more optimizations

lib/blockchain.js

@@ -9,7 +9,6 @@ var NULL = '0000000000000000000000000000000000000000000000000000000000000000';
 
 function BlockChain() {
   this.tip = NULL;
-  this.header = {};
   this.work = {};
   this.work[NULL] = 0;
   this.height = {};
@@ -19,7 +18,7 @@ function BlockChain() {
   };
   this.next = {};
   this.prev = {};
-  this.cachedHeaders = [];
+  this.cache = [];
 }
 
 BlockChain.NULL = NULL;
@@ -46,7 +45,6 @@ BlockChain.prototype.addData = function(header) {
   var prevHash = BufferUtil.reverse(header.prevHash).toString('hex');
   var hash = header.hash;
 
-  this.header[hash] = header;
   this.work[hash] = this.work[prevHash] + getWork(header.bits);
   this.prev[hash] = prevHash;
 };
@@ -115,7 +113,7 @@ BlockChain.prototype.confirm = function(hash) {
   this.next[prevHash] = hash;
   this.hashByHeight[height] = hash;
   this.height[hash] = height;
-  this.cachedHeaders.unshift(this.header[hash]);
+  this.cache.push(this.getCachedDataForHash(hash));
 };
 
 BlockChain.prototype.unconfirm = function(hash) {
@@ -127,7 +125,7 @@ BlockChain.prototype.unconfirm = function(hash) {
   delete this.next[prevHash];
   delete this.hashByHeight[height];
   delete this.height[hash];
-  this.cachedHeaders.shift();
+  this.cache.pop();
 };
 
 BlockChain.prototype.hasData = function(hash) {
@@ -183,8 +181,24 @@ BlockChain.prototype.getCurrentHeight = function() {
   return this.height[this.tip];
 };
 
-BlockChain.prototype.getHeaders = function() {
-  return this.cachedHeaders;
+BlockChain.prototype.loadFromCache = function(cache) {
+  for(var i = 0; i < cache.length; i++) {
+    this.prev[cache[i].hash] = cache[i].prevHash;
+    this.work[cache[i].hash] = cache[i].work;
+    this.confirm(cache[i].hash);
+  }
+};
+
+BlockChain.prototype.getCache = function() {
+  return this.cache;
+};
+
+BlockChain.prototype.getCachedDataForHash = function(hash) {
+  return {
+    hash: hash,
+    prevHash: this.prev[hash],
+    work: this.work[hash]
+  };
 };
 
 module.exports = BlockChain;

lib/node.js

@@ -131,7 +131,7 @@ BitcoreNode.prototype.initialize = function() {
       .then(function() {
         // Update header cache every 100 blocks
         if(block.height % 100 === 0) {
-          return self.blockService.saveHeaders(self.blockchain.getHeaders())
+          return self.blockService.saveBlockchainCache(self.blockchain.getCache());
         }
       })
       .catch(function(error) {

lib/services/block.js

@@ -39,7 +39,7 @@ var Index = {
   tip: 'tip', // tip -> { hash: hex, height: int }, the latest tip
   work: 'wk-', // wk-<hash> -> amount of work for block
   header: 'header-', // header-<hash> -> JSON for block header
-  headersCached: 'hc-'
+  blockchain: 'bc-'
 };
 _.extend(Index, {
   getNextBlock: helper(Index.next),
@@ -49,7 +49,7 @@ _.extend(Index, {
   getBlockByTs: function(block) {
     return Index.timestamp + block.header.time;
   },
-  getBlockHeader: helper(Index.header)
+  getBlockHeader: helper(Index.header),
 });
 
 function BlockService(opts) {
@@ -469,26 +469,22 @@ BlockService.prototype.getBlockchain = function() {
 
   console.log('Fetching hashes from db...');
 
-  return self.database.getAsync(Index.headersCached, {valueEncoding: 'json'})
+  return self.database.getAsync(Index.blockchain, {valueEncoding: 'json'})
     .catch(function(err) {
       if(err instanceof LevelUp.errors.NotFoundError) {
         return [];
       }
       throw err;
     })
-    .then(function(cachedHeaders) {
-      console.log(cachedHeaders.length + ' headers cached');
-      cachedHeaders = cachedHeaders.map(function(json) {
-        return bitcore.Block.BlockHeader.fromJSON(json);
-      });
-      console.log('Cached headers parsed. Loading remaining headers from DB');
+    .then(function(blockchainCache) {
+      console.log(blockchainCache.length + ' headers cached');
 
       var fetchHeader = function(blockHash) {
         if (blockHash === BlockChain.NULL) {
           console.log('All headers fetched, total =', headers.length);
           return Promise.resolve();
-        } else if(cachedHeaders[0] && cachedHeaders[0].hash === blockHash) {
-          headers = headers.concat(cachedHeaders);
+        } else if(blockchainCache.length && blockchainCache[blockchainCache.length - 1].hash === blockHash) {
+          console.log(headers.length + ' non-cached headers loaded');
           return Promise.resolve();
         }
         var headerKey = Index.getBlockHeader(blockHash);
@@ -512,6 +508,8 @@ BlockService.prototype.getBlockchain = function() {
 
           return fetchHeader(tip)
             .then(function() {
+              blockchain.loadFromCache(blockchainCache);
+
               while (headers.length !== 0) {
                 var header = headers.pop();
                 blockchain.proposeNewHeader(header);
@@ -522,8 +520,8 @@ BlockService.prototype.getBlockchain = function() {
     });
 };
 
-BlockService.prototype.saveHeaders = function(headers) {
-  return this.database.putAsync(Index.headersCached, JSON.stringify(headers));
+BlockService.prototype.saveBlockchainCache = function(cache) {
+  return this.database.putAsync(Index.blockchain, JSON.stringify(cache));
 }
 
 module.exports = BlockService;