From 0ff742c1b6001417b5926e512efe2d1b6370f2d5 Mon Sep 17 00:00:00 2001
From: Patrick Nagurny <patrick@bitpay.com>
Date: Tue, 8 Sep 2015 14:04:14 -0400
Subject: [PATCH] add isMainChain method

---
 docs/services/bitcoind.md      |  1 +
 integration/regtest-node.js    | 11 +++++++++--
 integration/regtest.js         |  8 ++++++++
 lib/services/bitcoind.js       |  4 ++++
 src/libbitcoind.cc             | 31 +++++++++++++++++++++++++++++++
 src/libbitcoind.h              |  2 ++
 test/services/bitcoind.unit.js |  1 +
 7 files changed, 56 insertions(+), 2 deletions(-)

diff --git a/docs/services/bitcoind.md b/docs/services/bitcoind.md
index 39b469f0..8251aea8 100644
--- a/docs/services/bitcoind.md
+++ b/docs/services/bitcoind.md
@@ -8,6 +8,7 @@ The bitcoin service adds a native interface to Bitcoin Core for querying informa
 - `bitcoind.getBlock(blockHash|blockHeight, callback)` - Get any block asynchronously by block hash or height as a node buffer.
 - `bitcoind.isSpent(txid, outputIndex)` - Returns a boolean if a txid and outputIndex is already spent.
 - `bitcoind.getBlockIndex(blockHash)` - Will return the block chain work and previous hash.
+- `bitcoind.isMainChain(blockHash)` - Returns true if block is on the main chain. Returns false if it is an orphan.
 - `bitcoind.estimateFee(blocks)` - Estimates the fees required to have a transaction included in the number of blocks specified as the first argument.
 - `bitcoind.sendTransaction(transaction, allowAbsurdFees)` - Will attempt to add a transaction to the mempool and broadcast to peers.
 - `bitcoind.getTransaction(txid, queryMempool, callback)` - Get any tx asynchronously by reading it from disk, with an argument to optionally not include the mempool.
diff --git a/integration/regtest-node.js b/integration/regtest-node.js
index bc4909bb..1ea90be1 100644
--- a/integration/regtest-node.js
+++ b/integration/regtest-node.js
@@ -131,6 +131,8 @@ describe('Node Functionality', function() {
     });
   });
 
+  var invalidatedBlockHash;
+
   it('will handle a reorganization', function(done) {
 
     var count;
@@ -151,12 +153,12 @@ describe('Node Functionality', function() {
           if (err) {
             return next(err);
           }
-          blockHash = response.result;
+          invalidatedBlockHash = response.result;
           next();
         });
       },
       function(next) {
-        client.invalidateBlock(blockHash, next);
+        client.invalidateBlock(invalidatedBlockHash, next);
       },
       function(next) {
         client.getBlockCount(function(err, response) {
@@ -206,4 +208,9 @@ describe('Node Functionality', function() {
     });
 
   });
+
+  it('isMainChain() will return false for stale/orphan block', function(done) {
+    bitcoind.isMainChain(invalidatedBlockHash).should.equal(false);
+    setImmediate(done);
+  });
 });
diff --git a/integration/regtest.js b/integration/regtest.js
index e7f48287..f1c68dc6 100644
--- a/integration/regtest.js
+++ b/integration/regtest.js
@@ -251,6 +251,14 @@ describe('Daemon Binding Functionality', function() {
     });
   });
 
+  describe('isMainChain', funciton() {
+    [1,2,3,4,5,6,7,8,9].forEach(function(i) {
+      it('block ' + i + ' is on the main chain', function() {
+        bitcoind.isMainChain(blockHashes[i]).should.equal(true);
+      });
+    });
+  });
+
   describe('send transaction functionality', function() {
 
     it('will not error and return the transaction hash', function() {
diff --git a/lib/services/bitcoind.js b/lib/services/bitcoind.js
index 9585f69d..5cd3319f 100644
--- a/lib/services/bitcoind.js
+++ b/lib/services/bitcoind.js
@@ -189,6 +189,10 @@ Bitcoin.prototype.getBlockIndex = function(blockHash) {
   return bindings.getBlockIndex(blockHash);
 };
 
+Bitcoin.prototype.isMainChain = function(blockHash) {
+  return bindings.isMainChain(blockHash);
+};
+
 Bitcoin.prototype.estimateFee = function(blocks) {
   return bindings.estimateFee(blocks);
 };
diff --git a/src/libbitcoind.cc b/src/libbitcoind.cc
index 9212206f..b3e0fd6d 100644
--- a/src/libbitcoind.cc
+++ b/src/libbitcoind.cc
@@ -1350,6 +1350,36 @@ NAN_METHOD(GetBlockIndex) {
   NanReturnValue(obj);
 };
 
+
+/**
+ * IsMainChain()
+ * bitcoind.isMainChain()
+ *
+ * @param {string} - block hash
+ * @returns {boolean} - True if the block is in the main chain. False if it is an orphan.
+ */
+NAN_METHOD(IsMainChain) {
+  Isolate* isolate = Isolate::GetCurrent();
+  HandleScope scope(isolate);
+
+  CBlockIndex* blockIndex;
+
+  String::Utf8Value hash_(args[0]->ToString());
+  std::string hashStr = std::string(*hash_);
+  uint256 hash = uint256S(hashStr);
+  if (mapBlockIndex.count(hash) == 0) {
+    NanReturnValue(Undefined(isolate));
+  } else {
+    blockIndex = mapBlockIndex[hash];
+  }
+
+  if (chainActive.Contains(blockIndex)) {
+    NanReturnValue(NanNew<Boolean>(true));
+  } else {
+    NanReturnValue(NanNew<Boolean>(false));
+  }
+}
+
 /**
  * GetInfo()
  * bitcoindjs.getInfo()
@@ -1606,6 +1636,7 @@ init(Handle<Object> target) {
   NODE_SET_METHOD(target, "getInfo", GetInfo);
   NODE_SET_METHOD(target, "isSpent", IsSpent);
   NODE_SET_METHOD(target, "getBlockIndex", GetBlockIndex);
+  NODE_SET_METHOD(target, "isMainChain", IsMainChain);
   NODE_SET_METHOD(target, "getMempoolOutputs", GetMempoolOutputs);
   NODE_SET_METHOD(target, "addMempoolUncheckedTransaction", AddMempoolUncheckedTransaction);
   NODE_SET_METHOD(target, "sendTransaction", SendTransaction);
diff --git a/src/libbitcoind.h b/src/libbitcoind.h
index e35e40b6..12bdc7b5 100644
--- a/src/libbitcoind.h
+++ b/src/libbitcoind.h
@@ -22,6 +22,8 @@ NAN_METHOD(OnBlocksReady);
 NAN_METHOD(OnTipUpdate);
 NAN_METHOD(StopBitcoind);
 NAN_METHOD(GetBlock);
+NAN_METHOD(GetBlockIndex);
+NAN_METHOD(IsMainChain);
 NAN_METHOD(GetTransaction);
 NAN_METHOD(GetInfo);
 NAN_METHOD(IsSpent);
diff --git a/test/services/bitcoind.unit.js b/test/services/bitcoind.unit.js
index 7d6d8fd4..0704c1ce 100644
--- a/test/services/bitcoind.unit.js
+++ b/test/services/bitcoind.unit.js
@@ -371,6 +371,7 @@ describe('Bitcoin Service', function() {
       ['getBlock', 2],
       ['isSpent', 2],
       ['getBlockIndex', 1],
+      ['isMainChain', 1],
       ['estimateFee', 1],
       ['sendTransaction', 2],
       ['getTransaction', 3],