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// Copyright 2015-2018 Parity Technologies (UK) Ltd.
// This file is part of Parity.
//
// SPDX-License-Identifier: MIT
import abi from '@parity/shared/lib/contracts/abi/eip20';
import { action, computed, observable } from 'mobx';
import { BigNumber } from 'bignumber.js';
import { blockNumber$, makeContract$, post$ } from '@parity/light.js';
import { toWei } from '@parity/api/lib/util/wei';
import parityStore from './parityStore';
import tokensStore from './tokensStore';
const DEFAULT_GAS = new BigNumber(21000); // Default gas amount to show
const GAS_MULT_FACTOR = 1.2; // Since estimateGas is not always accurate, we add a 120% factor for buffer.
@observable blockNumber; // Current block number, used to calculate tx confirmations.
@observable estimated = DEFAULT_GAS; // Estimated gas amount for this transaction.
@observable tokenAddress; // 'ETH', or the token contract address
tx = {}; // The actual tx we are sending. No need to be observable.
@observable txStatus; // Status of the tx, see wiki for details.
if (!this.requestId) {
return Promise.reject(
new Error('The requestId has not been generated yet.')
);
}
// Since we accepted this request, we also start to listen to blockNumber,
// to calculate the number of confirmations
this.subscription = blockNumber$().subscribe(this.setBlockNumber);
return parityStore.api.signer.confirmRequest(
this.requestId,
null,
password
);
/**
* Back to defaults.
*/
clear = () => {
this.tx.amount = 0;
this.tx.to = '';
if (this.subscription) {
this.subscription.unsubscribe();
}
};
/**
* Get the number of confirmations our transaction has.
*/
if (!this.txStatus || !this.txStatus.confirmed) {
return -1;
}
return this.blockNumber - +this.txStatus.confirmed.blockNumber;
}
* If it's a token, then return the makeContract$ object.
*/
@computed
get contract () {
if (this.tokenAddress === 'ETH') {
return null;
}
return makeContract$(this.tokenAddress, abi);
}
/**
* Estimate the amount of gas for our transaction.
estimateGas = () => {
if (this.tokenAddress === 'ETH') {
return this.estimateGasForEth(this.txForEth);
return this.estimateGasForErc20(this.txForErc20);
/**
* Estimate gas to transfer in ERC20 contract. Expensive function, so we
* memoize it.
*/
estimateGasForErc20 = memoize(txForErc20 => {
return this.contract.contractObject.instance.transfer
.estimateGas(txForErc20.options, txForErc20.args)
.then(this.setEstimated)
.catch(noop);
}, JSON.stringify);
/**
* Estimate gas to transfer to an ETH address. Expensive function, so we
* memoize it.
*/
estimateGasForEth = memoize(txForEth => {
.estimateGas(txForEth)
.then(this.setEstimated)
.catch(noop);
}, JSON.stringify);
send = () => {
const send$ =
this.tokenAddress === 'ETH'
? post$(this.txForEth)
: this.contract.transfer$(
...this.txForErc20.args,
this.txForErc20.options
);
send$.subscribe(txStatus => {
if (txStatus.requested) {
this.requestId = txStatus.requested;
}
this.setTxStatus(txStatus);
});
};
if (!this.requestId) {
return Promise.reject(
new Error('The requestId has not been generated yet.')
);
}
return parityStore.api.signer.rejectRequest(this.requestId);
return tokensStore.tokens[this.tokenAddress];
/**
* This.tx is a user-friendly tx object. We convert it now as it can be
* passed to makeContract$(...).
*/
@computed
get txForErc20 () {
return {
args: [
this.tx.to,
new BigNumber(10).pow(this.token.decimals)
)
options: {
gasPrice: toWei(this.tx.gasPrice, 'shannon') // shannon == gwei
}
};
}
/**
* This.tx is a user-friendly tx object. We convert it now as it can be
* passed to post$(tx).
*/
@computed
get txForEth () {
return {
gasPrice: toWei(this.tx.gasPrice, 'shannon'), // shannon == gwei
to: this.tx.to,
value: toWei(this.tx.amount.toString())
};
}
setBlockNumber = blockNumber => {
this.blockNumber = blockNumber;
setEstimated = estimated => {
this.estimated = estimated.mul(GAS_MULT_FACTOR);
setTokenAddress = tokenAddress => {
this.tokenAddress = tokenAddress;
@action
setTxStatus = txStatus => {
this.txStatus = txStatus;
};
}
export default new SendStore();