github.com/prysmaticlabs/prysm@v1.4.4/beacon-chain/core/epoch/precompute/new.go (about)

     1  // Package precompute provides gathering of nicely-structured
     2  // data important to feed into epoch processing, such as attesting
     3  // records and balances, for faster computation.
     4  package precompute
     5  
     6  import (
     7  	"context"
     8  
     9  	"github.com/pkg/errors"
    10  	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
    11  	iface "github.com/prysmaticlabs/prysm/beacon-chain/state/interface"
    12  	"github.com/prysmaticlabs/prysm/shared/params"
    13  	"go.opencensus.io/trace"
    14  )
    15  
    16  // New gets called at the beginning of process epoch cycle to return
    17  // pre computed instances of validators attesting records and total
    18  // balances attested in an epoch.
    19  func New(ctx context.Context, state iface.BeaconState) ([]*Validator, *Balance, error) {
    20  	ctx, span := trace.StartSpan(ctx, "precomputeEpoch.New")
    21  	defer span.End()
    22  
    23  	pValidators := make([]*Validator, state.NumValidators())
    24  	pBal := &Balance{}
    25  
    26  	currentEpoch := helpers.CurrentEpoch(state)
    27  	prevEpoch := helpers.PrevEpoch(state)
    28  
    29  	if err := state.ReadFromEveryValidator(func(idx int, val iface.ReadOnlyValidator) error {
    30  		// Was validator withdrawable or slashed
    31  		withdrawable := prevEpoch+1 >= val.WithdrawableEpoch()
    32  		pVal := &Validator{
    33  			IsSlashed:                    val.Slashed(),
    34  			IsWithdrawableCurrentEpoch:   withdrawable,
    35  			CurrentEpochEffectiveBalance: val.EffectiveBalance(),
    36  		}
    37  		// Was validator active current epoch
    38  		if helpers.IsActiveValidatorUsingTrie(val, currentEpoch) {
    39  			pVal.IsActiveCurrentEpoch = true
    40  			pBal.ActiveCurrentEpoch += val.EffectiveBalance()
    41  		}
    42  		// Was validator active previous epoch
    43  		if helpers.IsActiveValidatorUsingTrie(val, prevEpoch) {
    44  			pVal.IsActivePrevEpoch = true
    45  			pBal.ActivePrevEpoch += val.EffectiveBalance()
    46  		}
    47  		// Set inclusion slot and inclusion distance to be max, they will be compared and replaced
    48  		// with the lower values
    49  		pVal.InclusionSlot = params.BeaconConfig().FarFutureSlot
    50  		pVal.InclusionDistance = params.BeaconConfig().FarFutureSlot
    51  
    52  		pValidators[idx] = pVal
    53  		return nil
    54  	}); err != nil {
    55  		return nil, nil, errors.Wrap(err, "failed to initialize precompute")
    56  	}
    57  	return pValidators, pBal, nil
    58  }