plugeth/les/bloombits.go
Felföldi Zsolt ca376ead88 les, light: LES/2 protocol version (#14970)
This PR implements the new LES protocol version extensions:

* new and more efficient Merkle proofs reply format (when replying to
  a multiple Merkle proofs request, we just send a single set of trie
  nodes containing all necessary nodes)
* BBT (BloomBitsTrie) works similarly to the existing CHT and contains
  the bloombits search data to speed up log searches
* GetTxStatusMsg returns the inclusion position or the
  pending/queued/unknown state of a transaction referenced by hash
* an optional signature of new block data (number/hash/td) can be
  included in AnnounceMsg to provide an option for "very light
  clients" (mobile/embedded devices) to skip expensive Ethash check
  and accept multiple signatures of somewhat trusted servers (still a
  lot better than trusting a single server completely and retrieving
  everything through RPC). The new client mode is not implemented in
  this PR, just the protocol extension.
2017-10-24 15:19:09 +02:00

85 lines
2.8 KiB
Go

// 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 les
import (
"time"
"github.com/ethereum/go-ethereum/common/bitutil"
"github.com/ethereum/go-ethereum/light"
)
const (
// bloomServiceThreads is the number of goroutines used globally by an Ethereum
// instance to service bloombits lookups for all running filters.
bloomServiceThreads = 16
// bloomFilterThreads is the number of goroutines used locally per filter to
// multiplex requests onto the global servicing goroutines.
bloomFilterThreads = 3
// bloomRetrievalBatch is the maximum number of bloom bit retrievals to service
// in a single batch.
bloomRetrievalBatch = 16
// bloomRetrievalWait is the maximum time to wait for enough bloom bit requests
// to accumulate request an entire batch (avoiding hysteresis).
bloomRetrievalWait = time.Microsecond * 100
)
// startBloomHandlers starts a batch of goroutines to accept bloom bit database
// retrievals from possibly a range of filters and serving the data to satisfy.
func (eth *LightEthereum) startBloomHandlers() {
for i := 0; i < bloomServiceThreads; i++ {
go func() {
for {
select {
case <-eth.shutdownChan:
return
case request := <-eth.bloomRequests:
task := <-request
task.Bitsets = make([][]byte, len(task.Sections))
compVectors, err := light.GetBloomBits(task.Context, eth.odr, task.Bit, task.Sections)
if err == nil {
for i, _ := range task.Sections {
if blob, err := bitutil.DecompressBytes(compVectors[i], int(light.BloomTrieFrequency/8)); err == nil {
task.Bitsets[i] = blob
} else {
task.Error = err
}
}
} else {
task.Error = err
}
request <- task
}
}
}()
}
}
const (
// bloomConfirms is the number of confirmation blocks before a bloom section is
// considered probably final and its rotated bits are calculated.
bloomConfirms = 256
// bloomThrottling is the time to wait between processing two consecutive index
// sections. It's useful during chain upgrades to prevent disk overload.
bloomThrottling = 100 * time.Millisecond
)