From 77032f758d713d43f62cc4134cf8b2a55cbda76c Mon Sep 17 00:00:00 2001
From: Christopher Jeffrey <chjjeffrey@gmail.com>
Date: Mon, 23 Jan 2017 12:41:07 -0800
Subject: [PATCH] chain: different checkpoints handling.

---
 lib/blockchain/chain.js      | 53 ++++++++++++++----------------------
 lib/blockchain/chainentry.js |  2 +-
 lib/protocol/networks.js     | 10 ++++---
 3 files changed, 28 insertions(+), 37 deletions(-)

diff --git a/lib/blockchain/chain.js b/lib/blockchain/chain.js
index 37ebc397..28d9c903 100644
--- a/lib/blockchain/chain.js
+++ b/lib/blockchain/chain.js
@@ -71,6 +71,7 @@ function Chain(options) {
 
   this.network = this.options.network;
   this.logger = this.options.logger;
+  this.checkpoints = this.options.checkpoints;
 
   this.locker = new Lock(true);
   this.invalid = new LRU(100);
@@ -1012,7 +1013,7 @@ Chain.prototype._reset = co(function* reset(block, silent) {
   // Reset state.
   this.tip = tip;
   this.height = tip.height;
-  this.synced = this.isFull();
+  this.synced = false;
 
   state = yield this.getDeploymentState();
 
@@ -1027,6 +1028,8 @@ Chain.prototype._reset = co(function* reset(block, silent) {
   // have been some orphans on a forked chain we
   // no longer need.
   this.purgeOrphans();
+
+  this.maybeSync();
 });
 
 /**
@@ -1344,7 +1347,7 @@ Chain.prototype.verifyCheckpoint = function verifyCheckpoint(prev, hash) {
   var height = prev.height + 1;
   var checkpoint;
 
-  if (!this.options.checkpoints)
+  if (!this.checkpoints)
     return true;
 
   checkpoint = this.network.checkpointMap[height];
@@ -1670,30 +1673,7 @@ Chain.prototype.getCoinView = co(function* getCoinView(tx) {
  */
 
 Chain.prototype.isFull = function isFull() {
-  return !this.isInitial();
-};
-
-/**
- * Test the chain to see if it is still in the initial
- * syncing phase. Mimic's bitcoind's `IsInitialBlockDownload()`
- * function.
- * @see IsInitalBlockDownload()
- * @returns {Boolean}
- */
-
-Chain.prototype.isInitial = function isInitial() {
-  if (this.options.checkpoints) {
-    if (this.height < this.network.lastCheckpoint)
-      return true;
-  }
-
-  if (this.tip.ts < util.now() - this.network.block.maxTipAge)
-    return true;
-
-  if (this.tip.chainwork.cmp(this.network.pow.chainwork) < 0)
-    return true;
-
-  return false;
+  return this.synced;
 };
 
 /**
@@ -1702,10 +1682,22 @@ Chain.prototype.isInitial = function isInitial() {
  */
 
 Chain.prototype.maybeSync = function maybeSync() {
-  if (!this.synced && this.isFull()) {
-    this.synced = true;
-    this.emit('full');
+  if (this.synced)
+    return;
+
+  if (!this.hasChainwork())
+    return;
+
+  if (this.checkpoints) {
+    this.logger.info('Minimum chainwork reached. Disabling checkpoints.');
+    this.checkpoints = false;
   }
+
+  if (this.tip.ts < util.now() - this.network.block.maxTipAge)
+    return;
+
+  this.synced = true;
+  this.emit('full');
 };
 
 /**
@@ -1716,9 +1708,6 @@ Chain.prototype.maybeSync = function maybeSync() {
  */
 
 Chain.prototype.hasChainwork = function hasChainwork() {
-  if (this.options.checkpoints)
-    return this.height >= this.network.lastCheckpoint;
-
   return this.tip.chainwork.cmp(this.network.pow.chainwork) >= 0;
 };
 
diff --git a/lib/blockchain/chainentry.js b/lib/blockchain/chainentry.js
index ffec6195..1721df13 100644
--- a/lib/blockchain/chainentry.js
+++ b/lib/blockchain/chainentry.js
@@ -353,7 +353,7 @@ ChainEntry.prototype.getMedianTimeAsync = co(function* getMedianTimeAsync() {
  */
 
 ChainEntry.prototype.isHistorical = function isHistorical() {
-  if (this.chain.options.checkpoints) {
+  if (this.chain.checkpoints) {
     if (this.height + 1 <= this.chain.network.lastCheckpoint)
       return true;
   }
diff --git a/lib/protocol/networks.js b/lib/protocol/networks.js
index d5dc6f16..89ed44d9 100644
--- a/lib/protocol/networks.js
+++ b/lib/protocol/networks.js
@@ -99,7 +99,8 @@ main.checkpointMap = {
   382320: 'b28afdde92b0899715e40362f56afdb20e3d135bedc68d0a0000000000000000',
   // Custom checkpoints
   401465: 'eed16cb3e893ed9366f27c39a9ecd95465d02e3ef40e45010000000000000000',
-  420000: 'a1ff746b2d42b834cb7d6b8981b09c265c2cabc016e8cc020000000000000000'
+  420000: 'a1ff746b2d42b834cb7d6b8981b09c265c2cabc016e8cc020000000000000000',
+  440000: '9bf296b8de5f834f7635d5e258a434ad51b4dbbcf7c08c030000000000000000'
 };
 
 /**
@@ -180,7 +181,7 @@ main.pow = {
    */
 
   chainwork: new BN(
-    '0000000000000000000000000000000000000000003a315fa3a5ef47f4384cf2',
+    '0000000000000000000000000000000000000000002fa4573e5f9cf6ca3e5e75',
     'hex'
   ),
 
@@ -505,7 +506,8 @@ testnet.checkpointMap = {
   700000: 'c14d3f6a1e7c7d66fd940951e44f3c3be1273bea4d2ab1786140000000000000',
   780000: '0381582e34c3755964dc2813e2b33e521e5596367144e1670851050000000000',
   840000: 'dac1648107bd4394e57e4083c86d42b548b1cfb119665f179ea80a0000000000',
-  900000: '9bd8ac418beeb1a2cf5d68c8b5c6ebaa947a5b766e5524898d6f350000000000'
+  900000: '9bd8ac418beeb1a2cf5d68c8b5c6ebaa947a5b766e5524898d6f350000000000',
+  1050000: 'd8190cf0af7f08e179cab51d67db0b44b87951a78f7fdc31b4a01a0000000000'
 };
 
 testnet.lastCheckpoint = 900000;
@@ -541,7 +543,7 @@ testnet.pow = {
   ),
   bits: 486604799,
   chainwork: new BN(
-    '00000000000000000000000000000000000000000000001e345893fa639796e9',
+    '00000000000000000000000000000000000000000000001a461538dc48da1a06',
     'hex'
   ),
   targetTimespan: 14 * 24 * 60 * 60,