You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: bench_test.go
    path of file: ./repos/go-ethereum/eth/filters
    
    the code of the file until where you have to start completion: // Copyright 2017 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.

package filters

import (
	"context"
	"fmt"
	"testing"
	"time"

	"github.com/ethereum/go-ethereum/common"
	"github.com/ethereum/go-ethereum/common/bitutil"
	"github.com/ethereum/go-ethereum/core/bloombits"
	"github.com/ethereum/go-ethereum/core/rawdb"
	"github.com/ethereum/go-ethereum/core/types"
	"github.com/ethereum/go-ethereum/ethdb"
	"github.com/ethereum/go-ethereum/node"
)

func BenchmarkBloomBits512(b *testing.B) {
	benchmarkBloomBits(b, 512)
}

func BenchmarkBloomBits1k(b *testing.B) {
	benchmarkBloomBits(b, 1024)
}

func BenchmarkBloomBits2k(b *testing.B) {
	benchmarkBloomBits(b, 2048)
}

func BenchmarkBloomBits4k(b *testing.B) {
	benchmarkBloomBits(b, 4096)
}

func BenchmarkBloomBits8k(b *testing.B) {
	benchmarkBloomBits(b, 8192)
}

func BenchmarkBloomBits16k(b *testing.B) {
	benchmarkBloomBits(b, 16384)
}

func BenchmarkBloomBits32k(b *testing.B) {
	benchmarkBloomBits(b, 32768)
}

const benchFilterCnt = 2000

func benchmarkBloomBits(b *testing.B, sectionSize uint64) {
	b.Skip("test disabled: this tests presume (and modify) an existing datadir.")
	benchDataDir := node.DefaultDataDir() + "/geth/chaindata"
	b.Log("Running bloombits benchmark   section size:", sectionSize)

	db, err := rawdb.NewLevelDBDatabase(benchDataDir, 128, 1024, "", false)
	if err != nil {
		b.Fatalf("error opening database at %v: %v", benchDataDir, err)
	}
	head := rawdb.ReadHeadBlockHash(db)
	if head == (common.Hash{}) {
		b.Fatalf("chain data not found at %v", benchDataDir)
	}

	clearBloomBits(db)
	b.Log("Generating bloombits data...")
	headNum := rawdb.ReadHeaderNumber(db, head)
	if headNum == nil || *headNum < sectionSize+512 {
		b.Fatalf("not enough blocks for running a benchmark")
	}

	start := time.Now()
	cnt := (*headNum - 512) / sectionSize
	var dataSize, compSize uint64
	for sectionIdx := uint64(0); sectionIdx < cnt; sectionIdx++ {
		bc, err :
    
func benchmarkBloomBits(b *testing.B, sectionSize uint64) {
	b.Skip("test disabled: this tests presume (and modify) an existing datadir.")
	benchDataDir := node.DefaultDataDir() + "/geth/chaindata"
	b.Log("Running bloombits benchmark   section size:", sectionSize)

	db, err := rawdb.NewLevelDBDatabase(benchDataDir, 128, 1024, "", false)
	if err != nil {
		b.Fatalf("error opening database at %v: %v", benchDataDir, err)
	}
	head := rawdb.ReadHeadBlockHash(db)
	if head == (common.Hash{}) {
		b.Fatalf("chain data not found at %v", benchDataDir)
	}

	clearBloomBits(db)
	b.Log("Generating bloombits data...")
	headNum := rawdb.ReadHeaderNumber(db, head)
	if headNum == nil || *headNum < sectionSize+512 {
		b.Fatalf("not enough blocks for running a benchmark")
	}

	start := time.Now()
	cnt := (*headNum - 512) / sectionSize
	var dataSize, compSize uint64
	for sectionIdx := uint64(0); sectionIdx < cnt; sectionIdx++ {
		bc, err := bloombits.NewGenerator(uint(sectionSize))
		if err != nil {
			b.Fatalf("failed to create generator: %v", err)
		}
		var header *types.Header
		for i := sectionIdx * sectionSize; i < (sectionIdx+1)*sectionSize; i++ {
			hash := rawdb.ReadCanonicalHash(db, i)
			if header = rawdb.ReadHeader(db, hash, i); header == nil {
				b.Fatalf("Error creating bloomBits data")
				return
			}
			bc.AddBloom(uint(i-sectionIdx*sectionSize), header.Bloom)
		}
		sectionHead := rawdb.ReadCanonicalHash(db, (sectionIdx+1)*sectionSize-1)
		for i := 0; i < types.BloomBitLength; i++ {
			data, err := bc.Bitset(uint(i))
			if err != nil {
				b.Fatalf("failed to retrieve bitset: %v", err)
			}
			comp := bitutil.CompressBytes(data)
			dataSize += uint64(len(data))
			compSize += uint64(len(comp))
			rawdb.WriteBloomBits(db, uint(i), sectionIdx, sectionHead, comp)
		}
		//if sectionIdx%50 == 0 {
		//	b.Log(" section", sectionIdx, "/", cnt)
		//}
	}

	d := time.Since(start)
	b.Log("Finished generating bloombits data")
	b.Log(" ", d, "total  ", d/time.Duration(cnt*sectionSize), "per block")
	b.Log(" data size:", dataSize, "  compressed size:", compSize, "  compression ratio:", float64(compSize)/float64(dataSize))

	b.Log("Running filter benchmarks...")
	start = time.Now()

	var (
		backend *testBackend
		sys     *FilterSystem
	)
	for i := 0; i < benchFilterCnt; i++ {
		if i%20 == 0 {
			db.Close()
			db, _ = rawdb.NewLevelDBDatabase(benchDataDir, 128, 1024, "", false)
			backend = &testBackend{db: db, sections: cnt}
			sys = NewFilterSystem(backend, Config{})
		}
		var addr common.Address
		addr[0] = byte(i)
		addr[1] = byte(i / 256)
		filter := sys.NewRangeFilter(0, int64(cnt*sectionSize-1), []common.Address{addr}, nil)
		if _, err := filter.Logs(context.Background()); err != nil {
			b.Error("filter.Logs error:", err)
		}
	}

	d = time.Since(start)
	b.Log("Finished running filter benchmarks")
	b.Log(" ", d, "total  ", d/time.Duration(benchFilterCnt), "per address", d*time.Duration(1000000)/time.Duration(benchFilterCnt*cnt*sectionSize), "per million blocks")
	db.Close()
}