106 lines
3.3 KiB
Go
106 lines
3.3 KiB
Go
// Copyright 2018 Vulcanize
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package every_block
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import (
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"fmt"
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"log"
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"math/big"
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"github.com/ethereum/go-ethereum/common"
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"github.com/vulcanize/vulcanizedb/pkg/core"
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)
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// Interface definition for a Fetcher
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type ERC20FetcherInterface interface {
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FetchBigInt(method, contractAbi, contractAddress string, blockNumber int64, methodArgs []interface{}) (big.Int, error)
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FetchBool(method, contractAbi, contractAddress string, blockNumber int64, methodArgs []interface{}) (bool, error)
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FetchAddress(method, contractAbi, contractAddress string, blockNumber int64, methodArgs []interface{}) (common.Address, error)
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GetBlockChain() core.BlockChain
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}
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// Initializes and returns a Fetcher with the given blockchain
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func NewFetcher(blockChain core.BlockChain) Fetcher {
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return Fetcher{
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BlockChain: blockChain,
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}
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}
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// Fetcher struct
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type Fetcher struct {
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BlockChain core.BlockChain
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ContractAbi string
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ContractAddress string
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}
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// Fetcher error
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type fetcherError struct {
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err string
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fetchMethod string
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}
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// Fetcher error method
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func (fe *fetcherError) Error() string {
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return fmt.Sprintf("Error fetching %s: %s", fe.fetchMethod, fe.err)
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}
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// Used to create a new Fetcher error for a given error and fetch method
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func newFetcherError(err error, fetchMethod string) *fetcherError {
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e := fetcherError{err.Error(), fetchMethod}
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log.Println(e.Error())
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return &e
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}
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// Method used to fetch big.Int result from contract
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func (f Fetcher) FetchBigInt(method, contractAbi, contractAddress string, blockNumber int64, methodArgs []interface{}) (big.Int, error) {
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var result = new(big.Int)
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err := f.BlockChain.FetchContractData(contractAbi, contractAddress, method, methodArgs, &result, blockNumber)
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if err != nil {
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return *result, newFetcherError(err, method)
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}
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return *result, nil
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}
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// Method used to fetch bool result from contract
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func (f Fetcher) FetchBool(method, contractAbi, contractAddress string, blockNumber int64, methodArgs []interface{}) (bool, error) {
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var result = new(bool)
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err := f.BlockChain.FetchContractData(contractAbi, contractAddress, method, methodArgs, &result, blockNumber)
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if err != nil {
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return *result, newFetcherError(err, method)
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}
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return *result, nil
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}
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// Method used to fetch address result from contract
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func (f Fetcher) FetchAddress(method, contractAbi, contractAddress string, blockNumber int64, methodArgs []interface{}) (common.Address, error) {
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var result = new(common.Address)
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err := f.BlockChain.FetchContractData(contractAbi, contractAddress, method, methodArgs, &result, blockNumber)
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if err != nil {
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return *result, newFetcherError(err, method)
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}
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return *result, nil
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}
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// Getter method for Fetcher's blockchain
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func (f Fetcher) GetBlockChain() core.BlockChain {
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return f.BlockChain
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}
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