ipld-eth-server/pkg/transformers/shared/log_fetcher.go
2019-01-24 14:41:30 -06:00

59 lines
1.8 KiB
Go

// VulcanizeDB
// Copyright © 2018 Vulcanize
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program 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 Affero General Public License for more details.
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
package shared
import (
"github.com/ethereum/go-ethereum"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/core/types"
"github.com/vulcanize/vulcanizedb/pkg/core"
)
type LogFetcher interface {
FetchLogs(contractAddresses []common.Address, topics []common.Hash, missingHeader core.Header) ([]types.Log, error)
}
type Fetcher struct {
blockChain core.BlockChain
}
func NewFetcher(blockchain core.BlockChain) *Fetcher {
return &Fetcher{
blockChain: blockchain,
}
}
// Checks all topic0s, on all addresses, fetching matching logs for the given header
func (fetcher Fetcher) FetchLogs(addresses []common.Address, topic0s []common.Hash, header core.Header) ([]types.Log, error) {
blockHash := common.HexToHash(header.Hash)
query := ethereum.FilterQuery{
BlockHash: &blockHash,
Addresses: addresses,
// Search for _any_ of the topics in topic0 position; see docs on `FilterQuery`
Topics: [][]common.Hash{topic0s},
}
logs, err := fetcher.blockChain.GetEthLogsWithCustomQuery(query)
if err != nil {
// TODO review aggregate fetching error handling
return []types.Log{}, err
}
return logs, nil
}