From d426169f333f944c2451905a8ff5588541ad66c8 Mon Sep 17 00:00:00 2001
From: Chris Kleeschulte <chrisk@bitpay.com>
Date: Mon, 24 Jul 2017 10:07:27 -0400
Subject: [PATCH] wip

---
 lib/services/header/encoding.js | 21 ++++++++++++---------
 lib/services/header/index.js    | 21 ++++++++++++++-------
 2 files changed, 26 insertions(+), 16 deletions(-)

diff --git a/lib/services/header/encoding.js b/lib/services/header/encoding.js
index 9bcdb69b..a05826dc 100644
--- a/lib/services/header/encoding.js
+++ b/lib/services/header/encoding.js
@@ -24,6 +24,7 @@ Encoding.prototype.decodeHeaderKey = function(buffer) {
 };
 
 Encoding.prototype.encodeHeaderValue = function(header) {
+  var hashBuf = new Buffer(header.hash, 'hex');
   var versionBuf = new Buffer(4);
   versionBuf.writeInt32BE(header.version);
   var prevHash = new Buffer(header.prevHash, 'hex');
@@ -37,19 +38,21 @@ Encoding.prototype.encodeHeaderValue = function(header) {
   var heightBuf = new Buffer(4);
   heightBuf.writeUInt32BE(header.height);
   var chainworkBuf = new Buffer(header.chainwork, 'hex');
-  return Buffer.concat([ versionBuf, prevHash.reverse(), merkleRoot.reverse(), tsBuf, bitsBuf, nonceBuf, heightBuf, chainworkBuf ]);
+  return Buffer.concat([hashBuf, versionBuf, prevHash.reverse(), merkleRoot.reverse(), tsBuf, bitsBuf, nonceBuf, heightBuf, chainworkBuf ]);
 };
 
 Encoding.prototype.decodeHeaderValue = function(buffer) {
-  var version = buffer.readInt32BE();
-  var prevHash = buffer.slice(4, 36).toString('hex');
-  var merkleRoot = buffer.slice(36, 68).toString('hex');
-  var ts = buffer.readUInt32BE(68);
-  var bits = buffer.readUInt32BE(72);
-  var nonce = buffer.readUInt32BE(76);
-  var height = buffer.readUInt32BE(80);
-  var chainwork = buffer.slice(84).toString('hex');
+  var hash = buffer.slice(0, 32).toString('hex');
+  var version = buffer.readInt32BE(32);
+  var prevHash = buffer.slice(36, 68).toString('hex');
+  var merkleRoot = buffer.slice(68, 100).toString('hex');
+  var ts = buffer.readUInt32BE(100);
+  var bits = buffer.readUInt32BE(104);
+  var nonce = buffer.readUInt32BE(108);
+  var height = buffer.readUInt32BE(112);
+  var chainwork = buffer.slice(116).toString('hex');
   return {
+    hash: hash,
     version: version,
     prevHash: prevHash,
     merkleRoot: merkleRoot,
diff --git a/lib/services/header/index.js b/lib/services/header/index.js
index ea2840ce..8b16505c 100644
--- a/lib/services/header/index.js
+++ b/lib/services/header/index.js
@@ -17,6 +17,7 @@ var HeaderService = function(options) {
   this._tip = null;
   this._p2p = this.node.services.p2p;
   this._db = this.node.services.db;
+  this._checkpoint = options.checkpoint || 0; // the # of header to look back on boot
   this._headers = new utils.SimpleMap();
 };
 
@@ -69,6 +70,9 @@ HeaderService.prototype.start = function(callback) {
     function(tip, next) {
       self._tip = tip;
       next();
+    },
+    function(next) {
+      self._getPersistedHeaders(next);
     }
   ], function(err) {
 
@@ -135,17 +139,24 @@ HeaderService.prototype._onHeaders = function(headers, convert) {
   var runningHeight = this._tip.height;
   var prevHeader = this._headers.getLastIndex();
 
+  var dbOps = [];
   for(var i = 0; i < headers.length; i++) {
     var header = headers[i];
     header.height = ++runningHeight;
     header.chainwork = this._getChainwork(header, prevHeader).toString(16, 32);
+    dbOps.push({
+      type: 'put',
+      key: this._encoding.encodeHeaderKey(header.hash),
+      value: this._encoding.encodeHeaderValue(header)
+    });
     prevHeader = header;
     this._headers.set(header.hash, header);
   }
 
-  this._tip.hash = newHeaders[newHeaders.length - 1].hash;
+  this._startingHash = this._tip.hash = newHeaders[newHeaders.length - 1].hash;
   this._tip.height = this._tip.height + newHeaders.length;
 
+  this._db.batch(dbOps);
   this._sync();
 
 };
@@ -180,7 +191,6 @@ HeaderService.prototype._sync = function() {
     log.debug('Header Service: download progress: ' + this._tip.height + '/' +
       this._numNeeded + '  (' + (this._tip.height / this._numNeeded*100).toFixed(2) + '%)');
 
-
     this._p2p.getHeaders({ startHash: this._tip.hash });
 
     return;
@@ -199,7 +209,6 @@ HeaderService.prototype.getAllHeaders = function() {
 HeaderService.prototype._getPersistedHeaders = function(callback) {
 
   var self = this;
-  var results = [];
   var start = self._encoding.encodeHeaderKey(0);
   var end = self._encoding.encodeHeaderKey(0xffffffff);
   var criteria = {
@@ -215,16 +224,14 @@ HeaderService.prototype._getPersistedHeaders = function(callback) {
   });
 
   stream.on('data', function(data) {
-    var res = {};
-    res[self._encoding.decodeHeaderKey(data.key).hash] = self._encoding.decodeHeaderValue(data.value);
-    results.push(res);
+    self._headers.set(self._encoding.decodeHeaderKey(data.key).hash, self._encoding.decodeHeaderValue(data.value));
   });
 
   stream.on('end', function() {
     if (streamErr) {
       return streamErr;
     }
-    callback(null, results);
+    callback();
   });
 
 };