Method SubscribeLogs

protocols/cpc/filters/filter_system.go:198–232

SubscribeLogs creates a subscription that will write all logs matching the given criteria to the given logs channel. Default value for the from and to block is "latest". If the fromBlock > toBlock an error is returned.

(crit cpchain.FilterQuery, logs chan []*types.Log)

// given criteria to the given logs channel. Default value for the from and to
// block is "latest". If the fromBlock > toBlock an error is returned.
func (es *EventSystem) SubscribeLogs(crit cpchain.FilterQuery, logs chan []*types.Log) (*Subscription, error) {
	var from, to rpc.BlockNumber
	if crit.FromBlock == nil {
		from = rpc.LatestBlockNumber
	} else {
		from = rpc.BlockNumber(crit.FromBlock.Int64())
	}
	if crit.ToBlock == nil {
		to = rpc.LatestBlockNumber
	} else {
		to = rpc.BlockNumber(crit.ToBlock.Int64())
	}

	// only interested in pending logs
	if from == rpc.PendingBlockNumber && to == rpc.PendingBlockNumber {
		return es.subscribePendingLogs(crit, logs), nil
	}
	// only interested in new mined logs
	if from == rpc.LatestBlockNumber && to == rpc.LatestBlockNumber {
		return es.subscribeLogs(crit, logs), nil
	}
	// only interested in mined logs within a specific block range
	if from >= 0 && to >= 0 && to >= from {
		return es.subscribeLogs(crit, logs), nil
	}
	// interested in mined logs from a specific block number, new logs and pending logs
	if from >= rpc.LatestBlockNumber && to == rpc.PendingBlockNumber {
		return es.subscribeMinedPendingLogs(crit, logs), nil
	}
	// interested in logs from a specific block number to new mined blocks
	if from >= 0 && to == rpc.LatestBlockNumber {
		return es.subscribeLogs(crit, logs), nil
	}
	return nil, fmt.Errorf("invalid from and to block combination: from > to")
}

// subscribeMinedPendingLogs creates a subscription that returned mined and
// pending logs that match the given criteria.