Merge pull request #37 from UVNishanth/master

fetched from upstream and resolved conflicts

blockchain.js

@@ -151,6 +151,15 @@ module.exports = class Blockchain {
     return this.instance;
   }
 
+  /**
+   * Check if Blockchain instance exists
+   * 
+   * @returns {Blockchain}
+   */
+  static hasInstance() {
+    return (this.instance ? true : false);
+  }
+
   /**
    * Creates the new instance of the blockchain configuration, giving the
    * clients the amount of starting gold specified in the clients array.
@@ -160,6 +169,7 @@ module.exports = class Blockchain {
    * @param {Class} cfg.blockClass - Implementation of the Block class.
    * @param {Class} cfg.transactionClass - Implementation of the Transaction class.
    * @param {Array} [cfg.clients] - An array of client/miner configurations.
+   * @param {String} [cfg.mnemonic] - BIP39 mnemonic which is used to generate client addresses.
    * @param {number} [cfg.powLeadingZeroes] - Number of leading zeroes required for a valid proof-of-work.
    * @param {number} [cfg.coinbaseAmount] - Amount of gold awarded to a miner for creating a block.
    * @param {number} [cfg.defaultTxFee] - Amount of gold awarded to a miner for accepting a transaction,
@@ -192,6 +202,7 @@ module.exports = class Blockchain {
     defaultTxFee = DEFAULT_TX_FEE,
     confirmedDepth = CONFIRMED_DEPTH,
     clients = [],
+    mnemonic,
     net,
   }) {
 
@@ -236,22 +247,35 @@ module.exports = class Blockchain {
 
     this.initialBalances = new Map();
 
+    // generate random mnemonic if mnemonic not passed
+    if (mnemonic === undefined){
+      const { generateMnemonic } = require('bip39');
+      this.mnemonic = generateMnemonic(256);
+    }
+    else{
+      this.mnemonic = mnemonic;
+    }
+
     clients.forEach((clientCfg) => {
       console.log(`Adding client ${clientCfg.name}`);
       let client;
       if (clientCfg.mining) {
         client = new this.minerClass({
           name: clientCfg.name,
+          password: clientCfg.password ? clientCfg.password : clientCfg.name+'_pswd',
           net: this.net,
           miningRounds: clientCfg.miningRounds,
         });
+        client.generateAddress(this.mnemonic);
         // Miners are stored as both miners and clients.
         this.miners.push(client);
       } else {
         client = new this.clientClass({
           name: clientCfg.name,
+          password: clientCfg.password ? clientCfg.password : clientCfg.name+'_pswd',
           net: this.net,
         });
+        client.generateAddress(this.mnemonic);
       }
 
       this.clientAddressMap.set(client.address, client);

client.js

@@ -20,24 +20,25 @@ module.exports = class Client extends EventEmitter {
    * @constructor
    * @param {Object} obj - The properties of the client.
    * @param {String} [obj.name] - The client's name, used for debugging messages.
+   * @param {String} [obj.password] - The client's password, used for generating address.
    * @param {Object} obj.net - The network used by the client
    *    to send messages to all miners and clients.
    * @param {Block} [obj.startingBlock] - The starting point of the blockchain for the client.
    * @param {Object} [obj.keyPair] - The public private keypair for the client.
    */
-  constructor({name, net, startingBlock, keyPair} = {}) {
+  constructor({name, password, net, startingBlock} = {}) {
     super();
 
     this.net = net;
     this.name = name;
 
-    if (keyPair === undefined) {
-      this.keyPair = utils.generateKeypair();
-    } else {
-      this.keyPair = keyPair;
-    }
+    this.password = password ? password : this.name+"_pswd";
 
-    this.address = utils.calcAddress(this.keyPair.public);
+
+    if (Blockchain.hasInstance()){
+       let bc = Blockchain.getInstance();
+       this.generateAddress(bc.mnemonic);
+    }
 
     // Establishes order of transactions.  Incremented with each
     // new output transaction from this client.  This feature
@@ -355,4 +356,19 @@ module.exports = class Client extends EventEmitter {
       block = this.blocks.get(block.prevBlockHash);
     }
   }
+
+  /**
+   * Generate client address using mnemonic set for the blockchain
+   * 
+   * @param {String} mnemonic - mnemonic set for the blockchain instance
+   */
+  generateAddress(mnemonic){
+    if (mnemonic === undefined){
+      throw new Error(`mnemonic not set`);
+    }
+    this.keyPair = utils.generateKeypairFromMnemonic(mnemonic, this.password);
+    this.address = utils.calcAddress(this.keyPair.public);
+    console.log(`${this.name}'s address is: ${this.address}`);
+  }
+
 };

driver.js

@@ -18,6 +18,7 @@ let bc = Blockchain.createInstance({
     {name: 'Minnie', amount: 400, mining: true},
     {name: 'Mickey', amount: 300, mining: true},
   ],
+  mnemonic: "antenna dwarf settle sleep must wool ocean once banana tiger distance gate great similar chief cheap dinner dolphin picture swing twenty two file nuclear",
   net: new FakeNet(),
 });
 
