Method filterNMiners

blockproducer/metastate.go:695–732

(
	tx *types.CreateDatabase,
	user proto.AccountAddress,
	minerCount int)

}

func (s *metaState) filterNMiners(
	tx *types.CreateDatabase,
	user proto.AccountAddress,
	minerCount int) (
	m MinerInfos, err error,
) {
	// create new merged map
	allProviderMap := make(map[proto.AccountAddress]*types.ProviderProfile)
	for k, v := range s.readonly.provider {
		allProviderMap[k] = v
	}
	for k, v := range s.dirty.provider {
		if v == nil {
			delete(allProviderMap, k)
		} else {
			allProviderMap[k] = v
		}
	}

	// delete selected target miners
	for _, m := range tx.ResourceMeta.TargetMiners {
		delete(allProviderMap, m)
	}

	// suppose 1/4 miners match
	newMiners := make(MinerInfos, 0, len(allProviderMap)/4)
	// filter all miners to slice and sort
	for _, po := range allProviderMap {
		newMiners, _ = filterAndAppendMiner(newMiners, po, tx, user)
	}
	if newMiners.Len() < minerCount {
		err = ErrNoEnoughMiner
		return
	}

	sort.Slice(newMiners, newMiners.Less)
	return newMiners[:minerCount], nil
}

func filterAndAppendMiner(
	miners MinerInfos,