ipld-eth-server/pkg/contract_watcher/header/fetcher/fetcher.go

72 lines
2.2 KiB
Go

// VulcanizeDB
// Copyright © 2019 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 fetcher
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"
)
// Fetcher is the fetching interface
type Fetcher interface {
FetchLogs(contractAddresses []string, topics []common.Hash, missingHeader core.Header) ([]types.Log, error)
}
type fetcher struct {
blockChain core.BlockChain
}
// NewFetcher returns a new Fetcher
func NewFetcher(blockchain core.BlockChain) Fetcher {
return &fetcher{
blockChain: blockchain,
}
}
// FetchLogs checks all topic0s, on all addresses, fetching matching logs for the given header
func (fetcher *fetcher) FetchLogs(contractAddresses []string, topic0s []common.Hash, header core.Header) ([]types.Log, error) {
addresses := hexStringsToAddresses(contractAddresses)
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
}
func hexStringsToAddresses(hexStrings []string) []common.Address {
var addresses []common.Address
for _, hexString := range hexStrings {
address := common.HexToAddress(hexString)
addresses = append(addresses, address)
}
return addresses
}