ipld-eth-server/examples/erc20_watcher/every_block/getter.go

65 lines
2.3 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 og 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 Og ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package every_block
import (
"math/big"
"github.com/vulcanize/vulcanizedb/examples/generic"
"github.com/vulcanize/vulcanizedb/pkg/core"
)
// Getter serves as a higher level data fetcher that invokes its underlying Fetcher methods for a given contract method
// Interface definition for a Getter
type ERC20GetterInterface interface {
GetTotalSupply(contractAbi, contractAddress string, blockNumber int64) (big.Int, error)
GetBalance(contractAbi, contractAddress string, blockNumber int64, methodArgs []interface{}) (big.Int, error)
GetAllowance(contractAbi, contractAddress string, blockNumber int64, methodArgs []interface{}) (big.Int, error)
GetBlockChain() core.BlockChain
}
// Getter struct
type Getter struct {
fetcher generic.Fetcher
}
// Initializes and returns a Getter with the given blockchain
func NewGetter(blockChain core.BlockChain) Getter {
return Getter{
fetcher: generic.Fetcher{
BlockChain: blockChain,
},
}
}
// Public getter methods for calling contract methods
func (g Getter) GetTotalSupply(contractAbi, contractAddress string, blockNumber int64) (big.Int, error) {
return g.fetcher.FetchBigInt("totalSupply", contractAbi, contractAddress, blockNumber, nil)
}
func (g Getter) GetBalance(contractAbi, contractAddress string, blockNumber int64, methodArgs []interface{}) (big.Int, error) {
return g.fetcher.FetchBigInt("balanceOf", contractAbi, contractAddress, blockNumber, methodArgs)
}
func (g Getter) GetAllowance(contractAbi, contractAddress string, blockNumber int64, methodArgs []interface{}) (big.Int, error) {
return g.fetcher.FetchBigInt("allowance", contractAbi, contractAddress, blockNumber, methodArgs)
}
// Method to retrieve the Getter's blockchain
func (g Getter) GetBlockChain() core.BlockChain {
return g.fetcher.BlockChain
}