mirror of https://github.com/certusone/vouch.git
76 lines
2.6 KiB
Go
76 lines
2.6 KiB
Go
// Copyright © 2020 Attestant Limited.
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package best
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import (
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"context"
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"sync"
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"time"
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eth2client "github.com/attestantio/go-eth2-client"
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spec "github.com/attestantio/go-eth2-client/spec/phase0"
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"golang.org/x/sync/semaphore"
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)
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// BeaconBlockProposal provies the best beacon block proposal from a number of beacon nodes.
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func (s *Service) BeaconBlockProposal(ctx context.Context, slot uint64, randaoReveal []byte, graffiti []byte) (*spec.BeaconBlock, error) {
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var mu sync.Mutex
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bestScore := float64(0)
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var bestProposal *spec.BeaconBlock
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sem := semaphore.NewWeighted(s.processConcurrency)
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var wg sync.WaitGroup
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for name, provider := range s.beaconBlockProposalProviders {
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wg.Add(1)
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go func(ctx context.Context, sem *semaphore.Weighted, wg *sync.WaitGroup, name string, provider eth2client.BeaconBlockProposalProvider, mu *sync.Mutex) {
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defer wg.Done()
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if err := sem.Acquire(ctx, 1); err != nil {
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log.Error().Err(err).Msg("Failed to acquire semaphore")
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return
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}
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defer sem.Release(1)
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log := log.With().Str("provider", name).Uint64("slot", slot).Logger()
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opCtx, cancel := context.WithTimeout(ctx, s.timeout)
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started := time.Now()
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proposal, err := provider.BeaconBlockProposal(opCtx, slot, randaoReveal, graffiti)
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s.clientMonitor.ClientOperation(name, "beacon block proposal", err == nil, time.Since(started))
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if err != nil {
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log.Warn().Err(err).Msg("Failed to obtain beacon block proposal")
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cancel()
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return
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}
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log.Trace().Dur("elapsed", time.Since(started)).Msg("Obtained beacon block proposal")
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cancel()
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// Obtain the slot of the block to which the proposal refers.
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// We use this to allow the scorer to score blocks with earlier parents lower.
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// TODO need a go-eth2-client provider to obtain this information.
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parentSlot := uint64(slot - 1)
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mu.Lock()
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score := scoreBeaconBlockProposal(ctx, name, parentSlot, proposal)
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if score > bestScore || bestProposal == nil {
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bestScore = score
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bestProposal = proposal
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}
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mu.Unlock()
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}(ctx, sem, &wg, name, provider, &mu)
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}
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wg.Wait()
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return bestProposal, nil
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}
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