bench_test.go

Documentation: github.com/cockroachdb/apd/v3

     1  // Copyright 2017 The Cockroach Authors.
     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
    12  // implied. See the License for the specific language governing
    13  // permissions and limitations under the License.
    14  
    15  package apd
    16  
    17  import (
    18  	"bytes"
    19  	"fmt"
    20  	"math/rand"
    21  	"testing"
    22  )
    23  
    24  // runBenches benchmarks a given function on random decimals on combinations of
    25  // three parameters:
    26  //
    27  //	precision:    desired output precision
    28  //	inScale:      the scale of the input decimal: the absolute value will be between
    29  //	              10^inScale and 10^(inScale+1)
    30  //	inNumDigits:  number of digits in the input decimal; if negative the number
    31  //	              will be negative and the number of digits are the absolute value.
    32  func runBenches(
    33  	b *testing.B, precision, inScale, inNumDigits []int, fn func(*testing.B, *Context, *Decimal),
    34  ) {
    35  	for _, p := range precision {
    36  		ctx := BaseContext.WithPrecision(uint32(p))
    37  		for _, s := range inScale {
    38  			for _, d := range inNumDigits {
    39  				numDigits := d
    40  				negative := false
    41  				if d < 0 {
    42  					numDigits = -d
    43  					negative = true
    44  				}
    45  				if numDigits > p {
    46  					// Skip cases where we have more digits than the desired precision.
    47  					continue
    48  				}
    49  
    50  				// Generate some random numbers with the given number of digits.
    51  				nums := make([]Decimal, 20)
    52  				for i := range nums {
    53  					var buf bytes.Buffer
    54  					if negative {
    55  						buf.WriteByte('-')
    56  					}
    57  					buf.WriteByte('1' + byte(rand.Intn(9)))
    58  					for j := 1; j < numDigits; j++ {
    59  						buf.WriteByte('0' + byte(rand.Intn(10)))
    60  					}
    61  					if _, _, err := nums[i].SetString(buf.String()); err != nil {
    62  						b.Fatal(err)
    63  					}
    64  					nums[i].Exponent = int32(s - numDigits)
    65  				}
    66  				b.Run(
    67  					fmt.Sprintf("P%d/S%d/D%d", p, s, d),
    68  					func(b *testing.B) {
    69  						for i := 0; i <= b.N; i++ {
    70  							fn(b, ctx, &nums[i%len(nums)])
    71  						}
    72  					},
    73  				)
    74  			}
    75  		}
    76  	}
    77  }
    78  
    79  func BenchmarkExp(b *testing.B) {
    80  	precision := []int{5, 10, 100}
    81  	scale := []int{-4, -1, 2}
    82  	digits := []int{-100, -10, -2, 2, 10, 100}
    83  	runBenches(
    84  		b, precision, scale, digits,
    85  		func(b *testing.B, ctx *Context, x *Decimal) {
    86  			if _, err := ctx.Exp(&Decimal{}, x); err != nil {
    87  				b.Fatal(err)
    88  			}
    89  		},
    90  	)
    91  }
    92  
    93  func BenchmarkLn(b *testing.B) {
    94  	precision := []int{2, 10, 100}
    95  	scale := []int{-100, -10, -2, 2, 10, 100}
    96  	digits := []int{2, 10, 100}
    97  	runBenches(
    98  		b, precision, scale, digits,
    99  		func(b *testing.B, ctx *Context, x *Decimal) {
   100  			if _, err := ctx.Ln(&Decimal{}, x); err != nil {
   101  				b.Fatal(err)
   102  			}
   103  		},
   104  	)
   105  }
   106  
   107  func BenchmarkDecimalString(b *testing.B) {
   108  	rng := rand.New(rand.NewSource(461210934723948))
   109  	corpus := func() []Decimal {
   110  		res := make([]Decimal, 8192)
   111  		for i := range res {
   112  			_, err := res[i].SetFloat64(rng.Float64())
   113  			if err != nil {
   114  				b.Fatal(err)
   115  			}
   116  		}
   117  		return res
   118  	}()
   119  	b.ResetTimer()
   120  	b.ReportAllocs()
   121  	for i := 0; i < b.N; i++ {
   122  		_ = corpus[rng.Intn(len(corpus))].String()
   123  	}
   124  }
   125  
   126  func BenchmarkDecimalSetFloat(b *testing.B) {
   127  	rng := rand.New(rand.NewSource(461210934723948))
   128  	corpus := func() []float64 {
   129  		res := make([]float64, 8192)
   130  		for i := range res {
   131  			res[i] = rng.ExpFloat64()
   132  		}
   133  		return res
   134  	}()
   135  	b.ResetTimer()
   136  	b.ReportAllocs()
   137  	for i := 0; i < b.N; i++ {
   138  		var d Decimal
   139  		_, err := d.SetFloat64(corpus[rng.Intn(len(corpus))])
   140  		if err != nil {
   141  			b.Fatal(err)
   142  		}
   143  	}
   144  }
   145
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