ipld-eth-server/pkg/transformers/price_feeds/fetcher.go
2018-09-04 16:19:03 -05:00

56 lines
1.7 KiB
Go

// Copyright © 2018 Vulcanize
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package price_feeds
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"
"github.com/vulcanize/vulcanizedb/pkg/transformers/shared"
"math/big"
)
type IPriceFeedFetcher interface {
FetchLogValues(blockNumber int64) ([]types.Log, error)
}
type PriceFeedFetcher struct {
blockChain core.BlockChain
contractAddresses []string
}
func NewPriceFeedFetcher(blockChain core.BlockChain, contractAddresses []string) PriceFeedFetcher {
return PriceFeedFetcher{
blockChain: blockChain,
contractAddresses: contractAddresses,
}
}
func (fetcher PriceFeedFetcher) FetchLogValues(blockNumber int64) ([]types.Log, error) {
var addresses []common.Address
for _, addr := range fetcher.contractAddresses {
addresses = append(addresses, common.HexToAddress(addr))
}
n := big.NewInt(blockNumber)
query := ethereum.FilterQuery{
FromBlock: n,
ToBlock: n,
Addresses: addresses,
Topics: [][]common.Hash{{common.HexToHash(shared.LogValueSignature)}},
}
return fetcher.blockChain.GetEthLogsWithCustomQuery(query)
}