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forkedblockchain.js
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forkedblockchain.js
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var BlockchainDouble = require("../blockchain_double.js");
var Account = require("ethereumjs-account");
var Block = require("ethereumjs-block");
var Log = require("./log.js");
var Receipt = require("./receipt.js");
var utils = require("ethereumjs-util");
var ForkedStorageTrie = require("./forkedstoragetrie.js");
var Web3 = require("web3");
var to = require("./to.js");
var Transaction = require("./transaction");
var async = require("async");
var BN = require("bn.js");
var inherits = require("util").inherits;
inherits(ForkedBlockchain, BlockchainDouble);
function ForkedBlockchain(options) {
this.options = options || {};
if (options.fork == null) {
throw new Error("ForkedBlockchain must be passed a fork parameter.");
}
this.fork = options.fork;
this.forkBlockNumber = options.fork_block_number;
this.forkVersion = null;
if (typeof this.fork === "string") {
if (this.fork.indexOf("@") >= 0) {
var split = this.fork.split("@");
this.fork = split[0];
this.forkBlockNumber = parseInt(split[1]);
}
this.fork = new Web3.providers.HttpProvider(this.fork);
}
this.time = options.time;
this.storageTrieCache = {};
BlockchainDouble.call(this, options);
this.createVMFromStateTrie = function() {
var vm = BlockchainDouble.prototype.createVMFromStateTrie.apply(this, arguments);
this.patchVM(vm);
return vm;
};
this.web3 = new Web3(this.fork);
}
ForkedBlockchain.prototype.initialize = function(accounts, callback) {
var self = this;
this.web3.eth.net.getId(function(err, version) {
if (err) {
return callback(err);
}
self.forkVersion = version;
BlockchainDouble.prototype.initialize.call(self, accounts, callback);
});
};
ForkedBlockchain.prototype.patchVM = function(vm) {
const trie = vm.stateManager._trie;
const lookupAccount = this.getLookupAccount(trie);
// Unfortunately forking requires a bit of monkey patching, but it gets the job done.
vm.stateManager._cache._lookupAccount = lookupAccount;
vm.stateManager._lookupStorageTrie = this.getLookupStorageTrie(trie, lookupAccount);
vm.stateManager.getContractCode = this.getCode.bind(this);
};
ForkedBlockchain.prototype.createStateTrie = function(db, root, options) {
return new ForkedStorageTrie(
db,
root,
Object.assign(
{
fork: this.fork,
forkBlockNumber: this.forkBlockNumber,
blockchain: this
},
options
)
);
};
ForkedBlockchain.prototype.createGenesisBlock = function(callback) {
var self = this;
var blockNumber = this.forkBlockNumber || "latest";
self.web3.eth.getBlock(blockNumber, function(err, json) {
if (err) {
return callback(err);
}
// If no start time was passed, set the time to where we forked from.
// We only want to do this if a block was explicitly passed. If a block
// number wasn't passed, then we're using the last block and the current time.
if (!self.time && self.forkBlockNumber) {
self.time = self.options.time = new Date(to.number(json.timestamp) * 1000);
self.setTime(self.time);
}
blockNumber = json.number;
// Update the relevant block numbers
self.forkBlockNumber = self.options.fork_block_number = blockNumber;
self.stateTrie.forkBlockNumber = self.stateTrie.options.forkBlockNumber = blockNumber;
self.createBlock(function(err, block) {
if (err) {
return callback(err);
}
block.header.number = utils.toBuffer(to.number(json.number) + 1);
block.header.parentHash = utils.toBuffer(json.hash);
callback(null, block);
});
});
};
ForkedBlockchain.prototype.getLookupStorageTrie = function(stateTrie, lookupAccount) {
lookupAccount = lookupAccount || this.getLookupAccount(stateTrie);
return (address, callback) => {
const storageTrie = stateTrie.copy();
storageTrie.address = address;
lookupAccount(address, (err, account) => {
if (err) {
return callback(err);
}
storageTrie.root = account.stateRoot;
callback(null, storageTrie);
});
};
};
ForkedBlockchain.prototype.isFallbackBlock = function(value, callback) {
var self = this;
self.getEffectiveBlockNumber(value, function(err, number) {
if (err) {
return callback(err);
}
callback(null, number <= to.number(self.forkBlockNumber));
});
};
ForkedBlockchain.prototype.isBlockHash = function(value) {
const isHash = typeof value === "string" && value.indexOf("0x") === 0 && value.length > 42;
return isHash || (Buffer.isBuffer(value) && value.byteLength > 20);
};
ForkedBlockchain.prototype.isFallbackBlockHash = function(value, callback) {
var self = this;
if (!this.isBlockHash(value)) {
return callback(null, false);
}
if (Buffer.isBuffer(value)) {
value = to.hex(value);
}
self.data.blockHashes.get(value, function(err, blockIndex) {
if (err) {
if (err.notFound) {
// If the block isn't found in our database, then it must be a fallback block.
