vitess.io/vitess@v0.16.2/go/vt/vtgate/evalengine/hash_code_test.go (about)

     1  /*
     2  Copyright 2021 The Vitess Authors.
     3  
     4  Licensed under the Apache License, Version 2.0 (the "License");
     5  you may not use this file except in compliance with the License.
     6  You may obtain a copy of the License at
     7  
     8      http://www.apache.org/licenses/LICENSE-2.0
     9  
    10  Unless required by applicable law or agreed to in writing, software
    11  distributed under the License is distributed on an "AS IS" BASIS,
    12  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13  See the License for the specific language governing permissions and
    14  limitations under the License.
    15  */
    16  
    17  package evalengine
    18  
    19  import (
    20  	"fmt"
    21  	"math/rand"
    22  	"testing"
    23  	"time"
    24  
    25  	"github.com/stretchr/testify/require"
    26  
    27  	"vitess.io/vitess/go/mysql/collations"
    28  	"vitess.io/vitess/go/sqltypes"
    29  )
    30  
    31  // The following test tries to produce lots of different values and compares them both using hash code and compare,
    32  // to make sure that these two methods agree on what values are equal
    33  func TestHashCodesRandom(t *testing.T) {
    34  	tested := 0
    35  	equal := 0
    36  	collation := collations.Local().LookupByName("utf8mb4_general_ci").ID()
    37  	endTime := time.Now().Add(1 * time.Second)
    38  	for time.Now().Before(endTime) {
    39  		tested++
    40  		v1, v2 := randomValues()
    41  		cmp, err := NullsafeCompare(v1, v2, collation)
    42  		require.NoErrorf(t, err, "%s compared with %s", v1.String(), v2.String())
    43  		typ, err := CoerceTo(v1.Type(), v2.Type())
    44  		require.NoError(t, err)
    45  
    46  		hash1, err := NullsafeHashcode(v1, collation, typ)
    47  		require.NoError(t, err)
    48  		hash2, err := NullsafeHashcode(v2, collation, typ)
    49  		require.NoError(t, err)
    50  		if cmp == 0 {
    51  			equal++
    52  			require.Equalf(t, hash1, hash2, "values %s and %s are considered equal but produce different hash codes: %d & %d", v1.String(), v2.String(), hash1, hash2)
    53  		}
    54  	}
    55  	t.Logf("tested %d values, with %d equalities found\n", tested, equal)
    56  }
    57  
    58  func randomValues() (sqltypes.Value, sqltypes.Value) {
    59  	if rand.Int()%2 == 0 {
    60  		// create a single value, and turn it into two different types
    61  		v := rand.Int()
    62  		return randomNumericType(v), randomNumericType(v)
    63  	}
    64  
    65  	// just produce two arbitrary random values and compare
    66  	return randomValue(), randomValue()
    67  }
    68  
    69  func randomNumericType(i int) sqltypes.Value {
    70  	r := rand.Intn(len(numericTypes))
    71  	return numericTypes[r](i)
    72  
    73  }
    74  
    75  var numericTypes = []func(int) sqltypes.Value{
    76  	func(i int) sqltypes.Value { return sqltypes.NULL },
    77  	func(i int) sqltypes.Value { return sqltypes.NewInt8(int8(i)) },
    78  	func(i int) sqltypes.Value { return sqltypes.NewInt32(int32(i)) },
    79  	func(i int) sqltypes.Value { return sqltypes.NewInt64(int64(i)) },
    80  	func(i int) sqltypes.Value { return sqltypes.NewUint64(uint64(i)) },
    81  	func(i int) sqltypes.Value { return sqltypes.NewUint32(uint32(i)) },
    82  	func(i int) sqltypes.Value { return sqltypes.NewFloat64(float64(i)) },
    83  	func(i int) sqltypes.Value { return sqltypes.NewDecimal(fmt.Sprintf("%d", i)) },
    84  	func(i int) sqltypes.Value { return sqltypes.NewVarChar(fmt.Sprintf("%d", i)) },
    85  	func(i int) sqltypes.Value { return sqltypes.NewVarChar(fmt.Sprintf("  %f aa", float64(i))) },
    86  }
    87  
    88  var randomGenerators = []func() sqltypes.Value{
    89  	randomNull,
    90  	randomInt8,
    91  	randomInt32,
    92  	randomInt64,
    93  	randomUint64,
    94  	randomUint32,
    95  	randomVarChar,
    96  	randomComplexVarChar,
    97  }
    98  
    99  func randomValue() sqltypes.Value {
   100  	r := rand.Intn(len(randomGenerators))
   101  	return randomGenerators[r]()
   102  }
   103  
   104  func randomNull() sqltypes.Value    { return sqltypes.NULL }
   105  func randomInt8() sqltypes.Value    { return sqltypes.NewInt8(int8(rand.Intn(255))) }
   106  func randomInt32() sqltypes.Value   { return sqltypes.NewInt32(rand.Int31()) }
   107  func randomInt64() sqltypes.Value   { return sqltypes.NewInt64(rand.Int63()) }
   108  func randomUint32() sqltypes.Value  { return sqltypes.NewUint32(rand.Uint32()) }
   109  func randomUint64() sqltypes.Value  { return sqltypes.NewUint64(rand.Uint64()) }
   110  func randomVarChar() sqltypes.Value { return sqltypes.NewVarChar(fmt.Sprintf("%d", rand.Int63())) }
   111  func randomComplexVarChar() sqltypes.Value {
   112  	return sqltypes.NewVarChar(fmt.Sprintf(" \t %f apa", float64(rand.Intn(1000))*1.10))
   113  }