Add blockchain

lib/blockchain.js

@@ -0,0 +1,45 @@
+'use strict';
+
+var bitcore = require('bitcore');
+var $ = bitcore.util.preconditions;
+var _ = bitcore.deps._;
+
+function BlockChain() {
+  this.tip = null;
+  this.headers = {};
+  this.next = {};
+  this.prev = {};
+}
+
+BlockChain.fromObject = function(obj) {
+  var blockchain = new BlockChain();
+  blockchain.tip = obj.tip;
+  blockchain.headers = obj.headers;
+  blockchain.next = obj.next;
+  blockchain.prev = obj.prev;
+  return blockchain;
+};
+
+BlockChain.prototype.setTip = function(block) {
+  $.checkArgument(block instanceof bitcore.Block, 'Argument is not a Block instance');
+  this.tip = block.hash;
+  this.headers[block.hash] = block.header;
+  var prevHash = bitcore.util.buffer.reverse(block.header.prevHash).toString('hex');
+  this.next[prevHash] = block.hash;
+  this.prev[block.hash] = prevHash;
+};
+
+BlockChain.prototype.toObject = function() {
+  return {
+    tip: this.tip,
+    headers: _.map(this.headers, function(header) { return header.toObject(); }),
+    next: this.next,
+    prev: this.prev
+  };
+};
+
+BlockChain.prototype.toJSON = function() {
+  return JSON.stringify(this.toObject());
+};
+
+module.exports = BlockChain;

lib/node.js

@@ -19,6 +19,7 @@ var BlockService = require('./services/block');
 var TransactionService = require('./services/transaction');
 var AddressService = require('./services/address');
 
+var BlockChain = require('./blockchain');
 var genesisBlocks = require('./data/genesis');
 
 var BitcoreNode = function(bus, networkMonitor, blockService, transactionService, addressService) {
@@ -89,16 +90,14 @@ BitcoreNode.prototype.sync = function() {
   var genesis = bitcore.Block.fromBuffer(genesisBlocks[bitcore.Networks.defaultNetwork.name]);
   var self = this;
   this.networkMonitor.on('ready', function() {
-    console.log('ready');
-    self.blockService.getLatest().then(function(latest) {
-        var start = genesis.hash;
-        console.log('latest', latest);
-        if (latest) {
-          start = latest.hash;
+    self.blockService.getBlockchain().then(function(blockchain) {
+        if (blockchain) {
+          self.blockchain = blockchain;
+        } else {
+          self.blockchain = new BlockChain();
+          self.blockchain.setTip(genesis);
         }
-        console.log('Starting sync from', start);
-        self.tip = latest;
-        self.networkMonitor.requestBlocks(start);
+        self.networkMonitor.requestBlocks(self.blockchain.tip);
       })
       .catch(function(err) {
         self.networkMonitor.stop();

lib/services/block.js

@@ -39,7 +39,8 @@ var Index = {
   prev: 'prev-', // prev-<hash> -> parent hash
   next: 'nxt-', // nxt-<hash> -> hash for the next block in the main chain that is a child
   height: 'bh-', // bh-<hash> -> height (-1 means disconnected)
-  tip: 'tip' // tip -> { hash: hex, height: int }, the latest tip
+  tip: 'tip', // tip -> { hash: hex, height: int }, the latest tip
+  blockchain: 'chain'
 };
 _.extend(Index, {
   getNextBlock: helper(Index.next),
@@ -381,4 +382,26 @@ BlockService.prototype.getBlockForTransaction = function(transaction) {
   });
 };
 
+BlockService.prototype.getBlockchain = function() {
+  var self = this;
+  return new Promise(function(resolve, reject) {
+    self.database.getAsync(Index.blockchain).then(function(blockchain) {
+      blockchain = BlockChain.fromObject(JSON.parse(blockchain));
+      return resolve(blockchain);
+    }).catch(function(arg) {
+      if (arg.message.indexOf('Key not found in database') !== -1) {
+        return resolve();
+      }
+      return reject(arg);
+    });
+  });
+};
+
+BlockService.prototype.saveBlockchain = function(blockchain) {
+  return this.database.putAsync({
+    key: Index.blockchain,
+    value: blockchain.toJSON()
+  });
+};
+
 module.exports = BlockService;