github.com/MetalBlockchain/subnet-evm@v0.4.9/eth/bloombits.go (about)

     1  // (c) 2019-2020, Ava Labs, Inc.
     2  //
     3  // This file is a derived work, based on the go-ethereum library whose original
     4  // notices appear below.
     5  //
     6  // It is distributed under a license compatible with the licensing terms of the
     7  // original code from which it is derived.
     8  //
     9  // Much love to the original authors for their work.
    10  // **********
    11  // Copyright 2017 The go-ethereum Authors
    12  // This file is part of the go-ethereum library.
    13  //
    14  // The go-ethereum library is free software: you can redistribute it and/or modify
    15  // it under the terms of the GNU Lesser General Public License as published by
    16  // the Free Software Foundation, either version 3 of the License, or
    17  // (at your option) any later version.
    18  //
    19  // The go-ethereum library is distributed in the hope that it will be useful,
    20  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    21  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    22  // GNU Lesser General Public License for more details.
    23  //
    24  // You should have received a copy of the GNU Lesser General Public License
    25  // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
    26  
    27  package eth
    28  
    29  import (
    30  	"time"
    31  
    32  	"github.com/MetalBlockchain/subnet-evm/core/rawdb"
    33  	"github.com/ethereum/go-ethereum/common/bitutil"
    34  )
    35  
    36  const (
    37  	// bloomServiceThreads is the number of goroutines used globally by an Ethereum
    38  	// instance to service bloombits lookups for all running filters.
    39  	bloomServiceThreads = 16
    40  
    41  	// bloomFilterThreads is the number of goroutines used locally per filter to
    42  	// multiplex requests onto the global servicing goroutines.
    43  	bloomFilterThreads = 3
    44  
    45  	// bloomRetrievalBatch is the maximum number of bloom bit retrievals to service
    46  	// in a single batch.
    47  	bloomRetrievalBatch = 16
    48  
    49  	// bloomRetrievalWait is the maximum time to wait for enough bloom bit requests
    50  	// to accumulate request an entire batch (avoiding hysteresis).
    51  	bloomRetrievalWait = time.Duration(0)
    52  )
    53  
    54  // startBloomHandlers starts a batch of goroutines to accept bloom bit database
    55  // retrievals from possibly a range of filters and serving the data to satisfy.
    56  func (eth *Ethereum) startBloomHandlers(sectionSize uint64) {
    57  	for i := 0; i < bloomServiceThreads; i++ {
    58  		go func() {
    59  			for {
    60  				select {
    61  				case <-eth.closeBloomHandler:
    62  					return
    63  
    64  				case request := <-eth.bloomRequests:
    65  					task := <-request
    66  					task.Bitsets = make([][]byte, len(task.Sections))
    67  					for i, section := range task.Sections {
    68  						head := rawdb.ReadCanonicalHash(eth.chainDb, (section+1)*sectionSize-1)
    69  						if compVector, err := rawdb.ReadBloomBits(eth.chainDb, task.Bit, section, head); err == nil {
    70  							if blob, err := bitutil.DecompressBytes(compVector, int(sectionSize/8)); err == nil {
    71  								task.Bitsets[i] = blob
    72  							} else {
    73  								task.Error = err
    74  							}
    75  						} else {
    76  							task.Error = err
    77  						}
    78  					}
    79  					request <- task
    80  				}
    81  			}
    82  		}()
    83  	}
    84  }