return callback(null, true);
} else {
return callback(err);
}
}
callback(null, false);
});
};
ForkedBlockchain.prototype.getFallbackBlock = function(numberOrHash, cb) {
var self = this;
if (Buffer.isBuffer(numberOrHash)) {
numberOrHash = to.rpcDataHexString(numberOrHash);
}
self.web3.eth.getBlock(numberOrHash, true, function(err, json) {
if (err) {
return cb(err);
}
if (json == null) {
return cb();
}
var block = new Block();
block.header.parentHash = utils.toBuffer(json.parentHash);
block.header.uncleHash = utils.toBuffer(json.sha3Uncles);
block.header.coinbase = utils.toBuffer(json.miner);
block.header.stateRoot = utils.toBuffer(json.stateRoot); // Should we include the following three?
block.header.transactionsTrie = utils.toBuffer(json.transactionsRoot);
block.header.receiptTrie = utils.toBuffer(json.receiptsRoot);
block.header.bloom = utils.toBuffer(json.logsBloom);
block.header.difficulty = utils.toBuffer("0x" + json.totalDifficulty.toString(16)); // BigNumber
block.header.number = utils.toBuffer(json.number);
block.header.gasLimit = utils.toBuffer(json.gasLimit);
block.header.gasUsed = utils.toBuffer(json.gasUsed);
block.header.timestamp = utils.toBuffer(json.timestamp);
block.header.extraData = utils.toBuffer(json.extraData);
(json.transactions || []).forEach(function(txJson, index) {
block.transactions.push(Transaction.fromJSON(txJson, Transaction.types.real));
});
// Fake block. Let's do the worst.
// TODO: Attempt to fill out all block data so as to produce the same hash! (can we?)
block.hash = function() {
return utils.toBuffer(json.hash);
};
cb(null, block);
});
};
ForkedBlockchain.prototype.getBlock = function(number, callback) {
let checkFn;
const isBlockHash = this.isBlockHash(number);
if (isBlockHash) {
checkFn = this.isFallbackBlockHash;
} else {
checkFn = this.isFallbackBlock;
}
checkFn.call(this, number, (err, isFallback) => {
if (err) {
return callback(err);
}
if (isFallback) {
return this.getFallbackBlock(number, callback);
}
const getBlock = BlockchainDouble.prototype.getBlock.bind(this);
if (isBlockHash) {
getBlock(number, callback);
} else {
this.getRelativeBlockNumber(number, (err, number) => {
if (err) {
return callback(err);
}
getBlock(number, callback);
});
}
});
};
ForkedBlockchain.prototype.getStorage = function(address, key, number, callback) {
this.getLookupStorageTrie(this.stateTrie)(address, (err, trie) => {
if (err) {
return callback(err);
}
this.getEffectiveBlockNumber(number, (err, number) => {
if (err) {
return callback(err);
}
trie.get(key, number, callback);
});
});
};
ForkedBlockchain.prototype.getCode = function(address, number, callback) {
var self = this;
if (typeof number === "function") {
callback = number;
number = "latest";
}
if (!number) {
number = "latest";
}
this.getEffectiveBlockNumber(number, function(err, effective) {
if (err) {
return callback(err);
}
number = effective;
self.stateTrie.keyExists(address, function(err, exists) {
if (err) {
return callback(err);
}
// If we've stored the value and we're looking at one of our stored blocks,
// get it from our stored data.