@@ -28,9 +29,9 @@ let [alice, bob] = bc.getClients('Alice', 'Bob');
 console.log("Initial balances:");
 alice.showAllBalances();
 
-// The miners will start mining blocks when start is called.  After 5 seconds,
+// The miners will start mining blocks when start is called.  After 8 seconds,
 // the code will terminate and show the final balances from Alice's perspective.
-bc.start(5000, () => {
+bc.start(8000, () => {
   console.log("Final balances, from Alice's perspective:");
   alice.showAllBalances();
 });
@@ -55,4 +56,3 @@ setTimeout(() => {
   donald.initialize();
 }, 2000);
 
-

miner.js

@@ -15,16 +15,17 @@ module.exports = class Miner extends Client {
    * @constructor
    * @param {Object} obj - The properties of the client.
    * @param {String} [obj.name] - The miner's name, used for debugging messages.
-   * * @param {Object} net - The network that the miner will use
+   * @param {Object} net - The network that the miner will use
    *      to send messages to all other clients.
+   * @param {String} [obj.password] - The client's password, used for generating address.
    * @param {Block} [startingBlock] - The most recently ALREADY ACCEPTED block.
    * @param {Object} [obj.keyPair] - The public private keypair for the client.
    * @param {Number} [miningRounds] - The number of rounds a miner mines before checking
    *      for messages.  (In single-threaded mode with FakeNet, this parameter can
    *      simulate miners with more or less mining power.)
    */
-  constructor({name, net, startingBlock, keyPair, miningRounds=Blockchain.NUM_ROUNDS_MINING} = {}) {
-    super({name, net, startingBlock, keyPair});
+  constructor({name, password, net, startingBlock, keyPair, miningRounds=Blockchain.NUM_ROUNDS_MINING} = {}) {
+    super({name, password, net, startingBlock, keyPair});
     this.miningRounds=miningRounds;
 
     // Set of transactions to be added to the next block.

mnemonic-driver.js

@@ -0,0 +1,71 @@
+"use strict";
+
+let Blockchain = require('./blockchain.js');
+
+// Used to create a client outside of the blockchain constructor.
+let Client = require('./client.js');
+
+
+// Used to create a miner outside of the blockchain constructor.
+let Miner = require('./miner.js');
+
+let FakeNet = require('./fake-net.js');
+
+console.log("Starting simulation.  This may take a moment...");
+
+// Creating genesis block
+let bc = Blockchain.createInstance({
+  clients: [
+    {name: 'Alice', amount: 233, password: 'alice_pswd'},
+    {name: 'Bob', amount: 99, password: 'bob_pswd'},
+    {name: 'Charlie', amount: 67, password: 'charlie_pswd'},
+    {name: 'Minnie', amount: 400, mining: true},
+    {name: 'Mickey', amount: 300, mining: true},
+  ],
+  mnemonic: "antenna dwarf settle sleep must wool ocean once banana tiger distance gate great similar chief cheap dinner dolphin picture swing twenty two file nuclear",
+  net: new FakeNet(),
+});
+
+// Late client - to demonstrate that clients can be initialized after blockchain initialization
+let trudy = new Client({name: 'Trudy', startingBlock: bc.genesis});
+bc.register(trudy);
+
+// Get Alice and Bob
+let [alice, bob] = bc.getClients('Alice', 'Bob');
+
+// Showing the initial balances from Alice's perspective, for no particular reason.
+console.log("Initial balances:");
+alice.showAllBalances();
+
+// The miners will start mining blocks when start is called.  After 8 seconds,
+// the code will terminate and show the final balances from Alice's perspective.
+bc.start(8000, () => {
+  console.log("Final balances, from Alice's perspective:");
+  alice.showAllBalances();
+});
+
+// Alice transfers some money to Bob.
+console.log(`Alice is transferring 40 gold to ${bob.address}`);
+alice.postTransaction([{ amount: 40, address: bob.address }]);
+
+// Alice transfers some money to Bob.
+console.log(`Alice is transferring 20 gold to ${trudy.address}`);
+alice.postTransaction([{ amount: 20, address: trudy.address }]);
+
+
+setTimeout(() => {
+  // Late miner - Donald has more mining power, represented by the miningRounds.
+  // (Mickey and Minnie have the default of 2000 rounds).
+  let donald = new Miner({
+    name: "Donald",
+    startingBlock: bc.genesis,
+    miningRounds: 3000,
+  });
+
+  console.log();
+  console.log("***Starting a late-to-the-party miner***");
+  console.log();
+  bc.register(donald);
+  donald.initialize();
+}, 2000);
+