bit_benchmark_test.go

Documentation: github.com/apache/arrow/go/v15/parquet/internal/utils

     1  // Licensed to the Apache Software Foundation (ASF) under one
     2  // or more contributor license agreements.  See the NOTICE file
     3  // distributed with this work for additional information
     4  // regarding copyright ownership.  The ASF licenses this file
     5  // to you under the Apache License, Version 2.0 (the
     6  // "License"); you may not use this file except in compliance
     7  // with the License.  You may obtain a copy of the License at
     8  //
     9  // http://www.apache.org/licenses/LICENSE-2.0
    10  //
    11  // Unless required by applicable law or agreed to in writing, software
    12  // distributed under the License is distributed on an "AS IS" BASIS,
    13  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    14  // See the License for the specific language governing permissions and
    15  // limitations under the License.
    16  
    17  package utils_test
    18  
    19  import (
    20  	"strconv"
    21  	"testing"
    22  
    23  	"github.com/apache/arrow/go/v15/arrow/bitutil"
    24  	"github.com/apache/arrow/go/v15/internal/bitutils"
    25  	"github.com/apache/arrow/go/v15/parquet/internal/testutils"
    26  )
    27  
    28  type linearBitRunReader struct {
    29  	reader *bitutil.BitmapReader
    30  }
    31  
    32  func (l linearBitRunReader) NextRun() bitutils.BitRun {
    33  	r := bitutils.BitRun{0, l.reader.Set()}
    34  	for l.reader.Pos() < l.reader.Len() && l.reader.Set() == r.Set {
    35  		r.Len++
    36  		l.reader.Next()
    37  	}
    38  	return r
    39  }
    40  
    41  func randomBitsBuffer(nbits, setPct int64) []byte {
    42  	rag := testutils.NewRandomArrayGenerator(23)
    43  	prob := float64(0)
    44  	if setPct != -1 {
    45  		prob = float64(setPct) / 100.0
    46  	}
    47  	buf := make([]byte, int(bitutil.BytesForBits(nbits)))
    48  	rag.GenerateBitmap(buf, nbits, prob)
    49  
    50  	if setPct == -1 {
    51  		wr := bitutil.NewBitmapWriter(buf, 0, int(nbits))
    52  		for i := int64(0); i < nbits; i++ {
    53  			if i%2 == 0 {
    54  				wr.Set()
    55  			} else {
    56  				wr.Clear()
    57  			}
    58  			wr.Next()
    59  		}
    60  	}
    61  	return buf
    62  }
    63  
    64  func testBitRunReader(rdr bitutils.BitRunReader) (setTotal int64) {
    65  	for {
    66  		br := rdr.NextRun()
    67  		if br.Len == 0 {
    68  			break
    69  		}
    70  		if br.Set {
    71  			setTotal += br.Len
    72  		}
    73  	}
    74  	return
    75  }
    76  
    77  func BenchmarkBitRunReader(b *testing.B) {
    78  	const numBits = 4096
    79  	for _, pct := range []int64{1, 0, 10, 25, 50, 60, 75, 99} {
    80  		buf := randomBitsBuffer(numBits, pct)
    81  		b.Run("set pct "+strconv.Itoa(int(pct)), func(b *testing.B) {
    82  			b.Run("linear", func(b *testing.B) {
    83  				b.SetBytes(numBits / 8)
    84  				for i := 0; i < b.N; i++ {
    85  					rdr := linearBitRunReader{bitutil.NewBitmapReader(buf, 0, numBits)}
    86  					testBitRunReader(rdr)
    87  				}
    88  			})
    89  			b.Run("internal", func(b *testing.B) {
    90  				b.SetBytes(numBits / 8)
    91  				for i := 0; i < b.N; i++ {
    92  					rdr := bitutils.NewBitRunReader(buf, 0, numBits)
    93  					testBitRunReader(rdr)
    94  				}
    95  			})
    96  		})
    97  	}
    98  }
    99  
   100  func testSetBitRunReader(rdr bitutils.SetBitRunReader) (setTotal int64) {
   101  	for {
   102  		br := rdr.NextRun()
   103  		if br.Length == 0 {
   104  			break
   105  		}
   106  		setTotal += br.Length
   107  	}
   108  	return
   109  }
   110  
   111  func BenchmarkSetBitRunReader(b *testing.B) {
   112  	const numBits = 4096
   113  	for _, pct := range []int64{1, 0, 10, 25, 50, 60, 75, 99} {
   114  		buf := randomBitsBuffer(numBits, pct)
   115  		b.Run("set pct "+strconv.Itoa(int(pct)), func(b *testing.B) {
   116  			b.Run("reader", func(b *testing.B) {
   117  				b.SetBytes(numBits / 8)
   118  				for i := 0; i < b.N; i++ {
   119  					rdr := bitutils.NewSetBitRunReader(buf, 0, numBits)
   120  					testSetBitRunReader(rdr)
   121  				}
   122  			})
   123  			b.Run("reverse rdr", func(b *testing.B) {
   124  				b.SetBytes(numBits / 8)
   125  				for i := 0; i < b.N; i++ {
   126  					rdr := bitutils.NewReverseSetBitRunReader(buf, 0, numBits)
   127  					testSetBitRunReader(rdr)
   128  				}
   129  			})
   130  		})
   131  	}
   132  }
   133
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