if (exists && number > to.number(self.forkBlockNumber)) {
BlockchainDouble.prototype.getCode.call(self, address, number, callback);
} else {
// Else, we need to fetch it from web3. If our number is greater than
// the fork, let's just use "latest".
if (number > to.number(self.forkBlockNumber)) {
number = "latest";
}
self.fetchCodeFromFallback(address, number, function(err, code) {
if (code) {
code = utils.toBuffer(code);
}
callback(err, code);
});
}
});
});
};
ForkedBlockchain.prototype.getLookupAccount = function(trie) {
return (address, callback) => {
// If the account doesn't exist in our state trie, get it off the wire.
trie.keyExists(address, (err, exists) => {
if (err) {
return callback(err);
}
if (exists) {
trie.get(address, (err, data) => {
if (err) {
return callback(err);
}
const account = new Account(data);
callback(null, account);
});
} else {
this.fetchAccountFromFallback(address, to.number(trie.forkBlockNumber), callback);
}
});
};
};
ForkedBlockchain.prototype.getAccount = function(address, number, callback) {
var self = this;
if (typeof number === "function") {
callback = number;
number = "latest";
}
this.getEffectiveBlockNumber(number, function(err, effective) {
if (err) {
return callback(err);
}
number = effective;
// If the account doesn't exist in our state trie, get it off the wire.
self.stateTrie.keyExists(address, function(err, exists) {
if (err) {
return callback(err);
}
if (exists && number > to.number(self.forkBlockNumber)) {
BlockchainDouble.prototype.getAccount.call(self, address, number, function(err, acc) {
if (err) {
return callback(err);
}
callback(null, acc);
});
} else {
self.fetchAccountFromFallback(address, number, callback);
}
});
});
};
ForkedBlockchain.prototype.getTransaction = function(hash, callback) {
var self = this;
BlockchainDouble.prototype.getTransaction.call(this, hash, function(err, tx) {
if (err) {
return callback(err);
}
if (tx != null) {
return callback(null, tx);
}
self.web3.eth.getTransaction(hash, function(err, result) {
if (err) {
return callback(err);
}
if (result) {
result = Transaction.fromJSON(result, Transaction.types.signed);
}
callback(null, result);
});
});
};
ForkedBlockchain.prototype.getTransactionReceipt = function(hash, callback) {
var self = this;
BlockchainDouble.prototype.getTransactionReceipt.call(this, hash, function(err, receipt) {
if (err) {
return callback(err);
}
if (receipt) {
return callback(null, receipt);
}
self.web3.eth.getTransactionReceipt(hash, function(err, receiptJson) {
if (err) {
return callback(err);
}
if (!receiptJson) {
return callback();
}
async.parallel(
{
tx: self.getTransaction.bind(self, hash),
block: self.getBlock.bind(self, receiptJson.blockNumber)
},
function(err, result) {
if (err) {
return callback(err);
}
var logs = receiptJson.logs.map(function(log) {
return new Log(log);
});
var receipt = new Receipt(
result.tx,
result.block,
logs,
receiptJson.gasUsed,
receiptJson.cumulativeGasUsed,
receiptJson.contractAddress,
receiptJson.status,
to.hex(receiptJson.logsBloom)
);
callback(null, receipt);
}
);
});
});
};
ForkedBlockchain.prototype.fetchAccountFromFallback = function(address, blockNumber, callback) {
var self = this;
address = to.hex(address);
async.parallel(
{
code: this.fetchCodeFromFallback.bind(this, address, blockNumber),
balance: this.fetchBalanceFromFallback.bind(this, address, blockNumber),
nonce: this.fetchNonceFromFallback.bind(this, address, blockNumber)
},
function(err, results) {
if (err) {
return callback(err);
}
var code = results.code;
var balance = results.balance;
var nonce = results.nonce;
var account = new Account({
nonce: nonce,
balance: balance
});
// This puts the code on the trie, keyed by the hash of the code.
