch.hashset))
}
}
func SubTestSketchProtoConversion() func(*testing.T) {
return func(t *testing.T) {
s := createTestStatisticsSamples(t)
sc := &stmtctx.StatementContext{TimeZone: time.Local}
maxSize := 1000
sampleSketch, ndv, err := buildFMSketch(sc, extractSampleItemsDatums(s.samples), maxSize)
require.NoError(t, err)
require.Equal(t, int64(6232), ndv)
p := FMSketchToProto(sampleSketch)
f := FMSketchFromProto(p)
require.Equal(t, f.mask, sampleSketch.mask)
require.Equal(t, len(f.hashset), len(sampleSketch.hashset))
for val := range sampleSketch.hashset {
require.True(t, f.hashset[val])
}
}
}
func SubTestFMSketchCoding() func(*testing.T) {
return func(t *testing.T) {
s := createTestStatisticsSamples(t)
sc := &stmtctx.StatementContext{TimeZone: time.Local}
maxSize := 1000
sampleSketch, ndv, err := buildFMSketch(sc, extractSampleItemsDatums(s.samples), maxSize)
require.NoError(t, err)
require.Equal(t, int64(6232), ndv)
bytes, err := EncodeFMSketch(sampleSketch)
require.NoError(t, err)
fmsketch, err := DecodeFMSketch(bytes)
require.NoError(t, err)
require.Equal(t, fmsketch.NDV(), sampleSketch.NDV())
rcSketch, ndv, err := buildFMSketch(sc, s.rc.(*recordSet).data, maxSize)
require.NoError(t, err)
require.Equal(t, int64(73344), ndv)
bytes, err = EncodeFMSketch(rcSketch)
require.NoError(t, err)
fmsketch, err = DecodeFMSketch(bytes)
require.NoError(t, err)
require.Equal(t, fmsketch.NDV(), rcSketch.NDV())
pkSketch, ndv, err := buildFMSketch(sc, s.pk.(*recordSet).data, maxSize)
require.NoError(t, err)
require.Equal(t, int64(100480), ndv)
bytes, err = EncodeFMSketch(pkSketch)
require.NoError(t, err)
fmsketch, err = DecodeFMSketch(bytes)
require.NoError(t, err)
require.Equal(t, fmsketch.NDV(), pkSketch.NDV())
}
}