ethers.js/lib/provider.js

161 lines
5.0 KiB
JavaScript

'use strict';
var utils = require('./utils.js');
var XMLHttpRequest = require('xmlhttprequest').XMLHttpRequest;
function Web3Connector(provider) {
if (!(this instanceof Web3Connector)) { throw new Error('missing new'); }
var nextMessageId = 1;
utils.defineProperty(this, 'sendMessage', function(method, params) {
//console.log('mm', method, params);
return new Promise(function(resolve, reject) {
provider.sendAsync({
id: (nextMessageId++),
jsonrpc: '2.0',
method: method,
params: params
}, function(error, result) {
if (error) {
reject(error);
} else {
if (result.error) {
var error = new Error(result.error.message);
error.code = result.error.code;
error.data = result.error.data;
reject(error);
} else {
resolve(result.result);
}
}
});
});
});
}
function rpcSendAsync(url) {
return {
sendAsync: function(payload, callback) {
var request = new XMLHttpRequest();
request.open('POST', url, true);
request.setRequestHeader('Content-Type','application/json');
request.onreadystatechange = function() {
if (request.readyState !== 4) { return; }
if (typeof(callback) !== 'function') { return; }
var result = request.responseText;
try {
callback(null, JSON.parse(result));
} catch (error) {
callback(new Error('invalid response'));
}
};
try {
request.send(JSON.stringify(payload));
} catch (error) {
var connectionError = new Error('connection error');
connectionError.error = error;
callback(connectionError);
}
}
}
}
function Provider(provider) {
if (!(this instanceof Provider)) { throw new Error('missing new'); }
var client = null;
if (typeof(provider) === 'string') {
// An RPC URL
if (provider.substring(0, 7) === 'http://') {
client = new Web3Connector(rpcSendAsync(provider));
// An ethers.io URL
} else if (provider.substring(0, 5) === 'ws://' || provider.substirng(0, 6) === 'wss://') {
//client =
// Etherscan
} else if (string === 'testnet.etherscan.io' || string === 'etherscan.io') {
// client =
}
// A Web3 Instance
} else if (provider.currentProvider && provider.currentProvider.sendAsync) {
client = new Web3Connector(provider.currentProvider);
// A Web3 Provider
} else if (provider.sendAsync) {
client = new Web3Connector(provider);
}
if (!client) { throw new Error('invalid connector'); }
utils.defineProperty(this, 'client', client);
}
function validBlock(value) {
if (value == null) { return 'latest'; }
if (value === 'latest' || value === 'pending') { return value; }
if (typeof(value) === 'number' && value == parseInt(value)) {
return parseInt(value);
}
throw new Error('invalid blockNumber');
}
function postProcess(client, method, params, makeBN) {
return new Promise(function(resolve, reject) {
client.sendMessage(method, params).then(function (result) {
if (!utils.isHexString(result)) {
reject(new Error('invalid server response'));
} else {
result = result.substring(2);
if (makeBN) {
result = new utils.BN(result, 16);
} else {
result = parseInt(result, 16);
}
resolve(result);
}
}, function(error) {
reject(error);
});
});
}
utils.defineProperty(Provider.prototype, 'getBalance', function(address, blockNumber) {
return postProcess(this.client, 'eth_getBalance', [address, validBlock(blockNumber)], true);
});
utils.defineProperty(Provider.prototype, 'getTransactionCount', function(address, blockNumber) {
return postProcess(this.client, 'eth_getTransactionCount', [address, validBlock(blockNumber)], false);
});
utils.defineProperty(Provider.prototype, 'getGasPrice', function() {
return postProcess(this.client, 'eth_gasPrice', [], true);
});
utils.defineProperty(Provider.prototype, 'sendTransaction', function(signedTransaction) {
return this.client.sendMessage('eth_sendRawTransaction', [signedTransaction]);
});
utils.defineProperty(Provider.prototype, 'call', function(transaction) {
return this.client.sendMessage('eth_call', [transaction]);
});
utils.defineProperty(Provider.prototype, 'estimateGas', function(transaction) {
return postProcess(this.client, 'eth_estimateGas', [transaction], true);
});
module.exports = Provider;