// It does not actually link an account to code in the trie.
account.setCode(self.stateTrie, utils.toBuffer(code), function(err) {
if (err) {
return callback(err);
}
callback(null, account);
});
}
);
};
ForkedBlockchain.prototype.fetchCodeFromFallback = function(address, blockNumber, callback) {
var self = this;
address = to.hex(address);
// Allow an optional blockNumber
if (typeof blockNumber === "function") {
callback = blockNumber;
blockNumber = this.forkBlockNumber;
}
this.getSafeFallbackBlockNumber(blockNumber, function(err, safeBlockNumber) {
if (err) {
return callback(err);
}
self.web3.eth.getCode(address, safeBlockNumber, function(err, code) {
if (err) {
return callback(err);
}
code = "0x" + utils.toBuffer(code).toString("hex");
callback(null, code);
});
});
};
ForkedBlockchain.prototype.fetchBalanceFromFallback = function(address, blockNumber, callback) {
var self = this;
address = to.hex(address);
// Allow an optional blockNumber
if (typeof blockNumber === "function") {
callback = blockNumber;
blockNumber = this.forkBlockNumber;
}
this.getSafeFallbackBlockNumber(blockNumber, function(err, safeBlockNumber) {
if (err) {
return callback(err);
}
self.web3.eth.getBalance(address, safeBlockNumber, function(err, balance) {
if (err) {
return callback(err);
}
balance = "0x" + new BN(balance).toString(16);
callback(null, balance);
});
});
};
ForkedBlockchain.prototype.fetchNonceFromFallback = function(address, blockNumber, callback) {
var self = this;
address = to.hex(address);
// Allow an optional blockNumber
if (typeof blockNumber === "function") {
callback = blockNumber;
blockNumber = this.forkBlockNumber;
}
this.getSafeFallbackBlockNumber(blockNumber, function(err, safeBlockNumber) {
if (err) {
return callback(err);
}
self.web3.eth.getTransactionCount(address, safeBlockNumber, function(err, nonce) {
if (err) {
return callback(err);
}
nonce = "0x" + self.web3.utils.toBN(nonce).toString(16);
callback(null, nonce);
});
});
};
ForkedBlockchain.prototype.getHeight = function(callback) {
this.latestBlock(function(err, block) {
if (err) {
return callback(err);
}
callback(null, to.number(block.header.number));
});
};
ForkedBlockchain.prototype.getRelativeBlockNumber = function(number, callback) {
var self = this;
this.getEffectiveBlockNumber(number, function(err, effective) {
if (err) {
return callback(err);
}
callback(null, effective - to.number(self.forkBlockNumber) - 1);
});
};
ForkedBlockchain.prototype.getSafeFallbackBlockNumber = function(blockNumber, callback) {
var forkBlockNumber = to.number(this.forkBlockNumber);
if (blockNumber == null) {
return callback(null, forkBlockNumber);
}
this.getEffectiveBlockNumber(blockNumber, function(err, effective) {
if (err) {
return callback(err);
}
if (effective > forkBlockNumber) {
effective = forkBlockNumber;
}
callback(null, effective);
});
};
ForkedBlockchain.prototype.getBlockLogs = function(number, callback) {
var self = this;
this.getEffectiveBlockNumber(number, function(err, effective) {
if (err) {
return callback(err);
}
self.getRelativeBlockNumber(effective, function(err, relative) {
if (err) {
return callback(err);
}
if (relative < 0) {
self.getBlock(number, function(err, block) {
if (err) {
return callback(err);
}
self.web3.currentProvider.send(
{
jsonrpc: "2.0",
method: "eth_getLogs",
params: [
{
fromBlock: to.hex(number),
toBlock: to.hex(number)
}
],
id: new Date().getTime()
},
function(err, res) {
if (err) {
return callback(err);
}
var logs = res.result.map(function(log) {
// To make this result masquerade as the right information.
log.block = block;
return new Log(log);
});
callback(null, logs);
}
);
});
} else {
BlockchainDouble.prototype.getBlockLogs.call(self, relative, callback);
}
});
});
};
module.exports = ForkedBlockchain;